Kidoh Masafumi, Utsunomiya Daisuke, Oda Seitaro, Funama Yoshinori, Yuki Hideaki, Nakaura Takeshi, Kai Noriyuki, Nozaki Takeshi, Yamashita Yasuyuki
Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Department of Medical Physics, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Int J Cardiovasc Imaging. 2015 Dec;31 Suppl 2:205-11. doi: 10.1007/s10554-015-0782-z. Epub 2015 Oct 6.
Size-specific dose estimate (SSDE) takes into account the patient size but remains to be fully validated for adult coronary computed tomography angiography (CCTA). We investigated the appropriateness of SSDE for accurate estimation of patient dose by comparing the SSDE and the volume CT dose index (CTDIvol) in adult CCTA. This prospective study received institutional review board approval, and informed consent was obtained from each patient. We enrolled 37 adults who underwent CCTA with a 320-row CT. High-sensitivity metal oxide semiconductor field effect transistor dosimeters were placed on the anterior chest. CTDIvol reported by the scanner based on a 32-cm phantom was recorded. We measured chest diameter to convert CTDIvol to SSDE. Using linear regression, we then correlated SSDE with the mean measured skin dose. We also performed linear regression analyses between the skin dose/CTDIvol and the body mass index (BMI), and the skin dose/SSDE and BMI. There was a strong linear correlation (r = 0.93, P < 0.001) between SSDE (mean 37 ± 22 mGy) and mean skin dose (mean 17.7 ± 10 mGy). There was a moderate negative correlation between the skin dose/CTDIvol and BMI (r = 0.45, P < 0.01). The skin dose/SSDE was not affected by BMI (r = 0.06, P > 0.76). SSDE yields a more accurate estimation of the radiation dose without estimation errors attributable to the body size of adult patients undergoing CCTA.
特定体型剂量估计（SSDE）考虑了患者体型，但在成人冠状动脉计算机断层扫描血管造影（CCTA）中仍有待充分验证。我们通过比较成人CCTA中SSDE和容积CT剂量指数（CTDIvol）来研究SSDE对准确估计患者剂量的适用性。这项前瞻性研究获得了机构审查委员会的批准，并获得了每位患者的知情同意。我们纳入了37例接受320排CT进行CCTA的成人患者。将高灵敏度金属氧化物半导体场效应晶体管剂量计放置在前胸部。记录扫描仪根据32厘米体模报告的CTDIvol。我们测量胸部直径以将CTDIvol转换为SSDE。然后，我们使用线性回归将SSDE与平均测量皮肤剂量进行关联。我们还对皮肤剂量/CTDIvol与体重指数（BMI）以及皮肤剂量/SSDE与BMI进行了线性回归分析。SSDE（平均37±22 mGy）与平均皮肤剂量（平均17.7±10 mGy）之间存在强线性相关性（r = 0.93，P <0.001）。皮肤剂量/CTDIvol与BMI之间存在中度负相关性（r = 0.45，P <0.01）。皮肤剂量/SSDE不受BMI影响（r = 0.06，P> 0.76）。SSDE能更准确地估计辐射剂量，且不存在因接受CCTA的成年患者体型导致的估计误差。
