Diffusion‐prepared imaging with amplitude navigation for correction of motion‐induced signal loss

作者：Philip K. Lee, Xuetong Zhou, Brian A. Hargreaves · 发表于：Magnetic Resonance in Medicine · 年份：2025 · DOI：10.1002/mrm.30484 · 被引用次数：2 · 研究领域：Advanced MRI Techniques and Applications、Advanced Neuroimaging Techniques and Applications、Medical Imaging Techniques and Applications

Abstract Purpose Diffusion‐prepared imaging is a flexible alternative to conventional spin‐echo diffusion‐weighted EPI that allows selection of different imaging readouts and k‐space traversals, and permits control of image contrast or image artifacts. We investigate a new signal model and reconstruction for diffusion‐prepared imaging that addresses signal variations caused by motion‐sensitizing diffusion gradients. Methods A signal model, sampling theory, and reconstruction framework were developed assuming that motion‐induced phases and the measured signals are random variables. The reconstruction incorporates real‐valued amplitude weights estimated from low‐resolution images into a linear system. A diffusion‐prepared sequence was applied in phantom and in vivo acquisitions using different methods for managing phase errors from eddy currents or motion. This acquisition was performed with a high number of NEX and retrospectively undersampled to analyze errors in ADC estimation, and compared to spin‐echo diffusion‐weighted EPI, as well as conventional diffusion‐prepared methods. The B 1 sensitivity of the sequence was investigated using simulation and phantom experiments. Results Images reconstructed using the proposed method had similar image structures when compared to conventional spin‐echo diffusion‐weighted EPI, and demonstrated improved SNR efficiency compared to previous diffusion‐prepared approaches. ADC errors followed a trend consistent with the derived signal model...