The role of 3D-computed tomography angiography (3D-CTA) in investigation of spontaneous subarachnoid haemorrhage: comparison with digital subtraction angiography (DSA) and surgical findings.

Spontaneous subarachnoid haemorrhage is a clinical condition that may be attributed to various underlying causes, such as rupture of intracranial aneurysms and arteriovenous malformations (AVMs). Suspected cerebrovascular abnormalities can be detected either with digital subtraction angiography (DSA) or with computed tomography angiography (CTA) combined with postprocessing tools, namely multiplanar reformation, maximum intensity projection, shaded surface display, virtual endoscopy and direct volume rendering. We prospectively studied a group of 205 patients with spontaneous subarachnoid haemorrhage. One-hundred-ninety-eight patients underwent both DSA and CTA, and formed our study group. Patients with intracranial aneurysms underwent surgical or endovascualar treatment. DSA was negative for 35 patients, detected 178/179 aneurysms and 15 AVMs. CTA correctly detected 176/179 aneurysms and all 15 cases of AVMs, whereas it was negative in 35 cases. After 3D reconstruction the size, location and the relationship to the parent vessel of the aneurysms, the extent of the AVMs with the main feeding vessel(s), nidus and draining veins were reliably shown by CTA, although DSA provided more anatomic details related to the anatomy of the adjacent vessels. The accuracy, sensitivity, positive predictive accuracy and negative predictive accuracy for CTA was 98, 97.9, 100 and 94.3% and for DSA was 99, 99.3, 100 and 98%, respectively. It is suggested that CTA is a reliable alternative to DSA in detecting intracranial aneurysms. The role of CTA in demonstrating AVMs can be considered complementary to that of DSA.