Oral Presentation at the European Congress of Radiology, Vienna, 2019

Purpose

To determine if diffusion-weighted imaging of nerves can provide additional information or change the diagnosis compared to T2/STIR imaging

Methods and Materials

88 MRI scans (48 lumbar plexus, 24 brachial plexus, 16 peripheral nerve) performed on a 3.0T MR750w (GE Healthcare, USA) for to assess nerve damage/disease were extracted from PACS, anonymised and segregated into scans with T2w STIR (2.5-5mm/0-1mm gap; TR-5150ms, TE-48ms, TI-187-188ms, bandwidth-62.6 kHz, FOV 24x24, matrix- 288x128) Structural Nerve Imaging (SNI) and Diffusion-Weighted (4mm/1mm overlap, TR-8743, TE-63.5,TI-249.5,Bandwidth-250kHz, FOV- 40x40cm, matrix-64x128) Functional Nerve Imaging (FNI). Scans were read by a senior specialist radiologist (16 years experience). Visibility of focal signal abnormality, diffuse signal abnormality, nerve fibre continuity and muscular changes were recorded in each scan (present vs absent). Results from both sets of images were compared and the value of functional nerve imaging evaluated.

Results

Overall, FNI changed the diagnosis in 58 (66%) cases compared to SNI. The number of cases where the diagnosis changed in lumbar plexus, brachial plexus and peripheral nerves were 36 (75%), 16 (67%) and 5 (31%) respectively. Findings visualised on FNI but not on SNI were focal signal abnormalities (24/27%) and diffuse signal abnormalities (39/45%). Nerve fibre continuity and muscular changes appeared similar on both with no change reported in 82 (93%) and 85 (97%) scans.

Conclusion

Diffusion-Weighted imaging of nerves, especially for visualisation of the lumbar and brachial plexus, on 3.0T MR, adds to the diagnosis and could replace T2-STIRw structural imaging