title: The application of automatic tube current modulation (ATCM) on image quality and radiation dose at abdominal computed tomography (CT): A phantom study.
abstract: Multi-phase spiral Computed tomography (CT) of abdomen has been widely used as an effective imaging modality to diagnose variety of diseases. As a result, the accumulated radiation exposure on the abdomen is substantially higher than other human organ regions. According to ALARA (as low as reasonably achievable) principle, how to control radiation dose without compromising imaging quality becomes a research topic of high interest. However, how to achieve dose optimization of the abdomen CT examinations in Chinese patients have not been fully investigated in previous studies. In this study, we develop an abdomen-equivalent tissue model made by well-known CTP579 auxiliary testing model and the real CT data acquired from 68 Chinese male subjects. Combining with catphan600, we simulated the visibility of low and high contrast objects at adult abdomen under variety of x-ray dose levels. Using the automatic tube current modulation (ATCM) technique, we reduced the total radiation dose and identified a proper noise index (NI) for Chinese patients to maintain low or high contrast detectability of abdominal CT image. Our numerical experiments showed that in the phantom study for Chinese patients, when a NI was set at 10, the radiation dose reduced by 34.3% with low contrast objects detectable, while setting NI at 14 the dose level decreased by 65.1% without change the detectability of high contrast targets. The subjective ratings from three radiologists also yielded high consistence with Kappa > 0.75. This study demonstrated the feasibility of performing the CT dose optimization studies through a unique phantom with the ATCM method.
authors.affiliation: Department of Diagnostic Imaging, Peking Union Medical College and Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Xinming
authors.initials: X
authors.lastname: Zhao
authors.forename: Junfeng
authors.initials: J
authors.lastname: Song
authors.forename: Ning
authors.initials: N
authors.lastname: Guo
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.forename: Jianxin
authors.initials: J
authors.lastname: Liu
authors.forename: Weiwei
authors.initials: W
authors.lastname: Qi
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liang
authors.forename: Shichao
authors.initials: S
authors.lastname: Feng
authors.forename: Mancang
authors.initials: M
authors.lastname: Hu
authors.forename: Chunwu
authors.initials: C
authors.lastname: Zhou
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Wang
authors.forename: Nan
authors.initials: N
authors.lastname: Hong
mesh_terms: D000465:Algorithms; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011860:Radiography, Abdominal / Q000295:instrumentation* / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods
keywords: Abdomen; MSCT; image quality; phantom; radiation dose