FIG 3.

cDSA with variation among raters in vessels selected for analysis. Left vertebral arteriogram in a lateral projection shows a right occipital lobe AVM supplied by the calcarine and parieto-occipital branches of the right PCA, with dominant drainage into 2 internal occipital veins superior to the nidus and minor drainage into a tentorial vein inferiorly. A, Rater 1 placed the arterial ROI on the calcarine branch of the PCA distal to the overlapping minor venous egress and placed the venous ROI on the more superior internal occipital vein. B, Rater 2 placed the arterial ROI on the calcarine branch of the PCA proximal to the overlapping minor venous egress and placed the venous ROI on the more superior internal occipital vein. C, Rater 3 placed the arterial ROI on the calcarine branch of the PCA proximal to the overlapping minor venous egress and placed the venous ROI on the more superior internal occipital vein, though distal relative to rater 2. D, Rater 4 placed the arterial ROI on the calcarine branch of the PCA distal to the overlapping minor venous egress, similar to rater 1. Rater 4 also placed the venous ROI on the more inferior internal occipital vein, unlike the other raters. Despite differences in the vessels selected for analysis, time-density curves (E) and AUCs (F) were largely reproducible because the ROIs were placed so close to the nidus by all raters.