Detection and assessment of circle of Willis aneurysms in acute subarachnoid hemorrhage with three-dimensional computed tomographic angiography: Correlation with digital substraction angiography findings

In this retrospective study, we examined the usefulness of computed tomogra phic mographic angiography (CTA) for the detection and assessment of circle of Willis aneurisms in patients with acute nontraumatic subarachnoid hemor rhage (SAH). using selective digital substraction angiography (DSA) as the gold standard. Thirty-five patients who presented with acute, nontraumatic SAW, diagnosed on the basis of unenhanced computed tomography or lumbar pun cture findings or both, underwent both CTA and DSA. The CTA images were: in terpreted for the presence, location, size, and shape of the aneurysm, pres ence of a neck, and relationship of the aneurysm to adjacent arterial branc hes. The CTA and DSA images were then compared, with the latter images serv ing as the gold standard. DSA revealed 37 aneurysms in 32 patients and rule d out intracranial aneurysms in the remaining three. The sensitivity and sp ecificity of CTA for aneurysm detection were 97% and 100% respectively. The size of the smallest aneurysm shown was 4 mm, and the largest aneurysm was 21 mm, The size and lobularity of the aneurysms estimated from CTA images corresponded well with those estimated from DSA images, In addition, CTA pr ovided a three-dimensional representation of the aneurysmal lesion, which w as considered useful for surgical planning, Our results confirm the accurac y of CTA in comparison with DSA, Because of its reliability, minimal invasi veness, and rapidity, CTA may become the technique of choice for neuroradio logic work-up of SAH patients. DSA then would be used to diagnose intracran ial aneurysms only In selected, questionable cases.