MRI fat suppression techniques in traumatic and entrapment-related brachial plexus conditions: A scoping review

Traumatic and entrapment-related brachial plexus injuries are diagnostically complex conditions that often lead to substantial functional deficits. Magnetic resonance imaging (MRI) remains the modality of choice for preoperative evaluation, particularly when combined with fat-suppression techniques that enhance visualization of neural structures. Despite their role, the frequency and context of fat-suppression technique usage in brachial plexus imaging remain poorly defined.

This scoping review aimed to systematically identify and categorize fat-suppression methods reported in MRI protocols for traumatic and entrapment-related brachial plexus injuries. A search of PubMed, Cochrane, CINAHL, and Web of Science was performed from inception to October 2023, following the Arksey and O'Malley methodological framework and reported in accordance with PRISMA-ScR guidelines. Studies were eligible if they described MRI protocols for mechanical brachial plexus injuries; non-mechanical etiologies (e.g., inflammatory or neoplastic conditions) were excluded.

Of 8647 screened records, 98 studies met inclusion criteria. Short tau inversion recovery (STIR) was the most frequently reported 2D fat suppression method (n = 37). Among 3D sequences, 3D STIR with sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) was most commonly reported. Most protocols utilized 1.5 Tesla MRI systems, a substantial minority employed 3 T systems. Dixon techniques were noted with increasing frequency in more recent literature.

Our findings demonstrate sustained reporting of STIR while highlighting the increasing use of Dixon and advanced 3D sequences in recent publications. These results provide a comprehensive reference point for radiologists, suggesting areas for protocol optimization and standardization in brachial plexus pathology.