Esempio n. 1
0
import math

import numpy as np
from matplotlib import pyplot as plt

import pypulseq as pp

# ======
# SETUP
# ======
seq = pp.Sequence()  # Create a new sequence object
# Define FOV and resolution
fov = 256e-3
Nx = 64
Ny = 64

# Set system limits
system = pp.Opts(max_grad=32, grad_unit='mT/m', max_slew=130, slew_unit='T/m/s', rf_ringdown_time=30e-6,
                 rf_dead_time=100e-6, adc_dead_time=20e-6)

# ======
# CREATE EVENTS
# ======
# Create 90 degree slice selection pulse and gradient
rf, gz, _ = pp.make_sinc_pulse(flip_angle=np.pi / 2, system=system, duration=3e-3, slice_thickness=3e-3,
                               apodization=0.5, time_bw_product=4, return_gz=True)

# Define other gradients and ADC events
delta_k = 1 / fov
k_width = Nx * delta_k
readout_time = 3.2e-4
Esempio n. 2
0
import numpy as np
from matplotlib import pyplot as plt

import pypulseq as pp

# ======
# SETUP
# ======
dG = 250e-6

# Set system limits
system = pp.Opts(max_grad=32, grad_unit='mT/m', max_slew=130, slew_unit='T/m/s', rf_ringdown_time=100e-6,
                 rf_dead_time=100e-6, adc_dead_time=10e-6)

seq = pp.Sequence(system)  # Create a new sequence object
# Define FOV and resolution
fov = 256e-3
Nx, Ny = 128, 128
n_echo = 16
n_slices = 1
rf_flip = 180
if isinstance(rf_flip, int):
    rf_flip = np.zeros(n_echo) + rf_flip
slice_thickness = 5e-3
TE = 12e-3
TR = 2000e-3
TE_eff = 60e-3
k0 = round(TE_eff / TE)
pe_type = 'linear'
Esempio n. 3
0
import math

import numpy as np
import pypulseq as pp
import sigpy.mri.rf as rf_ext

import sigpy2pulseq as sp

# ======
# SETUP
# ======
# Create a new sequence object and library options
seq = pp.Sequence()

# Define FOV and resolution
fov = 256e-3
Nx = 256
Ny = 256
alpha = 90  # flip angle
slice_thickness = 3e-3  # slice
TE = np.array([4.3e-3])
TR = 300e-3
rf_spoiling_inc = 117  # RF spoiling increment

ext_pulse_library = 1  # 0 - pypulseq, 1 - sigpy
ext_pulse_type = 'slr'
disp_pulse = 0

system = pp.Opts(max_grad=28,
                 grad_unit='mT/m',
                 max_slew=150,