Fig 1.
From July 2020 to June 2021, 271 patients were eligible for the study, and according to the inclusion and exclusion criteria, final 51 subjects were selected as the study population.
Table 1.
Comparison of CT scan protocol, radiation dose and contrast agent volume reduction.
Fig 2.
Violin plot comparison of size-specific dose estimation.
The blue graph represents the reduction protocol group, while the red graph represents the standard protocol group in the violin plot chart. The Y-axis represents the size-specific dose estimate of the portal phase. The blue empty circles represent the size-specific dose estimate of each individual in the reduction protocol group, and the blue filled squares with upper and lower black lines represent the mean value (9.5 ± 2.3 mGy∙cm). Similarly, the red empty squares represent the size-specific dose estimate of each individual in the standard protocol group, and the red filled circles with upper and lower black lines represent the mean value (13.9 ± 4.8 mGy∙cm).
Fig 3.
The box plot comparison of the contrast-to-noise ratio of each abdominal organs (AortaArterial phase and AortaPortal phase are value measured on arterial and portal phase, respectively).
Table 2.
Paired t-test results of objective image quality.
Fig 4.
The box plot comparison of each organ’s figure of merit between the reduction and standard protocol groups.
The figures of merit of the reduction protocol group were significantly higher than those of the standard protocol group (p < 0.001).
Fig 5.
A. A 53-year-old woman with a branch duct type intraductal papillary mucinous tumor in the pancreas tail. A & B, Arterial and pancreatic parenchymal phase of computed tomography images of the reduction protocol group, respectively. C & D, Arterial and pancreatic parenchymal phase of computed tomography images of the standard protocol group, respectively. The reduction protocol images show reduction of beam hardening artefacts related kyphoplasty, and higher CNR of the pancreatic lesion based on the more enhancement of surrounding vessels and pancreatic parenchyma, compared to the standard protocol images. B. A 53-year-old woman with a branch duct type intraductal papillary mucinous tumor in the pancreas tail.
Table 3.
Intra-rater and inter-rater agreement of subjective image quality score.
Table 4.
Paired comparison of subjective image quality by the Wilcoxon signed-rank test.