Department of Radiology, The First Hospital of China Medical University, No. 155 Nanjingbei Street, Shenyang, 110001, Liaoning, People's Republic of China.
Department of Clinical Medicine, Jining Medical University, No. 16 Hehua Road, Jining, 272000, Shandong, People's Republic of China.
Jpn J Radiol. 2019 Apr;37(4):292-300. doi: 10.1007/s11604-018-00809-9. Epub 2019 Jan 2.
To evaluate the effectiveness of two orthogonal topograms on radiation dose and image quality (IQ) associated with topogram-based automatic tube voltage selection (ATVS) for lung CT scanning.
Thirty-seven patients were enrolled in this study. At baseline, only an anteroposterior topogram was obtained and at follow-up, both anteroposterior and lateral topograms were performed. ATVS was turned on during all scans. Objective and subjective IQ evaluations were performed and compared; tube voltage and radiation dose of each scan were noted and analyzed.
A significant difference was observed regarding the objective parameters between baseline and follow-up only in image noise and signal-noise ratio (SNR) in the upper one-third of the image (image noise: 7.49 ± 1.08 vs. 9.10 ± 1.13, p < 0.001; SNR: 4.08 ± 0.87 vs. 3.37 ± 0.63, p < 0.001). No differences were found between baseline and follow-up in the subjective assessment of IQ. The radiation dose was significantly lower at follow-up than that at baseline (2.73 ± 0.83 mSv vs. 3.55 ± 1.24 mSv, respectively; p < 0.001).
Using two orthogonal topograms associated with ATVS could significantly reduce the total radiation dose for lung CT scanning, while subjective IQ was maintained.
评估两种正交侧位片在基于侧位片自动管电压选择（ATVS）的肺部 CT 扫描中与辐射剂量和图像质量（IQ）相关的有效性。
本研究纳入了 37 名患者。在基线时，仅获得前后位侧位片，而在随访时，同时获得前后位和侧位侧位片。所有扫描均开启 ATVS。进行了客观和主观 IQ 评估，并进行了比较；记录并分析了每次扫描的管电压和辐射剂量。
仅在图像噪声和上三分之一图像的信噪比（SNR）方面观察到基线和随访之间的客观参数存在显著差异（图像噪声：7.49±1.08 与 9.10±1.13，p<0.001；SNR：4.08±0.87 与 3.37±0.63，p<0.001）。在 IQ 的主观评估方面，基线和随访之间没有差异。随访时的辐射剂量明显低于基线时（分别为 2.73±0.83 mSv 和 3.55±1.24 mSv，p<0.001）。
使用与 ATVS 相关的两种正交侧位片可以显著降低肺部 CT 扫描的总辐射剂量，同时保持主观 IQ。
