Application of CT angiography of complex cerebrovascular lesions during surgical decision making

Helical computed tomographic angiography (CTA) is a relatively new noninvasive volumetric imaging technique. Since early reports in the 1990s, CTA has rapidly improved image resolution and scan volume. Cerebral arteries can be imaged clearly, which is advantageous in the diagnosis of vascular diseases such as cerebral aneurysms, arteriovenous malformations, and cerebrovascular occlusive disease. Before attacking a cerebrovascular lesion near or in the skull base, precise preoperative knowledge of anatomic relationships between the bony and neurovascular structures is critical for obtaining successful outcomes. The sensitivity of CTA for the detection of cerebral aneurysms < or = 5 mm in diameter may be higher than that of digital subtraction angiography (DSA), with equal specificity and high interoperator reliability. With minor modification to the technique, paraclinoid vascular lesions can be depicted using CTA. We present our experience using CTA in addition to DSA to obtain important anatomic information about skull base vascular lesions that assisted in the clinical decision-making process.