Goldstein A
Department of Radiology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
Med Phys. 1998 Jun;25(6):1033-40. doi: 10.1118/1.598285.
Panoramic radiology entrance skin exposure (ESE) was measured for a Siemens Orthopantomograph 10 E using a thimble chamber and TLDs. Thimble chamber measurements are shown to be inaccurate for the moving, narrow beam panoramic scan geometry due to partial volume and partial charged-particle equilibrium effects. For 75 KVp, 8 mA panoramic scans the TLD measured beam central ray ESE on the scan central plane (patient midsagittal plane) was an approximately constant 20 mR for the first 7.5 cm from the entrance slit. A theoretical model of central plane ESE for a fixed rotation center agrees very well with the TLD measurements and is consistent with all of the known ESE (and dose) properties near rotation centers. Head phantom skin dose measurements demonstrate the dependence of skin dose on exact equipment mode of use and patient anatomy. Central plane, beam central ray ESE is judged to be a convenient, universal measure of panoramic radiology radiation output.
使用指形电离室和热释光剂量计（TLD）测量了西门子口腔全景体层摄影仪10 E的全景放射学体表入射剂量（ESE）。由于部分体积和部分带电粒子平衡效应，对于移动的窄束全景扫描几何结构，指形电离室测量结果显示不准确。对于75千伏峰值、8毫安的全景扫描，在扫描中心平面（患者正中矢状面）上，TLD测量的束中心射线ESE在距入口狭缝的前7.5厘米处约为恒定的20毫伦琴。固定旋转中心的中心平面ESE理论模型与TLD测量结果非常吻合，并且与旋转中心附近所有已知的ESE（和剂量）特性一致。头部体模皮肤剂量测量证明了皮肤剂量对设备确切使用模式和患者解剖结构的依赖性。中心平面束中心射线ESE被认为是全景放射学辐射输出的一种方便、通用的测量方法。
