表 3. SNR values of six kinds of reconstruction images (n=47) .

六种重建图像的SNR值分析（n=47）

Rebuild method	ROI1	ROI2	ROI3
ROI1: Region of interest in aorta; ROI2: Region of interest in muscle; ROI3: Region of interest in lung tissue.
FBP	1.88±0.41	2.61±0.33	26.65±8.32
ASIR50%	2.80±0.65	3.79±0.55	29.72±12.27
ASIR70%	3.49±0.83	4.57±0.77	31.15±14.56
DL-L	2.57±0.55	3.35±0.43	32.06±15.36
DL-M	3.25±0.69	4.11±0.54	32.59±18.11
DL-H	4.53±0.97	5.39±0.76	31.59±15.29
P	<0.001	<0.001	<0.001