TY  - JOUR
AU  - Rauch, Julian
AU  - Laun, Frederik B
AU  - Bachert, Peter
AU  - Ladd, Mark E
AU  - Kuder, Tristan Anselm
TI  - Compensation of concomitant field effects in double diffusion encoding by means of added oscillating gradients.
JO  - Magnetic resonance imaging
VL  - 105
SN  - 0730-725X
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - DKFZ-2023-02309
SP  - 133-141
PY  - 2024
N1  - #EA:E020#LA:E020# / 2024 Jan;105:133-141
AB  - Maxwell or concomitant fields imprint additional phases on the transverse magnetization. This concomitant phase may cause severe image artifacts like signal voids or distort the quantitative parameters due to the induced intravoxel dephasing. In particular, double diffusion encoding (DDE) schemes with two pairs of bipolar diffusion weighting gradients separated by a refocusing radiofrequency (RF) pulse are prone to concomitant field-induced artifacts. In this work, a method for reducing concomitant field effects in these DDE sequences based on additional oscillating gradients is presented. These oscillating gradient pulses obtained by constrained optimization were added to the original gradient waveforms. The modified sequences reduced the accumulated concomitant phase without significant changes in the original sequence characteristics. The proposed method was applied to a DDE acquisition scheme consisting of 60 pairs of diffusion wave vectors. For phantom as well as for in vivo experiments, a considerable increase in the signal-to-noise ratio (SNR) was obtained. For phantom measurements with a diffusion weighting of b = 2000 s/mm2 for each of the gradient pairs, an SNR increase of up to 40
KW  - Concomitant fields (Other)
KW  - Diffusion weighting (Other)
KW  - Double diffusion encoding (Other)
KW  - Optimization (Other)
KW  - Oscillating gradients (Other)
KW  - Sequence design (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:37939973
DO  - DOI:10.1016/j.mri.2023.11.006
UR  - https://inrepo02.dkfz.de/record/285284
ER  -