Computerized tomography angiography in patients with subarachnoid hemorrhage: from aneurysm detection to treatment without conventional angiography

Object. The purpose of this study was to determine prospectively whether an d to what extent computerized tomography (CT) angiography can serve as the sole imaging method for a preoperative workup in patients with ruptured int racranial aneurysms. Methods. During a 1-year period, all patient who presented to the authors' hospital with subarachnoid hemorrhage demonstrated by unenhanced CT scannin g or lumbar puncture underwent CT angiography. Two radiologists evaluated t he CT angiography source images and maximum intensity projection slabs and arrived at a consensus. They categorized the quality of the CT angiography as adequate or inadequate and classified aneurysms that were detected as de finitely or possibly present. The parent artery of anterior communicating a rtery aneurysms was identified by asymmetrical anterior cerebral artery siz e and asymmetrical aneurysm location. The parent artery was indicated by th e larger A, segment in cases of asymmetrical A, size. Only CT angiograms of adequate quality that revealed aneurysms classified as definitely present and with an unequivocal parent artery were presented to the neurosurgeons, who decided whether preoperative digital subtraction (DS) angiography shoul d still be performed. Forty-nine of the 100 studied patients did not undergo surgery because of p oor clinical condition, nonaneurysmal cause of the hemorrhage, or endovascu lar treatment of the ruptured aneurysm. Of the 51 patients who underwent su rgery, radiologists required DS angiography in 17 patients. the imaging tec hnique provided greater certainty in 13 instances. The neurosurgeons requir ed DS angiography 11 times: this provided additional information in two ins tances. Twenty-three (45%) of the 51 patients were surgically treated succe ssfully on the basis of CT angiography findings alone. Conclusions. Computerized tomography angiography can replace DS angiography as the preoperative neuroimaging technique in a substantial proportion of patients with ruptured intracranial aneurysms.