Motion-Robust and Blood-Suppressed M1-Optimized Diffusion MR Imaging of the Liver

Liver DWI has been shown to enable the detection, characterization and treatment monitoring of focal liver lesions, as well as the assessment of diffuse liver disease (eg: fibrosis and cirrhosis)1,2. However, liver DWI is challenging because of the relatively short T2 of liver tissue and the motion sensitivity of diffusion encoding sequences3,4. Recently, advanced motion-robust DW gradient waveform design techniques5-7 enabled first motion moment-nulled (M1-nulled) and/or second motion moment nulled (M2-nulled) DWI with optimized echo time (TE). However, these motion moment-nulled gradient waveforms also compensate the signal from moving blood, which is nulled in standard liver DWI. Importantly, non-suppressed blood signal can mimic focal liver lesions and may confound the assessment and detection of true focal lesions in DWI, as well as introduce bias and variability in quantitative diffusion measures. Consequently, the lack of blood suppression in motion moment-nulled DWI techniques may hinder their clinical applicability for liver DWI.