MR arthrography of the hip: evaluation of isotropic 3D intermediate-weighted FSE and hybrid GRE T1-weighted sequences.

Purpose: To compare the diagnostic performance of three-dimensional (3D) intermediate-weighted FSE (IW-3D) and 3D hybrid T1-weighted sequences (Hy-3D) and 2D fast-spin-echo sequences (FSE) in diagnosing chondral and labral lesions at 1.5 Tesla hip MR arthrography (MRA).

Materials And Methods: Institutional review board approval was obtained and informed consent was waived. Ninety-two consecutive patients were evaluated. Chondral and labral lesions were retrospectively and independently evaluated by two radiologists. Intra-operative findings were used as the reference standard (arthroscopy = 73, open surgery = 19). Sensitivity (Se), specificity (Sp), and accuracy (Acc) values that obtained were compared using McNemar test. A value of p < 0.05 was considered statistically significant. Inter-observer agreement was calculated using kappa statistics.

Results: Surgeons revealed 81 labrum and 44 chondral lesions, respectively. The highest Se, Sp, and Acc for Reader 1 were 96.3, 90.9, and 95.6%, respectively, in evaluating labral lesions (by reading 2D data set) and 90.9, 100, and 95.7% in evaluating chondral lesions (by reading IW-3D images). The highest Se, Sp, and Acc for Reader 2 were 93.8, 81.8, and 92.4% in evaluating labral lesions (using 2D images) and 88.6, 97.9, and 93.5%, respectively, in evaluating chondral lesions (using Hy-3D). The difference of diagnostic accuracy achieved was not significant (p > 0.05). A near-perfect inter-observer agreement was achieved by reading 2D data set (k = 0.88) and Hy-3D (k = 0.83) and IW-3D (k = 0.85).

Conclusions: At 1.5 Tesla hip MRA, the accuracy of IW-3D and Hy-3D images was not significantly higher than the 2D sequences in evaluating acetabular labrum and chondral lesions.