A prospective study on the detection of labral lesions by indirect MR-arthrography of the shoulder.

Purpose: Aim of this prospective study was the evaluation of signal-alterations of anatomic shoulder structures before and after intravenous application of Gd-DTPA. Furthermore the tested clinical value of indirect MR-arthrography in detecting labral lesions was tested. Material and Methods: 52 patients with suspected shoulder injury were examined on a 1.5T system: Sequences were T(1-)weighted axial and oblique-coronary, additionally oblique-coronary T-2-weighted, PD-weighted- and axial FLASH-2D-Sequences. After intravenous injection of contrast medium T-1-weighted sequences were repeated. Signalintensities (S1) of anatomic structures were measured by ROI-technique, the percentual contrast-enhancement (CE) and alterations in SNR (sig- nal-noise-ratio) and CNR (contrast-noise-ratio) were calculated. Labral tears were graded by three observers, their results could be confirmed by arthroscopy or open surgery in 24 patients. Results: Contrast-enhancement was shown in all structures, most remarkable in the joint cavity. In pathologic findings of the labrum the SI and CE were significantly higher compared to intact strictures(p < 0.05). Sensitivity and specificity in the detection of labral tears were 70% and 71.4% whithout contrast media, respectively 100% and 71,4% with indirect arthrography. Conclusions: The indirect arthrography improves the signal parameters of the structures. The detection of labral lesions is improved, but still remains difficult.