Safety of MR scanning in patients with nonferromagnetic aneurysm clips.

The purpose of this study was to report our surveillance of patients with nonferromagnetic aneurysm clips (NFAC) who have undergone magnetic resonance imaging (MRI). Forty-six patients with NFAC underwent MRI over a 7-year period. Medical records were studied for evidence of subjective or objective clinical findings as a result of the MRI scan. In two patients with subjective complaints, computed tomograms (CT) were reviewed and patient interviews conducted. No significant neurologic signs or longterm symptoms were experienced. Two patients did not complete their MRI scans due to transient unilateral head pain in one and head "pressure" in another. CT scans in these patients demonstrated no evidence for hemorrhage or visible change in clip position. We documented no objective adverse outcome of patients undergoing MRI with NFAC, confirming that MRI can be performed safely in patients with nonferromagnetic aneurysm clips. The cause of subjective complaints in two of our patients is unknown.