Figure 1.
Biomedical RANDO standard male phantom.
Figure 2.
The cross section of the phantom.
It has circular holes (arrows) to place the radiation dose meter. We evaluated the image quality about display of the circular hole (for placing a radiation dose meter) and the boundary of the image.
Figure 3.
The schematic diagram of CTDIvol variations according to the mA value.
CTDIvol decreases as the mA value decreases.
Figure 4.
Image noise analysis based on the different reconstruction models.
The schematic diagram of SD and CNR variations according to the mA values. All three reconstruction algorithms showed increased noise as the tube current decreased: FBP presented the most noticeable variations, followed by 50% ASiR and then by MBIR; the three models showed decreased CNRs as the tube current decreased, but at the same tube current, MBIR presented the highest CNR, which was followed by 50% ASiR and then by FBP.
Figure 5.
The schematic diagram of the SD decrease and CNR increase rates by 50% ASiR and MBIR (compared with those by FBP).
As the mA value decreased, MBIR brought about gradually augmented variations in the two parameters, whereas 50% ASiR did not give rise to noticeable variations.