Comparison of MR Imaging and CT in Patients with lntracranial Aneurysm

CT and MR imaging of the brain were performed without complications in 16 patients who had undergone surgery for a ruptured aneurysm with the use of nonferromagnetic Yasargil 316 or Sugita Elgiloy clips. MR was performed on a 0.3-T Fonar ,B-3000M imaging system. The artifacts caused by the clips were smaller on MR than on CT, and, therefore, anatomic structures such as the brainstem and temporal lobes were better visualized on MR. Brain-tissue lesions corresponding to the frontotemporal surgical approach were seen with MR in seven patients and with CT in six. In three patients temporal-lobe lesions seen on MR were not seen on CT because of beam-hardening artifacts. Lesions unrelated to the region of surgery were seen with MR in nine patients and with CT in five. In conclusion, MR was safe and superior to CT both in demonstrating anatomic details and in detecting tissue lesions in patients with aneurysm clips.