title: A study on optimal scan conditions of Big Bore multi-slice computed tomography based on radiation dose and image noise.
abstract: The newly introduced Big Bore computed tomography (CT) has a possibility to increase the tube current product scan time (mA s) for compensation of image degradation due to larger gentry opening without sound guideline. The objective of this paper is to derive optimal scan conditions for Big Bore CT scanner, mainly relating to the dose of diagnostic CT. The weighted CT dose index (CTDI(w)) was estimated at five typical protocols, such as head and neck, brain, paediatric, chest and abdomen. Noises were analysed in a circle of 1 or 2 cm of diameter in CT image slice. The results showed that measured CTDI(w) values generally follow the theoretical rule at all scanning conditions of every protocol. Although image noises decrease with increment of mA s, analysed image noises do follow the theoretical rule, but only in specific protocols. This phenomenon is presumed to result from the photon energy spectra arriving at the detection system of the Big Bore scanner.
authors.affiliation: Korea Institute of Nuclear Safety, 19 Guseong-Dong, Yuseong-Gu, Daejeon 305-338, Republic of Korea. jslee@kins.re.kr
authors.forename: Jae-Seong
authors.initials: JS
authors.lastname: Lee
authors.forename: Sung-Joon
authors.initials: SJ
authors.lastname: Ye
authors.forename: Eun-Hee
authors.initials: EH
authors.lastname: Kim
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging; D002648:Child; D006257:Head / Q000000981:diagnostic imaging; D006801:Humans; D009333:Neck / Q000000981:diagnostic imaging; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D013902:Radiography, Thoracic / Q000295:instrumentation*; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*