Optimized velocity-selective arterial spin labelling module
AssigneeIsis Innovation Limited
InventorsPeter Jezzard, James Meakin
Life of this patent
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Abstract
A velocity selective preparation method is disclosed, for velocity selective arterial spin labelling (VSASL), the VSASL method using non-selective radiofrequency pulses and magnetic field gradients to modulate the longitudinal magnetization of the spins as a function of their velocity, wherein said velocity selective preparation method comprises an n-segment B1 insensitive rotation that is resistant to eddy current artifacts.
Claims7
A velocity selective preparation method, for velocity selective arterial spin labelling (VSASL), said VSASL method using non-selective radiofrequency pulses and magnetic field gradients to modulate the longitudinal magnetization of the spins as a function of their velocity, wherein said velocity selective preparation method comprises an n-segment B1 insensitive rotation that is resistant to eddy current artifacts by careful arrangement of gradient pulse positions at the zero crossings of the RF pulse waveforms.
The method of claim 7 wherein the first gradient moment of the symBIR-8 preparation is given by:
- m1symBIR8=4·GMAX·(F+R)·(F+2R+TRF)
- where F is the flat top time and R is the gradient rise time.
Dependencies are inferred from the claim text.