Use of Fat-Suppressed T2-Weighted MRI Images to Reduce the Magic Angle Effect in Peroneal Tendons.

ABSTRACT

INTRODUCTION: Peroneal tendon disorders pose a diagnostic conundrum to the clinician. Magnetic resonance imaging (MRI) is widely used to assess tendon pathology. A recognized artifact of MRI, the magic angle effect (MAE), can lead to spurious results and inappropriate management. The aim of this study is to assess whether T2 fat-suppressed sequences (T2FSs) reduce the frequency of MAE compared with proton density fat-suppressed (PDFS) images. METHODS: MRI scans of 18 patients were prospectively assessed for MAE. The peroneal tendons were assessed at 5 defined levels on PDFS and T2FS images. The frequency of MAE in the peroneal tendons were compared between the 2 scan sequences. RESULTS: In the peroneus brevis tendon, 17/72 levels, on PDFS scans, showed MAE compared with 2/72 levels on the T2FS scans, demonstrating a reduction in the MAE by 85% (P = .0003). In the peroneus longus tendon 14/72 levels, on PDFS scans, demonstrated MAE compared with 4/72 on T2FSs, demonstrating a reduction of 71% (P = .02). CONCLUSION: The inclusion of T2-weighted sequences is useful in MRI scanning for peroneal tendons to mitigate the MAE artifact, avoid potential misdiagnosis, and guide subsequent management of peroneal tendon disorders. Levels of Evidence Level IV Case series.