Total Bolus Extraction Method Improves Arterial Image Quality in Dynamic CTAs Derived from Whole-Brain CTP Data

Table 1

Results of the observer study on arterial image quality in standard dynamic CTAs (dCTAs) and the proposed ToBE dynamic CTAs derived from 15 4D CT perfusion scans. The scores are presented as mean (standard deviation) over all 15 images and were scored on a 5-point scale (5 = good quality, 1 = poor quality) for all arteries, except the small intradural arteries. The small intradural arteries are presented as the number of scans with >3 visible small artery branches/total number of small arteries assessed (ratio in percentage; standard error).

Category	Standard dCTAs	ToBE dCTAs	Test results
Large extradural arteries	4.5 (0.7)	4.9 (0.4)	𝑃=𝟎.𝟎𝟎𝟏^∗
Intradural arteries
Large	4.4 (1.0)	4.7 (0.7)	𝑃<𝟎.𝟎𝟎𝟏^∗
Medium	3.7 (1.1)	4.4 (0.8)	𝑃<𝟎.𝟎𝟎𝟏^∗
Small	104/180 (57.8%; 3.7%)	159/180 (88.3%; 2.4%)	𝑃<𝟎.𝟎𝟎𝟏^∗∗
Cerebellar and ophthalmic arteries	2.5 (1.6)	2.9 (1.7)	𝑃=0.007
Communicating arteries	2.7 (1.8)	2.9 (1.9)	𝑃=0.10

∗Significant, Wilcoxon Signed Rank statistical test.
∗∗Significant, McNemar statistical test.