Multi b-value Distortion Correction for Ovarian Diffusion-Weighted MRI

Motivation: DW-MRI is now a standard sequence in ovarian MRI protocols. It is commonly implemented with Echo-Planar Imaging (EPI), which is prone to geometric distortions induced by static magnetic field (B0) inhomogeneities. Correcting distortion artifacts is important for anatomical and quantitative biomarker accuracy. Goal(s): To study multi b-value Reverse Polarity Gradient (mRPG) compared to commonly used RPG and FSL-topup. Approach: Pre-surgical ovarian MRI were collected and distortion corrected with the three methods. Results: mRPG showed better performance than RPG and topup in correcting EPI distortions in ADC maps, with less computational time. Impact: mRPG improves distortion artifacts compared to RPG and topup. It yields more accurate spatial and signal intensity corrections which are reflected in quantitative measures such as ADC, without significantly increasing scanning time and with shorter computational time.