移动CT头部扫描辐射剂量场的空间分布

目的 初步探究移动CT在进行头部扫描时产生的杂散辐射在空间中的分布，以期为移动CT的辐射防护提供科学依据。方法 选择CareTom移动式多排CT头部序列进行单次扫描，用TLD（LiF：Mg，Cu，P）型热释光探测器测得辐射剂量值，并用Matlab软件绘制出辐射剂量场的空间分布。结果 移动CT前方的辐射剂量稍高于后方，周围空间辐射剂量场则大致呈从前向后的“倒三角”形分布。最大数值出现在中心水平层面，移动CT正前方距离扫描孔中心最近的测量点（距中心0.5 m），为0.255 mGy。结论 移动CT头部扫描产生的杂散辐射剂量较低，但为了避免长期低剂量辐射的损伤，检查技师和其他医护人员应尽量站在移动CT机的侧面和后方2 m以外的地方，并在扫描时尽可能地配置放射防护装备。

Spatial distribution of radiation dose field from mobile CT head scanning

Objective To identify the spatial distribution of stray radiation from mobile CT head scanning for the purpose of radiation protection. Methods The head series of CareTom mobile CT were scanned and the radiation dose was measured using TLD (LiF: Mg, Cu, P). The isodose maps of radiation dose field were plotted using Matlab software. Results Radiation dose in the front of the mobile CT was slightly higher than that in the back. The maximum value of 0.255 mGy was found to be at 0.5 m from the scanning hole center. Conclusions The stray radiation dose from mobile CT head scanning was relatively low. However in order to avoid the damage to the operators and other medical workers from long-term low dose exposure, it should keep 2 m away from mobile CT, beside or behind, when in operation.