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The goal of this study was to assess the usefulness of spiral CT angiography (CTA) with three- dimensional reconstructions in defining intracranial aneurysms, particularly around the Circle of Willis. Two hundred consecutive patients with angiographic and/or surgical correlation were studied between 1993 and 1998, with CTA performed on a GE HiSpeed unit and Windows workstation. The following clinical situations were evaluated: conventional CT suspicion of an aneurysm; follow-up of treated aneurysm remnants or of untreated aneurysms; subarachnoid haemorrhage (SAH) and negative angiography; family or past aneurysm history; and for improved definition of aneurysm anatomy. Spiral CTA detected 140 of 144 aneurysms, and an overall sensitivity of 97%, including 30 of 32 aneurysms 3 mm or less in size. In 38 patients with SAH and negative angiography, CTA found six of the seven aneurysms finally diagnosed. There was no significant artefact in 17 of 23 patients (74%) with clips. The specificity of CTA was 86% with 8 false-positive cases. Spiral CTA is very useful in demonstrating intracranial aneurysms.

Thirteen papers on different aspects of cerebral cavernomas are reviewed; interest in this condition has increased since magnetic resonance imaging (MRI) became widely available. The prevalence of cavernomas is uncertain, but they are the most common of the angiographically occult vascular malformations. Some are isolated occurrences, and some are familial, with a dominant inheritance. Screening with MRI of first-degree relatives is justified. The reported annual risk of haemorrhage varies widely and is probably between 1 and 3%, with a possible increase in risk after a first haemorrhage; the risk may also be higher in deep or brain stem cavernomas. Opinions on when surgery should be offered vary, with prophylactic surgery not usually recommended. After symptomatic haemorrhages, surgery may be more justified for easily accessible lesions. For those that are more difficult to approach safely, especially in the brain stem, operation is not usually recommended unless there has been at least one clinically significant haemorrhage. Epilepsy owing to hemisphere cavernomas can often be successfully managed medically, with surgery reserved for intractable seizures. In children with epilepsy, there is a stronger argument for surgery. Radiosurgery has been used for symptomatic cavernomas that are surgically inaccessible. Strong arguments have been advanced both for and against this treatment, and the risks probably outweigh the benefits. Suggestions for a randomised trial have been made.

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