Table 2.

Image quality scores and percentages of diagnostic vs non-diagnostic image quality

Measure	Conventional CCTA	Subtraction CCTA	p-value
Image quality
Score (mean ± SD)	2.1 ± 0.9	3.1 ± 0.7	<0.001
Interobserver kappa coefficient	0.825	0.803
Segment percentages
Diagnostic image quality	49%	83%	<0.001
Non-diagnostic image quality	51%	17%

CCTA, coronary CT angiography; SD, standard deviation.