[Significance of magnetic resonance imaging in the diagnosis and surgical treatment in patients with intracranial arterial aneurysmal ruptures].

In 123 patients with arterial aneurysms, brain MRI was performed in the routine and vascular modes. Ninety-five patients were hospitalized. Of them, 73 patients were operated on. Among the patients operated on, the diagnosis was verified and it corresponded to preoperative MRI diagnosis. In a group of patients who had died without being operated on, the diagnosis was verified at autopsy. In 11 cases, the diagnosis should be clarified by direct cerebral angiography. Analyzing MRI criteria that may be used to diagnose an aneurysm has indicated that the detection rate of some aneurysmal elements is not equal. The greatest problems arise in identifying the aneurysmal neck and carrying vessel, particularly in the presence of intracerebral hematoma that surrounds the aneurysm. The neck of aneurysm and its carrying artery could be visualized in 63 and 80% of cases, respectively. Nevertheless, aneurysmal clipping was successfully performed in 64 cases as shown by only MRI data. Aneurysmal MRI criteria were systematized, MRI signs being classified into direct and indirect and their rates presented. According to MRI, including MR angiography, the accuracy of diagnosis ranged from 61 to 88%. If there are no direct MRI signs of aneurysm, its preoperative diagnosis should be clarified by traditional cerebral serial angiography.