表 2. Comparison of the image quality of the normal-dose images and low-dose images (n=100) .

常规剂量和低剂量图像质量比较（n=100）

Variable	ND-IR	LD-FBP	LD-IR	LD-DL
ND: Normal dose; LD: Low dose; IR: Iterative reconstruction; FBP: Filtered back projection; DL: Deep learning; SNR: Signal-to-noise ratio; CNR: Contrast-to-noise ratio; FOM: Figure of merit. *P<0.05, vs. LD-DL.
CT value/HU	108.9±8.59	108.89±10.91	108.98±10.83	109.13±10.55
Noise/HU	9.71±1.19*	20.36±1.49*	15.26±1.19*	9.10±1.26
SNR	11.41±1.77*	5.39±0.72*	7.19±0.97*	12.22±2.07
CNR	4.51±1.28*	2.22±0.61*	2.95±0.8*	5.11±1.31
FOM	25.99±12.97*	11.85±6.21*	21.08±10.95*	62.45±35.5