Improvements in the Quantitative Assessment of Cerebral Blood Volume and Flow with the Removal of Vessel Voxels from MR Perfusion Images
Representative images of the segmented normal brain parenchyma ((a), (c), (e), (g), (i), (k)) and vessel masks generated from CBV images and CBF images calculated using the cSVD ((b), (d), (f), (h), (j), (l)) and sSVD ((m), (n)) techniques in the final vessel removal step. In the color-coded vessel masks, yellow voxels are detected with a CBV threshold (CBV > 8 mL/100 g) only, cyan voxels are found from the CBF threshold (CBF > 100 mL/100 g/min) only, and red voxels are found from both. Different degrees of stenosis are shown in this figure: bilateral normal arteries (0% stenosis): subject #14 ((a) and (b)); 40% stenosis (right side): subject #11 ((c) and (d)); 75% stenosis (right side): subject #26 ((e) and (f)); 90% stenosis (left side): subject #29 ((g) and (h)); 90% stenosis (right side): subject #23 ((i), (j), and (m)); 95% stenosis (right side): subject #20 ((k), (l), and (n)). In patients with unilateral high-grade stenosis ((j), (l), (m), (n)), the CBV threshold (yellow + red) detected insufficient vessels on the normal side, and the cSVD CBF masks ((j), (l)) and sSVD CBF masks ((m), (n)) (cyan + red) detected insufficient vessels on the lesion side.