title: [Estimation of radiation dose and image quality of coronary 320-row area detector CT angiography by optimal prospective ECG-gated protocols for different heart rate].
abstract: The purpose of this study is to estimate radiation dose and image quality of ECG-gated coronary 320-area detector CT (ADCT) angiography which was acquired using the protocols that were considered as optimal methods for different heart rates (HR) in 1031 consecutive patients (M/F=580/451, 65 ± 12 yr) without arrhythmias. We set up 5 protocols for 320-ADCT based on the relationship among heart rates, temporal resolution, gantry rotation speed, optimal reconstruction phase and slow filling phase on 64-multidetector-row computed tomography (MDCT), ie, 1) mid-diastolic (75% of RR) 1 beat scan (MD 1 beat, N=761(73.8%)) for HR ≤ 60, 2) mid-diastolic (75% of RR) 2 beat scan (MD 2 beat, N=135) for 61 ≤ HR ≤ 65, 3) end-systolic and mid-diastolic (37-80% of RR) 2 beat scan (ES-MD 2 beat, N=92) for 66 ≤ HR ≤ 75, 4) end-systolic (R+280-430 ms) 2 beat scan (ES 2 beat, N=21) for 76 ≤ HR ≤ 80, and 5) end-systolic (R+250-400 ms) 3 beat scan (ES 3 beat, N=22) for 81 ≤ HR ≤ 105. Image quality was classified into 3 categories (excellent (3 points), acceptable (2 points), and unacceptable (1 point)). Scanning time, DLP.e and image quality score were 1.4 ± 0.1 s, 220 ± 59 mGy·cm, 3.0 ± 0.2 points in MD 1 beat, 2.2 ± 0.2 s, 434 ± 118 mGy·cm, 2.9 ± 0.3 points in MD 2 beat, 2.1 ± 0.2 s, 729 ± 229 mGy·cm, 2.7 ± 0.5 points in ES-MD 2 beat, 1.9 ± 0.1 s, 432 ± 148 mGy·cm, 2.2 ± 0.6 points in ES 2 beat, and 2.4 ± 0.2 s, 669 ± 152 mGy·cm, 2.3 ± 0.6 points in ES 3 beat respectively. In conclusion, the prospective ECG-gated scan protocol for coronary 320-ADCT angiography in any HR group was considered reasonable and proper for image quality and radiation dose.
authors: Department of Radiological Technology, Takase Clinic.
authors: Tomonari
authors: T
authors: Sano
authors: Hideyuki
authors: H
authors: Matsutani
authors: Takeshi
authors: T
authors: Kondo
authors: Shinichiro
authors: S
authors: Fujimoto
authors: Takako
authors: T
authors: Sekine
authors: Takehiro
authors: T
authors: Arai
authors: Hitomi
authors: H
authors: Morita
authors: Shinichi
authors: S
authors: Takase
mesh_terms: D000368:Aged; D055424:Cardiac-Gated Imaging Techniques / Q000295:instrumentation* / Q000379:methods*; D017023:Coronary Angiography / Q000295:instrumentation* / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006339:Heart Rate; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000295:instrumentation* / Q000379:methods*; D011446:Prospective Studies; D058996:Quality Improvement; D011829:Radiation Dosage