Diffusion-Prepared Imaging with Amplitude Navigation

This article describes a new approach for handling signal flucations in diffusion prepared sequences caused by shot-to-shot motion. I think it has some nice analysis on sampling, as well as a characterization of a tricky B1 artifact that affects the DWI contrast.

The SNR efficiency of a diffusion preparation can be improved by up to ~50% compared to conventional methods, but there is an increase in the minimum sampling time to achieve accurate Apparent Diffusion Coefficient (ADC) estimates. This increase in SNR efficiency makes assumptions on the degree of subject motion, as well as the phase contributions from systematic errors such as eddy currents.

Python code that implements this reconstruction is available here.

Lee PK, Zhou X, Hargreaves BA. “Diffusion-prepared imaging with amplitude navigation for correction of motion-induced signal loss,” Magnetic Resonance in Medicine. 2025. doi.org/10.1002/mrm.30484