def dicom_to_nifti(dicom_input, output_file):
"""
This function will convert an anatomical dicom series to a nifti
Examples: See unit test
:param output_file: filepath to the output nifti
:param dicom_input: directory with the dicom files for a single scan, or list of read in dicoms
"""
if len(dicom_input) <= 0:
raise ConversionError('NO_DICOM_FILES_FOUND')
# remove duplicate slices based on position and data
dicom_input = _remove_duplicate_slices(dicom_input)
# remove localizers based on image type
dicom_input = _remove_localizers_by_imagetype(dicom_input)
if settings.validate_slicecount:
# remove_localizers based on image orientation (only valid if slicecount is validated)
dicom_input = _remove_localizers_by_orientation(dicom_input)
# validate all the dicom files for correct orientations
common.validate_slicecount(dicom_input)
if settings.validate_orientation:
# validate that all slices have the same orientation
common.validate_orientation(dicom_input)
if settings.validate_orthogonal:
# validate that we have an orthogonal image (to detect gantry tilting etc)
common.validate_orthogonal(dicom_input)
# sort the dicoms
dicom_input = common.sort_dicoms(dicom_input)
if settings.validate_sliceincrement:
# validate that all slices have a consistent slice increment
common.validate_sliceincrement(dicom_input)
# Get data; originally z,y,x, transposed to x,y,z
data = common.get_volume_pixeldata(dicom_input)
affine = common.create_affine(dicom_input)
# Convert to nifti
nii_image = nibabel.Nifti1Image(data, affine)
# Set TR and TE if available
if Tag(0x0018, 0x0081) in dicom_input[0] and Tag(0x0018,
0x0081) in dicom_input[0]:
common.set_tr_te(nii_image, float(dicom_input[0].RepetitionTime),
float(dicom_input[0].EchoTime))
# Save to disk
if output_file is not None:
logger.info('Saving nifti to disk %s' % output_file)
nii_image.to_filename(output_file)
return {'NII_FILE': output_file, 'NII': nii_image}
def test_validate_slicecount(self):
validate_slicecount(read_dicom_directory(test_data.GE_ANATOMICAL))
self.assertRaises(ConversionValidationError, validate_slicecount,
read_dicom_directory(test_data.FAILING_SLICECOUNT))
def dicom_to_nifti(dicom_input, output_file):
"""
This function will convert an anatomical dicom series to a nifti
Examples: See unit test
:param output_file: filepath to the output nifti
:param dicom_input: directory with the dicom files for a single scan, or list of read in dicoms
"""
if len(dicom_input) <= 0:
raise ConversionError('NO_DICOM_FILES_FOUND')
# remove duplicate slices based on position and data
dicom_input = remove_duplicate_slices(dicom_input)
# remove localizers based on image type
dicom_input = remove_localizers_by_imagetype(dicom_input)
# if no dicoms remain we should raise exception
if len(dicom_input) < 1:
raise ConversionValidationError('TOO_FEW_SLICES/LOCALIZER')
if settings.validate_slicecount:
common.validate_slicecount(dicom_input)
# remove_localizers based on image orientation (only valid if slicecount is validated)
dicom_input = remove_localizers_by_orientation(dicom_input)
# validate all the dicom files for correct orientations
common.validate_slicecount(dicom_input)
if settings.validate_orientation:
# validate that all slices have the same orientation
common.validate_orientation(dicom_input)
if settings.validate_orthogonal:
# validate that we have an orthogonal image (to detect gantry tilting etc)
common.validate_orthogonal(dicom_input)
# sort the dicoms
dicom_input = common.sort_dicoms(dicom_input)
# validate slice increment inconsistent
slice_increment_inconsistent = False
if settings.validate_slice_increment:
# validate that all slices have a consistent slice increment
common.validate_slice_increment(dicom_input)
elif common.is_slice_increment_inconsistent(dicom_input):
slice_increment_inconsistent = True
if settings.validate_instance_number:
# validate that all slices have a consistent instance_number
common.validate_instance_number(dicom_input)
# if inconsistent increment and we allow resampling then do the resampling based conversion to maintain the correct geometric shape
if slice_increment_inconsistent and settings.resample:
nii_image, max_slice_increment = _convert_slice_incement_inconsistencies(dicom_input)
# do the normal conversion
else:
# Get data; originally z,y,x, transposed to x,y,z
data = common.get_volume_pixeldata(dicom_input)
affine, max_slice_increment = common.create_affine(dicom_input)
# Convert to nifti
nii_image = nibabel.Nifti1Image(data.squeeze(), affine)
# Set TR and TE if available
if Tag(0x0018, 0x0080) in dicom_input[0] and Tag(0x0018, 0x0081) in dicom_input[0]:
common.set_tr_te(nii_image, float(dicom_input[0].RepetitionTime), float(dicom_input[0].EchoTime))
# Save to disk
if output_file is not None:
logger.info('Saving nifti to disk %s' % output_file)
nii_image.header.set_slope_inter(1, 0)
nii_image.header.set_xyzt_units(2) # set units for xyz (leave t as unknown)
nii_image.to_filename(output_file)
return {'NII_FILE': output_file,
'NII': nii_image,
'MAX_SLICE_INCREMENT': max_slice_increment}
def test_validate_slicecount(self):
validate_slicecount(read_dicom_directory(test_data.GE_ANATOMICAL))
self.assertRaises(ConversionValidationError,
validate_slicecount,
read_dicom_directory(test_data.FAILING_SLICECOUNT))
def dicom_to_nifti(dicom_input, output_file):
"""
This function will convert an anatomical dicom series to a nifti
Examples: See unit test
:param output_file: filepath to the output nifti
:param dicom_input: directory with the dicom files for a single scan, or list of read in dicoms
"""
if len(dicom_input) <= 0:
raise ConversionError('NO_DICOM_FILES_FOUND')
# remove duplicate slices based on position and data
dicom_input = _remove_duplicate_slices(dicom_input)
# remove localizers based on image type
dicom_input = _remove_localizers_by_imagetype(dicom_input)
if settings.validate_slicecount:
# remove_localizers based on image orientation (only valid if slicecount is validated)
dicom_input = _remove_localizers_by_orientation(dicom_input)
# validate all the dicom files for correct orientations
common.validate_slicecount(dicom_input)
if settings.validate_orientation:
# validate that all slices have the same orientation
common.validate_orientation(dicom_input)
if settings.validate_orthogonal:
# validate that we have an orthogonal image (to detect gantry tilting etc)
common.validate_orthogonal(dicom_input)
# sort the dicoms
dicom_input = common.sort_dicoms(dicom_input)
# validate slice increment inconsistent
slice_increment_inconsistent = False
if settings.validate_slice_increment:
# validate that all slices have a consistent slice increment
common.validate_slice_increment(dicom_input)
elif common.is_slice_increment_inconsistent(dicom_input):
slice_increment_inconsistent = True
# if inconsistent increment and we allow resampling then do the resampling based conversion to maintain the correct geometric shape
if slice_increment_inconsistent and settings.resample:
nii_image, max_slice_increment = _convert_slice_incement_inconsistencies(dicom_input)
# do the normal conversion
else:
# Get data; originally z,y,x, transposed to x,y,z
data = common.get_volume_pixeldata(dicom_input)
affine, max_slice_increment = common.create_affine(dicom_input)
# Convert to nifti
nii_image = nibabel.Nifti1Image(data, affine)
# Set TR and TE if available
if Tag(0x0018, 0x0081) in dicom_input[0] and Tag(0x0018, 0x0081) in dicom_input[0]:
common.set_tr_te(nii_image, float(dicom_input[0].RepetitionTime), float(dicom_input[0].EchoTime))
# Save to disk
if output_file is not None:
logger.info('Saving nifti to disk %s' % output_file)
nii_image.to_filename(output_file)
return {'NII_FILE': output_file,
'NII': nii_image,
'MAX_SLICE_INCREMENT': max_slice_increment}
