the Comparison of Radiation Dose and Image Quality from Using automatic tube Current Modulation system and Fixed tube Current technique for Chest Computed tomography examination


  • Chunpenmongkol S, Uadrang S, Sookpeng S


Radiation dose, CT Image quality, Chest CT, Automatic tube current modulation


At the present time, automatic tube current modulation (ATCM) system for computed tomography (CT) scanner is widely used. Department of radiation diagnostic, Lopburi cancer hospital has been used the ATCM system for a Chest CT examination. The aim of this research was to compare radiation dose and image noise from the use of a fixed tube current time product of 250 mAs and those from using the Toshiba ATCM system with different image noise levels such as high quality (HQ), quality (Q), standard (STD), low dose (LD) and screening (S). The experiment was carried out in a phantom. The tube current times products, volume computed tomography dose index (CTDIvol), dose length product (DLP) obtained from the scans were recorded and the effective dose was calculated. The skin dose was also measured using NanodotTM dosimeters and the image noise was measured using ImageJ. The results reveal that the setting up of image noise levels of HQ, Q, STD, LD and S, when compared to the fixed 250 mAs, resulted in reductions of the average CTDIvol, DLP and E by 14%, 33%, 47%, 80% and 86%, but increases the image noise by 8%, 13%, 22% ,69% and 91% respectively. Although the lowest value of E of 2.7 mSv from the image noise of “S” level was 7 times lower than that obtained from the fixed mAs technique, it was 2 times higher than the value recommended by the national lung screening trial research, U.S. In the future, the use of Iterative reconstruction technique with ATCM system should be studied, in order to reduce the radiation dose while maintaining the image quality. Moreover, the complete quantitative image quality assessment and qualitative assessment by radiologists should be performed to select an appropriate protocol used for a specific lesion detection.


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How to Cite

Chunpenmongkol S, Uadrang S, Sookpeng S. the Comparison of Radiation Dose and Image Quality from Using automatic tube Current Modulation system and Fixed tube Current technique for Chest Computed tomography examination. j dept med ser [Internet]. 2019 Jun. 1 [cited 2022 Oct. 7];44(3):40-6. Available from:



Original Article