Coronary CT angiography radiation dose trends: A 10-year analysis to develop institutional diagnostic reference levels. Issue 113 (April 2019)

• Record Type: Journal Article
• Authors: Lin, Zhu Xiao; Zhou, Chang Sheng; Schoepf, U. Joseph; Eid, Marwen; Duguay, Taylor M.; Greenberg, William T.; Luo, Song; Quan, Wei; Zhou, Fan; Lu, Guang Ming; Zhang, Long Jiang
• Is Part Of: European journal of radiology. Issue 113(2019)
• Page Start: 140
• Page End: 147
• Publication Date: 2019-04
• Subjects: IDRL institutional diagnostic reference levels -- CCTA coronary CT angiography -- CABG coronary artery bypass grafting -- CTDIvol volume CT dose index -- DLP dose-length product -- SSDE size-specific dose estimate; Coronary CT angiography -- Diagnostic reference levels -- Radiation dose; Medical radiology -- Periodicals; Radiology -- Periodicals; Radiologie médicale -- Périodiques; Medical radiology; Periodicals; 616.075705
• DOI: 10.1016/j.ejrad.2019.02.012
• Languages: English
• ISSNs: 0720-048X

Abstract

Abstract: Purpose: To develop institutional diagnostic reference levels (IDRL) for coronary CT angiography (CCTA) according to patient size by analyzing radiation dose changes over the past 10 years. Materials and methods: This IRB approved retrospective investigation analyzed radiation dose data from CCTA between 2007 and 2016 at our institution. Annual trends in radiation dose were described for each scanner type and scanning mode. Radiation levels were analyzed for normorhythmic patients, patients with prior coronary artery bypass grafting (CABG), arrhythmia, and according to patient size and tube voltage. Median, and quartile values for volume CT dose index (CTDIvol), dose-length product (DLP), and size-specific dose estimate (SSDE) were calculated. Wilcoxon rank-sum test and Kruskal Wallis test were performed to assess the significance of quantitative data. Results: 35, 375 examinations from 33, 317 patients (median age, 58 [50–66] years; male patients, 21, 087 [58.7%]) were analyzed. CTDIvol, DLP, and SSDE significantly decreased by 9.0%, 30.8%, and 40.1% (all P < 0.05) for all examinations, respectively. All radiation dose metrics progressively decreased across scanning modes (especially retrospectively ECG-gated spiral and prospectively ECG-triggered high-pitch spiral acquisition mode), but did not significantly change across scanners in the last 6 years. CTDIvol and DLP increased with patient size when water-equivalent diameters were >19 cm for normorhythmic and CABG patients. In arrhythmic patients, CTDIvol increased progressively with water-equivalent diameters across all groups. Conclusion: CCTA radiation dose has progressively decreased in the past decade except in patients with prior CABG and arrhythmia. Size-specific IDRLs may optimize radiation utilization in these patients going forward.