Does Immobilization Post Injection Reduce Contrast Extravasation in MR Arthrography of the Shoulder?

Background: Contrast leakage after arthrography is common. We sought to investigate if immobilization could prevent it. Purpose: The purpose of this study was to determine the effects on contrast extravasation and image quality produced by strict immobilization of the shoulder between arthrography puncture and subsequent MR imaging. Material and methods: Fifty patients underwent shoulder MR arthrography using a standard shoulder puncture in the anteroinferior quadrant. Ten milliliters of contrast mixture of saline, iodinated contrast, and gadolinium contrast was injected by a senior musculoskeletal (MSK) radiologist using a 21G needle. Half of the patients were immediately immobilized using a shoulder sling, and the other half were allowed to move their shoulder and arm freely during the time before MR imaging. MR arthrography was performed with a 3 T system using standard T1 and PD weighted sequences. The MR images were reviewed independently by 2 MSK radiologists and graded for extravasation using a five-point scale (1: none, 2: less than 2 cm, 3: 2-5 cm, 4: 5-10 cm, 5: more than 10 cm) and for image quality using a 5 point scale (1: poor, 5: good). The Pearson correlation was calculated to assess the correlation between leakage and image quality. Results: There was no significant difference in amount of leakage between both groups, and global image quality was found equal in both groups. A negative correlation was found between leakage and quality assessment. Conclusion: This study shows that it cannot be avoided by strict shoulder immobilization and that it negatively affects image quality and interpretation.