MR Arthrogram Features That Can Be Used to Distinguish Between True Inferior Glenohumeral Ligament Complex Tears and Iatrogenic Extravasation.

To listen to the podcast associated with this article, please select one of the following: iTunes or Google Play. OBJECTIVE. The purpose of this study is to identify features seen at shoulder MR arthrography that distinguish between iatrogenic contrast material extravasation and inferior glenohumeral ligament (IGHL) complex tears. MATERIALS AND METHODS. MR arthrograms (n = 1740) were screened for extravasation through the IGHL complex. Cases were defined on the basis of surgical findings or definitive lack of extravasation in a fully distended joint immediately after contrast agent injection. The location of the disruption and the morphologic features of the torn margin were assessed and compared between groups. RESULTS. Anterior band disruption was present in eight of 16 patients with true tears and in zero of 19 patients with iatrogenic contrast material extravasation (p < 0.001). Isolated extravasation through the posterior half of the axillary pouch was present in 12 patients with iatrogenic extravasa...