Noncontrast MR imaging and MR arthrography of the ulnar collateral ligament of the elbow: prospective evaluation of two-dimensional pulse sequences for detection of complete tears

Objective: To compare MR imaging techniques with differing contrast and spa tial resolution for evaluation of complete disruption of the ulnar collater al ligament (UCL) anterior bundle in a cadaveric elbow model. Design: Compl ete UCL tears were surgically created at the typical location for clinical tears in eight of 28 fresh frozen cadaveric elbow specimens. All specimens underwent 1.5 T MR imaging in the oblique coronal plane, using an extremity coil. The sequences employed were: T1-weighted spin echo (T1 SE), proton d ensity-weighted (PD) fast spin echo (FSE), fat-suppressed T2-weighted FSE ( T2 FSE), gradient recalled echo (GRE) with a high matrix, PD FSE with a hig h matrix (HRPD), and fat suppressed T1-weighted SE with intra-articular gad olinium (MRAr). Two radiologists independently graded the UCL with separate and side-by-side assessments. Results: Sensitivity/specificity pairs were as follows for reader A and reader B, respectively: T1 SE: 0.25/0.95, 0.50/ 0.95; PD FSE: 0.38/1.00, 0.25/1.00; T2 FSE: 0.50/0.95, 0.63/0.95; GRE: 0.63 /0.85, 0.63/0.60; MRAr: 0.88/1.00,1.00/0.80; HRPD: 0.50/1.00,0.88/0.80. Kap pa statistics for measuring interobserver reliability for each sequence wer e poor under T1 SE (-0.13) and GRE (0.19), moderate under HRPD (0.41) and T 2 FSE (0.44) and good under MRAr (0.62) and PD FSE (0.78). For both readers , the rating for overall image quality was highest for HR-PD, and the ratin g for UCL lesion conspicuity was the highest for MRAr. Conclusions: Of the MR imaging pulse sequences tested, MRAr showed the greatest ability to iden tify complete ligamentous injuries with good agreement between readers and had the highest subjective preference for lesion conspicuity. However, HRPD had the least interobserver variability and the highest subjective prefere nce for overall image quality.