Fig. 1.

Two-dimensional (2D) PC MRI. The images on the top row show the 2D PC phase image (A) and the 2D PC magnitude image (B). ROIs are drawn in white in the right carotid artery (1), the left carotid artery (2), and the basilar artery (3). The four background ROIs in static tissue are drawn in the sternocleidomastoid muscle on both sides (4 and 5) and two lower ROIs placed symmetrically relative to the three vessel ROIs (6 and 7). The images on the bottom row show the 2D PC magnetic resonance angiogram of carotid arteries (C), the basilar artery (D), and the sagittal 2D PC MIP image (E). The white line indicates the plane of the 2D PC phase and magnitude image. Abbreviations: MRI, magnetic resonance imaging; PC, phase-contrast; ROI, region of interest.