Seitaro Oda1, Daisuke Utsunomiya2, Hideaki Yuki2, Noriyuki Kai3, Masahiro Hatemura3, Yoshinori Funama4, Masafumi Kidoh2, Morikatsu Yoshida2, Tomohiro Namimoto2, Yasuyuki Yamashita2. 1. Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjyo, Chuo-ku, Kumamoto 860-8556, Japan. Electronic address: seisei0430@nifty.com. 2. Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjyo, Chuo-ku, Kumamoto 860-8556, Japan. 3. Department of Central Radiology, Kumamoto University Hospital, Kumamoto, Japan. 4. Department of Medical Physics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
Abstract
BACKGROUND: Among CT scanners, 320-row instruments feature decreased photon energy and yield strong contrast enhancement. Consequently, the contrast medium (CM) dose can be reduced. The results of low-tube-voltage coronary CT angiography (CCTA) performed on 320-row scanners have not been adequately assessed. OBJECTIVE: We evaluated the effects of a low-contrast-dose protocol on the image quality of CCTA using 80 kVp tube voltage, iterative reconstruction (IR), and a 320-row scanner. METHODS: We randomly assigned 90 patients (mean body weight, 56.5 ± 11.0 kg) to 1 of 3 CCTA protocols. Under protocol A, 30 were scanned using a conventional 120-kVp protocol and a standard CM dose (280 mg iodine/kg body weight [mgI/kg]). Another 30 underwent scanning at 80 kVp with a 25% CM dose reduction (210 mgI/kg; protocol B). Under protocol C, the remaining 30 patients were scanned at 80 kVp with a 50% CM dose reduction (140 mgI/kg). The 120 and 80 kVp images were processed with IR. Images obtained under the 3 protocols were subjected to quantitative and qualitative analysis. RESULTS: The amount of CM used in protocol A, B, and C was 43.6 ± 10.1, 30.3 ± 4.4, and 21.0 ± 4.0 mL, respectively. Mean CT attenuation of the coronary arteries tended to be higher under protocol B than the other 2 protocols. The contrast-to-noise ratio was significantly higher under protocol B. The mean visual scores were significantly higher for protocols A and B than protocol C. The mean effective radiation dose was significantly lower under the 80-kVp protocol. CONCLUSION: With a 320-row scanner and our refined CM injection and timing protocol, it is technically feasible to obtain sufficient vascular enhancement with a reduction in the CM and/or radiation dose at 80-kVp CCTA with IR.
RCT Entities:
BACKGROUND: Among CT scanners, 320-row instruments feature decreased photon energy and yield strong contrast enhancement. Consequently, the contrast medium (CM) dose can be reduced. The results of low-tube-voltage coronary CT angiography (CCTA) performed on 320-row scanners have not been adequately assessed. OBJECTIVE: We evaluated the effects of a low-contrast-dose protocol on the image quality of CCTA using 80 kVp tube voltage, iterative reconstruction (IR), and a 320-row scanner. METHODS: We randomly assigned 90 patients (mean body weight, 56.5 ± 11.0 kg) to 1 of 3 CCTA protocols. Under protocol A, 30 were scanned using a conventional 120-kVp protocol and a standard CM dose (280 mg iodine/kg body weight [mgI/kg]). Another 30 underwent scanning at 80 kVp with a 25% CM dose reduction (210 mgI/kg; protocol B). Under protocol C, the remaining 30 patients were scanned at 80 kVp with a 50% CM dose reduction (140 mgI/kg). The 120 and 80 kVp images were processed with IR. Images obtained under the 3 protocols were subjected to quantitative and qualitative analysis. RESULTS: The amount of CM used in protocol A, B, and C was 43.6 ± 10.1, 30.3 ± 4.4, and 21.0 ± 4.0 mL, respectively. Mean CT attenuation of the coronary arteries tended to be higher under protocol B than the other 2 protocols. The contrast-to-noise ratio was significantly higher under protocol B. The mean visual scores were significantly higher for protocols A and B than protocol C. The mean effective radiation dose was significantly lower under the 80-kVp protocol. CONCLUSION: With a 320-row scanner and our refined CM injection and timing protocol, it is technically feasible to obtain sufficient vascular enhancement with a reduction in the CM and/or radiation dose at 80-kVp CCTA with IR.
Authors: Babs M F Hendriks; Madeleine Kok; Casper Mihl; Sebastiaan C A M Bekkers; Joachim E Wildberger; Marco Das Journal: Br J Radiol Date: 2016-01-22 Impact factor: 3.039
Authors: Sock Keow Tan; Chai Hong Yeong; Raja Rizal Azman Raja Aman; Kwan Hoong Ng; Yang Faridah Abdul Aziz; Kok Han Chee; Zhonghua Sun Journal: Br J Radiol Date: 2018-03-29 Impact factor: 3.039