예제 #1
0
def sysu_media_wmh_segmentation(flair,
                                t1=None,
                                do_preprocessing=True,
                                use_ensemble=True,
                                use_axial_slices_only=True,
                                antsxnet_cache_directory=None,
                                verbose=False):
    """
    Perform WMH segmentation using the winning submission in the MICCAI
    2017 challenge by the sysu_media team using FLAIR or T1/FLAIR.  The
    MICCAI challenge is discussed in

    https://pubmed.ncbi.nlm.nih.gov/30908194/

    with the sysu_media's team entry is discussed in

     https://pubmed.ncbi.nlm.nih.gov/30125711/

    with the original implementation available here:

    https://github.com/hongweilibran/wmh_ibbmTum

    Arguments
    ---------
    flair : ANTsImage
        input 3-D FLAIR brain image (not skull-stripped).

    t1 : ANTsImage
        input 3-D T1 brain image (not skull-stripped).

    do_preprocessing : boolean
        perform n4 bias correction?

    use_ensemble : boolean
        check whether to use all 3 sets of weights.

    use_axial_slices_only : boolean
        If True, use original implementation which was trained on axial slices.
        If False, use ANTsXNet variant implementation which applies the slice-by-slice
        models to all 3 dimensions and averages the results.

    antsxnet_cache_directory : string
        Destination directory for storing the downloaded template and model weights.
        Since these can be resused, if is None, these data will be downloaded to a
        ~/.keras/ANTsXNet/.

    verbose : boolean
        Print progress to the screen.

    Returns
    -------
    WMH segmentation probability image

    Example
    -------
    >>> image = ants.image_read("flair.nii.gz")
    >>> probability_mask = sysu_media_wmh_segmentation(image)
    """

    from ..architectures import create_sysu_media_unet_model_2d
    from ..utilities import brain_extraction
    from ..utilities import crop_image_center
    from ..utilities import get_pretrained_network
    from ..utilities import preprocess_brain_image
    from ..utilities import pad_or_crop_image_to_size

    if flair.dimension != 3:
        raise ValueError("Image dimension must be 3.")

    if antsxnet_cache_directory == None:
        antsxnet_cache_directory = "ANTsXNet"

    ################################
    #
    # Preprocess images
    #
    ################################

    flair_preprocessed = flair
    if do_preprocessing == True:
        flair_preprocessing = preprocess_brain_image(
            flair,
            truncate_intensity=(0.01, 0.99),
            do_brain_extraction=False,
            do_bias_correction=True,
            do_denoising=False,
            antsxnet_cache_directory=antsxnet_cache_directory,
            verbose=verbose)
        flair_preprocessed = flair_preprocessing["preprocessed_image"]

    number_of_channels = 1
    if t1 is not None:
        t1_preprocessed = t1
        if do_preprocessing == True:
            t1_preprocessing = preprocess_brain_image(
                t1,
                truncate_intensity=(0.01, 0.99),
                do_brain_extraction=False,
                do_bias_correction=True,
                do_denoising=False,
                antsxnet_cache_directory=antsxnet_cache_directory,
                verbose=verbose)
            t1_preprocessed = t1_preprocessing["preprocessed_image"]
        number_of_channels = 2

    ################################
    #
    # Estimate mask
    #
    ################################

    brain_mask = None
    if verbose == True:
        print("Estimating brain mask.")
    if t1 is not None:
        brain_mask = brain_extraction(t1, modality="t1")
    else:
        brain_mask = brain_extraction(flair, modality="flair")

    reference_image = ants.make_image((200, 200, 200),
                                      voxval=1,
                                      spacing=(1, 1, 1),
                                      origin=(0, 0, 0),
                                      direction=np.identity(3))

    center_of_mass_reference = ants.get_center_of_mass(reference_image)
    center_of_mass_image = ants.get_center_of_mass(brain_mask)
    translation = np.asarray(center_of_mass_image) - np.asarray(
        center_of_mass_reference)
    xfrm = ants.create_ants_transform(
        transform_type="Euler3DTransform",
        center=np.asarray(center_of_mass_reference),
        translation=translation)
    flair_preprocessed_warped = ants.apply_ants_transform_to_image(
        xfrm, flair_preprocessed, reference_image)
    brain_mask_warped = ants.threshold_image(
        ants.apply_ants_transform_to_image(xfrm, brain_mask, reference_image),
        0.5, 1.1, 1, 0)

    if t1 is not None:
        t1_preprocessed_warped = ants.apply_ants_transform_to_image(
            xfrm, t1_preprocessed, reference_image)

    ################################
    #
    # Gaussian normalize intensity based on brain mask
    #
    ################################

    mean_flair = flair_preprocessed_warped[brain_mask_warped > 0].mean()
    std_flair = flair_preprocessed_warped[brain_mask_warped > 0].std()
    flair_preprocessed_warped = (flair_preprocessed_warped -
                                 mean_flair) / std_flair

    if number_of_channels == 2:
        mean_t1 = t1_preprocessed_warped[brain_mask_warped > 0].mean()
        std_t1 = t1_preprocessed_warped[brain_mask_warped > 0].std()
        t1_preprocessed_warped = (t1_preprocessed_warped - mean_t1) / std_t1

    ################################
    #
    # Build models and load weights
    #
    ################################

    number_of_models = 1
    if use_ensemble == True:
        number_of_models = 3

    unet_models = list()
    for i in range(number_of_models):
        if number_of_channels == 1:
            weights_file_name = get_pretrained_network(
                "sysuMediaWmhFlairOnlyModel" + str(i),
                antsxnet_cache_directory=antsxnet_cache_directory)
        else:
            weights_file_name = get_pretrained_network(
                "sysuMediaWmhFlairT1Model" + str(i),
                antsxnet_cache_directory=antsxnet_cache_directory)
        unet_models.append(
            create_sysu_media_unet_model_2d((200, 200, number_of_channels)))
        unet_models[i].load_weights(weights_file_name)

    ################################
    #
    # Extract slices
    #
    ################################

    dimensions_to_predict = [2]
    if use_axial_slices_only == False:
        dimensions_to_predict = list(range(3))

    total_number_of_slices = 0
    for d in range(len(dimensions_to_predict)):
        total_number_of_slices += flair_preprocessed_warped.shape[
            dimensions_to_predict[d]]

    batchX = np.zeros((total_number_of_slices, 200, 200, number_of_channels))

    slice_count = 0
    for d in range(len(dimensions_to_predict)):
        number_of_slices = flair_preprocessed_warped.shape[
            dimensions_to_predict[d]]

        if verbose == True:
            print("Extracting slices for dimension ", dimensions_to_predict[d],
                  ".")

        for i in range(number_of_slices):
            flair_slice = pad_or_crop_image_to_size(
                ants.slice_image(flair_preprocessed_warped,
                                 dimensions_to_predict[d], i), (200, 200))
            batchX[slice_count, :, :, 0] = flair_slice.numpy()
            if number_of_channels == 2:
                t1_slice = pad_or_crop_image_to_size(
                    ants.slice_image(t1_preprocessed_warped,
                                     dimensions_to_predict[d], i), (200, 200))
                batchX[slice_count, :, :, 1] = t1_slice.numpy()

            slice_count += 1

    ################################
    #
    # Do prediction and then restack into the image
    #
    ################################

    if verbose == True:
        print("Prediction.")

    prediction = unet_models[0].predict(batchX, verbose=verbose)
    if number_of_models > 1:
        for i in range(1, number_of_models, 1):
            prediction += unet_models[i].predict(batchX, verbose=verbose)
    prediction /= number_of_models

    permutations = list()
    permutations.append((0, 1, 2))
    permutations.append((1, 0, 2))
    permutations.append((1, 2, 0))

    prediction_image_average = ants.image_clone(flair_preprocessed_warped) * 0

    current_start_slice = 0
    for d in range(len(dimensions_to_predict)):
        current_end_slice = current_start_slice + flair_preprocessed_warped.shape[
            dimensions_to_predict[d]] - 1
        which_batch_slices = range(current_start_slice, current_end_slice)
        prediction_per_dimension = prediction[which_batch_slices, :, :, :]
        prediction_array = np.transpose(np.squeeze(prediction_per_dimension),
                                        permutations[dimensions_to_predict[d]])
        prediction_image = ants.copy_image_info(
            flair_preprocessed_warped,
            pad_or_crop_image_to_size(ants.from_numpy(prediction_array),
                                      flair_preprocessed_warped.shape))
        prediction_image_average = prediction_image_average + (
            prediction_image - prediction_image_average) / (d + 1)
        current_start_slice = current_end_slice + 1

    probability_image = ants.apply_ants_transform_to_image(
        ants.invert_ants_transform(xfrm), prediction_image_average, flair)

    return (probability_image)
예제 #2
0
def lung_extraction(image,
                    modality="proton",
                    antsxnet_cache_directory=None,
                    verbose=False):

    """
    Perform proton or ct lung extraction using U-net.

    Arguments
    ---------
    image : ANTsImage
        input image

    modality : string
        Modality image type.  Options include "ct", "proton", "protonLobes", 
        "maskLobes", and "ventilation".

    antsxnet_cache_directory : string
        Destination directory for storing the downloaded template and model weights.
        Since these can be resused, if is None, these data will be downloaded to a
        ~/.keras/ANTsXNet/.

    verbose : boolean
        Print progress to the screen.

    Returns
    -------
    Dictionary of ANTs segmentation and probability images.

    Example
    -------
    >>> output = lung_extraction(lung_image, modality="proton")
    """

    from ..architectures import create_unet_model_2d
    from ..architectures import create_unet_model_3d
    from ..utilities import get_pretrained_network
    from ..utilities import get_antsxnet_data
    from ..utilities import pad_or_crop_image_to_size

    if image.dimension != 3:
        raise ValueError( "Image dimension must be 3." )

    if antsxnet_cache_directory == None:
        antsxnet_cache_directory = "ANTsXNet"

    image_mods = [modality]
    channel_size = len(image_mods)

    weights_file_name = None
    unet_model = None

    if modality == "proton":
        weights_file_name = get_pretrained_network("protonLungMri",
            antsxnet_cache_directory=antsxnet_cache_directory)

        classes = ("background", "left_lung", "right_lung")
        number_of_classification_labels = len(classes)

        reorient_template_file_name_path = get_antsxnet_data("protonLungTemplate",
            antsxnet_cache_directory=antsxnet_cache_directory)
        reorient_template = ants.image_read(reorient_template_file_name_path)

        resampled_image_size = reorient_template.shape

        unet_model = create_unet_model_3d((*resampled_image_size, channel_size),
            number_of_outputs=number_of_classification_labels,
            number_of_layers=4, number_of_filters_at_base_layer=16, dropout_rate=0.0,
            convolution_kernel_size=(7, 7, 5), deconvolution_kernel_size=(7, 7, 5))
        unet_model.load_weights(weights_file_name)

        if verbose == True:
            print("Lung extraction:  normalizing image to the template.")

        center_of_mass_template = ants.get_center_of_mass(reorient_template * 0 + 1)
        center_of_mass_image = ants.get_center_of_mass(image * 0 + 1)
        translation = np.asarray(center_of_mass_image) - np.asarray(center_of_mass_template)
        xfrm = ants.create_ants_transform(transform_type="Euler3DTransform",
            center=np.asarray(center_of_mass_template), translation=translation)
        warped_image = ants.apply_ants_transform_to_image(xfrm, image, reorient_template)

        batchX = np.expand_dims(warped_image.numpy(), axis=0)
        batchX = np.expand_dims(batchX, axis=-1)
        batchX = (batchX - batchX.mean()) / batchX.std()

        predicted_data = unet_model.predict(batchX, verbose=int(verbose))

        origin = warped_image.origin
        spacing = warped_image.spacing
        direction = warped_image.direction

        probability_images_array = list()
        for i in range(number_of_classification_labels):
            probability_images_array.append(
            ants.from_numpy(np.squeeze(predicted_data[0, :, :, :, i]),
                origin=origin, spacing=spacing, direction=direction))

        if verbose == True:
            print("Lung extraction:  renormalize probability mask to native space.")

        for i in range(number_of_classification_labels):
            probability_images_array[i] = ants.apply_ants_transform_to_image(
                ants.invert_ants_transform(xfrm), probability_images_array[i], image)

        image_matrix = ants.image_list_to_matrix(probability_images_array, image * 0 + 1)
        segmentation_matrix = np.argmax(image_matrix, axis=0)
        segmentation_image = ants.matrix_to_images(
            np.expand_dims(segmentation_matrix, axis=0), image * 0 + 1)[0]

        return_dict = {'segmentation_image' : segmentation_image,
                       'probability_images' : probability_images_array}
        return(return_dict)

    if modality == "protonLobes" or modality == "maskLobes":
        reorient_template_file_name_path = get_antsxnet_data("protonLungTemplate",
            antsxnet_cache_directory=antsxnet_cache_directory)
        reorient_template = ants.image_read(reorient_template_file_name_path)

        resampled_image_size = reorient_template.shape

        spatial_priors_file_name_path = get_antsxnet_data("protonLobePriors",
            antsxnet_cache_directory=antsxnet_cache_directory)
        spatial_priors = ants.image_read(spatial_priors_file_name_path)
        priors_image_list = ants.ndimage_to_list(spatial_priors)

        channel_size = 1 + len(priors_image_list)
        number_of_classification_labels = 1 + len(priors_image_list)

        unet_model = create_unet_model_3d((*resampled_image_size, channel_size),
            number_of_outputs=number_of_classification_labels, mode="classification", 
            number_of_filters_at_base_layer=16, number_of_layers=4,
            convolution_kernel_size=(3, 3, 3), deconvolution_kernel_size=(2, 2, 2),
            dropout_rate=0.0, weight_decay=0, additional_options=("attentionGating",))

        if modality == "protonLobes":
            penultimate_layer = unet_model.layers[-2].output
            outputs2 = Conv3D(filters=1,
                            kernel_size=(1, 1, 1),
                            activation='sigmoid',
                            kernel_regularizer=regularizers.l2(0.0))(penultimate_layer)
            unet_model = Model(inputs=unet_model.input, outputs=[unet_model.output, outputs2])
            weights_file_name = get_pretrained_network("protonLobes",
                antsxnet_cache_directory=antsxnet_cache_directory)
        else:
            weights_file_name = get_pretrained_network("maskLobes",
                antsxnet_cache_directory=antsxnet_cache_directory)

        unet_model.load_weights(weights_file_name)

        if verbose == True:
            print("Lung extraction:  normalizing image to the template.")

        center_of_mass_template = ants.get_center_of_mass(reorient_template * 0 + 1)
        center_of_mass_image = ants.get_center_of_mass(image * 0 + 1)
        translation = np.asarray(center_of_mass_image) - np.asarray(center_of_mass_template)
        xfrm = ants.create_ants_transform(transform_type="Euler3DTransform",
            center=np.asarray(center_of_mass_template), translation=translation)
        warped_image = ants.apply_ants_transform_to_image(xfrm, image, reorient_template)
        warped_array = warped_image.numpy()
        if modality == "protonLobes":
            warped_array = (warped_array - warped_array.mean()) / warped_array.std()
        else:
            warped_array[warped_array != 0] = 1
       
        batchX = np.zeros((1, *warped_array.shape, channel_size))
        batchX[0,:,:,:,0] = warped_array
        for i in range(len(priors_image_list)):
            batchX[0,:,:,:,i+1] = priors_image_list[i].numpy()

        predicted_data = unet_model.predict(batchX, verbose=int(verbose))

        origin = warped_image.origin
        spacing = warped_image.spacing
        direction = warped_image.direction

        probability_images_array = list()
        for i in range(number_of_classification_labels):
            if modality == "protonLobes":
                probability_images_array.append(
                    ants.from_numpy(np.squeeze(predicted_data[0][0, :, :, :, i]),
                    origin=origin, spacing=spacing, direction=direction))
            else:
                probability_images_array.append(
                    ants.from_numpy(np.squeeze(predicted_data[0, :, :, :, i]),
                    origin=origin, spacing=spacing, direction=direction))

        if verbose == True:
            print("Lung extraction:  renormalize probability images to native space.")

        for i in range(number_of_classification_labels):
            probability_images_array[i] = ants.apply_ants_transform_to_image(
                ants.invert_ants_transform(xfrm), probability_images_array[i], image)

        image_matrix = ants.image_list_to_matrix(probability_images_array, image * 0 + 1)
        segmentation_matrix = np.argmax(image_matrix, axis=0)
        segmentation_image = ants.matrix_to_images(
            np.expand_dims(segmentation_matrix, axis=0), image * 0 + 1)[0]

        if modality == "protonLobes":
            whole_lung_mask = ants.from_numpy(np.squeeze(predicted_data[1][0, :, :, :, 0]),
                origin=origin, spacing=spacing, direction=direction)
            whole_lung_mask = ants.apply_ants_transform_to_image(
                ants.invert_ants_transform(xfrm), whole_lung_mask, image)

            return_dict = {'segmentation_image' : segmentation_image,
                           'probability_images' : probability_images_array,
                           'whole_lung_mask_image' : whole_lung_mask}
            return(return_dict)
        else:
            return_dict = {'segmentation_image' : segmentation_image,
                           'probability_images' : probability_images_array}
            return(return_dict)


    elif modality == "ct":

        ################################
        #
        # Preprocess image
        #
        ################################

        if verbose == True:
            print("Preprocess CT image.")

        def closest_simplified_direction_matrix(direction):
            closest = np.floor(np.abs(direction) + 0.5)
            closest[direction < 0] *= -1.0
            return closest

        simplified_direction = closest_simplified_direction_matrix(image.direction)

        reference_image_size = (128, 128, 128)

        ct_preprocessed = ants.resample_image(image, reference_image_size, use_voxels=True, interp_type=0)
        ct_preprocessed[ct_preprocessed < -1000] = -1000
        ct_preprocessed[ct_preprocessed > 400] = 400
        ct_preprocessed.set_direction(simplified_direction)
        ct_preprocessed.set_origin((0, 0, 0))
        ct_preprocessed.set_spacing((1, 1, 1))

        ################################
        #
        # Reorient image
        #
        ################################

        reference_image = ants.make_image(reference_image_size,
                                          voxval=0,
                                          spacing=(1, 1, 1),
                                          origin=(0, 0, 0),
                                          direction=np.identity(3))
        center_of_mass_reference = np.floor(ants.get_center_of_mass(reference_image * 0 + 1))
        center_of_mass_image = np.floor(ants.get_center_of_mass(ct_preprocessed * 0 + 1))
        translation = np.asarray(center_of_mass_image) - np.asarray(center_of_mass_reference)
        xfrm = ants.create_ants_transform(transform_type="Euler3DTransform",
            center=np.asarray(center_of_mass_reference), translation=translation)
        ct_preprocessed = ((ct_preprocessed - ct_preprocessed.min()) /
            (ct_preprocessed.max() - ct_preprocessed.min()))
        ct_preprocessed_warped = ants.apply_ants_transform_to_image(
            xfrm, ct_preprocessed, reference_image, interpolation="nearestneighbor")
        ct_preprocessed_warped = ((ct_preprocessed_warped - ct_preprocessed_warped.min()) /
            (ct_preprocessed_warped.max() - ct_preprocessed_warped.min())) - 0.5

        ################################
        #
        # Build models and load weights
        #
        ################################

        if verbose == True:
            print("Build model and load weights.")

        weights_file_name = get_pretrained_network("lungCtWithPriorsSegmentationWeights",
            antsxnet_cache_directory=antsxnet_cache_directory)

        classes = ("background", "left lung", "right lung", "airways")
        number_of_classification_labels = len(classes)

        luna16_priors = ants.ndimage_to_list(ants.image_read(get_antsxnet_data("luna16LungPriors")))
        for i in range(len(luna16_priors)):
            luna16_priors[i] = ants.resample_image(luna16_priors[i], reference_image_size, use_voxels=True)
        channel_size = len(luna16_priors) + 1

        unet_model = create_unet_model_3d((*reference_image_size, channel_size),
            number_of_outputs=number_of_classification_labels, mode="classification",
            number_of_layers=4, number_of_filters_at_base_layer=16, dropout_rate=0.0,
            convolution_kernel_size=(3, 3, 3), deconvolution_kernel_size=(2, 2, 2),
            weight_decay=1e-5, additional_options=("attentionGating",))
        unet_model.load_weights(weights_file_name)

        ################################
        #
        # Do prediction and normalize to native space
        #
        ################################

        if verbose == True:
            print("Prediction.")

        batchX = np.zeros((1, *reference_image_size, channel_size))
        batchX[:,:,:,:,0] = ct_preprocessed_warped.numpy()

        for i in range(len(luna16_priors)):
            batchX[:,:,:,:,i+1] = luna16_priors[i].numpy() - 0.5

        predicted_data = unet_model.predict(batchX, verbose=verbose)

        probability_images = list()
        for i in range(number_of_classification_labels):
            if verbose == True:
                print("Reconstructing image", classes[i])
            probability_image = ants.from_numpy(np.squeeze(predicted_data[:,:,:,:,i]),
                origin=ct_preprocessed_warped.origin, spacing=ct_preprocessed_warped.spacing,
                direction=ct_preprocessed_warped.direction)
            probability_image = ants.apply_ants_transform_to_image(
                ants.invert_ants_transform(xfrm), probability_image, ct_preprocessed)
            probability_image = ants.resample_image(probability_image,
               resample_params=image.shape, use_voxels=True, interp_type=0)
            probability_image = ants.copy_image_info(image, probability_image)
            probability_images.append(probability_image)

        image_matrix = ants.image_list_to_matrix(probability_images, image * 0 + 1)
        segmentation_matrix = np.argmax(image_matrix, axis=0)
        segmentation_image = ants.matrix_to_images(
            np.expand_dims(segmentation_matrix, axis=0), image * 0 + 1)[0]

        return_dict = {'segmentation_image' : segmentation_image,
                       'probability_images' : probability_images}
        return(return_dict)

    elif modality == "ventilation":

        ################################
        #
        # Preprocess image
        #
        ################################

        if verbose == True:
            print("Preprocess ventilation image.")

        template_size = (256, 256)

        image_modalities = ("Ventilation",)
        channel_size = len(image_modalities)

        preprocessed_image = (image - image.mean()) / image.std()
        ants.set_direction(preprocessed_image, np.identity(3))

        ################################
        #
        # Build models and load weights
        #
        ################################

        unet_model = create_unet_model_2d((*template_size, channel_size),
            number_of_outputs=1, mode='sigmoid',
            number_of_layers=4, number_of_filters_at_base_layer=32, dropout_rate=0.0,
            convolution_kernel_size=(3, 3), deconvolution_kernel_size=(2, 2),
            weight_decay=0)

        if verbose == True:
            print("Whole lung mask: retrieving model weights.")

        weights_file_name = get_pretrained_network("wholeLungMaskFromVentilation",
            antsxnet_cache_directory=antsxnet_cache_directory)
        unet_model.load_weights(weights_file_name)

        ################################
        #
        # Extract slices
        #
        ################################

        spacing = ants.get_spacing(preprocessed_image)
        dimensions_to_predict = (spacing.index(max(spacing)),)

        total_number_of_slices = 0
        for d in range(len(dimensions_to_predict)):
            total_number_of_slices += preprocessed_image.shape[dimensions_to_predict[d]]

        batchX = np.zeros((total_number_of_slices, *template_size, channel_size))

        slice_count = 0
        for d in range(len(dimensions_to_predict)):
            number_of_slices = preprocessed_image.shape[dimensions_to_predict[d]]

            if verbose == True:
                print("Extracting slices for dimension ", dimensions_to_predict[d], ".")

            for i in range(number_of_slices):
                ventilation_slice = pad_or_crop_image_to_size(ants.slice_image(preprocessed_image, dimensions_to_predict[d], i), template_size)
                batchX[slice_count,:,:,0] = ventilation_slice.numpy()
                slice_count += 1

        ################################
        #
        # Do prediction and then restack into the image
        #
        ################################

        if verbose == True:
            print("Prediction.")

        prediction = unet_model.predict(batchX, verbose=verbose)

        permutations = list()
        permutations.append((0, 1, 2))
        permutations.append((1, 0, 2))
        permutations.append((1, 2, 0))

        probability_image = ants.image_clone(image) * 0

        current_start_slice = 0
        for d in range(len(dimensions_to_predict)):
            current_end_slice = current_start_slice + preprocessed_image.shape[dimensions_to_predict[d]] - 1
            which_batch_slices = range(current_start_slice, current_end_slice)

            prediction_per_dimension = prediction[which_batch_slices,:,:,0]
            prediction_array = np.transpose(np.squeeze(prediction_per_dimension), permutations[dimensions_to_predict[d]])
            prediction_image = ants.copy_image_info(image,
                pad_or_crop_image_to_size(ants.from_numpy(prediction_array),
                image.shape))
            probability_image = probability_image + (prediction_image - probability_image) / (d + 1)

            current_start_slice = current_end_slice + 1

        return(probability_image)

    else:
        return ValueError("Unrecognized modality.")
예제 #3
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def brain_age(t1,
              do_preprocessing=True,
              number_of_simulations=0,
              sd_affine=0.01,
              antsxnet_cache_directory=None,
              verbose=False):

    """
    Estimate BrainAge from a T1-weighted MR image using the DeepBrainNet
    architecture and weights described here:

    https://github.com/vishnubashyam/DeepBrainNet

    and described in the following article:

    https://academic.oup.com/brain/article-abstract/doi/10.1093/brain/awaa160/5863667?redirectedFrom=fulltext

    Preprocessing on the training data consisted of:
       * n4 bias correction,
       * brain extraction, and
       * affine registration to MNI.
    The input T1 should undergo the same steps.  If the input T1 is the raw
    T1, these steps can be performed by the internal preprocessing, i.e. set
    do_preprocessing = True

    Arguments
    ---------
    t1 : ANTsImage
        raw or preprocessed 3-D T1-weighted brain image.

    do_preprocessing : boolean
        See description above.

    number_of_simulations : integer
        Number of random affine perturbations to transform the input.

    sd_affine : float
        Define the standard deviation of the affine transformation parameter.

    antsxnet_cache_directory : string
        Destination directory for storing the downloaded template and model weights.
        Since these can be resused, if is None, these data will be downloaded to a
        ~/.keras/ANTsXNet/.

    verbose : boolean
        Print progress to the screen.

    Returns
    -------
    List consisting of the segmentation image and probability images for
    each label.

    Example
    -------
    >>> image = ants.image_read("t1.nii.gz")
    >>> deep = brain_age(image)
    >>> print("Predicted age: ", deep['predicted_age']
    """

    from ..utilities import preprocess_brain_image
    from ..utilities import get_pretrained_network
    from ..utilities import randomly_transform_image_data

    if t1.dimension != 3:
        raise ValueError( "Image dimension must be 3." )

    if antsxnet_cache_directory == None:
        antsxnet_cache_directory = "ANTsXNet"

    ################################
    #
    # Preprocess images
    #
    ################################

    t1_preprocessed = t1
    if do_preprocessing == True:
        t1_preprocessing = preprocess_brain_image(t1,
            truncate_intensity=(0.01, 0.99),
            brain_extraction_modality="t1",
            template="croppedMni152",
            template_transform_type="antsRegistrationSyNQuickRepro[a]",
            do_bias_correction=True,
            do_denoising=True,
            antsxnet_cache_directory=antsxnet_cache_directory,
            verbose=verbose)
        t1_preprocessed = t1_preprocessing["preprocessed_image"] * t1_preprocessing['brain_mask']

    t1_preprocessed = (t1_preprocessed - t1_preprocessed.min()) / (t1_preprocessed.max() - t1_preprocessed.min())

    ################################
    #
    # Load model and weights
    #
    ################################

    model_weights_file_name = get_pretrained_network("brainAgeDeepBrainNet", antsxnet_cache_directory=antsxnet_cache_directory)
    model = keras.models.load_model(model_weights_file_name)

    # The paper only specifies that 80 slices are used for prediction.  I just picked
    # a reasonable range spanning the center of the brain

    which_slices = list(range(45, 125))

    batchX = np.zeros((len(which_slices), *t1_preprocessed.shape[0:2], 3))

    input_image = list()
    input_image.append(t1_preprocessed)

    input_image_list = list()
    input_image_list.append(input_image)

    if number_of_simulations > 0:
        data_augmentation = randomly_transform_image_data(
            reference_image=t1_preprocessed,
            input_image_list=input_image_list,
            number_of_simulations=number_of_simulations,
            transform_type='affine',
            sd_affine=sd_affine,
            input_image_interpolator='linear')

    brain_age_per_slice = None
    for i in range(number_of_simulations + 1):

        batch_image = t1_preprocessed
        if i > 0:
            batch_image = data_augmentation['simulated_images'][i-1][0]

        for j in range(len(which_slices)):

            slice = (ants.slice_image(batch_image, axis=2, idx=which_slices[j])).numpy()
            batchX[j,:,:,0] = slice
            batchX[j,:,:,1] = slice
            batchX[j,:,:,2] = slice

        if verbose == True:
            print("Brain age (DeepBrainNet):  predicting brain age per slice (batch = ", i, ")")

        if i == 0:
            brain_age_per_slice = model.predict(batchX, verbose=verbose)
        else:
            prediction = model.predict(batchX, verbose=verbose)
            brain_age_per_slice = brain_age_per_slice + (prediction - brain_age_per_slice) /  (i+1)

    predicted_age = statistics.median(brain_age_per_slice)[0]

    return_dict = {'predicted_age' : predicted_age,
                   'brain_age_per_slice' : brain_age_per_slice}
    return(return_dict)
예제 #4
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def el_bicho(ventilation_image,
             mask,
             use_coarse_slices_only=True,
             antsxnet_cache_directory=None,
             verbose=False):
    """
    Perform functional lung segmentation using hyperpolarized gases.

    https://pubmed.ncbi.nlm.nih.gov/30195415/

    Arguments
    ---------
    ventilation_image : ANTsImage
        input ventilation image.

    mask : ANTsImage
        input mask.

    use_coarse_slices_only : boolean
        If True, apply network only in the dimension of greatest slice thickness.
        If False, apply to all dimensions and average the results.

    antsxnet_cache_directory : string
        Destination directory for storing the downloaded template and model weights.
        Since these can be resused, if is None, these data will be downloaded to a
        ~/.keras/ANTsXNet/.

    verbose : boolean
        Print progress to the screen.

    Returns
    -------
    Ventilation segmentation and corresponding probability images

    Example
    -------
    >>> image = ants.image_read("ventilation.nii.gz")
    >>> mask = ants.image_read("mask.nii.gz")
    >>> lung_seg = el_bicho(image, mask, use_coarse_slices=True, verbose=False)
    """

    from ..architectures import create_unet_model_2d
    from ..utilities import get_pretrained_network
    from ..utilities import pad_or_crop_image_to_size

    if ventilation_image.dimension != 3:
        raise ValueError("Image dimension must be 3.")

    if ventilation_image.shape != mask.shape:
        raise ValueError(
            "Ventilation image and mask size are not the same size.")

    if antsxnet_cache_directory == None:
        antsxnet_cache_directory = "ANTsXNet"

    ################################
    #
    # Preprocess image
    #
    ################################

    template_size = (256, 256)
    classes = (0, 1, 2, 3, 4)
    number_of_classification_labels = len(classes)

    image_modalities = ("Ventilation", "Mask")
    channel_size = len(image_modalities)

    preprocessed_image = (ventilation_image -
                          ventilation_image.mean()) / ventilation_image.std()
    ants.set_direction(preprocessed_image, np.identity(3))

    mask_identity = ants.image_clone(mask)
    ants.set_direction(mask_identity, np.identity(3))

    ################################
    #
    # Build models and load weights
    #
    ################################

    unet_model = create_unet_model_2d(
        (*template_size, channel_size),
        number_of_outputs=number_of_classification_labels,
        number_of_layers=4,
        number_of_filters_at_base_layer=32,
        dropout_rate=0.0,
        convolution_kernel_size=(3, 3),
        deconvolution_kernel_size=(2, 2),
        weight_decay=1e-5,
        additional_options=("attentionGating"))

    if verbose == True:
        print("El Bicho: retrieving model weights.")

    weights_file_name = get_pretrained_network(
        "elBicho", antsxnet_cache_directory=antsxnet_cache_directory)
    unet_model.load_weights(weights_file_name)

    ################################
    #
    # Extract slices
    #
    ################################

    spacing = ants.get_spacing(preprocessed_image)
    dimensions_to_predict = (spacing.index(max(spacing)), )
    if use_coarse_slices_only == False:
        dimensions_to_predict = list(range(3))

    total_number_of_slices = 0
    for d in range(len(dimensions_to_predict)):
        total_number_of_slices += preprocessed_image.shape[
            dimensions_to_predict[d]]

    batchX = np.zeros((total_number_of_slices, *template_size, channel_size))

    slice_count = 0
    for d in range(len(dimensions_to_predict)):
        number_of_slices = preprocessed_image.shape[dimensions_to_predict[d]]

        if verbose == True:
            print("Extracting slices for dimension ", dimensions_to_predict[d],
                  ".")

        for i in range(number_of_slices):
            ventilation_slice = pad_or_crop_image_to_size(
                ants.slice_image(preprocessed_image, dimensions_to_predict[d],
                                 i), template_size)
            batchX[slice_count, :, :, 0] = ventilation_slice.numpy()

            mask_slice = pad_or_crop_image_to_size(
                ants.slice_image(mask_identity, dimensions_to_predict[d], i),
                template_size)
            batchX[slice_count, :, :, 1] = mask_slice.numpy()

            slice_count += 1

    ################################
    #
    # Do prediction and then restack into the image
    #
    ################################

    if verbose == True:
        print("Prediction.")

    prediction = unet_model.predict(batchX, verbose=verbose)

    permutations = list()
    permutations.append((0, 1, 2))
    permutations.append((1, 0, 2))
    permutations.append((1, 2, 0))

    probability_images = list()
    for l in range(number_of_classification_labels):
        probability_images.append(ants.image_clone(mask) * 0)

    current_start_slice = 0
    for d in range(len(dimensions_to_predict)):
        current_end_slice = current_start_slice + preprocessed_image.shape[
            dimensions_to_predict[d]] - 1
        which_batch_slices = range(current_start_slice, current_end_slice)

        for l in range(number_of_classification_labels):
            prediction_per_dimension = prediction[which_batch_slices, :, :, l]
            prediction_array = np.transpose(
                np.squeeze(prediction_per_dimension),
                permutations[dimensions_to_predict[d]])
            prediction_image = ants.copy_image_info(
                ventilation_image,
                pad_or_crop_image_to_size(ants.from_numpy(prediction_array),
                                          ventilation_image.shape))
            probability_images[l] = probability_images[l] + (
                prediction_image - probability_images[l]) / (d + 1)

        current_start_slice = current_end_slice + 1

    ################################
    #
    # Convert probability images to segmentation
    #
    ################################

    image_matrix = ants.image_list_to_matrix(
        probability_images[1:(len(probability_images))], mask * 0 + 1)
    background_foreground_matrix = np.stack([
        ants.image_list_to_matrix([probability_images[0]], mask * 0 + 1),
        np.expand_dims(np.sum(image_matrix, axis=0), axis=0)
    ])
    foreground_matrix = np.argmax(background_foreground_matrix, axis=0)
    segmentation_matrix = (np.argmax(image_matrix, axis=0) +
                           1) * foreground_matrix
    segmentation_image = ants.matrix_to_images(
        np.expand_dims(segmentation_matrix, axis=0), mask * 0 + 1)[0]

    return_dict = {
        'segmentation_image': segmentation_image,
        'probability_images': probability_images
    }
    return (return_dict)
예제 #5
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def claustrum_segmentation(t1,
                           do_preprocessing=True,
                           use_ensemble=True,
                           antsxnet_cache_directory=None,
                           verbose=False):
    """
    Claustrum segmentation

    Described here:

        https://arxiv.org/abs/2008.03465

    with the implementation available at:

        https://github.com/hongweilibran/claustrum_multi_view


    Arguments
    ---------
    t1 : ANTsImage
        input 3-D T1 brain image.

    do_preprocessing : boolean
        perform n4 bias correction.

    use_ensemble : boolean
        check whether to use all 3 sets of weights.

    antsxnet_cache_directory : string
        Destination directory for storing the downloaded template and model weights.
        Since these can be resused, if is None, these data will be downloaded to a
        ~/.keras/ANTsXNet/.

    verbose : boolean
        Print progress to the screen.

    Returns
    -------
    Claustrum segmentation probability image

    Example
    -------
    >>> image = ants.image_read("t1.nii.gz")
    >>> probability_mask = claustrum_segmentation(image)
    """

    from ..architectures import create_sysu_media_unet_model_2d
    from ..utilities import brain_extraction
    from ..utilities import get_pretrained_network
    from ..utilities import preprocess_brain_image
    from ..utilities import pad_or_crop_image_to_size

    if t1.dimension != 3:
        raise ValueError("Image dimension must be 3.")

    if antsxnet_cache_directory == None:
        antsxnet_cache_directory = "ANTsXNet"

    image_size = (180, 180)

    ################################
    #
    # Preprocess images
    #
    ################################

    number_of_channels = 1
    t1_preprocessed = ants.image_clone(t1)
    brain_mask = ants.threshold_image(t1, 0, 0, 0, 1)
    if do_preprocessing == True:
        t1_preprocessing = preprocess_brain_image(
            t1,
            truncate_intensity=(0.01, 0.99),
            brain_extraction_modality="t1",
            do_bias_correction=True,
            do_denoising=True,
            antsxnet_cache_directory=antsxnet_cache_directory,
            verbose=verbose)
        t1_preprocessed = t1_preprocessing["preprocessed_image"]
        brain_mask = t1_preprocessing["brain_mask"]

    reference_image = ants.make_image((170, 256, 256),
                                      voxval=1,
                                      spacing=(1, 1, 1),
                                      origin=(0, 0, 0),
                                      direction=np.identity(3))
    center_of_mass_reference = ants.get_center_of_mass(reference_image)
    center_of_mass_image = ants.get_center_of_mass(brain_mask)
    translation = np.asarray(center_of_mass_image) - np.asarray(
        center_of_mass_reference)
    xfrm = ants.create_ants_transform(
        transform_type="Euler3DTransform",
        center=np.asarray(center_of_mass_reference),
        translation=translation)
    t1_preprocessed_warped = ants.apply_ants_transform_to_image(
        xfrm, t1_preprocessed, reference_image)
    brain_mask_warped = ants.threshold_image(
        ants.apply_ants_transform_to_image(xfrm, brain_mask, reference_image),
        0.5, 1.1, 1, 0)

    ################################
    #
    # Gaussian normalize intensity based on brain mask
    #
    ################################

    mean_t1 = t1_preprocessed_warped[brain_mask_warped > 0].mean()
    std_t1 = t1_preprocessed_warped[brain_mask_warped > 0].std()
    t1_preprocessed_warped = (t1_preprocessed_warped - mean_t1) / std_t1

    t1_preprocessed_warped = t1_preprocessed_warped * brain_mask_warped

    ################################
    #
    # Build models and load weights
    #
    ################################

    number_of_models = 1
    if use_ensemble == True:
        number_of_models = 3

    if verbose == True:
        print("Claustrum:  retrieving axial model weights.")

    unet_axial_models = list()
    for i in range(number_of_models):
        weights_file_name = get_pretrained_network(
            "claustrum_axial_" + str(i),
            antsxnet_cache_directory=antsxnet_cache_directory)
        unet_axial_models.append(
            create_sysu_media_unet_model_2d((*image_size, number_of_channels),
                                            anatomy="claustrum"))
        unet_axial_models[i].load_weights(weights_file_name)

    if verbose == True:
        print("Claustrum:  retrieving coronal model weights.")

    unet_coronal_models = list()
    for i in range(number_of_models):
        weights_file_name = get_pretrained_network(
            "claustrum_coronal_" + str(i),
            antsxnet_cache_directory=antsxnet_cache_directory)
        unet_coronal_models.append(
            create_sysu_media_unet_model_2d((*image_size, number_of_channels),
                                            anatomy="claustrum"))
        unet_coronal_models[i].load_weights(weights_file_name)

    ################################
    #
    # Extract slices
    #
    ################################

    dimensions_to_predict = [1, 2]

    batch_coronal_X = np.zeros(
        (t1_preprocessed_warped.shape[1], *image_size, number_of_channels))
    batch_axial_X = np.zeros(
        (t1_preprocessed_warped.shape[2], *image_size, number_of_channels))

    for d in range(len(dimensions_to_predict)):
        number_of_slices = t1_preprocessed_warped.shape[
            dimensions_to_predict[d]]

        if verbose == True:
            print("Extracting slices for dimension ", dimensions_to_predict[d],
                  ".")

        for i in range(number_of_slices):
            t1_slice = pad_or_crop_image_to_size(
                ants.slice_image(t1_preprocessed_warped,
                                 dimensions_to_predict[d], i), image_size)
            if dimensions_to_predict[d] == 1:
                batch_coronal_X[i, :, :, 0] = np.rot90(t1_slice.numpy(), k=-1)
            else:
                batch_axial_X[i, :, :, 0] = np.rot90(t1_slice.numpy())

    ################################
    #
    # Do prediction and then restack into the image
    #
    ################################

    if verbose == True:
        print("Coronal prediction.")

    prediction_coronal = unet_coronal_models[0].predict(batch_coronal_X,
                                                        verbose=verbose)
    if number_of_models > 1:
        for i in range(1, number_of_models, 1):
            prediction_coronal += unet_coronal_models[i].predict(
                batch_coronal_X, verbose=verbose)
    prediction_coronal /= number_of_models

    for i in range(t1_preprocessed_warped.shape[1]):
        prediction_coronal[i, :, :, 0] = np.rot90(
            np.squeeze(prediction_coronal[i, :, :, 0]))

    if verbose == True:
        print("Axial prediction.")

    prediction_axial = unet_axial_models[0].predict(batch_axial_X,
                                                    verbose=verbose)
    if number_of_models > 1:
        for i in range(1, number_of_models, 1):
            prediction_axial += unet_axial_models[i].predict(batch_axial_X,
                                                             verbose=verbose)
    prediction_axial /= number_of_models

    for i in range(t1_preprocessed_warped.shape[2]):
        prediction_axial[i, :, :,
                         0] = np.rot90(np.squeeze(prediction_axial[i, :, :,
                                                                   0]),
                                       k=-1)

    if verbose == True:
        print("Restack image and transform back to native space.")

    permutations = list()
    permutations.append((0, 1, 2))
    permutations.append((1, 0, 2))
    permutations.append((1, 2, 0))

    prediction_image_average = ants.image_clone(t1_preprocessed_warped) * 0

    for d in range(len(dimensions_to_predict)):
        which_batch_slices = range(
            t1_preprocessed_warped.shape[dimensions_to_predict[d]])
        prediction_per_dimension = None
        if dimensions_to_predict[d] == 1:
            prediction_per_dimension = prediction_coronal[
                which_batch_slices, :, :, :]
        else:
            prediction_per_dimension = prediction_axial[
                which_batch_slices, :, :, :]
        prediction_array = np.transpose(np.squeeze(prediction_per_dimension),
                                        permutations[dimensions_to_predict[d]])
        prediction_image = ants.copy_image_info(
            t1_preprocessed_warped,
            pad_or_crop_image_to_size(ants.from_numpy(prediction_array),
                                      t1_preprocessed_warped.shape))
        prediction_image_average = prediction_image_average + (
            prediction_image - prediction_image_average) / (d + 1)

    probability_image = ants.apply_ants_transform_to_image(
        ants.invert_ants_transform(xfrm), prediction_image_average,
        t1) * ants.threshold_image(brain_mask, 0.5, 1, 1, 0)

    return (probability_image)
예제 #6
0
    'sub-10', 'sub-11', 'sub-12', 'sub-13', 'sub-14', 'sub-15', 'sub-16'
])
num_subs = 15
mask_thresh = .1

gm_mask = ants.image_read(
    os.path.join(
        root,
        'sub-01/anat/sub-01_space-MNI152NLin2009cAsym_label-GM_probseg.nii.gz')
)
funcROI = ants.image_read(
    os.path.join(
        root,
        'sub-01/func/sub-01_task-sherlockPart1_space-MNI152NLin2009cAsym_desc-preproc_bold.nii.gz'
    ))
epi3d = ants.slice_image(funcROI, axis=3, idx=0)
reg = ants.registration(fixed=epi3d,
                        moving=gm_mask,
                        type_of_transform='Rigid',
                        reg_iterations=[100, 100, 20])
gm_mask_size = reg['warpedmovout']

for sub in sublist:
    sub_dir = root + sub + '/func/'
    data_dir = root + sub + '/anat/'
    sub_mask = ants.image_read(
        os.path.join(
            data_dir,
            sub + '_space-MNI152NLin2009cAsym_label-GM_probseg.nii.gz'))
    funcROI = ants.image_read(
        os.path.join(
예제 #7
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def ew_david(flair,
             t1,
             do_preprocessing=True,
             do_slicewise=True,
             antsxnet_cache_directory=None,
             verbose=False):

    """
    Perform White matter hypterintensity probabilistic segmentation
    using deep learning

    Preprocessing on the training data consisted of:
       * n4 bias correction,
       * brain extraction, and
       * affine registration to MNI.
    The input T1 should undergo the same steps.  If the input T1 is the raw
    T1, these steps can be performed by the internal preprocessing, i.e. set
    \code{doPreprocessing = TRUE}

    Arguments
    ---------
    flair : ANTsImage
        input 3-D FLAIR brain image (not skull-stripped).

    t1 : ANTsImage
        input 3-D T1 brain image (not skull-stripped).

    do_preprocessing : boolean
        perform n4 bias correction?

    do_slicewise : boolean
        apply 2-D modal along direction of maximal slice thickness.

    verbose : boolean
        Print progress to the screen.

    Returns
    -------
    WMH segmentation probability image

    Example
    -------
    >>> image = ants.image_read("flair.nii.gz")
    >>> probability_mask = sysu_media_wmh_segmentation(image)
    """

    from ..architectures import create_unet_model_2d
    from ..architectures import create_unet_model_3d
    from ..utilities import get_pretrained_network
    from ..utilities import preprocess_brain_image
    from ..utilities import extract_image_patches
    from ..utilities import reconstruct_image_from_patches
    from ..utilities import pad_or_crop_image_to_size

    if flair.dimension != 3:
        raise ValueError( "Image dimension must be 3." )

    if t1.dimension != 3:
        raise ValueError( "Image dimension must be 3." )

    if antsxnet_cache_directory == None:
        antsxnet_cache_directory = "ANTsXNet"

    if do_slicewise == False:

        ################################
        #
        # Preprocess images
        #
        ################################

        t1_preprocessed = t1
        t1_preprocessing = None
        if do_preprocessing == True:
            t1_preprocessing = preprocess_brain_image(t1,
                truncate_intensity=(0.01, 0.99),
                do_brain_extraction=True,
                template="croppedMni152",
                template_transform_type="AffineFast",
                do_bias_correction=True,
                do_denoising=False,
                antsxnet_cache_directory=antsxnet_cache_directory,
                verbose=verbose)
            t1_preprocessed = t1_preprocessing["preprocessed_image"] * t1_preprocessing['brain_mask']

        flair_preprocessed = flair
        if do_preprocessing == True:
            flair_preprocessing = preprocess_brain_image(flair,
                truncate_intensity=(0.01, 0.99),
                do_brain_extraction=False,
                do_bias_correction=True,
                do_denoising=False,
                antsxnet_cache_directory=antsxnet_cache_directory,
                verbose=verbose)
            flair_preprocessed = ants.apply_transforms(fixed=t1_preprocessed,
                moving=flair_preprocessing["preprocessed_image"],
                transformlist=t1_preprocessing['template_transforms']['fwdtransforms'])
            flair_preprocessed = flair_preprocessed * t1_preprocessing['brain_mask']

        ################################
        #
        # Build model and load weights
        #
        ################################

        patch_size = (112, 112, 112)
        stride_length = (t1_preprocessed.shape[0] - patch_size[0],
                        t1_preprocessed.shape[1] - patch_size[1],
                        t1_preprocessed.shape[2] - patch_size[2])

        classes = ("background", "wmh" )
        number_of_classification_labels = len(classes)
        labels = (0, 1)

        image_modalities = ("T1", "FLAIR")
        channel_size = len(image_modalities)

        unet_model = create_unet_model_3d((*patch_size, channel_size),
            number_of_outputs = number_of_classification_labels,
            number_of_layers = 4, number_of_filters_at_base_layer = 16, dropout_rate = 0.0,
            convolution_kernel_size = (3, 3, 3), deconvolution_kernel_size = (2, 2, 2),
            weight_decay = 1e-5, nn_unet_activation_style=False, add_attention_gating=True)

        weights_file_name = get_pretrained_network("ewDavidWmhSegmentationWeights",
            antsxnet_cache_directory=antsxnet_cache_directory)
        unet_model.load_weights(weights_file_name)

        ################################
        #
        # Do prediction and normalize to native space
        #
        ################################

        if verbose == True:
            print("ew_david:  prediction.")

        batchX = np.zeros((8, *patch_size, channel_size))

        t1_preprocessed = (t1_preprocessed - t1_preprocessed.mean()) / t1_preprocessed.std()
        t1_patches = extract_image_patches(t1_preprocessed, patch_size=patch_size,
                                            max_number_of_patches="all", stride_length=stride_length,
                                            return_as_array=True)
        batchX[:,:,:,:,0] = t1_patches

        flair_preprocessed = (flair_preprocessed - flair_preprocessed.mean()) / flair_preprocessed.std()
        flair_patches = extract_image_patches(flair_preprocessed, patch_size=patch_size,
                                            max_number_of_patches="all", stride_length=stride_length,
                                            return_as_array=True)
        batchX[:,:,:,:,1] = flair_patches

        predicted_data = unet_model.predict(batchX, verbose=verbose)

        probability_images = list()
        for i in range(len(labels)):
            print("Reconstructing image", classes[i])
            reconstructed_image = reconstruct_image_from_patches(predicted_data[:,:,:,:,i],
                domain_image=t1_preprocessed, stride_length=stride_length)

            if do_preprocessing == True:
                probability_images.append(ants.apply_transforms(fixed=t1,
                    moving=reconstructed_image,
                    transformlist=t1_preprocessing['template_transforms']['invtransforms'],
                    whichtoinvert=[True], interpolator="linear", verbose=verbose))
            else:
                probability_images.append(reconstructed_image)

        return(probability_images[1])

    else:  # do_slicewise

        ################################
        #
        # Preprocess images
        #
        ################################

        t1_preprocessed = t1
        t1_preprocessing = None
        if do_preprocessing == True:
            t1_preprocessing = preprocess_brain_image(t1,
                truncate_intensity=(0.01, 0.99),
                do_brain_extraction=False,
                do_bias_correction=True,
                do_denoising=False,
                antsxnet_cache_directory=antsxnet_cache_directory,
                verbose=verbose)
            t1_preprocessed = t1_preprocessing["preprocessed_image"]

        flair_preprocessed = flair
        if do_preprocessing == True:
            flair_preprocessing = preprocess_brain_image(flair,
                truncate_intensity=(0.01, 0.99),
                do_brain_extraction=False,
                do_bias_correction=True,
                do_denoising=False,
                antsxnet_cache_directory=antsxnet_cache_directory,
                verbose=verbose)
            flair_preprocessed = flair_preprocessing["preprocessed_image"]

        resampling_params = list(ants.get_spacing(flair_preprocessed))

        do_resampling = False
        for d in range(len(resampling_params)):
            if resampling_params[d] < 0.8:
                resampling_params[d] = 1.0
                do_resampling = True

        resampling_params = tuple(resampling_params)

        if do_resampling:
            flair_preprocessed = ants.resample_image(flair_preprocessed, resampling_params, use_voxels=False, interp_type=0)
            t1_preprocessed = ants.resample_image(t1_preprocessed, resampling_params, use_voxels=False, interp_type=0)

        flair_preprocessed = (flair_preprocessed - flair_preprocessed.mean()) / flair_preprocessed.std()
        t1_preprocessed = (t1_preprocessed - t1_preprocessed.mean()) / t1_preprocessed.std()

        ################################
        #
        # Build model and load weights
        #
        ################################

        template_size = (256, 256)

        classes = ("background", "wmh" )
        number_of_classification_labels = len(classes)
        labels = (0, 1)

        image_modalities = ("T1", "FLAIR")
        channel_size = len(image_modalities)

        unet_model = create_unet_model_2d((*template_size, channel_size),
            number_of_outputs = number_of_classification_labels,
            number_of_layers = 4, number_of_filters_at_base_layer = 32, dropout_rate = 0.0,
            convolution_kernel_size = (3, 3), deconvolution_kernel_size = (2, 2),
            weight_decay = 1e-5, nn_unet_activation_style=True, add_attention_gating=True)

        if verbose == True:
            print("ewDavid:  retrieving model weights.")

        weights_file_name = get_pretrained_network("ewDavidWmhSegmentationSlicewiseWeights",
            antsxnet_cache_directory=antsxnet_cache_directory)
        unet_model.load_weights(weights_file_name)

        ################################
        #
        # Extract slices
        #
        ################################

        use_coarse_slices_only = True

        spacing = ants.get_spacing(flair_preprocessed)
        dimensions_to_predict = (spacing.index(max(spacing)),)
        if use_coarse_slices_only == False:
            dimensions_to_predict = list(range(3))

        total_number_of_slices = 0
        for d in range(len(dimensions_to_predict)):
            total_number_of_slices += flair_preprocessed.shape[dimensions_to_predict[d]]

        batchX = np.zeros((total_number_of_slices, *template_size, channel_size))

        slice_count = 0
        for d in range(len(dimensions_to_predict)):
            number_of_slices = flair_preprocessed.shape[dimensions_to_predict[d]]

            if verbose == True:
                print("Extracting slices for dimension ", dimensions_to_predict[d], ".")

            for i in range(number_of_slices):
                flair_slice = pad_or_crop_image_to_size(ants.slice_image(flair_preprocessed, dimensions_to_predict[d], i), template_size)
                batchX[slice_count,:,:,0] = flair_slice.numpy()

                t1_slice = pad_or_crop_image_to_size(ants.slice_image(t1_preprocessed, dimensions_to_predict[d], i), template_size)
                batchX[slice_count,:,:,1] = t1_slice.numpy()

                slice_count += 1


        ################################
        #
        # Do prediction and then restack into the image
        #
        ################################

        if verbose == True:
            print("Prediction.")

        prediction = unet_model.predict(batchX, verbose=verbose)

        permutations = list()
        permutations.append((0, 1, 2))
        permutations.append((1, 0, 2))
        permutations.append((1, 2, 0))

        prediction_image_average = ants.image_clone(flair_preprocessed) * 0

        current_start_slice = 0
        for d in range(len(dimensions_to_predict)):
            current_end_slice = current_start_slice + flair_preprocessed.shape[dimensions_to_predict[d]] - 1
            which_batch_slices = range(current_start_slice, current_end_slice)
            prediction_per_dimension = prediction[which_batch_slices,:,:,1]
            prediction_array = np.transpose(np.squeeze(prediction_per_dimension), permutations[dimensions_to_predict[d]])
            prediction_image = ants.copy_image_info(flair_preprocessed,
                pad_or_crop_image_to_size(ants.from_numpy(prediction_array),
                flair_preprocessed.shape))
            prediction_image_average = prediction_image_average + (prediction_image - prediction_image_average) / (d + 1)

            current_start_slice = current_end_slice + 1

        if do_resampling:
            prediction_image_average = ants.resample_image_to_target(prediction_image_average, flair)

        return(prediction_image_average)
예제 #8
0
def tid_neural_image_assessment(image,
                                mask=None,
                                patch_size=101,
                                stride_length=None,
                                padding_size=0,
                                dimensions_to_predict=0,
                                antsxnet_cache_directory=None,
                                which_model="tidsQualityAssessment",
                                verbose=False):
    """
    Perform MOS-based assessment of an image.

    Use a ResNet architecture to estimate image quality in 2D or 3D using subjective
    QC image databases described in

    https://www.sciencedirect.com/science/article/pii/S0923596514001490

    or

    https://doi.org/10.1109/TIP.2020.2967829

    where the image assessment is either "global", i.e., a single number or an image
    based on the specified patch size.  In the 3-D case, neighboring slices are used
    for each estimate.  Note that parameters should be kept as consistent as possible
    in order to enable comparison.  Patch size should be roughly 1/12th to 1/4th of
    image size to enable locality. A global estimate can be gained by setting
    patch_size = "global".

    Arguments
    ---------
    image : ANTsImage (2-D or 3-D)
        input image.

    mask : ANTsImage (2-D or 3-D)
        optional mask for designating calculation ROI.

    patch_size : integer
        prime number of patch_size.  101 is good.  Otherwise, choose "global" for a single
        global estimate of quality.

    stride_length : integer or vector of image dimension length
        optional value to speed up computation (typically less than patch size).

    padding_size : positive or negative integer or vector of image dimension length
        de(padding) to remove edge effects.

    dimensions_to_predict : integer or vector
        if image dimension is 3, this parameter specifies which dimensions should be used for
        prediction.  If more than one dimension is specified, the results are averaged.

    antsxnet_cache_directory : string
        Destination directory for storing the downloaded template and model weights.
        Since these can be resused, if is None, these data will be downloaded to
        ~/.keras/ANTsXNet/.

    which_model : string
        model type e.g. string tidsQualityAssessment, koniqMS, koniqMS2 or koniqMS3 where
        the former predicts mean opinion score (MOS) and MOS standard deviation and
        the latter koniq models predict mean opinion score (MOS) and sharpness.

    verbose : boolean
        Print progress to the screen.

    Returns
    -------
    List of QC results predicting both both human rater's mean and standard
    deviation of the MOS ("mean opinion scores") or sharpness depending on the
    selected network.  Both aggregate and spatial scores are returned, the latter
    in the form of an image.

    Example
    -------
    >>> image = ants.image_read(ants.get_data("r16"))
    >>> mask = ants.get_mask(image)
    >>> tid = tid_neural_image_assessment(image, mask=mask, patch_size=101, stride_length=7)
    """

    from ..utilities import get_pretrained_network
    from ..utilities import pad_or_crop_image_to_size
    from ..utilities import extract_image_patches
    from ..utilities import reconstruct_image_from_patches

    def is_prime(n):
        if n == 2 or n == 3:
            return True
        if n < 2 or n % 2 == 0:
            return False
        if n < 9:
            return True
        if n % 3 == 0:
            return False
        r = int(n**0.5)
        f = 5
        while f <= r:
            if n % f == 0:
                return False
            if n % (f + 2) == 0:
                return False
            f += 6
        return True

    valid_models = ("tidsQualityAssessment", "koniqMS", "koniqMS2", "koniqMS3")
    if not which_model in valid_models:
        raise ValueError("Please pass valid model")

    if antsxnet_cache_directory == None:
        antsxnet_cache_directory = "ANTsXNet"

    if verbose == True:
        print("Neural QA:  retreiving model and weights.")

    is_koniq = "koniq" in which_model
    model_and_weights_file_name = get_pretrained_network(
        which_model, antsxnet_cache_directory=antsxnet_cache_directory)
    tid_model = tf.keras.models.load_model(model_and_weights_file_name,
                                           compile=False)

    padding_size_vector = padding_size
    if isinstance(padding_size, int):
        padding_size_vector = np.repeat(padding_size, image.dimension)
    elif len(padding_size) == 1:
        padding_size_vector = np.repeat(padding_size[0], image.dimension)

    if isinstance(dimensions_to_predict, int):
        dimensions_to_predict = (dimensions_to_predict, )

    padded_image_size = image.shape + padding_size_vector
    padded_image = pad_or_crop_image_to_size(image, padded_image_size)

    number_of_channels = 3

    if stride_length is None and patch_size != "global":
        stride_length = round(min(patch_size) / 2)
        if image.dimension == 3:
            stride_length = (stride_length, stride_length, 1)

    ###############
    #
    #  Global
    #
    ###############

    if patch_size == 'global':
        if which_model == "tidsQualityAssessment":
            evaluation_image = ants.iMath(padded_image, "Normalize") * 255

        if is_koniq:
            evaluation_image = ants.iMath(padded_image,
                                          "Normalize") * 2.0 - 1.0

        if image.dimension == 2:
            batchX = np.zeros((1, evaluation_image.shape, number_of_channels))
            for k in range(3):
                batchX[0, :, :, k] = evaluation_image.numpy()
            predicted_data = tid_model.predict(batchX, verbose=verbose)

            if which_model == "tidsQualityAssessment":
                return_dict = {
                    'MOS': None,
                    'MOS.standardDeviation': None,
                    'MOS.mean': predicted_data[0, 0],
                    'MOS.standardDeviationMean': predicted_data[0, 1]
                }
                return (return_dict)

            elif is_koniq:
                return_dict = {
                    'MOS.mean': predicted_data[0, 0],
                    'sharpness.mean': predicted_data[0, 1]
                }
                return (return_dict)

        elif image.dimension == 3:
            mos_mean = 0
            mos_standard_deviation = 0

            x = tuple(range(image.dimension))
            for d in range(len(dimensions_to_predict)):
                not_padded_image_size = list(padded_image_size)
                del (not_padded_image_size[dimensions_to_predict[d]])
                batchX = np.zeros(
                    (padded_image_size[dimensions_to_predict[d]],
                     (*tuple(not_padded_image_size)), number_of_channels))

                batchX[0, :, :,
                       0] = (ants.slice_image(
                           evaluation_image,
                           axis=0,
                           idx=dimensions_to_predict[d])).numpy()
                batchX[0, :, :,
                       1] = (ants.slice_image(
                           evaluation_image,
                           axis=0,
                           idx=dimensions_to_predict[d])).numpy()
                batchX[0, :, :,
                       2] = (ants.slice_image(
                           evaluation_image,
                           axis=1,
                           idx=dimensions_to_predict[d])).numpy()
                for i in range(1, padded_image_size[dimensions_to_predict[d]] -
                               1):
                    batchX[i, :, :, 0] = (ants.slice_image(
                        evaluation_image,
                        axis=i - 1,
                        idx=dimensions_to_predict[d])).numpy()
                    batchX[i, :, :,
                           1] = (ants.slice_image(
                               evaluation_image,
                               axis=i,
                               idx=dimensions_to_predict[d])).numpy()
                    batchX[i, :, :, 2] = (ants.slice_image(
                        evaluation_image,
                        axis=i + 1,
                        idx=dimensions_to_predict[d])).numpy()
                batchX[padded_image_size[dimensions_to_predict[d]], :, :,
                       0] = (ants.slice_image(
                           evaluation_image,
                           axis=padded_image_size[dimensions_to_predict[d]] -
                           1,
                           idx=dimensions_to_predict[d])).numpy()
                batchX[padded_image_size[dimensions_to_predict[d]], :, :,
                       1] = (ants.slice_image(
                           evaluation_image,
                           axis=padded_image_size[dimensions_to_predict[d]],
                           idx=dimensions_to_predict[d])).numpy()
                batchX[padded_image_size[dimensions_to_predict[d]], :, :,
                       2] = (ants.slice_image(
                           evaluation_image,
                           axis=padded_image_size[dimensions_to_predict[d]],
                           idx=dimensions_to_predict[d])).numpy()

                predicted_data = tid_model.predict(batchX, verbose=verbose)
                mos_mean += predicted_data[0, 0]
                mos_standard_deviation += predicted_data[0, 1]

            mos_mean /= len(dimensions_to_predict)
            mos_standard_deviation /= len(dimensions_to_predict)
            if which_model == "tidsQualityAssessment":
                return_dict = {
                    'MOS.mean': mos_mean,
                    'MOS.standardDeviationMean': mos_standard_deviation
                }
                return (return_dict)
            elif is_koniq:
                return_dict = {
                    'MOS.mean': mos_mean,
                    'sharpness.mean': mos_standard_deviation
                }
                return (return_dict)

    ###############
    #
    #  Patchwise
    #
    ###############

    else:

        evaluation_image = padded_image

        if not is_prime(patch_size):
            print(
                "patch_size should be a prime number:  13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97..."
            )

        stride_length_vector = stride_length
        if isinstance(stride_length, int):
            if image.dimension == 2:
                stride_length_vector = (stride_length, stride_length)
        elif len(stride_length) == 1:
            if image.dimension == 2:
                stride_length_vector = (stride_length[0], stride_length[0])

        patch_size_vector = (patch_size, patch_size)

        if image.dimension == 2:
            dimensions_to_predict = (1, )

        permutations = list()

        mos = image * 0
        mos_standard_deviation = image * 0

        for d in range(len(dimensions_to_predict)):
            if image.dimension == 3:
                permutations.append((0, 1, 2))
                permutations.append((0, 2, 1))
                permutations.append((1, 2, 0))

                if dimensions_to_predict[d] == 0:
                    patch_size_vector = (patch_size, patch_size,
                                         number_of_channels)
                    if isinstance(stride_length, int):
                        stride_length_vector = (stride_length, stride_length,
                                                1)
                elif dimensions_to_predict[d] == 1:
                    patch_size_vector = (patch_size, number_of_channels,
                                         patch_size)
                    if isinstance(stride_length, int):
                        stride_length_vector = (stride_length, 1,
                                                stride_length)
                elif dimensions_to_predict[d] == 2:
                    patch_size_vector = (number_of_channels, patch_size,
                                         patch_size)
                    if isinstance(stride_length, int):
                        stride_length_vector = (1, stride_length,
                                                stride_length)
                else:
                    raise ValueError(
                        "dimensions_to_predict elements should be 1, 2, and/or 3 for 3-D image."
                    )

            patches = extract_image_patches(evaluation_image,
                                            patch_size=patch_size_vector,
                                            stride_length=stride_length_vector,
                                            return_as_array=False)

            batchX = np.zeros(
                (len(patches), patch_size, patch_size, number_of_channels))

            is_good_patch = np.repeat(False, len(patches))
            for i in range(len(patches)):
                if patches[i].var() > 0:
                    is_good_patch[i] = True
                    patch_image = patches[i]
                    patch_image = patch_image - patch_image.min()

                    if patch_image.max() > 0:
                        if which_model == "tidsQualityAssessment":
                            patch_image = patch_image / patch_image.max() * 255
                        elif is_koniq:
                            patch_image = patch_image / patch_image.max(
                            ) * 2.0 - 1.0

                    if image.dimension == 2:
                        for j in range(number_of_channels):
                            batchX[i, :, :, j] = patch_image
                    elif image.dimension == 3:
                        batchX[i, :, :, :] = np.transpose(
                            np.squeeze(patch_image.numpy()),
                            permutations[dimensions_to_predict[d]])

            good_batchX = batchX[is_good_patch, :, :, :]
            predicted_data = tid_model.predict(good_batchX, verbose=verbose)

            patches_mos = list()
            patches_mos_standard_deviation = list()

            zero_patch_image = patch_image * 0

            count = 0
            for i in range(len(patches)):
                if is_good_patch[i]:
                    patches_mos.append(zero_patch_image +
                                       predicted_data[count, 0])
                    patches_mos_standard_deviation.append(zero_patch_image +
                                                          predicted_data[count,
                                                                         1])
                    count += 1
                else:
                    patches_mos.append(zero_patch_image)
                    patches_mos_standard_deviation.append(zero_patch_image)

            mos += pad_or_crop_image_to_size(
                reconstruct_image_from_patches(
                    patches_mos,
                    evaluation_image,
                    stride_length=stride_length_vector), image.shape)
            mos_standard_deviation += pad_or_crop_image_to_size(
                reconstruct_image_from_patches(
                    patches_mos_standard_deviation,
                    evaluation_image,
                    stride_length=stride_length_vector), image.shape)

        mos /= len(dimensions_to_predict)
        mos_standard_deviation /= len(dimensions_to_predict)

        if mask is None:

            if which_model == "tidsQualityAssessment":
                return_dict = {
                    'MOS': mos,
                    'MOS.standardDeviation': mos_standard_deviation,
                    'MOS.mean': mos.mean(),
                    'MOS.standardDeviationMean': mos_standard_deviation.mean()
                }
                return (return_dict)

            elif is_koniq:
                return_dict = {
                    'MOS': mos,
                    'sharpness': mos_standard_deviation,
                    'MOS.mean': mos.mean(),
                    'sharpness.mean': mos_standard_deviation.mean()
                }
                return (return_dict)

        else:

            if which_model == "tidsQualityAssessment":
                return_dict = {
                    'MOS':
                    mos * mask,
                    'MOS.standardDeviation':
                    mos_standard_deviation * mask,
                    'MOS.mean': (mos[mask >= 0.5]).mean(),
                    'MOS.standardDeviationMean':
                    (mos_standard_deviation[mask >= 0.5]).mean()
                }
                return (return_dict)

            elif is_koniq:
                return_dict = {
                    'MOS': mos * mask,
                    'sharpness': mos_standard_deviation * mask,
                    'MOS.mean': (mos[mask >= 0.5]).mean(),
                    'sharpness.mean':
                    (mos_standard_deviation[mask >= 0.5]).mean()
                }
                return (return_dict)
예제 #9
0
def sysu_media_wmh_segmentation(flair,
                                t1=None,
                                use_ensemble=True,
                                antsxnet_cache_directory=None,
                                verbose=False):
    """
    Perform WMH segmentation using the winning submission in the MICCAI
    2017 challenge by the sysu_media team using FLAIR or T1/FLAIR.  The
    MICCAI challenge is discussed in

    https://pubmed.ncbi.nlm.nih.gov/30908194/

    with the sysu_media's team entry is discussed in

     https://pubmed.ncbi.nlm.nih.gov/30125711/

    with the original implementation available here:

    https://github.com/hongweilibran/wmh_ibbmTum

    The original implementation used global thresholding as a quick
    brain extraction approach.  Due to possible generalization difficulties,
    we leave such post-processing steps to the user.  For brain or white
    matter masking see functions brain_extraction or deep_atropos,
    respectively.

    Arguments
    ---------
    flair : ANTsImage
        input 3-D FLAIR brain image (not skull-stripped).

    t1 : ANTsImage
        input 3-D T1 brain image (not skull-stripped).

    use_ensemble : boolean
        check whether to use all 3 sets of weights.

    antsxnet_cache_directory : string
        Destination directory for storing the downloaded template and model weights.
        Since these can be resused, if is None, these data will be downloaded to a
        ~/.keras/ANTsXNet/.

    verbose : boolean
        Print progress to the screen.

    Returns
    -------
    WMH segmentation probability image

    Example
    -------
    >>> image = ants.image_read("flair.nii.gz")
    >>> probability_mask = sysu_media_wmh_segmentation(image)
    """

    from ..architectures import create_sysu_media_unet_model_2d
    from ..utilities import get_pretrained_network
    from ..utilities import pad_or_crop_image_to_size
    from ..utilities import preprocess_brain_image
    from ..utilities import binary_dice_coefficient

    if flair.dimension != 3:
        raise ValueError("Image dimension must be 3.")

    if antsxnet_cache_directory == None:
        antsxnet_cache_directory = "ANTsXNet"

    image_size = (200, 200)

    ################################
    #
    # Preprocess images
    #
    ################################

    def closest_simplified_direction_matrix(direction):
        closest = (np.abs(direction) + 0.5).astype(int).astype(float)
        closest[direction < 0] *= -1.0
        return closest

    simplified_direction = closest_simplified_direction_matrix(flair.direction)

    flair_preprocessing = preprocess_brain_image(
        flair,
        truncate_intensity=None,
        brain_extraction_modality=None,
        do_bias_correction=False,
        do_denoising=False,
        antsxnet_cache_directory=antsxnet_cache_directory,
        verbose=verbose)
    flair_preprocessed = flair_preprocessing["preprocessed_image"]
    flair_preprocessed.set_direction(simplified_direction)
    flair_preprocessed.set_origin((0, 0, 0))
    flair_preprocessed.set_spacing((1, 1, 1))
    number_of_channels = 1

    t1_preprocessed = None
    if t1 is not None:
        t1_preprocessing = preprocess_brain_image(
            t1,
            truncate_intensity=None,
            brain_extraction_modality=None,
            do_bias_correction=False,
            do_denoising=False,
            antsxnet_cache_directory=antsxnet_cache_directory,
            verbose=verbose)
        t1_preprocessed = t1_preprocessing["preprocessed_image"]
        t1_preprocessed.set_direction(simplified_direction)
        t1_preprocessed.set_origin((0, 0, 0))
        t1_preprocessed.set_spacing((1, 1, 1))
        number_of_channels = 2

    ################################
    #
    # Reorient images
    #
    ################################

    reference_image = ants.make_image((256, 256, 256),
                                      voxval=0,
                                      spacing=(1, 1, 1),
                                      origin=(0, 0, 0),
                                      direction=np.identity(3))
    center_of_mass_reference = np.floor(
        ants.get_center_of_mass(reference_image * 0 + 1))
    center_of_mass_image = np.floor(
        ants.get_center_of_mass(flair_preprocessed))
    translation = np.asarray(center_of_mass_image) - np.asarray(
        center_of_mass_reference)
    xfrm = ants.create_ants_transform(
        transform_type="Euler3DTransform",
        center=np.asarray(center_of_mass_reference),
        translation=translation)
    flair_preprocessed_warped = ants.apply_ants_transform_to_image(
        xfrm,
        flair_preprocessed,
        reference_image,
        interpolation="nearestneighbor")
    crop_image = ants.image_clone(flair_preprocessed) * 0 + 1
    crop_image_warped = ants.apply_ants_transform_to_image(
        xfrm, crop_image, reference_image, interpolation="nearestneighbor")
    flair_preprocessed_warped = ants.crop_image(flair_preprocessed_warped,
                                                crop_image_warped, 1)

    if t1 is not None:
        t1_preprocessed_warped = ants.apply_ants_transform_to_image(
            xfrm,
            t1_preprocessed,
            reference_image,
            interpolation="nearestneighbor")
        t1_preprocessed_warped = ants.crop_image(t1_preprocessed_warped,
                                                 crop_image_warped, 1)

    ################################
    #
    # Gaussian normalize intensity
    #
    ################################

    mean_flair = flair_preprocessed.mean()
    std_flair = flair_preprocessed.std()
    if number_of_channels == 2:
        mean_t1 = t1_preprocessed.mean()
        std_t1 = t1_preprocessed.std()

    flair_preprocessed_warped = (flair_preprocessed_warped -
                                 mean_flair) / std_flair
    if number_of_channels == 2:
        t1_preprocessed_warped = (t1_preprocessed_warped - mean_t1) / std_t1

    ################################
    #
    # Build models and load weights
    #
    ################################

    number_of_models = 1
    if use_ensemble == True:
        number_of_models = 3

    if verbose == True:
        print("White matter hyperintensity:  retrieving model weights.")

    unet_models = list()
    for i in range(number_of_models):
        if number_of_channels == 1:
            weights_file_name = get_pretrained_network(
                "sysuMediaWmhFlairOnlyModel" + str(i),
                antsxnet_cache_directory=antsxnet_cache_directory)
        else:
            weights_file_name = get_pretrained_network(
                "sysuMediaWmhFlairT1Model" + str(i),
                antsxnet_cache_directory=antsxnet_cache_directory)
        unet_model = create_sysu_media_unet_model_2d(
            (*image_size, number_of_channels))
        unet_loss = binary_dice_coefficient(smoothing_factor=1.)
        unet_model.compile(optimizer=keras.optimizers.Adam(learning_rate=2e-4),
                           loss=unet_loss)
        unet_model.load_weights(weights_file_name)
        unet_models.append(unet_model)

    ################################
    #
    # Extract slices
    #
    ################################

    dimensions_to_predict = [2]

    total_number_of_slices = 0
    for d in range(len(dimensions_to_predict)):
        total_number_of_slices += flair_preprocessed_warped.shape[
            dimensions_to_predict[d]]

    batchX = np.zeros(
        (total_number_of_slices, *image_size, number_of_channels))

    slice_count = 0
    for d in range(len(dimensions_to_predict)):
        number_of_slices = flair_preprocessed_warped.shape[
            dimensions_to_predict[d]]

        if verbose == True:
            print("Extracting slices for dimension ", dimensions_to_predict[d],
                  ".")

        for i in range(number_of_slices):
            flair_slice = pad_or_crop_image_to_size(
                ants.slice_image(flair_preprocessed_warped,
                                 dimensions_to_predict[d], i), image_size)
            batchX[slice_count, :, :, 0] = flair_slice.numpy()
            if number_of_channels == 2:
                t1_slice = pad_or_crop_image_to_size(
                    ants.slice_image(t1_preprocessed_warped,
                                     dimensions_to_predict[d], i), image_size)
                batchX[slice_count, :, :, 1] = t1_slice.numpy()
            slice_count += 1

    ################################
    #
    # Do prediction and then restack into the image
    #
    ################################

    if verbose == True:
        print("Prediction.")

    prediction = unet_models[0].predict(np.transpose(batchX,
                                                     axes=(0, 2, 1, 3)),
                                        verbose=verbose)
    if number_of_models > 1:
        for i in range(1, number_of_models, 1):
            prediction += unet_models[i].predict(np.transpose(batchX,
                                                              axes=(0, 2, 1,
                                                                    3)),
                                                 verbose=verbose)
    prediction /= number_of_models
    prediction = np.transpose(prediction, axes=(0, 2, 1, 3))

    permutations = list()
    permutations.append((0, 1, 2))
    permutations.append((1, 0, 2))
    permutations.append((1, 2, 0))

    prediction_image_average = ants.image_clone(flair_preprocessed_warped) * 0

    current_start_slice = 0
    for d in range(len(dimensions_to_predict)):
        current_end_slice = current_start_slice + flair_preprocessed_warped.shape[
            dimensions_to_predict[d]]
        which_batch_slices = range(current_start_slice, current_end_slice)
        prediction_per_dimension = prediction[which_batch_slices, :, :, :]
        prediction_array = np.transpose(np.squeeze(prediction_per_dimension),
                                        permutations[dimensions_to_predict[d]])
        prediction_image = ants.copy_image_info(
            flair_preprocessed_warped,
            pad_or_crop_image_to_size(ants.from_numpy(prediction_array),
                                      flair_preprocessed_warped.shape))
        prediction_image_average = prediction_image_average + (
            prediction_image - prediction_image_average) / (d + 1)
        current_start_slice = current_end_slice

    probability_image = ants.apply_ants_transform_to_image(
        ants.invert_ants_transform(xfrm), prediction_image_average,
        flair_preprocessed)
    probability_image = ants.copy_image_info(flair, probability_image)

    return (probability_image)
예제 #10
0
def ew_david(flair,
             t1,
             do_preprocessing=True,
             which_model="sysu",
             which_axes=2,
             number_of_simulations=0,
             sd_affine=0.01,
             antsxnet_cache_directory=None,
             verbose=False):
    """
    Perform White matter hyperintensity probabilistic segmentation
    using deep learning

    Preprocessing on the training data consisted of:
       * n4 bias correction,
       * intensity truncation,
       * brain extraction, and
       * affine registration to MNI.
    The input T1 should undergo the same steps.  If the input T1 is the raw
    T1, these steps can be performed by the internal preprocessing, i.e. set
    \code{do_preprocessing = True}

    Arguments
    ---------
    flair : ANTsImage
        input 3-D FLAIR brain image (not skull-stripped).

    t1 : ANTsImage
        input 3-D T1 brain image (not skull-stripped).

    do_preprocessing : boolean
        perform n4 bias correction, intensity truncation, brain extraction.

    which_model : string
        one of:
            * "sysu" -- same as the original sysu network (without site specific preprocessing),
            * "sysu-ri" -- same as "sysu" but using ranked intensity scaling for input images,
            * "sysuWithAttention" -- "sysu" with attention gating,
            * "sysuWithAttentionAndSite" -- "sysu" with attention gating with site branch (see "sysuWithSite"),
            * "sysuPlus" -- "sysu" with attention gating and nn-Unet activation,
            * "sysuPlusSeg" -- "sysuPlus" with deep_atropos segmentation in an additional channel, and
            * "sysuWithSite" -- "sysu" with global pooling on encoding channels to predict "site".
            * "sysuPlusSegWithSite" -- "sysuPlusSeg" combined with "sysuWithSite"
        In addition to both modalities, all models have T1-only and flair-only variants except
        for "sysuPlusSeg" (which only has a T1-only variant) or "sysu-ri" (which has neither single
        modality variant).

    which_axes : string or scalar or tuple/vector
        apply 2-D model to 1 or more axes.  In addition to a scalar
        or vector, e.g., which_axes = (0, 2), one can use "max" for the
        axis with maximum anisotropy (default) or "all" for all axes.

    number_of_simulations : integer
        Number of random affine perturbations to transform the input.

    sd_affine : float
        Define the standard deviation of the affine transformation parameter.

    antsxnet_cache_directory : string
        Destination directory for storing the downloaded template and model weights.
        Since these can be resused, if is None, these data will be downloaded to a
        ~/.keras/ANTsXNet/.

    verbose : boolean
        Print progress to the screen.

    Returns
    -------
    WMH segmentation probability image

    Example
    -------
    >>> image = ants.image_read("flair.nii.gz")
    >>> probability_mask = sysu_media_wmh_segmentation(image)
    """

    from ..architectures import create_unet_model_2d
    from ..utilities import deep_atropos
    from ..utilities import get_pretrained_network
    from ..utilities import preprocess_brain_image
    from ..utilities import randomly_transform_image_data
    from ..utilities import pad_or_crop_image_to_size

    do_t1_only = False
    do_flair_only = False

    if flair is None and t1 is not None:
        do_t1_only = True
    elif flair is not None and t1 is None:
        do_flair_only = True

    use_t1_segmentation = False
    if "Seg" in which_model:
        if do_flair_only:
            raise ValueError("Segmentation requires T1.")
        else:
            use_t1_segmentation = True

    if use_t1_segmentation and do_preprocessing == False:
        raise ValueError(
            "Using the t1 segmentation requires do_preprocessing=True.")

    if antsxnet_cache_directory == None:
        antsxnet_cache_directory = "ANTsXNet"

    do_slicewise = True

    if do_slicewise == False:

        raise ValueError("Not available.")

        # ################################
        # #
        # # Preprocess images
        # #
        # ################################

        # t1_preprocessed = t1
        # t1_preprocessing = None
        # if do_preprocessing == True:
        #     t1_preprocessing = preprocess_brain_image(t1,
        #         truncate_intensity=(0.01, 0.99),
        #         brain_extraction_modality="t1",
        #         template="croppedMni152",
        #         template_transform_type="antsRegistrationSyNQuickRepro[a]",
        #         do_bias_correction=True,
        #         do_denoising=False,
        #         antsxnet_cache_directory=antsxnet_cache_directory,
        #         verbose=verbose)
        #     t1_preprocessed = t1_preprocessing["preprocessed_image"] * t1_preprocessing['brain_mask']

        # flair_preprocessed = flair
        # if do_preprocessing == True:
        #     flair_preprocessing = preprocess_brain_image(flair,
        #         truncate_intensity=(0.01, 0.99),
        #         brain_extraction_modality="t1",
        #         do_bias_correction=True,
        #         do_denoising=False,
        #         antsxnet_cache_directory=antsxnet_cache_directory,
        #         verbose=verbose)
        #     flair_preprocessed = ants.apply_transforms(fixed=t1_preprocessed,
        #         moving=flair_preprocessing["preprocessed_image"],
        #         transformlist=t1_preprocessing['template_transforms']['fwdtransforms'])
        #     flair_preprocessed = flair_preprocessed * t1_preprocessing['brain_mask']

        # ################################
        # #
        # # Build model and load weights
        # #
        # ################################

        # patch_size = (112, 112, 112)
        # stride_length = (t1_preprocessed.shape[0] - patch_size[0],
        #                 t1_preprocessed.shape[1] - patch_size[1],
        #                 t1_preprocessed.shape[2] - patch_size[2])

        # classes = ("background", "wmh" )
        # number_of_classification_labels = len(classes)
        # labels = (0, 1)

        # image_modalities = ("T1", "FLAIR")
        # channel_size = len(image_modalities)

        # unet_model = create_unet_model_3d((*patch_size, channel_size),
        #     number_of_outputs = number_of_classification_labels,
        #     number_of_layers = 4, number_of_filters_at_base_layer = 16, dropout_rate = 0.0,
        #     convolution_kernel_size = (3, 3, 3), deconvolution_kernel_size = (2, 2, 2),
        #     weight_decay = 1e-5, additional_options=("attentionGating"))

        # weights_file_name = get_pretrained_network("ewDavidWmhSegmentationWeights",
        #     antsxnet_cache_directory=antsxnet_cache_directory)
        # unet_model.load_weights(weights_file_name)

        # ################################
        # #
        # # Do prediction and normalize to native space
        # #
        # ################################

        # if verbose == True:
        #     print("ew_david:  prediction.")

        # batchX = np.zeros((8, *patch_size, channel_size))

        # t1_preprocessed = (t1_preprocessed - t1_preprocessed.mean()) / t1_preprocessed.std()
        # t1_patches = extract_image_patches(t1_preprocessed, patch_size=patch_size,
        #                                     max_number_of_patches="all", stride_length=stride_length,
        #                                     return_as_array=True)
        # batchX[:,:,:,:,0] = t1_patches

        # flair_preprocessed = (flair_preprocessed - flair_preprocessed.mean()) / flair_preprocessed.std()
        # flair_patches = extract_image_patches(flair_preprocessed, patch_size=patch_size,
        #                                     max_number_of_patches="all", stride_length=stride_length,
        #                                     return_as_array=True)
        # batchX[:,:,:,:,1] = flair_patches

        # predicted_data = unet_model.predict(batchX, verbose=verbose)

        # probability_images = list()
        # for i in range(len(labels)):
        #     print("Reconstructing image", classes[i])
        #     reconstructed_image = reconstruct_image_from_patches(predicted_data[:,:,:,:,i],
        #         domain_image=t1_preprocessed, stride_length=stride_length)

        #     if do_preprocessing == True:
        #         probability_images.append(ants.apply_transforms(fixed=t1,
        #             moving=reconstructed_image,
        #             transformlist=t1_preprocessing['template_transforms']['invtransforms'],
        #             whichtoinvert=[True], interpolator="linear", verbose=verbose))
        #     else:
        #         probability_images.append(reconstructed_image)

        # return(probability_images[1])

    else:  # do_slicewise

        ################################
        #
        # Preprocess images
        #
        ################################

        use_rank_intensity_scaling = False
        if "-ri" in which_model:
            use_rank_intensity_scaling = True

        t1_preprocessed = None
        t1_preprocessing = None
        brain_mask = None
        if t1 is not None:
            if do_preprocessing == True:
                t1_preprocessing = preprocess_brain_image(
                    t1,
                    truncate_intensity=(0.01, 0.995),
                    brain_extraction_modality="t1",
                    do_bias_correction=False,
                    do_denoising=False,
                    antsxnet_cache_directory=antsxnet_cache_directory,
                    verbose=verbose)
                brain_mask = ants.threshold_image(
                    t1_preprocessing["brain_mask"], 0.5, 1, 1, 0)
                t1_preprocessed = t1_preprocessing["preprocessed_image"]

        t1_segmentation = None
        if use_t1_segmentation:
            atropos_seg = deep_atropos(t1,
                                       do_preprocessing=True,
                                       verbose=verbose)
            t1_segmentation = atropos_seg['segmentation_image']

        flair_preprocessed = None
        if flair is not None:
            flair_preprocessed = flair
            if do_preprocessing == True:
                if brain_mask is None:
                    flair_preprocessing = preprocess_brain_image(
                        flair,
                        truncate_intensity=(0.01, 0.995),
                        brain_extraction_modality="flair",
                        do_bias_correction=False,
                        do_denoising=False,
                        antsxnet_cache_directory=antsxnet_cache_directory,
                        verbose=verbose)
                    brain_mask = ants.threshold_image(
                        flair_preprocessing["brain_mask"], 0.5, 1, 1, 0)
                else:
                    flair_preprocessing = preprocess_brain_image(
                        flair,
                        truncate_intensity=None,
                        brain_extraction_modality=None,
                        do_bias_correction=False,
                        do_denoising=False,
                        antsxnet_cache_directory=antsxnet_cache_directory,
                        verbose=verbose)
                flair_preprocessed = flair_preprocessing["preprocessed_image"]

        if t1_preprocessed is not None:
            t1_preprocessed = t1_preprocessed * brain_mask
        if flair_preprocessed is not None:
            flair_preprocessed = flair_preprocessed * brain_mask

        if t1_preprocessed is not None:
            resampling_params = list(ants.get_spacing(t1_preprocessed))
        else:
            resampling_params = list(ants.get_spacing(flair_preprocessed))

        do_resampling = False
        for d in range(len(resampling_params)):
            if resampling_params[d] < 0.8:
                resampling_params[d] = 1.0
                do_resampling = True

        resampling_params = tuple(resampling_params)

        if do_resampling:
            if flair_preprocessed is not None:
                flair_preprocessed = ants.resample_image(flair_preprocessed,
                                                         resampling_params,
                                                         use_voxels=False,
                                                         interp_type=0)
            if t1_preprocessed is not None:
                t1_preprocessed = ants.resample_image(t1_preprocessed,
                                                      resampling_params,
                                                      use_voxels=False,
                                                      interp_type=0)
            if t1_segmentation is not None:
                t1_segmentation = ants.resample_image(t1_segmentation,
                                                      resampling_params,
                                                      use_voxels=False,
                                                      interp_type=1)
            if brain_mask is not None:
                brain_mask = ants.resample_image(brain_mask,
                                                 resampling_params,
                                                 use_voxels=False,
                                                 interp_type=1)

        ################################
        #
        # Build model and load weights
        #
        ################################

        template_size = (208, 208)

        image_modalities = ("T1", "FLAIR")
        if do_flair_only:
            image_modalities = ("FLAIR", )
        elif do_t1_only:
            image_modalities = ("T1", )
        if use_t1_segmentation:
            image_modalities = (*image_modalities, "T1Seg")
        channel_size = len(image_modalities)

        unet_model = None
        if which_model == "sysu" or which_model == "sysu-ri":
            unet_model = create_unet_model_2d(
                (*template_size, channel_size),
                number_of_outputs=1,
                mode="sigmoid",
                number_of_filters=(64, 96, 128, 256, 512),
                dropout_rate=0.0,
                convolution_kernel_size=(3, 3),
                deconvolution_kernel_size=(2, 2),
                weight_decay=0,
                additional_options=("initialConvolutionKernelSize[5]", ))
        elif which_model == "sysuWithAttention":
            unet_model = create_unet_model_2d(
                (*template_size, channel_size),
                number_of_outputs=1,
                mode="sigmoid",
                number_of_filters=(64, 96, 128, 256, 512),
                dropout_rate=0.0,
                convolution_kernel_size=(3, 3),
                deconvolution_kernel_size=(2, 2),
                weight_decay=0,
                additional_options=("attentionGating",
                                    "initialConvolutionKernelSize[5]"))
        elif which_model == "sysuWithAttentionAndSite":
            unet_model = create_unet_model_2d(
                (*template_size, channel_size),
                number_of_outputs=1,
                mode="sigmoid",
                scalar_output_size=3,
                scalar_output_activation="softmax",
                number_of_filters=(64, 96, 128, 256, 512),
                dropout_rate=0.0,
                convolution_kernel_size=(3, 3),
                deconvolution_kernel_size=(2, 2),
                weight_decay=0,
                additional_options=("attentionGating",
                                    "initialConvolutionKernelSize[5]"))
        elif which_model == "sysuWithSite":
            unet_model = create_unet_model_2d(
                (*template_size, channel_size),
                number_of_outputs=1,
                mode="sigmoid",
                scalar_output_size=3,
                scalar_output_activation="softmax",
                number_of_filters=(64, 96, 128, 256, 512),
                dropout_rate=0.0,
                convolution_kernel_size=(3, 3),
                deconvolution_kernel_size=(2, 2),
                weight_decay=0,
                additional_options=("initialConvolutionKernelSize[5]", ))
        elif which_model == "sysuPlusSegWithSite":
            unet_model = create_unet_model_2d(
                (*template_size, channel_size),
                number_of_outputs=1,
                mode="sigmoid",
                scalar_output_size=3,
                scalar_output_activation="softmax",
                number_of_filters=(64, 96, 128, 256, 512),
                dropout_rate=0.0,
                convolution_kernel_size=(3, 3),
                deconvolution_kernel_size=(2, 2),
                weight_decay=0,
                additional_options=("nnUnetActivationStyle", "attentionGating",
                                    "initialConvolutionKernelSize[5]"))
        else:
            unet_model = create_unet_model_2d(
                (*template_size, channel_size),
                number_of_outputs=1,
                mode="sigmoid",
                number_of_filters=(64, 96, 128, 256, 512),
                dropout_rate=0.0,
                convolution_kernel_size=(3, 3),
                deconvolution_kernel_size=(2, 2),
                weight_decay=0,
                additional_options=("nnUnetActivationStyle", "attentionGating",
                                    "initialConvolutionKernelSize[5]"))

        if verbose == True:
            print("ewDavid:  retrieving model weights.")

        weights_file_name = None
        if which_model == "sysu" and flair is not None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysu",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysu-ri" and flair is not None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuRankedIntensity",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysu" and flair is None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuT1Only",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysu" and flair is not None and t1 is None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuFlairOnly",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuWithAttention" and flair is not None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuWithAttention",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuWithAttention" and flair is None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuWithAttentionT1Only",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuWithAttention" and flair is not None and t1 is None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuWithAttentionFlairOnly",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuWithAttentionAndSite" and flair is not None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuWithAttentionAndSite",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuWithAttentionAndSite" and flair is None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuWithAttentionAndSiteT1Only",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuWithAttentionAndSite" and flair is not None and t1 is None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuWithAttentionAndSiteFlairOnly",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuPlus" and flair is not None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuPlus",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuPlus" and flair is None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuPlusT1Only",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuPlus" and flair is not None and t1 is None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuPlusFlairOnly",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuPlusSeg" and flair is not None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuPlusSeg",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuPlusSeg" and flair is None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuPlusSegT1Only",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuPlusSegWithSite" and flair is not None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuPlusSegWithSite",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuPlusSegWithSite" and flair is None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuPlusSegWithSiteT1Only",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuWithSite" and flair is not None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuWithSite",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuWithSite" and flair is None and t1 is not None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuWithSiteT1Only",
                antsxnet_cache_directory=antsxnet_cache_directory)
        elif which_model == "sysuWithSite" and flair is not None and t1 is None:
            weights_file_name = get_pretrained_network(
                "ewDavidSysuWithSiteFlairOnly",
                antsxnet_cache_directory=antsxnet_cache_directory)
        else:
            raise ValueError(
                "Incorrect model specification or image combination.")

        unet_model.load_weights(weights_file_name)

        ################################
        #
        # Data augmentation and extract slices
        #
        ################################

        wmh_probability_image = None
        if t1 is not None:
            wmh_probability_image = ants.image_clone(t1_preprocessed) * 0
        else:
            wmh_probability_image = ants.image_clone(flair_preprocessed) * 0

        wmh_site = np.array([0, 0, 0])

        data_augmentation = None
        if number_of_simulations > 0:
            if do_flair_only:
                data_augmentation = randomly_transform_image_data(
                    reference_image=flair_preprocessed,
                    input_image_list=[[flair_preprocessed]],
                    number_of_simulations=number_of_simulations,
                    transform_type='affine',
                    sd_affine=sd_affine,
                    input_image_interpolator='linear')
            elif do_t1_only:
                if use_t1_segmentation:
                    data_augmentation = randomly_transform_image_data(
                        reference_image=t1_preprocessed,
                        input_image_list=[[t1_preprocessed]],
                        segmentation_image_list=[t1_segmentation],
                        number_of_simulations=number_of_simulations,
                        transform_type='affine',
                        sd_affine=sd_affine,
                        input_image_interpolator='linear',
                        segmentation_image_interpolator='nearestNeighbor')
                else:
                    data_augmentation = randomly_transform_image_data(
                        reference_image=t1_preprocessed,
                        input_image_list=[[t1_preprocessed]],
                        number_of_simulations=number_of_simulations,
                        transform_type='affine',
                        sd_affine=sd_affine,
                        input_image_interpolator='linear')
            else:
                if use_t1_segmentation:
                    data_augmentation = randomly_transform_image_data(
                        reference_image=t1_preprocessed,
                        input_image_list=[[
                            flair_preprocessed, t1_preprocessed
                        ]],
                        segmentation_image_list=[t1_segmentation],
                        number_of_simulations=number_of_simulations,
                        transform_type='affine',
                        sd_affine=sd_affine,
                        input_image_interpolator='linear',
                        segmentation_image_interpolator='nearestNeighbor')
                else:
                    data_augmentation = randomly_transform_image_data(
                        reference_image=t1_preprocessed,
                        input_image_list=[[
                            flair_preprocessed, t1_preprocessed
                        ]],
                        number_of_simulations=number_of_simulations,
                        transform_type='affine',
                        sd_affine=sd_affine,
                        input_image_interpolator='linear')

        dimensions_to_predict = list((0, ))
        if which_axes == "max":
            spacing = ants.get_spacing(wmh_probability_image)
            dimensions_to_predict = (spacing.index(max(spacing)), )
        elif which_axes == "all":
            dimensions_to_predict = list(range(3))
        else:
            if isinstance(which_axes, int):
                dimensions_to_predict = list((which_axes, ))
            else:
                dimensions_to_predict = list(which_axes)

        total_number_of_slices = 0
        for d in range(len(dimensions_to_predict)):
            total_number_of_slices += wmh_probability_image.shape[
                dimensions_to_predict[d]]

        batchX = np.zeros(
            (total_number_of_slices, *template_size, channel_size))

        for n in range(number_of_simulations + 1):

            batch_flair = flair_preprocessed
            batch_t1 = t1_preprocessed
            batch_t1_segmentation = t1_segmentation
            batch_brain_mask = brain_mask

            if n > 0:

                if do_flair_only:
                    batch_flair = data_augmentation['simulated_images'][n -
                                                                        1][0]
                    batch_brain_mask = ants.apply_ants_transform_to_image(
                        data_augmentation['simulated_transforms'][n - 1],
                        brain_mask,
                        flair_preprocessed,
                        interpolation="nearestneighbor")

                elif do_t1_only:
                    batch_t1 = data_augmentation['simulated_images'][n - 1][0]
                    batch_brain_mask = ants.apply_ants_transform_to_image(
                        data_augmentation['simulated_transforms'][n - 1],
                        brain_mask,
                        t1_preprocessed,
                        interpolation="nearestneighbor")
                else:
                    batch_flair = data_augmentation['simulated_images'][n -
                                                                        1][0]
                    batch_t1 = data_augmentation['simulated_images'][n - 1][1]
                    batch_brain_mask = ants.apply_ants_transform_to_image(
                        data_augmentation['simulated_transforms'][n - 1],
                        brain_mask,
                        flair_preprocessed,
                        interpolation="nearestneighbor")
                if use_t1_segmentation:
                    batch_t1_segmentation = data_augmentation[
                        'simulated_segmentation_images'][n - 1]

            if use_rank_intensity_scaling:
                if batch_t1 is not None:
                    batch_t1 = ants.rank_intensity(batch_t1,
                                                   batch_brain_mask) - 0.5
                if batch_flair is not None:
                    batch_flair = ants.rank_intensity(flair_preprocessed,
                                                      batch_brain_mask) - 0.5
            else:
                if batch_t1 is not None:
                    batch_t1 = (batch_t1 -
                                batch_t1[batch_brain_mask == 1].mean()
                                ) / batch_t1[batch_brain_mask == 1].std()
                if batch_flair is not None:
                    batch_flair = (
                        batch_flair -
                        batch_flair[batch_brain_mask == 1].mean()
                    ) / batch_flair[batch_brain_mask == 1].std()

            slice_count = 0
            for d in range(len(dimensions_to_predict)):

                number_of_slices = None
                if batch_t1 is not None:
                    number_of_slices = batch_t1.shape[dimensions_to_predict[d]]
                else:
                    number_of_slices = batch_flair.shape[
                        dimensions_to_predict[d]]

                if verbose == True:
                    print("Extracting slices for dimension ",
                          dimensions_to_predict[d])

                for i in range(number_of_slices):

                    brain_mask_slice = pad_or_crop_image_to_size(
                        ants.slice_image(batch_brain_mask,
                                         dimensions_to_predict[d], i),
                        template_size)

                    channel_count = 0
                    if batch_flair is not None:
                        flair_slice = pad_or_crop_image_to_size(
                            ants.slice_image(batch_flair,
                                             dimensions_to_predict[d], i),
                            template_size)
                        flair_slice[brain_mask_slice == 0] = 0
                        batchX[slice_count, :, :,
                               channel_count] = flair_slice.numpy()
                        channel_count += 1
                    if batch_t1 is not None:
                        t1_slice = pad_or_crop_image_to_size(
                            ants.slice_image(batch_t1,
                                             dimensions_to_predict[d], i),
                            template_size)
                        t1_slice[brain_mask_slice == 0] = 0
                        batchX[slice_count, :, :,
                               channel_count] = t1_slice.numpy()
                        channel_count += 1
                    if t1_segmentation is not None:
                        t1_segmentation_slice = pad_or_crop_image_to_size(
                            ants.slice_image(batch_t1_segmentation,
                                             dimensions_to_predict[d], i),
                            template_size)
                        t1_segmentation_slice[brain_mask_slice == 0] = 0
                        batchX[slice_count, :, :,
                               channel_count] = t1_segmentation_slice.numpy(
                               ) / 6 - 0.5

                    slice_count += 1

            ################################
            #
            # Do prediction and then restack into the image
            #
            ################################

            if verbose == True:
                if n == 0:
                    print("Prediction")
                else:
                    print("Prediction (simulation " + str(n) + ")")

            prediction = unet_model.predict(batchX, verbose=verbose)

            permutations = list()
            permutations.append((0, 1, 2))
            permutations.append((1, 0, 2))
            permutations.append((1, 2, 0))

            prediction_image_average = ants.image_clone(
                wmh_probability_image) * 0

            current_start_slice = 0
            for d in range(len(dimensions_to_predict)):
                current_end_slice = current_start_slice + wmh_probability_image.shape[
                    dimensions_to_predict[d]]
                which_batch_slices = range(current_start_slice,
                                           current_end_slice)
                if isinstance(prediction, list):
                    prediction_per_dimension = prediction[0][
                        which_batch_slices, :, :, 0]
                else:
                    prediction_per_dimension = prediction[
                        which_batch_slices, :, :, 0]
                prediction_array = np.transpose(
                    np.squeeze(prediction_per_dimension),
                    permutations[dimensions_to_predict[d]])
                prediction_image = ants.copy_image_info(
                    wmh_probability_image,
                    pad_or_crop_image_to_size(
                        ants.from_numpy(prediction_array),
                        wmh_probability_image.shape))
                prediction_image_average = prediction_image_average + (
                    prediction_image - prediction_image_average) / (d + 1)
                current_start_slice = current_end_slice

            wmh_probability_image = wmh_probability_image + (
                prediction_image_average - wmh_probability_image) / (n + 1)
            if isinstance(prediction, list):
                wmh_site = wmh_site + (np.mean(prediction[1], axis=0) -
                                       wmh_site) / (n + 1)

        if do_resampling:
            if t1 is not None:
                wmh_probability_image = ants.resample_image_to_target(
                    wmh_probability_image, t1)
            if flair is not None:
                wmh_probability_image = ants.resample_image_to_target(
                    wmh_probability_image, flair)

        if isinstance(prediction, list):
            return ([wmh_probability_image, wmh_site])
        else:
            return (wmh_probability_image)
예제 #11
0
import ants
import os
import numpy as np

root = '/gsfs0/data/poskanzc/Sherlock/preproc/fmriprep/'
all_subjects = ['sub-01', 'sub-02', 'sub-03', 'sub-04', 'sub-05', 'sub-06', 'sub-07', 'sub-08', 'sub-10', 'sub-11', 'sub-12', 'sub-13', 'sub-14', 'sub-15', 'sub-16']
mask = '_CSF_WM_mask_union_bin_shrinked.nii.gz'

for sub in all_subjects:
    sub_dir = root + sub +'/func/'
    mask_dir = root + sub +'/'+ sub +'_ROIs/' +sub + mask
    sub_out_dir = root + sub + '/' + sub + '_ROIs/'

    epi = ants.image_read(os.path.join(sub_dir,sub + '_task-sherlockPart1_space-MNI152NLin2009cAsym_desc-preproc_bold.nii.gz'))
    epi3d = ants.slice_image(epi,axis=3,idx=0)
    noiseROI = ants.image_read(os.path.join(mask_dir))

    reg = ants.registration(fixed=epi3d, moving=noiseROI,type_of_transform='Rigid', reg_iterations = [100,100,20] )
    rAnat = reg['warpedmovout']

    rAnat.to_filename(os.path.join(sub_out_dir, sub + '_CSF_WM_mask_union_shrinked_funcSize.nii.gz'))