CT-angiographic evaluation of intracranial aneurysms - a review of the literature and first experiences with 4- and 16-slice multi detector CT scanners

Intracranial aneurysms are a common pathology faced by the diagnostic radiologist in daily practice. They can present as symptomatic aneurysms with a subarachnoid hemorrhage or as an incidental finding in another radiological study. Moreover, clipped or coiled aneurysms sometimes require a postinterventional work-up to exclude residual perfusion.Previous studies assessing the value of CT angiography in the diagnosis of intracranial aneurysms have been conducted using single slice spiral CT-scanners. They have shown a limited sensitivity in the diagnosis of small aneuryms with a diameter of equal to or smaller than 3 mm.Presently, there is only limited experience regarding the use of multi-detector row CT (MDCT) in the diagnosis of intracranial aneurysms. We have examined eight patients with a total of eleven aneurysms with MDCT technology, five patients with a 4-slice MDCT and three with a 16-slice MDCT. Of these, five were untreated aneurysms and six posttherapeutic with a status post surgical clipping. The mean diameter of the aneurysms was 5 mm (range 2 to 13 mm, median 3 mm). Of the treated aneuryms, two showed residual perfusion of the aneurysmal neck with a diameter of 2 and 6 mm respectively. In all cases, MDCT-angiography was in full agreement with the DSA diagnosis.Studies on larger patient populations will need to demonstrate the value of CTA in the diagnosis of intracranial aneurysms compared to the reference standard DSA.