@proceedings {810, title = {Motion-Robust and Blood-Suppressed M1-Optimized Diffusion MR Imaging of the Liver}, volume = {116}, year = {2019}, abstract = {

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.

}, author = {Yuxin Zhang and {\'O}scar Pe{\~n}a-Nogales and James H. Holmes and Diego Hernando} } @proceedings {725, title = {Monte-Carlo Analysis of Quantitative Diffusion Measurements Using Motion-Compensated Diffusion Weighting Waveforms}, year = {2017}, pages = {1733}, address = {Honolulu, HI, USA}, abstract = {

Advanced diffusion MRI acquisition strategies based on motion-compensated diffusion-econding waveforms have been proposed to reduce the signal voids caused by tissue motion. However, quantitative diffusion measurements obtained from these motion-compensated waveforms may be baised relative to standard monopolar gradient waveforms. This study evaluated the effect of different diffusion encoding gradient waveforms on the signal decay and diffusion measurements, using Monte-Carlo simulations with different microstructures and several reconstruction signal models. The results show substantial bias in observed signal decay and quantiative diffusion measurements in the same microstructure across different gradient waveforms, in the presence of restricted diffusion.

}, author = {Yuxin Zhang and {\'O}scar Pe{\~n}a-Nogales and James H. Holmes and Diego Hernando} }