Diagnostic Efficacy of 3-T MRI for Knee Injuries Using Arthroscopy as a Reference Standard: A Meta-Analysis

Abstract

OBJECTIVE. The objectives of our study were to assess the evidence for the diagnostic efficacy of 3-T MRI for meniscal and anterior cruciate ligament (ACL) injuries in the knee using arthroscopy as the reference standard and to compare these results with the results of a previous meta-analysis assessing 1.5-T MRI. MATERIALS AND METHODS. The online Cochrane Library, MEDLINE, and PubMed databases were searched using the following terms: MRI AND ((3 OR three) AND (Tesla OR T)) AND knee AND arthroscopy AND (menisc* OR ligament). Patient demographics, patient characteristics, MRI scanning details, and diagnostic results were investigated. The methodologic quality of the included studies was assessed using the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. A meta-analysis of studies using 3-T MRI was performed, and the results were compared with a previous meta-analysis of studies using 1.5-T MRI. RESULTS. One hundred one studies were identified by the search strategy, and 13 studies were included in our review. Twelve studies were considered to have level 1b evidence, and one study was considered to have level 2b evidence. All 13 studies had high methodologic integrity and low risk of bias using the QUADAS-2 tool. The studies included 1197 patients with a mean age of 41.9 years. Ten of the 13 studies were eligible for meta-analysis. The mean sensitivity and mean specificity of 3-T MRI for knee injuries by location were as follows: medial meniscus, 0.94 (95% CI, 0.91–0.96) and 0.79 (95% CI, 0.75–0.83), respectively; lateral meniscus, 0.81 (95% CI, 0.75–0.85) and 0.87 (95% CI, 0.84–0.89); and ACL, 0.92 (95% CI, 0.83–0.96) and 0.99 (95% CI, 0.96–1.00). The specificity of 3-T MRI for injuries of the lateral meniscus was significantly lower than that of 1.5-T MRI (p = 0.0013). CONCLUSION. This study does not provide evidence that 3-T scanners have superior diagnostic efficacy for meniscal damage and ACL integrity when compared with previous studies of 1.5-T machines.