3D Brachial Plexus Neurography With Variable‐Rate Selective Excitation RF Pulses

ABSTRACT Background Slab‐selective radiofrequency (RF) pulses are commonly required in three‐dimensional (3D) turbo spin echo (TSE) in brachial plexus magnetic resonance neurography (MRN). However, their long selective RF pulses lead to violation of Carr–Purcell–Meiboom–Gill conditions, which might increase imaging artifacts. Hypothesis That VERSE STIR‐TSE would yield comparable motion artifact to conventional STIR‐TSE with superior nerve conspicuity and greater subjective appeal. Study Type Prospective, cross‐sectional study. Population Twenty‐four subjects (16 females; mean age: 43.7 years; range: 19–76 years) evaluated for clinical suspicion of brachial plexopathy, undergoing brachial plexus MRI (10 left, 9 right, 5 bilateral, 29 total scans analyzed). Agar phantoms mimicking nerve and muscle were also evaluated. Field Strength/Sequence 3‐Tesla, 3D STIR‐TSE with and without VERSE. Assessment Three radiologists, blinded to the sequence type and clinical data, qualitatively evaluated nerve conspicuity, motion, and preferred sequence on a 5‐point scale. Statistical Tests Wilcoxon signed‐rank tests compared nerve conspicuity (0–4 scale), motion artifact (0–4 scale), and preferred series between the non‐VERSE and VERSE pulse sequences. Gwet's AC2 assessed inter‐rater agreement. A p ‐value < 0.05 was considered statistically significant. Results The VERSE STIR‐TSE sequence was significantly preferred by all raters. Motion artifact was not significantly different between the sequences ( p = 0.11). Conspicuity of the suprascapular nerve was significantly greater with VERSE for both its proximal segments (median: 3, interquartile range: (2, 4), vs. 3 (1, 4)) and distal segments (4 (2, 4) vs. 3 (2, 4)), but conspicuity of the axillary nerve was not significantly different between the sequences ( p = 0.27–0.61). Phantom scans confirmed a 74% and 49% increase in signal with VERSE in the muscle and nerve‐mimicking phantoms, respectively. Data Conclusion STIR‐TSE with VERSE provided overall superior image quality for brachial plexus MRN as compared to conventional STIR‐TSE. Evidence Level 2. Technical Level 1.