Ultra-fast Magnetic Resonance Neurography of the Brachial Plexus at 1.5 T: Is Noncontrast Three-dimensional Short Tau Inversion Recovery Sufficiently Reliable?

Purpose or Learning Objective: Magnetic resonance neurography is crucial for brachial plexus (BP) assessment but still faces the dilemma between image quality and scan time. Although proposed magnetic resonance neurography protocols rely on both two-dimensional and three-dimensional acquisitions, state-of-the-art ultra-fast 1.5-T three-dimensional short tau inversion recovery may be diagnostically sufficient. Our study aimed to compare ultra-fast bilateral coronal three-dimensional T2-weighted turbo spin-echo short tau inversion recovery with unilateral sagittal two-dimensional T2-weighted turbo spin-echo Dixon for image quality, diagnostic reliability, and time efficiency in noncontrast BP magnetic resonance neurography at 1.5 T.

Methods or Background: Free-breathing three-dimensional-inversion recovery and two-dimensional-Dixon images acquired at 1.5 T were retrospectively collected from a comparable number of healthy and pathologic cases and assessed by three raters in blinded conditions. Pediatric patients, different acquisition methods, and low-quality scans were excluded. Image quality was analyzed both objectively and subjectively. Presence of signal abnormality was assessed for each component of the brachial plexus, and interrater agreement was calculated. Diagnostic accuracy was evaluated against the final radiologic reports.

Results or Findings: The magnetic resonance neurography scans of 72 brachial plexuses from 36 patients (13 women, 50.3 ± 17.6 years of age) were included. Two-dimensional Dixon demonstrated superior image-quality parameters, general depiction of nerves, and interrater agreement, whereas three-dimensional-inversion recovery provided better vascular suppression. Overall neurographic quality, resistance to motion artifacts, nerve identifiability, and image interpretation were comparable between the two sequences. Diagnostic accuracy was similar for both techniques (three-dimensional-inversion recovery: 79.6%; two-dimensional-Dixon: 78.7%), although bilateral coverage by three-dimensional-inversion recovery required almost half the acquisition time as two-dimensional-Dixon (4 minutes, 30 seconds versus 8 minutes, 20 seconds).

Conclusion: Three-dimensional inversion recovery seems sufficiently reliable for bilateral brachial plexus magnetic resonance neurography at 1.5 T capable of overcoming the need for concurrent two-dimensional-Dixon, offering a significant time advantage without compromising diagnostic reliability. A full-three-dimensional abbreviated protocol supported by time-efficient breathing control and advanced reconstruction tools could further optimize brachial plexus magnetic resonance neurography workflows.

Publication History

Article published online:
02 June 2025