摘要
目的:测量CT轴向扫描和螺旋扫描两种模式的剂量分布及其影响因素。方法:利用Gafchromic免洗胶片测量GE LightSpeed 64排CT的剂量分布。胶片经CT机扫描曝光后,利用HP scanjet 7400c扫描仪扫描获得数字图像,并利用ImageJ软件进行图像处理,以获得CT剂量分布。结果:在轴向扫描过程中,峰值半高宽与标称射束准直宽度偏差小于4mm,视野大小和过滤器形状对轴向剂量分布的影响可以忽略。在螺旋扫描过程中,过扫描范围的大小主要与射束准直宽度有关,螺距、重建层厚和视野对过扫描范围的影响较小。结论:免洗胶片可用于快速检测CT轴向和螺旋扫描的剂量分布。
Objective To measure the dose profiles in axial scanning and helical scanning with computed tomography (CT), and investigate the related influence factors. Methods Gafchromic disposable film was used to measure the dose profile of GE LightSpeed 64 CT scanner. After being exposed by CT scanner, the disposable film was scanned with HP scanjet 7400c to obtain digital image, and then ImageJ software was applied to process the digital image for obtaining the dose profile. Results In axial scanning mode, the deviation between full width at half-maximum and nominal beam collimation width was within 4 mm, and moreover, the effects of field of view and types of filters on the dose profile in axial scanning were ignorable. In helical scanning mode, the overranging was mainly dependent on beam collimation width, and moreover, pitch, reconstruction slice thickness and field of view had trivial effects on overranging. Conclusion Disposable film is capable of rapidly measuring the dose profiles in axial scanning and helical scanning with CT.
作者
戴兴
徐加利
梁保辉
DAI Xing;XU Jiali;LIANG Baohui(School of Medical Imaging,Benbu Medical College,Bengbu 233000,China;Department of Radiology,the First Affiliated Hospital of Bengbu Medical College,Bengbu 233004,China)
出处
《中国医学物理学杂志》
CSCD
2019年第5期529-533,共5页
Chinese Journal of Medical Physics
基金
安徽高校自然科学研究重点项目(KJ2017A239)
蚌埠医学院校级科研课题(byky1639)
