CT angiography for the detection of cerebral aneurysms : an analysis of 436 verified cases

Background: The aim of the study was to evaluate the clinical value of computed tomography angiography (CTA) in patients suspected of cerebral aneurysms based on 436 verified cases, which is the largest CTA series in the world literature apart from multicenter studies. Material/Methods: The authors analyzed retrospectively the results of CTA performed with the use of a single-slice CT unit in 436 consecutive patients with suspicion of cerebral aneurysms during five years and compared them with cerebral angiography and/or surgical findings. Results: CTA revealed 369 cerebral aneurysms in 309 patients. There were 21 (4.8%) false negative and 14 (3.2%) false positive results. The false positives involved unclear cases (small aneurysms vs. vascular loop) and the false negatives concerned small aneurysms (£3 mm), mostly on the internal carotid artery and multiple aneurysms. The overall efficiency results were: sensitivity 94.4%, specificity 97.3%, accuracy 96.1%, positive predictive value 96.2%, and negative predictive value 96.0%. The highest accuracy was found for middle cerebral artery aneurysms (97.6%), followed by the vertebro-basilar system (96.6%), anterior communicating artery complex (96.5%), and internal carotid artery (93.6%) aneurysms. The sensitivity was 100% for aneurysms >5 mm, 96.7% for aneurysms 3-5 mm, and 77.8% for aneurysms £3 mm. Among 316 patients who were treated surgically, an operation was performed only on the basis of CTA in 264 cases (83.5%). Conclusions: CTA is a minimally invasive neuroimaging method of high diagnostic efficiency and should be a primary vascular examination in patients with suspicion of aneurysm allowing, in most cases, avoidance of invasive cerebral angiography.