Detection of the glenoid bare spot by non-arthrographic MR imaging, conventional MR arthrography, and 3D high-resolution T1-weighted VIBE MR arthrography: comparison with CT arthrography.

OBJECTIVES

To determine the diagnostic accuracy of non-arthrographic MR imaging, conventional MR arthrography, and 3D T1-weighted volumetric interpolated breath-hold examination (VIBE) MR arthrography sequences as compared with a CT arthrography in the diagnosis of glenoid bare spot.

METHODS

A retrospective study of 216 patients who underwent non-arthrographic MR imaging, conventional MR arthrography, VIBE MRI arthrography, and CT arthrogram between January 2011 and March 2022 was conducted. The diagnostic accuracy of non-arthrographic MR imaging, direct MR arthrography, and VIBE MRI arthrography in the detection of glenoid bare spot was compared with that of CT arthrography. All studies were reviewed by 2 MSK radiologists. Interobserver agreement for MR imaging and MR arthrographic findings was calculated.

RESULTS

Sixteen of 216 patients were excluded. Twenty-three of 200 shoulders had glenoid bare spot on CT arthrographic images. The glenoid bare spot was detected in 11 (47.8%) and 7 (30.4%) patients on conventional non-arthrographic MR images and in 18 (78.3%) and 16 (69.6%) patients on conventional MR arthrograms by observers 1 and 2, respectively. Both observers separately described the bare spot in 22 of 23 patients (95.7%) on 3D volumetric MR arthrograms. Interobserver variabilities were fair agreement for conventional non-arthrographic MR imaging (κ = 0.35, p < 0.05), moderate agreement for conventional MR arthrogram (κ = 0.50, p < 0.05), and near-perfect agreement for 3D volumetric MR arthrogram reading (κ = 0.87, p < 0.05).

CONCLUSIONS

A 3D high-resolution T1-weighted VIBE MR arthrography sequence may yield diagnostic performance that is comparable with that of CT arthrography in the diagnosis of glenoid bare spot.

KEY POINTS

•Glenoid bare spot should not be misdiagnosed as a transchondral defect of the glenoid surface by radiologists. •A 3D high-resolution T1-weighted VIBE MR arthrography sequence may be used as a high-sensitivity imaging technique in the diagnosis of glenoid bare spot.