One-shot CT and MR arthrography of the shoulder with a mixture of iodinated and paramagnetic contrast agents using arthroscopy as a gold standard

Purpose. Our aim was to perform computed tomography arthrography (CTA) and magnetic resonance arthrography (MRA) of the shoulder as a one-shot examination and to evaluate its value on the basis of arthroscopy as a gold standard. Materials and methods. Fifteen men and 16 women with planned arthroscopy for chronic (n=17) or traumatic tear of the rotator cuff (n=8), congenital atraumatic (n=1) or traumatic glenohumeral instability (n=2), traumatic tear of the rotator cuff with glenohumeral instability (n=1), or "frozen shoulder" (n=2) underwent plain helical CT in neutral position and intra-articular CT-guided injection of a mixture of iodinated and paramagnetic contrast agents (gadodiamide at 1:250 and iobitridol 350 at 1:5 in 20 ml of saline solution). CT helical scans in intra- and extrarotation and T1-weighted MRA scans in the neutral position were obtained. CTA and MRA were evaluated separately and jointly (CTA-MRA) in different blinded sessions, giving a 0-3 score to the agreement of CTA, MRA, and CTA-MRA with arthroscopy. Results. The injected volume of the solution ranged from 10 to 24 ml. No side effects were observed. CTA obtained a score of 2.33±0.62, MRA 2.47±0.52, and CTA-MRA 2.67±0.49. Significant differences were found for CTA-MRA versus CTA (p=0.0281) and MRA (p=0.0277). There was no significant difference for CTA versus MRA. Conclusions. CTA and MRA can be performed as a one-shot exam. CTA-MRA seems to give more information than CTA or MRA separately.