CT-ANGIOGRAPHY OF CEREBRAL VENOUS CIRCULA TION - ANATOMICAL VISUALIZATION AND DIAGNOSTIC PITFALLS IN INTERPRETATION

Purpose: To show the frequency of visualisation of the dural sinuses a nd cerebral veins with CT-angiography (CTA) with special reference to anatomical variants. Methods: 34 CTA (1 mm slice thickness, 120 mi non ionic KM, 2 ml/s flow, 40s prescanning delay) were performed in 30 pat ients to examine the cerebral venous system. In an anatomic study of c adavers (n = 10) without known disease of the cerebral veins the great sinuses were opened and examined. Results: The superior sagittal, the transverse, the sigmoid and the straight sinus could be evaluated in all cases (100%), The cortical and deep cerebral veins as well as the small sinuses were visualised in 12-97% of the examinations. A sinoven ous thrombosis was diagnosed in 4 of the 30 patients. Asymmetric super ior sagittal sinus bifurcation (12/30). a hypoplastic sinus transversu s (2/30) and a persistent sinus occipitalis (4/30) were found as anato mical variants, In 10 of the 30 patients we discovered 17 dural sinus filling defects produced by large arachnoid granulations. Similar find ings could be demonstrated in the pathologico-anatomic examination ser ies. Conclusion: CT angiography is suitable for detailed evaluation of the cerebral veins. Anatomic variants, arachnoid granulations, as wel l as fibrous bands and septa, which may lead to misinterpretation in c onventional CT, can be clearly demonstrated. The sensitivity and speci ficity of CT in diagnosis of sinovenous thrombosis were increased ther eby.