Dynamic 3D MR Angiography of Intra- and Extracranial Vascular Malformations at 3T: A Technical Note

Conventional catheter DSA (A, B) reveals a high-flow AVM with a left central nidus fed by a central branch of the middle cerebral artery and an enlarged callosomarginal artery. A superficial and cortical vein is draining into the frontoparietal superior sagittal sinus. The time difference between A and B is 0.5 seconds.

The dynamic MRA (D, E) depicts both the arterial feeders and the drainage vein. The nidus itself is poorly depicted and superposed by the early filled enlarged cortical vein. A region-of-interest analysis of the time signal intensity course (C, F) was performed within the internal carotid artery (region 1), the drainage vein (region 2), the parietal superior sagittal sinus (region 3), which was fed by the drainage vein, and the frontal superior sagittal sinus (region 4), showing anterograde flow and no blood supply from the iAVM as established by conventional DSA. The time course of the signal intensity within the region of interest is given in arbitrary units. The difference of contrast arrival time between the internal carotid artery (region 1) and the dominant drainage vein (region 2) was 2 seconds. The difference of time to peak was 1 second, whereas the difference of contrast arrival time between the internal carotid artery and the normally fed frontal superior sagittal sinus was 4 seconds, and the difference of time to peak was 3 seconds. This reflects the flow pattern of the high-flow AVM, where the venous drainage system is already filled in the early arterial perfusion phase. The regular time of the venous perfusion phase is shown by the time course of the frontal sagittal superior sinus, and is in the normal range (4–7 seconds) as given by Noguchi et al (7).