E2310. 3D MRI of Biceps Tendon Pathology: Virtual FABS (Elbow Flexion, Shoulder Abduction, and Forearm Supination) Reconstruction - Added Value
  1. Vikram Aggarwal; UT Southwestern Medical Center
  2. Flavio Duarte Silva; UT Southwestern Medical Center
  3. Uma Thakur; UT Southwestern Medical Center
  4. Avneesh Chhabra; UT Southwestern Medical Center
The biceps muscle has two heads, the long head, and the short head. At the radial tuberosity, the two heads rotate 90 degrees externally in a sagittal plane with the long head component positioned posterior and more proximal to the short head. This tendon is stabilized by bicipital aponeurosis. Biceps tears at the elbow commonly occur in young and middle-aged men, in their dominant arms, and frequently due to strength training and weightlifting activities.

Educational Goals / Teaching Points
The aim of the educational exhibit is to demonstrate anatomy of biceps insertion at elbow and anatomic variations, how to reconstruct biceps tendon along their longitudinal axis using oblique axial reconstructions from 3D elbow MRIs mimicking virtual FABS-type orientation, and illustrate different biceps pathologies on FABS reconstructions. The exhibit covers single distal insertion, dual-head insertion, lacertus fibrosus outline, and pathology variations, (e.g., insertional tendinopathy, bicipital radial bursitis, partial and full-thickness individual biceps head tears, complete and incomplete tears with and without retraction, lacertus fibrosus tears), how to measure accurate retraction, radial neuropathy, and isolated myotendinous strain with intact heads. Postoperative normal and abnormal appearances will also be shown for reader learning.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Diagnosis of a complete distal bicep tendon tear is rendered clinically in lieu of signs of tenderness, bruising, and weakness of elbow flexion and supination. However, only one-third of patients may experience audible pop, and only 38% have visible deformity in surgical proven complete tears. The clinical presentation of partial distal bicep tendon tear can be even more subtle and/or challenging and as a result, the diagnosis can be delayed or missed completely. With enhanced understanding of the anatomy and biomechanics of the distal biceps tendon, surgeons are more likely to recreate the normal anatomy and restore supination and flexion functions at the elbow. MRI has been found to be more accurate, and the flexed abduction supination view (FABS) has been observed to provide an optimal view of the distal biceps tendon(s). However, obtaining FABS adds to time, cost, discomfort to the patient. 3D isotropic fast spin-echo MRI can be obtained quickly on newer scanners with software modifications, such as partial k-space sampling and enhanced parallel imaging. The FABS-type virtual reconstructions can be obtained from such MRI scans and evaluated with routine MRI 2D sequences for individual biceps head assessment.

Virtual FABS orientation reconstruction from 3D isotropic elbow MRI can optimally display both heads of biceps and a spectrum of pathology at its distal attachment.