MRI IN CEREBRAL VENOUS THROMBOSIS

Fifty-three patients with cerebral venous thrombosis (CVT) were explor ed by MRI. Three types of signal abnormalities were observed in thromb osed sinuses : 1) isosignal on Tl-weighted sequence and low-intensity signal on T2-weighted sequence (early stage); 2) high-intensity signal on Tl-and T2-weighted sequences (intermediate stage); 3) isosignal on Tl-weighted sequence and high-intensity signal on T2-weighted sequenc e (late stage). Signal abnormalities in dural sinuses enabling CVT to be diagnosed were absent in 2 out of 53 cases. Twenty-six out of 53 pa tients had venous infarction. These lesions were haemorrhagic in 20 ca ses. MRI made it possible to follow the course of CVT in 15 cases, sho wing partial or complete recanalization of the occluded sinuses in 14 cases. Our study confirmed that MRI is an excellent non-invasive metho d to explore CVT. It diagnoses the venous thrombosis, studies parenchy mal lesions and follows the course of CVT under treatment. However, MR I is less sensitive than arteriography, particularly in cases of CVT i nvolving only the cortical veins.