Gray blood magnetic resonance for carotid wall imaging and visualization of deep-seated and superficial vascular calcifications.

White blood and black blood magnetic resonance imaging methods are often used for lumenography and visualization of the arterial wall, respectively. However, the use of white blood imaging invariably obscures arterial wall boundaries, and thus, impedes precise measurement of arterial wall area. Conversely, black blood imaging imposes strict limits on sequence timing to suppress the arterial lumen, and by itself, precludes separation of superficial calcification from the hypointense arterial lumen. In this work, a three-dimensional arterial wall imaging methodology providing gray blood image contrast is described that remedies the above limitations. When applied to the carotid arteries, the described gray blood imaging method is found to clearly depict the inner and outer arterial wall boundaries as well as superficial and deep-seated vascular calcifications. A tailored phase-encoding schedule is also presented that enables concurrent gray and black blood, or "dual contrast," imaging of the arterial wall with no increase in the acquisition time. Taken together, presented data demonstrate that gray and dual blood contrast magnetic resonance imaging provide an efficient means for viewing and characterizing the composition of atherosclerotic plaques.