Exploring the Diagnostic Utility of Ferumoxytol for Brachial Plexus MR Neurography

Background Ferumoxytol has been described as an alternative contrast agent for vascular suppression in MR neurography (MRN), but its diagnostic utility in patients has yet to be evaluated. Purpose To evaluate the impact of ferumoxytol on vascular suppression, nerve conspicuity, and evaluation of nerve abnormalities at three-dimensional (3D) brachial plexus MRN, compared with noncontrast and gadolinium-enhanced MRN, in participants with suspected Parsonage-Turner syndrome (PTS) or thoracic outlet syndrome (TOS). Materials and Methods This prospective study included participants who underwent 3D MRN with and/or without gadolinium chelate for clinical suspicion of PTS or TOS and subsequently underwent 3D MRN with ferumoxytol (within 3 months of the clinical examination). Two musculoskeletal radiologists qualitatively evaluated 3D short-tau inversion-recovery fast spin-echo scans for the degree of vascular suppression, nerve conspicuity, and presence of nerve abnormalities. Wilcoxon signed-rank or McNemar tests were used for comparing noncontrast and gadolinium-enhanced scans with ferumoxytol-enhanced scans. Results This study included 18 participants (mean age, 42 years ± 15.2 [SD]; 10 men). Ferumoxytol-enhanced scans demonstrated improved vascular suppression compared with both noncontrast scans (both raters, P < .001) and gadolinium-enhanced scans (both P = .04). For rater 2, ferumoxytol-enhanced acquisitions demonstrated improved conspicuity of several nerve segments relative to the noncontrast scan, including segments of the suprascapular (P = .01), axillary (P = .02), and long thoracic nerves (P = .004). The distribution of scores for these nerve segments for rater 1 also favored ferumoxytol-enhanced versus noncontrast scans, but the differences were not statistically significant (all P ≥ .06). There was no evidence of a difference in nerve conspicuity between ferumoxytol-enhanced and gadolinium-enhanced scans (P ≥ .17 for all nerve segments) and also no evidence of discrepancies in abnormal nerve findings between the acquisitions (all P ≥ .48). Conclusion Ferumoxytol improved vascular suppression compared with noncontrast and gadolinium-enhanced 3D short-tau inversion-recovery fast spin-echo sequences in brachial plexus MRN, enhancing the conspicuity of several nerve branches versus noncontrast scans, with similar detection of abnormal nerve findings. © RSNA, 2026 Supplemental material is available for this article.