Joint fluid enhancement at MRI of the glenohumeral joint with intravenous injection of gadodiamide in standard and triple dose: a prospective comparative study of stable and unstable shoulders.

Abstract

To investigate the joint fluid enhancement at MRI of unstable and stable glenohumeral joints after intravenous administration of different doses of gadodiamide. Fourteen patients with unilateral anterior shoulder instability and six healthy controls had both shoulders examined on two occasions using either a standard dose (0.1 mmol/kg) or a triple dose (0.3 mmol/kg) of gadodiamide in an open MRI magnet (0.2 T). The joint fluid enhancement in the unstable shoulders was on average 134% following the lower dose and 182% for the triple dose, whereas corresponding values in the stable shoulder in the same individuals were 69% and 142%, and (65% and 159%) in the healthy controls. Enhancement of the joint fluid was higher after the triple dose than after the standard dose in both the unstable shoulders (P < 0.0001) and the controls (P < 0.0005). Compared with the stable controls enhancement in the unstable shoulders was higher for the lower dose (P < 0.0001) while there was no significant difference between the groups following the higher dose. The improved enhancement following the higher dose was especially evident in stable shoulders, while the lower dose was found satisfactory for unstable shoulders.