US 11,747,423 B2
Method of performing diffusion weighted magnetic resonance measurements
Irvin Teh, Leeds (GB); Samo Lasic, Lund (SE); Markus Nilsson, Oxie (SE); and Filip Szczepankiewicz, Lund (SE)
Assigned to Random Walk Imaging AB, Åkarp (SE)
Appl. No. 17/594,685
Filed by Random Walk Imaging AB, Äkarp (SE)
PCT Filed Apr. 24, 2020, PCT No. PCT/SE2020/050414
§ 371(c)(1), (2) Date Oct. 26, 2021,
PCT Pub. No. WO2020/218966, PCT Pub. Date Oct. 29, 2020.
Claims priority of application No. 1950507-2 (SE), filed on Apr. 26, 2019.
Prior Publication US 2022/0221542 A1, Jul. 14, 2022
Int. Cl. G01R 33/563 (2006.01); A61B 5/055 (2006.01); G01R 33/565 (2006.01)
CPC G01R 33/56341 (2013.01) [A61B 5/055 (2013.01); G01R 33/56509 (2013.01); G06T 2207/10092 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for performing a diffusion weighted magnetic resonance measurement on a sample, the method comprising:
operating a magnetic resonance scanner to apply a diffusion encoding sequence to the sample; and
operating the magnetic resonance scanner to acquire from the sample one or more echo signals;
wherein the diffusion encoding sequence comprises a diffusion encoding time-dependent magnetic field gradient g(t) with non-zero components gl(t) along at least two orthogonal directions y and z, and a b-tensor having at least two non-zero eigenvalues, the magnetic field gradient comprising a first and subsequent second encoding block,
wherein an n-th order gradient moment magnitude along direction l∈(y, z) is given by |Mnl(t)|=|∫0tgl(t′)t′ndt′|, and
the first encoding block is adapted to yield, at an end of the first encoding block:
along said direction y, |Mny(t)|≤Tn for each 0≤n≤m, where Tn is a predetermined n-th order threshold, and
along said direction z, |Mnz(t)|≤Tn for each 0≤n≤m−1 and |Mnz(t)|>Tn for n=m; and
the second encoding block is adapted to yield, at an end of the second encoding block:
along each one of said directions l∈(y, z): |Mnl(t)|≤Tn for each 0≤n≤m,
wherein m is an integer order equal to or greater than 1.