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 2

The lesion number, volume, equivalent mass, Agatston score, CT attenuation value of the main calcium lesion, image noise, and SNR in FBP and all levels of SAFIRE.

Index	FBP	SAFIRE 1	SAFIRE 2	SAFIRE 3	SAFIRE 4	SAFIRE 5	value
Lesion number ()	5.0 (2.0-7.0)	4.0 (2.0-7.0)	4.0 (1.0-6.0)	4.0 (1.0-5.0)	3.0 (1.0-5.0)	3.0 (1.0-5.0)	<0.001
Volume (mm^3)	54.6 (20.5-164.7)	48.9 (16.6-141.5)	40.7 (14.9-135.2)	36.2 (13.5-129.1)	33.4 (11.7-119.6)	31.0 (10.3-111.2)	<0.001
Equivalent mass (mg)	12.1 (4.7-38.5)	10.5 (4.4-35.2)	9.6 (3.8-34.6)	8.9 (3.4-33.7)	8.2 (2.8-30.8)	7.3 (2.3-28.3)	<0.001
Agatston score	73.5 (28.9-198.3)	63.5 (20.1-172.0)	57.7 (18.2-164.8)	51.1 (16.5-159.1)	46.1 (14.4-148.5)	38.1 (12.1-134.9)	<0.001
Lesion CT value (HU)							<0.001
Image noise (HU)							<0.001
SNR	19.8 (14.1-28.6)	22.9 (16.1-31.4)	25.8 (17.0-36.0)	29.1 (19.3-41.4)	33.0 (21.7-47.0)	39.5 (26.6-57.2)	<0.001

FBP: filtered back projection; SAFIRE: sinogram-affirmed iterative reconstruction; SNR: signal-to-noise ratio.