Flexed elbow, abducted shoulder, forearm supinated (FABS) reconstruction from three-dimensional elbow MRI: diagnostic performance assessment in biceps head anatomy and pathology

• Published in: Clinical radiology Vol. 79; no. 4; pp. e567 - e573
• Main Authors: Aggarwal, V.A., Thakur, U., Silva, F.D., Ray, G., Weinschenk, C., Gandy, M., Xi, Y., Chhabra, A.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2024
• Subjects: Elbow - diagnostic imaging; Elbow - pathology; Forearm - diagnostic imaging; Forearm - pathology; Humans; Magnetic Resonance Imaging - methods; Shoulder - pathology; Tendon Injuries - pathology
• ISSN: 0009-9260; 1365-229X
• DOI: 10.1016/j.crad.2023.12.018

To determine inter-reader analysis and diagnostic performance on digitally reconstructed virtual flexed, abducted, supinated (FABS) imaging from three-dimensional (3D) isotropic elbow magnetic resonance imaging (MRI). Six musculoskeletal radiologists independently evaluated elbow MRI images with virtual FABS reconstructions, blinded to clinical findings and final diagnoses. Each radiologist recorded a binary result as to whether the tendon was intact and if both heads were visible, along with a categorical value to the type of tear and extent of retraction in centimetres where applicable. Kappa and interclass correlation (ICC) were reported with 95% confidence intervals. Areas under the receiver operating curve (AUC) were reported. FABS reconstructions were obtained successfully in all 48 cases. With respect to tendon intactness, visibility of both heads, and type of tear, the Kappa values were 0.66 (0.53–0.78), 0.24 (0.12–0.37), and 0.55 (0.43–0.66), respectively. For the extent of retraction, the ICC was 0.85 (0.79–0.91) when including the tendons with and without retraction and 0.78 (0.61–0.91) when only including tendons with retraction. For tear versus no tear, AUC values were 0.82 (0.74–0.89) to 0.96 (0.91–1.01). Digital reconstruction of FABS positioning is feasible and allows good assessment of individual tendon head tears and retraction with high diagnostic performance. •MRI visualization of individual biceps tendon heads is difficult.•Flexed, Abducted, and Supinated (FABS) position can aid in tendon visualization.•FABS can be digitally reconstructed using 3D MRI.•Digital reconstructions allow good assessment of individual tendon heads.