Abstract:Objective To explore the feasibility of low-dose high-resolution CT scanning imaging and explore the optimal combination
of high-resolution imaging scanning parameters at low dose. Methods The Catphan 600 was scanned on the Force CT and HD750
CT by varying the combination of current and voltage with both iterative reconstruction (ADMIRE3/ASIR 50%) and filtered back
projection (FBP) reconstruction, and the volume CT dose index (CTDIvol) was recorded. The effects of iterative reconstruction and
FBP reconstruction on spatial resolution, density resolution and image noise were analyzed. According to the value of CTDIvol, the
patients were divided into a low-dose group (<2 mGy) and a high group (>8 mGy). The relationship between radiation dose and
the subjective evaluation of spatial resolution and density resolution was analyzed to explore the optimal combination of scanning
parameters of spatial resolution and density resolution under low-dose scanning. Results Compared with FBP reconstruction, the
noise level of the iterative reconstruction image was lower (P<0.05). Partial overlap exists in spatial resolution in different radiation
dose groups (low dose and high dose groups). In the low-dose group, the best scanning parameter combination of spatial resolution/
density resolution was 120 kV/25 mAs (60 mA). Conclusion Low dose and high-resolution imaging can be realized with the lowdose
scanning scheme of tube voltage 120 kV and tube current 25 mAs (60 mA) and the combined iterative reconstruction algorithm.
It provides the theoretical basis and the selection of scanning parameters for clinical chest low-dose high-resolution CT.