Diffusion-weighted MR neurography of the brachial and lumbosacral plexus: 3.0 T versus 1.5 T imaging

• DW MRN of brachial and lumbosacral plexus at 1.5 T and at 3.0 T was compared.
• For lumbosacral plexus, nerve conspicuity on MIP images was superior at 3.0 T, also visible length and mean sharpness of the nerves.
• For brachial plexus, nerve conspicuity at 3.0 T was rather inferior, nerve length was not significantly different, mean sharpness was superior at 3.0 T.

PurposeTo compare intraindividually the nerve conspicuity of the brachial and lumbosacral plexus on diffusion-weighted (DW) MR neurography (MRN) at two different field strengths.Materials and methods16 healthy volunteers were investigated at 3.0 T and 1.5 T applying optimized variants of a DW spin-echo echo-planar imaging sequence with short TI inversion recovery fat suppression. Full-volume (FV) and curved sub-volume (CSV) maximum intensity projection (MIP) images were reconstructed and nerve conspicuity was visually assessed. Moreover, visible length and sharpness of the nerves were quantitatively analyzed.ResultsOn FV MIP images, nerve conspicuity at 3.0 T compared to 1.5 T was worse for brachial plexus (P = 0.00228), but better for lumbosacral plexus (P = 0.00666). On CSV MIP images, nerve conspicuity did not differ significantly for brachial plexus, but was better at 3.0 T for lumbosacral plexus (P = 0.00091). The visible length of the analyzed nerves did not differ significantly with the exception of some lumbosacral nerves, which were significantly longer at 3.0 T. The sharpness of all investigated nerves was significantly higher at 3.0 T by about 40–60% for cervical and 97–169% for lumbosacral nerves.ConclusionDW MRN imaging at 3.0 T compared to 1.5 T is superior for lumbosacral plexus, but not for brachial plexus.