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Updated: May 9, 2026

Retrospective Cardiac Gating with A Prototype Small-Animal X-ray Computed Tomograph
Published on: February 21, 2025
Low-dose chest computed tomography with sinogram-affirmed iterative reconstruction, iterative reconstruction in image
Hye Jeon Hwang1, Joon Beom Seo, Hyun Joo Lee
1Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Objective:
This study aimed to determine optimal strength of sinogram-affirmed iterative reconstruction (SAFIRE) and to evaluate image quality (IQ) of low-dose chest computed tomography (LDCT) using SAFIRE compared with iterative reconstruction in image space (IRIS) and filtered back projection (FBP).
Methods:
Thirty patients underwent LDCT. Computed tomography (CT) was reconstructed using 5 strengths of SAFIRE (S1-S5), IRIS, and FBP. Objective noise of CT was measured. Two radiologists evaluated CT for subjective IQ, beam-hardening artifacts, and overall IQ.
Results:
Measured noise was highest in FBP, followed by S1, S2, S3, IRIS, S4, and S5. S2 and S3 demonstrated significantly higher overall IQ scores than the other strengths (P < 0.05). Overall IQ and beam-hardening artifacts of S2 and S3 were significantly better than those in FBP and IRIS (P < 0.001).
Conclusions:
S2 or S3 strengths of SAFIRE can be used practically in clinical routines and may have more potential than IRIS and FBP for LDCT with improved IQ.
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