def bloch(b1, gr, tp, t1, t2, df, dp, mode, mx=None, my=None, mz=None):
"""
Bloch simulation of rotations due to B1, gradient and
off-resonance, including relaxation effects. At each time
point, the rotation matrix and decay matrix are calculated.
Simulation can simulate the steady-state if the sequence
is applied repeatedly, or the magnetization starting at m0.
INPUT:
b1 = (1xM) RF pulse in G. Can be complex.
gr = ((1,2,or 3)xM) 1,2 or 3-dimensional gradient in G/cm.
tp = (1xM) time duration of each b1 and gr point, in seconds,
or 1x1 time step if constant for all points
or monotonically INCREASING endtime of each
interval..
t1 = T1 relaxation time in seconds.
t2 = T2 relaxation time in seconds.
df = (1xN) Array of off-resonance frequencies (Hz)
dp = ((1,2,or 3)xP) Array of spatial positions (cm).
Width should match width of gr.
mode= Bitmask mode:
Bit 0: 0-Simulate from start or M0, 1-Steady State
Bit 1: 1-Record m at time points. 0-just end time.
(optional)
mx,my,mz (NxP) arrays of starting magnetization, where N
is the number of frequencies and P is the number
of spatial positions.
OUTPUT:
mx,my,mz = NxP arrays of the resulting magnetization
components at each position and frequency.
"""
if isinstance(b1, NUMBER):
b1 = np.ones(1) * b1
ntime = b1.size
grx, gry, grz = process_gradient_argument(gr, ntime)
tp = process_time_points(tp, ntime)
df, nf = process_off_resonance_arguments(df)
dx, dy, dz, n_pos = process_positions(dp)
print('num: ' + str(n_pos))
t1, t2 = process_relaxations(t1, t2, n_pos)
mx, my, mz = process_magnetization(mx, my, mz, ntime, nf * n_pos, mode)
if (2 & mode):
ntout = ntime
else:
ntout = 1
bloch_c(b1.real, b1.imag, grx, gry, grz, tp, ntime, t1, t2, df, nf, dx, dy,
dz, n_pos, mode, mx, my, mz)
reshape_matrices(mx, my, mz, ntout, n_pos, nf)
return mx, my, mz
def bloch(b1, gr, tp, t1, t2, df, dp, mode, mx=None, my=None, mz=None):
"""
Bloch simulation of rotations due to B1, gradient and
off-resonance, including relaxation effects. At each time
point, the rotation matrix and decay matrix are calculated.
Simulation can simulate the steady-state if the sequence
is applied repeatedly, or the magnetization starting at m0.
INPUT:
b1 = (1xM) RF pulse in G. Can be complex.
gr = ((1,2,or 3)xM) 1,2 or 3-dimensional gradient in G/cm.
tp = (1xM) time duration of each b1 and gr point, in seconds,
or 1x1 time step if constant for all points
or monotonically INCREASING endtime of each
interval..
t1 = T1 relaxation time in seconds.
t2 = T2 relaxation time in seconds.
df = (1xN) Array of off-resonance frequencies (Hz)
dp = ((1,2,or 3)xP) Array of spatial positions (cm).
Width should match width of gr.
mode= Bitmask mode:
Bit 0: 0-Simulate from start or M0, 1-Steady State
Bit 1: 1-Record m at time points. 0-just end time.
(optional)
mx,my,mz (NxP) arrays of starting magnetization, where N
is the number of frequencies and P is the number
of spatial positions.
OUTPUT:
mx,my,mz = NxP arrays of the resulting magnetization
components at each position and frequency.
"""
if isinstance(b1, NUMBER):
b1 = np.ones(1) * b1
ntime = b1.size
grx, gry, grz = process_gradient_argument(gr, ntime)
tp = process_time_points(tp, ntime)
df, nf = process_off_resonance_arguments(df)
dx, dy, dz, n_pos = process_positions(dp)
mx, my, mz = process_magnetization(mx, my, mz, ntime, nf*n_pos, mode)
if (2 & mode):
ntout = ntime
else:
ntout = 1
bloch_c(b1.real, b1.imag, grx, gry, grz, tp, ntime, t1, t2, df, nf, dx, dy, dz, n_pos, mode, mx, my, mz)
reshape_matrices(mx, my, mz, ntout, n_pos, nf)
return mx, my, mz