Thomas Henry Magee MD, Presenter: Nothing to Disclose

MR arthrogram imaging of the shoulder is considered to be more accurate in assessing shoulder pathology than conventional MR imaging. Arthrography is a minimally invasive procedure. However most patients prefer to have conventional MR imaging rather than MR arthrogram imaging. We report the benefit of assessing pre arthrogram conventional MR imaging to determine whether an MR arthrogram is needed for further evaluation.

One hundred consecutive conventional shoulder MR and MR arthrography exams performed on the same patients were reviewed retrospectively by consensus reading of two musculoskeletal radiologists. Both conventional MR and MR arthrogram exams were performed on each patient on the same day. Conventional MR and MR arthrogram exams were assessed for labral tears and supraspinatus tendon tears. All patients went on to arthroscopy.

Of these one hundred patients, forty-three had SLAP (superior labral anterior to posterior) tears , twenty-eight had posterior labral tears , twenty-three had anterior labral tears and forty-seven had full thickness supraspinatus tendon tears on conventional MR exam. On MR arthrogram exam fifty one patients had SLAP tears, thirty-three had posterior labral tears, twenty-nine had anterior labral tears and forty- nine had full thickness supraspinatus tendon tears . MR arthrogram detected eight SLAP tears, five posterior labral tears, six anterior labral tears and two supraspinatus tendon tears not detected on conventional MR exam. All MR arthrogram findings were seen at arthroscopy. Eighteen of the twenty-one patients with additional finding on MR arthrogram exam had normal appearing conventional MR exams.

Use of pre and post MR arthrogram imaging may benefit patient care. When positive findings are demonstrated on MR exam, few additional findings are demonstrated on MR arthrogram exam. These patients may not need to proceed to MR arthrography. If the conventional MR exam is negative then additional information may be obtained by proceeding to MR arthrography.

Clinical relevance: Use of pre arthrogram imaging may allow for cancellation of a substantial number of MR arthrogram exams in patients with positive findings on conventional MR exam. If conventional MR imaging is negative proceeding to MR arthrography may demonstrate additional findings.

Magee, T, Utility of Pre and Post MR Arthrogram Imaging of the Shoulder: Effect on Patient Care.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14003447.html