Our own experience with CT angiography in early diagnosis of cerebral vascular malformations.

Computed tomography (CT) and intraarterial cerebral angiography are essential methods in early diagnosis of cerebral vascular malformations. In recent years however non-invasive or minimally invasive methods like MR angiography and CT angiography (CTA), which could potentially replace angiography, have been developed. The aim of presented study is to demonstrate our own experience in application of CTA in early diagnosis of cerebral vascular malformations. The material consists of 86 CTA examinations performed shortly after non-traumatic intracranial haemorrhage. Angiographic correlation has been available in 23 patients and surgical one--in 31 cases. CTA studies began with serio-CT to select the optimal time between contrast injection and CT scanning. After that 100-120 ml of non-ionic contrast medium was injected intravenously (5 ml per sec.) and spiral CT acqusition was performed with the delay calculated on the basis of the serio-CT. The obtained images were postprocessed on the workstation using always MIP and in many cases also SSD and VRT reconstructions. Vascular malformations have been diagnosed in 44 of 86 CTA studies including 38 patients with aneurysms (total number 51) and 6 patients with AVMs. In 17 cases the diameter of the aneurysm did not exceed 5 mm. In all surgical cases the CTA diagnosis of the aneurysm has been confirmed. There was however one false-negative case. On the other hand in 7 patients CTA revealed the small aneurysm, despite unclear angiographic appearance. In 2 of 6 patients with CTA suspicion of AVM this diagnosis has been excluded either by angiography or surgery. Comparison of CTA and angiography in 22 aneurysms showed in 17 cases superiority of CTA in evaluation of aneurysmal neck and the relationship between aneurysm and adjacent vessels (especially with VRT and SSD reconstructions). In patients with AVMs however the evaluation of supplying and draining vessels was better with angiography. On the base of our material we can conclude that CTA is very efficient in detecting and evaluating the aneurysms. We believe that CTA can replace angiography if it reveals aneurysm in a site corresponding with location of haemorrhage on CT. In patients with suspicion of AVM value of CTA is doubtful and angiography remains the method of choice.