Motion-robust and blood-suppressed diffusion MR imaging of the liver

M1‐optimized diffusion imaging (MODI) has the potential to enable reliable diffusion MRI of the abdomen. The images show example liver diffusion-weighted MRI and ADC maps from one healthy volunteer. ADC bias can be found in the left liver lobe (black arrows) from the standard monopolar waveform acquisition, which is mitigated by the other waveforms. In the ADC maps from M1‐nulled and M1–M2‐nulled acquisitions, even though there is reduced ADC bias, there is substantial unsuppressed signal from blood vessels. In contrast, MODI‐based liver DWI demonstrates high robustness to motion as well as substantial blood signal suppression (purple arrows)
Annie Zhang, Diego Hernando, and colleagues have recently developed a novel motion-robust and blood-suppressed diffusion weighted imaging (DWI) sequence. In this study, the DWI method entitled M1‐optimized diffusion imaging (MODI) was proposed to acquire motion‐robust, blood‐suppressed liver DWI with optimized (ie: minimum TE) diffusion encoding waveforms. The proposed diffusion gradient waveforms are also designed to satisfy a number of hardware and timing constraints, and to minimize concomitant gradient effects. Healthy volunteer experiments and a feasibility evaluation in patients have been performed to evaluate the proposed MODI method. Compared to the conventional monopolar DWI, MODI is able to provide ADC measurements with reduced bias, particularly in the left lobe of the liver. In contrast to alternative “motion moment-nulling” waveforms, MODI can dephase most of the blood signal throughout the liver and generate more reliable ADC maps. Overall, the proposed MODI method is promising for obtaining reliable DW images and quantitative ADC measurements over the entire liver.

Zhang Y, Peña-Nogales Ó, Holmes JH and Hernando D. Motion-robust and blood-suppressed M1-optimized diffusion MR imaging of the liver. Magnetic resonance in medicine. 2019 March DOI PMID