MRI of wrist ligament trauma was similar at 7 T and 3 T with arthroscopy as a reference standard.

OBJECTIVES

The aim was to compare the diagnostic accuracy of magnetic resonance imaging (MRI) at 7 Tesla (T) and 3 T in patients with clinically suspected injury of the triangular fibrocartilage complex (TFCC) or the scapholunate ligament (SLL) using wrist arthroscopy as a reference standard.

METHODS

Twenty-four patients scheduled for wrist arthroscopy due to suspected TFCC or SLL injury were examined with 7-T and 3-T MRI before arthroscopy. Four musculoskeletal radiologists independently evaluated the MR examinations in randomized order, and the findings were compared to those at wrist arthroscopy.

RESULTS

Sensitivity, specificity, and accuracy for TFCC injuries were 0.85, 0.68, and 0.82 for 7 T and 0.75, 0.73, and 0.77 for 3 T, respectively. For SLL injuries, the corresponding values were 0.70, 0.65, and 0.74 for 7 T and 0.69, 0.55, and 0.70 for 3 T, respectively. For both TFCC and SLL injuries, no statistically significant difference between 7 T and 3 T was found, and the confidence intervals for accuracy overlapped (0.67-0.94 vs 0.63-0.88 for TFCC injuries and 0.59-0.89 vs 0.52-0.86 for SLL injuries). In 14 of 24 patients (58%), MRI contributed findings of additional types of injuries, e.g., tendon injuries and ganglia, vital for a complete diagnosis.

CONCLUSIONS

The diagnostic accuracy of MRI at 7 T was similar to 3 T for detecting injury to the TFCC and the SLL. A majority of injuries were correctly diagnosed by MRI, but some injuries found using arthroscopy were missed.

KEY POINTS: Question Previous studies have found that MRI cannot reliably diagnose or rule out TFCC or SLL injury, compared to the current reference standard wrist arthroscopy. Findings The diagnostic accuracy for MRI at 7 T was similar to 3 T for detecting injuries to the TFCC and the SLL. Clinical relevance Although MRI cannot replace wrist arthroscopy, it is an important complementary tool in the diagnostic workup of suspected wrist ligament injuries, with the ability to diagnose additional types of pathologies not accessible by arthroscopy.