Fig 1.

Photograph (A) and maximum intensity projection (B) of the 7T T1-weighted turbo field echo MR imaging sequence of the CoW specimen of an 87-year-old man embedded in a 2% agarose solution within a Petri dish. The sample locations are illustrated by white lines. For each sample location, care was taken to avoid sampling near a visible air bubble or sampling of a collapsed arterial segment. The N below each arterial segment denotes the number of samples for that location within the 44 assessed samples obtained from the 5 CoW specimens. MR images were correlated with histologic sections by using fiducials placed within the agarose solution (arrows in A and B). A1 indicates A1 segment of the anterior cerebral artery; Dist-BA, distal segment of the basilar artery; Mid-BA, middle segment of the basilar artery; Prox-BA, proximal segment of the basilar artery; ACA, anterior cerebral artery; VA, vertebral artery.