title: Radiation dose exposure of patients undergoing 320-row cardiac CT for assessing coronary angiography and global left ventricular function.
abstract: A 320-row multidetector CT provides the capability for prospective electrocardiogram (ECG)-gated coronary CT angiography (CTA) and tube current modulated cardiac function assessment (CFA). We assessed and compared the effective radiation dose of these two modes. On a prospective basis, we performed ECG-gated cardiac CT on 119 patients (87 were males). For heart rates (HRs) </=65 beats/min (bpm), we used one-heartbeat acquisition and half-scan reconstruction. HRs from 66 to 79 bpm and >/=80 bpm were scanned with either two or three heartbeats acquisitions, respectively. We used two types of scans. One type was based on a prospective ECG-gated CTA mode and the other using a tube current modulated CFA mode covering an entire R-R interval. The mean BMI of patients was 25.4 (range 18.8-49.3). Fifty-one patients (42.9 %) underwent CFA scanning, while the remaining 68 (57.1 %) had CTA. The majority of patients completed the scan in a single heartbeat (59.7 %). The mean dose of CTA mode at 65-85 % phase window for one and two heartbeats was 3.68 mSv (2.40-7.23) and 8.61 mSv (6.76-10.60), respectively. The mean dose of CFA mode for a single heartbeat measurement with dose modulation (25 % dose for CFA, and 100 % dose during 65-85 % phase window for CTA) was 6.32 mSv (4.69-8.89). CTA with prospective ECG-gating allows for acceptable image quality and radiation dose. HR reduction is mandatory to minimize radiation exposure. Global left ventricle function can be assessed with a single heartbeat within an acceptable radiation dose.
authors.affiliation: Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, College of Medicine, Chang Gung University, 5 Fuhsing Road, Kweishan Hsiang, 333 Taoyuan, Taiwan.
authors.forename: Chien-Ming
authors.initials: CM
authors.lastname: Chen
authors.forename: Yuan-Chang
authors.initials: YC
authors.lastname: Liu
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Chen
authors.forename: Ming-Shien
authors.initials: MS
authors.lastname: Wen
authors.forename: Chien-Fu
authors.initials: CF
authors.lastname: Hung
authors.forename: Yung-Liang
authors.initials: YL
authors.lastname: Wan
mesh_terms: D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage; D000328:Adult; D055424:Cardiac-Gated Imaging Techniques; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011237:Predictive Value of Tests; D011433:Propranolol / Q000008:administration & dosage; D011829:Radiation Dosage; D012189:Retrospective Studies; D013624:Taiwan; D016277:Ventricular Function, Left / Q000187:drug effects; D055815:Young Adult
chemical_list: D000319:Adrenergic beta-Antagonists; D011433:Propranolol