Comparison of Diagnostic Accuracy of 3.0-T MR Arthrography and CT Arthrography in Intraarticular Hip Pathology

Purpose: To assess and compare the diagnostic efficacies of magnetic resonance arthrography (MRA) and computed tomography arthrography (CTA) in identifying labral and chondral lesions within the hip joints. To analyze the diagnostic confidence levels of radiologists when interpreting images obtained from MRA and CTA. Materials and Methods: Labral and chondral lesions in 100 hips of 95 patients on 3.0 tesla MRA, CTA (128- and 160-slice multi-detector computed tomography), and arthroscopic findings were retrospectively reviewed by three radiologists. We analyzed the sensitivity, specificity, accuracy, positive predictive value, and area under the curve (AUC) using receiver operating characteristic curves. The diagnostic confidence of the radiologists was also assessed during image interpretation. Results: Both MRA and CTA showed good diagnostic performances in the assessment of labral and chondral lesions. MRA showed higher sensitivity and accuracy, with a higher AUC for labral lesions than CTA (MRA/CTA: 97.3%/84.8% [p < 0.001], 93.8%/89.8%, and 0.945/0.896 [p = 0.003], respectively). CTA outperformed MRA in diagnostic performance in terms of sensitivity, specificity, accuracy, and AUC in acetabular cartilage lesions (MRA/CTA: 75.8%/93.9% [p = 0.020], 67.6%/88.2% [p < 0.001], 73.0%/92.0% and 0.717/0.911 [p < 0.001], respectively) and sensitivity, accuracy and AUC in femoral cartilage lesions (60.5%/78.9% [p = 0.020], 80.0%/87.0%, and 0.762/0.854 [p = 0.018], respectively). The diagnostic confidence was higher with MRA for labral lesions (p = 0.002) and with CTA for chondral lesions (p < 0.001). Conclusion: Both MRA and CTA showed strong diagnostic abilities for hip joint lesions, with MRA being better for labral lesions and CTA for chondral lesions. Radiologists showed greater confidence in diagnosing labral lesions using MRA and chondral lesions using CTA.