The sensitivity and specificity of MR arthrography for SLAP lesions is about 80% and 90% (Symanski et al., Arirachakaran et al.). Nacey et al. pointed out that in 1/3 of the patients who underwent arthroscopic SLAP repair, the lesions in MR arthrography did not show signal intensity of fluid / gadolinium in T2 / T1. The authors also found that the diagnosis of a SLAP lesion in the absence of fluid / Gd signal is still possible if secondary findings support a SLAP lesion (lateral orientation of signal, extension posterior to the biceps anchor, irregular morphology, abnormal width or depth).
Remark: Only patients with SLAP repair were included in the study group. Therefore, we do not know to what extent specificity is lost if we interpret these signal changes as possible tears (instead of degeneration).