## Spinach Bloch Equation Gradient Echo

Topics related to Spinach package
jackandrews_mrf
Posts: 2
Joined: Fri Oct 07, 2022 3:25 pm

### Spinach Bloch Equation Gradient Echo

Hi All,

My goal is to use Spinach for a gradient echo with multiple excitation pulses.
Does anyone have an idea for how to complete this using Spinach?

Thanks.
Last edited by jackandrews_mrf on Sun Oct 16, 2022 6:40 pm, edited 1 time in total.
kuprov
Posts: 123
Joined: Mon Mar 29, 2021 4:26 pm

### Re: Spinach Bloch Equation Gradient Echo

Just modify one of the imaging examples and pulse sequences - the job sounds straightforward.
jackandrews_mrf
Posts: 2
Joined: Fri Oct 07, 2022 3:25 pm

### Re: Spinach Bloch Equation Gradient Echo

Thank you very much for the reply.
My current implementation is included below:

for n = 1:number_of_frames
traj(:,end) = step(spin_system, parameters.pulse_op, traj(:,end), pi/6);
traj = evolution(spin_system, L, [], traj(:, end), defined_echo_time / (100-1), 100-1, 'trajectory');
record_the_signal_at_echo_time = parameters.coil'*traj;
fid = [fid record_the_signal_at_echo_time(1,50)];
traj = evolution(spin_system, L, [], traj(:,end), (defined_repetition_time - defined_echo_time) / (50-1), 50-1, 'trajectory');
end

Do you recommend another method for looping through multiple excitation pulses?

Thanks.
Last edited by jackandrews_mrf on Sun Oct 16, 2022 6:40 pm, edited 3 times in total.
kuprov
Posts: 123
Joined: Mon Mar 29, 2021 4:26 pm

### Re: Spinach Bloch Equation Gradient Echo

This is actually very nearly optimal - good thinking!