Masayuki Kanematsu1, Hiroshi Kondo2, Toshiharu Miyoshi3, Satoshi Goshima2, Yoshifumi Noda2, Yukichi Tanahashi2, Kyongtae T Bae4. 1. Departments of Radiology, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194, Japan; Radiology Services, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194, Japan. Electronic address: masa_gif@yahoo.co.jp. 2. Departments of Radiology, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194, Japan. 3. Radiology Services, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194, Japan. 4. Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
Abstract
PURPOSE: To evaluate the effect of tube current limitation on contrast enhancement, image quality, and radiation dose in whole-body 64-detector CT with a high heat-capacity X-ray tube and automated tube current modulation. MATERIALS AND METHODS: One hundred eighteen patients were randomized into three whole-body CT protocols: tube current limitation at 210 mA, 450 mA, and no limitation. Signal-to-noise ratio (SNR), dose-length product (DLP), estimated effective dose (ED), and image quality were assessed. RESULTS:Mean SNR of aorta was comparable among protocols, but that of liver was somewhat lower in 210-mA than in 450-mA and no-limitation protocols (p<0.05). Mean DLP with 210-mA (533.8 mGy cm) was reduced by 31% from that with 450-mA (768.4 mGy cm) and by 38% from that with no-limitation protocol (861.3 mGy cm), respectively. Image quality was slightly degraded (p<0.017) with 210 mA relative to the others in thorax and pelvis, but no difference was found in diagnostic acceptability. CONCLUSION: For whole-body CT using multidetector CT mounted with a high heat-capacity X-ray tube, an appropriate tube current limitation setting may help reduce excessive radiation dose without significant compromise in diagnostic acceptability.
RCT Entities:
PURPOSE: To evaluate the effect of tube current limitation on contrast enhancement, image quality, and radiation dose in whole-body 64-detector CT with a high heat-capacity X-ray tube and automated tube current modulation. MATERIALS AND METHODS: One hundred eighteen patients were randomized into three whole-body CT protocols: tube current limitation at 210 mA, 450 mA, and no limitation. Signal-to-noise ratio (SNR), dose-length product (DLP), estimated effective dose (ED), and image quality were assessed. RESULTS: Mean SNR of aorta was comparable among protocols, but that of liver was somewhat lower in 210-mA than in 450-mA and no-limitation protocols (p<0.05). Mean DLP with 210-mA (533.8 mGy cm) was reduced by 31% from that with 450-mA (768.4 mGy cm) and by 38% from that with no-limitation protocol (861.3 mGy cm), respectively. Image quality was slightly degraded (p<0.017) with 210 mA relative to the others in thorax and pelvis, but no difference was found in diagnostic acceptability. CONCLUSION: For whole-body CT using multidetector CT mounted with a high heat-capacity X-ray tube, an appropriate tube current limitation setting may help reduce excessive radiation dose without significant compromise in diagnostic acceptability.
Authors: Paul Jahnke; Stephan Schwarz; Marco Ziegert; Felix Benjamin Schwarz; Bernd Hamm; Michael Scheel Journal: Eur Radiol Date: 2018-08-16 Impact factor: 5.315