title: Radiation dose in cardiac CT angiography: protocols and image quality.
abstract: This paper aims to evaluate the radiation dose exposure of patients submitted to cardiac computed tomography angiography. The effective dose was obtained from the product of dose-length product values and the conversion factor established in the European Working Group for Guidelines on Quality Criteria in CT. The image noise and contrast- and signal-to-noise ratios were obtained for all images. Sixty-four- and 256-slice CT angiographies were used in 211 (68.5 %) and 97 (31.5 %) patients, respectively. The calculated mean effective dose with prospective CT angiography was 6.0±1.0 mSv and the retrospective mode was 8.4±1.2 mSv. The mean image noise values were 38.5±9.5 and 21.4 ± 5.3 for prospective and retrospective modes, respectively. It was observed that the image noise increased by 44.4 % using a prospective mode. Prospective CT angiography reduces radiation dose by ∼29 % compared with the retrospective mode, while maintaining diagnostic image quality and the ability to assess obstructions in patients.
authors.affiliation: Laboratório de Instrumentação Nuclear (LIN/COPPE/UFRJ), Centro de Tecnologia, Bloco I, Sala 133 Cidade Universitária, Ilha do Fundão, Rio de Janeiro (RJ) CEP 21949-900, Brasil. larissaconceicao@yahoo.com.br
authors.forename: L C G
authors.initials: LC
authors.lastname: Oliveira
authors.forename: I
authors.initials: I
authors.lastname: Gottlieb
authors.forename: P
authors.initials: P
authors.lastname: Rizzi
authors.forename: R T
authors.initials: RT
authors.lastname: Lopes
authors.forename: S
authors.initials: S
authors.lastname: Kodlulovich
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001331:Automation; D002118:Calcium / Q000378:metabolism; D055424:Cardiac-Gated Imaging Techniques; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed
chemical_list: D002118:Calcium