Matsunaga Yuta, Kawaguchi Ai, Kobayashi Masanao, Suzuki Shigetaka, Suzuki Shoichi, Chida Koichi
Department of Imaging, Nagoya Kyoritsu Hospital, 1-172, Hokke, Nakagawa-ku, Nagoya, Aichi 454-0933, Japan Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan
Department of Radiology, Toyota Memorial Hospital, Toyota 471-0821, Japan Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
Radiat Prot Dosimetry. 2016 Mar;168(4):523-30. doi: 10.1093/rpd/ncv374. Epub 2015 Jul 28.
The purpose of this study was to evaluate the maternal and foetal effective doses during foetal computed tomography (CT) and to compare the radiation dose, dose profile and image noise on 80-row CT in helical scanning mode and 320-row CT in wide-volume scanning mode. The radiation doses were measured using thermoluminescent dosemeters implanted at various organ sites of an anthropomorphic pregnant phantom. The foetal doses in the 320-row multi-detector CT (MDCT) and 80-row MDCT units were higher than the volume CT dose index (CTDIvol). The dose profile in the 320-row MDCT overlapped in two places but showed no overlap in the 80-row MDCT. There were no significant differences in image noise between the two scanning modes. The foetal dose evaluation by CTDIvol may underestimate the foetal radiation risk. When using the wide-volume mode, operators must take into account the number of scans and overlap between volumetric sections.
本研究的目的是评估胎儿计算机断层扫描（CT）期间的母体和胎儿有效剂量，并比较螺旋扫描模式下的80排CT和宽体扫描模式下的320排CT的辐射剂量、剂量分布和图像噪声。使用植入在拟人化孕妇体模各个器官部位的热释光剂量计测量辐射剂量。320排多层螺旋CT（MDCT）和80排MDCT设备中的胎儿剂量高于容积CT剂量指数（CTDIvol）。320排MDCT的剂量分布在两个位置重叠，但80排MDCT未显示重叠。两种扫描模式下的图像噪声没有显著差异。通过CTDIvol进行的胎儿剂量评估可能低估胎儿辐射风险。使用宽体模式时，操作人员必须考虑扫描次数和容积切片之间的重叠。
