Objective: To identify the common MRV findings in the patient diagnosed intracranial veno-occlusive disease at Ramathibodi Hospital and to identify the underlying conditions that probably predisposed the patient to the intracranial veno-occlusive disease.
Material and Method: Sixty-four patients with clinically suggestive intracranial veno-occlusive disease who underwent MRV were reviewed in terms of signs and symptoms, MRV methods, MRV findings, and clinical diagnosis after report MRV. In cases diagnosed to have intracranial veno-occlusive disease, the patients’ records were reviewed to identify predisposing conditions.
Results: Thirty-four patients were diagnosed to have intracranial veno-occlusive disease. The common findings were lack of typical high flow signal from a sinus that did not appear aplastic or hypoplastic, frayed appearance of flow signal from a sinus at a later stage of the thrombus, and collateral vessels and cerebral hemorrhage. The common sites were superior sagittal sinus, and left and right transverse sinuses. Hypoplasia, a normal variation, was incidentally found in eight patients (12.5%). The most common hypoplastic site was the left transverse sinus. Contributing factors in patients diagnosed to have intracranial veno occlusive disease in the present series were birth control pill in take, tumor (meningioma, and malignant schwannoma of the scalp), blood dyscrasia, AVM, hypotension, and abscess. The causes of intracranial venous thrombosis could not be identified in seven patients (21%).
Conclusion: The common MRV finding in acute intracranial veno-occlusive disease was lack of typical high flow signal from a sinus while frayed appearance of flow signal from a sinus was the common direct sign in chronic condition. In the present series, birth control pill intake was the most common contributing factor.

Keywords: Intracranial venoocclusive disease, Magnetic resonance venography