EuroSafe Imaging 2020
Performed at one institution, Diagnostic or prognostic study, Retrospective, Kv imaging, Radiation effects, CT-Angiography, CT, Radioprotection / Radiation dose, Paediatric, Cardiac
T. Yoshiura, T. Masuda, Y. Matsumoto, T. Ishibashi, T. Oku
Conclusion and recommendations
In the phantom study, it is reported that the radiation dose will change due to different heights of the bed when using ATCM for inspection . Therefore, we think that variation of the radiation dose and SD value of the CT number during the uncorrected group (Group A) is higher than for the corrected group (Group B).
SD value of CT number of the uncorrected group (Group A) was significantly higher than that of the corrected group (Group B). Toth reported that variations in dose and image quality changes are higher with a small bowtie filter than with a medium or large bowtie filter . The bowtie filter would be effective on this result. We must therefore be careful of the kind of bowtie filter.
The ATCM recognizes differences in body thickness and X-ray attenuation dose from positioning images and automatically adjusts the dose, so it is possible to perform examinations with optimal image quality. However, the radiation dose and image quality may be affected if the examination site cannot be positioned correctly on the scan isocenter. Therefore, it can be expected that the inspection part can be correctly positioned on the scan isocenter by obtaining the positioning image for the scout view from the side direction.
This study however has other limitations. Firstly, the range and mean BW of our patients was lower than that of North American and European individuals. Secondly, ours was a single center study and the study population was relatively small.
The new method (1.side scout view, 2. table correction by using the CT console grid, 3.front scout view, and main scan) is useful for optimaising the ATCM and bow-tie filter at the pediatric CT. When performing a pediatric CT examination by using the ATCM, it is important to pay attention to the height of the bed and to center it correctly.