3D DP-FISP for Diffusion Measurements in MR Microscopy at Ultra-High Field.

Ileana Ozana Jelescu¹, Denis Le Bihan¹, Luisa Ciobanu¹

A 3D diffusion-prepared fast imaging with steady-state free precession (DP-FISP) sequence was implemented at 17.2T to perform apparent diffusion coefficient (ADC) measurements in small biological samples (i.e. single cells). The sequence was tested on phantoms with different T₁s, including values similar to those of biological tissues, and was compared with a standard diffusion-weighted spin-echo (DW-SE) sequence. The FISP flip angle was optimized for minimal T₁ bias in ADC estimation (< 10%) for b-values up to 600 s/mm. Our sequence is less prone to artifacts than EPI and eight times faster than DW-SE. Future improvements include extension to higher b-values.