Potentialityof three-dimensional surface-rendered magnetic resonance angiography in the preoperative assessment of intracranial aneurysms in patients presenting with subarachnoid hemorrhage

Abstract

Background: Magnetic resonance angiography (MRA) using a maximum-intensity projection images has demonstrated a limited sensitivity for aneurysms smaller than 5 mm and has a limited ability to characterize features of aneurysms. Therefore, we are usually using three-dimensional surface-rendered (3-D SR) MRA as the first-line investigation in the diagnosis of aneurysms. The aim of the study was to evaluate the potentiality of 3-D SR MRA as the preoperative aneurysm assessment in patients with subarachnoid hemorrhage (SAH). Methods: A total of 121 SAH patients who had undergone 3-D SR MRA and aneurysm surgery between 1998 and 2009 were enrolled in this study. In addition, contrast-enhanced (CE) MRA was performed in 87 patients. The MR examination was performed under an adequate sedation and strict control of arterial blood pressure. Results: There were no cases in which the examinations could not be performed because of patient movement. We also did not encounter cases of rebleeding during the examination. In 114 of 121 (94.2%) patients, we were able to reach a diagnosis on the basis of 3-D SR MRA and CE MRA alone. A majority of ruptured aneurysms were located at the anterior part of the circle of Willis. The size of aneurysms ranged from 2.2 to 25.4mm, with a mean of approximately 6.7mm. On the other hand, digital subtraction angiography has been performed to acquire additional diagnostic confirmation for 13 patients. A total of 108 (89.2%) patients who underwent surgery with the aid of 3-D SR MRA and CE MRA alone were treated successfully. The 3-D SR MRA provided the neurosurgeons with the location of aneurysms as well as surgically important information regarding the configuration of its sac, neck and its relationship to the surrounding vessels. Conclusion: These results indicate that surgery can be performed in acutely ruptured aneurysms by using 3-D SR MRA in the majority of regular-sized aneurysms.