Kortesniemi M, Kiljunen T, Kangasmäki A
HUS Helsinki Medical Imaging Center, University of Helsinki, PO Box 340, FI-00029 HUS, Finland.
Phys Med Biol. 2006 Jun 21;51(12):3269-82. doi: 10.1088/0031-9155/51/12/018. Epub 2006 Jun 6.
Multi-slice CT provides an efficient imaging modality for trauma imaging. The purpose of this study was to provide absorbed and effective dose data from CT taking into account the patient size and compare such doses with the standard CT dose quantities based on standard geometry. The CT examination data from abdominal and thoracic scan series were collected from 36 trauma patients. The CTDI(vol), DLP(w) and effective dose were determined, and the influence of patient size was applied as a correction factor to calculated doses. The patient size was estimated from the patient weight as the effective radius based on the analysis from the axial images of abdominal and thoracic regions. The calculated mean CTDI(vol), DLP(w) and effective dose were 15.2 mGy, 431 mGy cm and 6.5 mSv for the thorax scan, and 18.5 mGy, 893 mGy cm and 14.8 mSv for the abdomen scan, respectively. The doses in the thorax and abdomen scans taking the patient size into account were 34% and 9% larger than the standard dose quantities, respectively. The use of patient size in dose estimation is recommended in order to provide realistic data for evaluation of the radiation exposure in CT, especially for paediatric patients and smaller adults.
多层螺旋CT为创伤成像提供了一种高效的成像方式。本研究的目的是在考虑患者体型的情况下，提供CT的吸收剂量和有效剂量数据，并将这些剂量与基于标准几何形状的标准CT剂量量进行比较。从36例创伤患者中收集腹部和胸部扫描系列的CT检查数据。确定CTDI(vol)、DLP(w)和有效剂量，并将患者体型的影响作为校正因子应用于计算剂量。根据腹部和胸部区域的轴向图像分析，以患者体重作为有效半径来估计患者体型。胸部扫描计算出的平均CTDI(vol)、DLP(w)和有效剂量分别为15.2 mGy、431 mGy·cm和6.5 mSv，腹部扫描分别为18.5 mGy、893 mGy·cm和14.8 mSv。考虑患者体型的胸部和腹部扫描剂量分别比标准剂量量高34%和9%。为了提供用于评估CT辐射暴露的实际数据，特别是对于儿科患者和体型较小的成年人，建议在剂量估计中使用患者体型。
