A 66-year-old male was admitted with right homonymous hemianopsia. Angiograms revealed a dural arteriovenous fistula (DAVF) involving the left transverse-sigmiod sinus. The DAVF was fed by the left occipital, middle meningeal, and posterior auricular arteries and drained into the left transverse sinus with occlusion of the left internal jugular vein and reversed flow of the left occipital cortical veins. Positron emission tomography (PET) study showed decreased regional cerebral blood flow (rCBF), regional oxygen extraction fraction (rOEF) and regional cerebral metabolic rate of oxygen (rCMRO2) and increased regional cerebral blood volume (rCBV). The patient was treated by transarterial and transvenous embolization. Before transvenous embolization, we attempted to observe the perisinus structure used by intravascular ultrasound (IVUS). IVUS was able to demonstrate multiple channels formed by DAVF and transvenous embolization was performed accurately at the exact fistulous site. After treatment, the DAVF had completely disappeared but clinical symptom had hardly any changed. A PET study showed that the rCBF and rCBV were normalized but rOEF and rCMRO2 had not changed. Eight months after treatment, PET study showed some normalization of rOEF and rCMRO2 of the left occipital lobe with the clinical symptom. IVUS is useful in determining the exact sites of transvenous embolization of DAVF.