Eric Aliotta1,2, Holden H Wu1,2, and Daniel B Ennis1,2
1Radiological Sciences, UCLA, Los Angeles, CA, United States, 2Biomedical Physics IDP, UCLA, Los Angeles, CA, United States
Bulk motion artifacts in liver DWI can be substantially reduced with first moment nulled diffusion encoding. However, the bipolar diffusion encoding gradient waveforms generally used for this purpose extend TE and limit SNR. We have developed a Convex Optimized Diffusion Encoding (CODE) framework to design time-optimal, motion compensated diffusion encoding gradients that remove sequence dead times and minimize TE. CODE gradients were designed and implemented for liver DWI on a 3.0T clinical scanner, then evaluated in healthy volunteers and patients. Bulk motion artifacts were significantly reduced and ADC maps were improved compared to conventional monopolar encoding.
