Musculoskeletal ImagingE2530. Feasibility of High-Resolution Ultrasound for SLAP tears of the Shoulder Compared to MR Arthrography
Choudur H1, Alali A1, Monteiro S2, Li D.1 1. Department of Radiology, McMaster University, Hamilton, Canada; 2. Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Canada
Address correspondence to A. Alali (email@example.com)
Objective: The purpose of this pilot study was to evaluate the feasibility and accuracy of high-resolution ultrasound in the detection of superior labral anteroposterior (SLAP) tears of the shoulder compared to MR arthrography.
Materials and Methods: A total of 48 adult patients were included in the study. They were referred to the radiology department by orthopedic surgeons with a clinical suspicion of a SLAP tear. All patients had high-resolution ultrasound of the superior labrum and biceps labral anchor prior to MR arthrography. Using a 13-MHz linear musculoskeletal probe, serial images of the superior labrum were obtained by a staff radiologist, in the plane parallel to the biceps labral anchor. The tear was described as type 1, fraying of the articular margin; type 2, tear extending into the labrum at its attachment to the bony glenoid, parallel to this attachment; type 3, tear extending perpendicular to its attachment to the bony glenoid; and type 4, tear extending through the labrum into the biceps labral anchor, perpendicular to its attachment to the bony glenoid. The MR arthrograms were also evaluated separately for a SLAP tear using a similar grading. MRI and ultrasound findings for the presence or absence of a tear and for grading of the tears was assessed with kappa statistics.
Results: MRI and ultrasound both demonstrated a SLAP tear in 19 of the 48 patients. MRI and ultrasound were in agreement on the absence of a tear in 27 patients. There was a disagreement between MRI and ultrasound in two of the 48 patients regarding the presence of tear. The two modalities demonstrated substantial agreement on the presence or absence of tear (kappa = 91.4%, p < 0.000) as well as the grading of the tear (kappa = 84.4%, p < 0.000).
Conclusion: In this pilot study, the feasibility and accuracy of high-resolution ultrasound for SLAP tears was evaluated and compared with MR arthrography. MRI and ultrasound demonstrated substantial agreement on the presence or absence of SLAP tears and the grading of the tears. Therefore, this pilot study supports the use of ultrasound as a screening tool for SLAP tears, especially as it is readily available, fast, and inexpensive.