MR imaging of helical platinum coils currently used to induce occlusion of intracranial aneurysm

Complex helical platinum coils are being used more frequently in interventional neuroradiology. The purpose of this paper is to study the behavior of these coils when imaged with MR. With the arteriovenous fistula technique, experimental aneurysms were surgically produced in the common carotid arteries of 10 New Zealand rabbits. Angiography was performed with microcatheters. Complex helical platinum coils were introduced into the aneurysms to produce thrombosis. The rabbits were studied with T1 spin-echo and fat-suppression MR techniques. Three months after embolization, the rabbits were sacrificed, and a detailed in vitro examination was performed with the same MR sequences. histologic examination was also done. Adequate visualization of the coils was obtained inside the aneurysm. The amount of clot formation, location of the coils, and patency of the carotid artery were well demonstrated. Migration or displacement of the coils was not seen in this study