Lisette van Dam

Chapter 7 116 or chronic CVT. The authors also found that visual assessment (evaluation of direct/ indirect signs) was more accurate than quantitative assessment (attenuation evaluation). 40 In summary, while CT is useful as primary imaging modality in patients with suspected acute CVT, additional imaging is generally required to diagnose and rule out CVT with more certainty. 2,5,15,26,41 Table 1 : (Non-)contrast-enhanced computed tomography (CT) findings in cerebral vein thrombosis. Direct signs Indirect signs Non-contrast CT (NCCT) Dense clot sign: direct visualization of the thrombus in the cerebral sinus and veins Cord or string sign (dense vessel sign): linear or cord-like density of a thrombosed cortical vein Haemorrhagic infarction Brain oedema Mass effect Subarachnoid haemorrhage Contrast- enhanced CT (CECT) Empty delta sign: thrombosed sinus seen as triangular area of enhancement with relatively low attenuation center Same findings as on NCCT Figure 1. Axial CT images of a patient with acute sinus thrombosis; A. Non-contrast CT image shows a hyperdense aspect of both transverse sinus (arrows) and B. CT venography after administration of iodinated contrast agent shows a filling defect in both transverse sinus (arrows).