Cardiovascular

Exploring the Diagnostic Utility of Ferumoxytol for Brachial Plexus MR Neurography.

TL;DR

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.

Key Findings

Ferumoxytol-enhanced scans demonstrated improved vascular suppression compared with both noncontrast scans and gadolinium-enhanced scans.

  • Vascular suppression improvement versus noncontrast scans was statistically significant for both raters (both P < .001)
  • Vascular suppression improvement versus gadolinium-enhanced scans was statistically significant for both raters (both P = .04)
  • Comparisons were made using Wilcoxon signed-rank or McNemar tests
  • Scans were evaluated qualitatively by two musculoskeletal radiologists

For rater 2, ferumoxytol-enhanced acquisitions demonstrated improved nerve conspicuity of several nerve segments relative to noncontrast scans.

  • Improved conspicuity was found for segments of the suprascapular nerve (P = .01), axillary nerve (P = .02), and long thoracic nerve (P = .004)
  • For rater 1, the distribution of scores for these same nerve segments also favored ferumoxytol-enhanced versus noncontrast scans, but differences were not statistically significant (all P ≥ .06)
  • Inter-rater agreement on the direction of effect was consistent even where statistical significance differed between raters

There was no evidence of a difference in nerve conspicuity between ferumoxytol-enhanced and gadolinium-enhanced scans.

  • No statistically significant differences in nerve conspicuity were found between ferumoxytol-enhanced and gadolinium-enhanced scans for any nerve segment (P ≥ .17 for all nerve segments)
  • This suggests ferumoxytol performs comparably to gadolinium chelate for nerve conspicuity

There was no evidence of discrepancies in detection of abnormal nerve findings between ferumoxytol-enhanced and other acquisition types.

  • No statistically significant differences in abnormal nerve findings were detected between acquisitions (all P ≥ .48)
  • Participants had clinical suspicion of Parsonage-Turner syndrome (PTS) or thoracic outlet syndrome (TOS)
  • Abnormal nerve findings were assessed qualitatively by two musculoskeletal radiologists

The study enrolled 18 participants with suspected PTS or TOS who underwent 3D MRN with ferumoxytol within 3 months of their clinical examination.

  • Mean participant age was 42 years ± 15.2 (SD); 10 of 18 participants were men
  • This was a prospective study design
  • Participants underwent 3D MRN with and/or without gadolinium chelate for clinical purposes before undergoing the ferumoxytol-enhanced research scan
  • Imaging used 3D short-tau inversion-recovery (STIR) fast spin-echo sequences

What This Means

This research suggests that ferumoxytol, an iron-based contrast agent used in MRI, can effectively suppress unwanted blood vessel signals during specialized nerve imaging of the brachial plexus (the network of nerves running from the neck and shoulder into the arm). The study compared three types of MRI scans in 18 patients who were being evaluated for suspected nerve conditions: scans without any contrast agent, scans with the standard gadolinium-based contrast agent, and scans with ferumoxytol. Both radiologists who reviewed the images agreed that ferumoxytol did a significantly better job at reducing vascular (blood vessel) interference compared to both the no-contrast and gadolinium approaches, which could make it easier to see nerves clearly. In terms of how well individual nerve branches could be seen, ferumoxytol performed better than no contrast agent for several specific nerves (suprascapular, axillary, and long thoracic nerves), though this finding was consistent for only one of the two raters. Importantly, ferumoxytol performed just as well as gadolinium for visualizing nerves, and neither contrast method differed in its ability to detect abnormal nerve findings relevant to the patients' suspected diagnoses. This research suggests ferumoxytol could be a useful alternative to gadolinium-based contrast agents for brachial plexus nerve MRI, particularly because it provides superior vascular suppression. This may be relevant for patients who cannot receive gadolinium (for example, due to kidney problems or allergy), as ferumoxytol is processed differently by the body. The study was small and prospective, and larger studies would be needed to confirm these findings across broader patient populations.

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Citation

Ensle F, Tan E, Queler S, Lin Y, Wang S, Sneag D. (2026). Exploring the Diagnostic Utility of Ferumoxytol for Brachial Plexus MR Neurography.. Radiology. https://doi.org/10.1148/radiol.254051