3D time-resolved vessel-selective angiography based on pseudo-continuous arterial spin labeling

Angiographic imaging is an important diagnostic tool for the assessment of the intracranial arterial status. Using arterial spin labeling (ASL) techniques, it is possible to visualize the arteries without the administration of exogenous contrast agents. Moreover, modifications of the labeling method allow for the visualization of single arterial trees. In this study, an approach is presented for time-resolved MR angiography based on superselective ASL and keyhole accelerated image acquisition in order to selectively visualize individual cerebral arteries in a clinically acceptable scan time. Keyhole percentage as well as the flip angle of the acquisition sequence was optimized in numerical simulations. Subsequently, the method was validated in healthy volunteers. As a result, image acquisition in 5 minutes with a temporal resolution of 100 ms and spatial resolution below 1 mm was achieved.