Figure 1.
Sequence timing diagrams of a) General Electric (GE) and b) Philips, shown at the same time scale (ms).
pCASL = pseudo-continuous arterial spin labeling, PLD = post-labeling delay.
Table 1.
Acquisition protocols.
Figure 2.
Intra-vendor a) GE (n = 22) and b) Philips (n = 22) and c) inter-vendor (n = 44) GM (red) and WM (blue) CBF differences are plotted against mean CBF. Continuous and broken lines indicate mean difference and limits of agreement (mean difference ±1.96 standard deviation of the paired difference) respectively. CBF = cerebral blood flow, GM = gray matter, WM = white matter.
Table 2.
Inter-session statistics.
Figure 3.
Cerebral blood flow maps of a representative subject of GE (b) and Philips (c), as compared to gray matter (GM) tissue probability map (a; for this example the GE 3D T1-weighted image was used).
Maps are registered, re-sliced, skull-stripped and shown in native space.
Figure 4.
Mean cerebral blood flow (CBF) maps of all subjects (n = 22) are shown for GE (a) and Philips (b), averaged for both sessions.
Voxel-wise significant inter-vendor differences are visualized by a binary parametric map projected on the gray matter (GM) probability map (c). Red voxels represent where GE <Philips, blue voxels represent where GE >Philips (Bonferroni corrected p<0.05). On the right, mean CBF histograms are shown for the total GM and white matter (WM) (d).
Figure 5.
a) GE and b) Philips intra- and c) inter-vendor within-subject coefficient of variability (wsCV)-maps. d) wsCV histograms are shown on the right for the total gray matter (GM) and white matter (WM).
Figure 6.
Single transversal cerebral blood flow slice of all subjects (n = 22) for GE (upper quadrants) and Philips (lower quadrants), session 1 (left quadrants) and session 2 (right quadrants), after spatial normalization.