Complete Intracranial Arterial and Venous Blood Flow Evaluation with 4D Flow MR Imaging

Whole-brain arterial imaging in a healthy volunteer. A depicts midsystolic blood flow with streamlines in the basilar artery, with flow in the bilateral vertebral arteries seen inferiorly and flow in the posterior cerebral artery seen superiorly. In addition, flow within the bilateral superior cerebellar arteries can be appreciated. B and C demonstrate flow in the right anterior and middle cerebral arteries. The pericallosal branch of the anterior cerebral artery is well visualized, as is the middle cerebral artery trifurcation. Magnitude images are provided in midline sagittal and axial planes for orientation.

Venous drainage in a patient with an AVM. A is a slightly oblique view of an axial section through the left frontoparietal AVM with streamlines overlaid to depict venous flow in the superior sagittal sinus and a right superficial vein. B shows the marked increase in blood flow in the superior sagittal sinus in the patient compared with a healthy subject (5.1 times greater). Note the arterial pulsatility of the venous drainage. C is a magnified oblique view of the high-velocity venous drainage from the AVM.

Quantification of arterial inflow to AVM nidus. A is an axial section from a time-of-flight MRA demonstrating the left frontoparietal nidus. B has singled out the 3 largest arteries supplying the nidus: vessel 1 is an anomalous branch of the anterior cerebral artery running along the septum pellucidum, and vessels 2 and 3 are posterior left middle cerebral artery branches. C shows the marked increase in blood flow through the left internal carotid artery in the patient compared with a healthy subject (3.3 times greater), as well as the relative arterial contribution to the AVM nidus of the blood vessels labeled on the MRA.

Disorganized, circulating blood flow within the AVM nidus. A is an axial magnitude section through the large left frontoparietal AVM. B has velocity data overlaid on this axial section. C is a magnified view of the AVM nidus with 3D velocity data from midsystole, as represented as a curved vector field, demonstrating somewhat disorganized, circulating flow. Note the high-velocity venous drainage in the superior sagittal sinus, which can be visualized through the semitransparent axial section. D is an oblique view at higher magnification.