Sinogram-Affirmed Iterative Reconstruction Negatively Impacts the Risk Category Based on Agatston Score: A Study Combining Coronary Calcium Score Measurement and Coronary CT Angiography

Table 4

Patients’ number (n2) in different risk categories of patients with coronary artery stenosis () between FBP and all levels of SAFIRE.

Risk category	FBP	SAFIRE 1	SAFIRE 2	SAFIRE 3^★	SAFIRE 4^★◎■	SAFIRE 5^★◎■
^#
Patient	0	0	0	0	0	0
1 vessel	0	0	0	0	0	0
≥2 vessels	0	0	0	0	0	0
Prevalence	0	0	0	0	0	0
^▲
Patient	0	1 (2.0%)	1 (2.0%)	2 (4.1%)	4 (8.2%)	4 (8.2%)
1 vessel	0	1	1	2	3	3
≥2 vessels	0	0	0	0	1	1
Prevalence	0	7.1%	7.1%	12.5%	21.1%	21.1%
^▲
Patient	13 (26.5%)	13 (26.5%)	13 (26.5%)	15 (30.6%)	15 (30.6%)	16 (32.7%)
1 vessel	10	10	10	11	11	12
≥2 vessels	3	3	3	4	4	4
Prevalence	32.5%	34.2%	34.2%	38.5%	40.5%	42.1%
Patient	23 (46.9%)	25 (51.0%)	26 (53.1%)	23 (46.9%)	23 (46.9%)	23 (46.9%)
1 vessel	15	15	15	13	14	13
≥2 vessels	8	10	11	10	9	10
Prevalence	92.0%	92.6%	92.9%	92.0%	92.0%	92.0%
Patient	13 (26.5%)	10 (20.4%)	9 (18.4%)	9 (18.4%)	7 (14.3%)	6 (12.2%)
1 vessel	4	3	3	3	1	1
≥2 vessels	9	7	6	6	6	5
Prevalence	100%	100%	100%	100%	100%	100%

FBP: filtered back projection; SAFIRE: sinogram-affirmed iterative reconstruction.^#The only patient whose Agatston score decreased to zero using SAFIRE 4 had no significant stenosis. The percentages (n2/49) were gradually increased for the low risk category (e.g., and ) but decreased for the high risk category (e.g., ) from FBP to SAFIRE 5. ^▲The prevalence (n2/n1) of coronary artery stenosis was gradually increased for the low risk category (e.g., and ) from FBP to SAFIRE 5. ^★ compared with FBP; ^◎ compared with SAFIRE 1; ^■ compared with SAFIRE 2.