基于数学形态学的图像快速去噪方法

针对图像去噪和保护有用信息这个矛盾．阐述了数学形态学在处理这个问题的方法和有效性。提出了一种基于数学形态学的快速图像去噪方法。对一幅典型的含噪图像进行实验分析，证明了这种方法的可行性和有效性。     

不同胶片剂量分析软件对伽玛刀验证胶片分析的结果比较

目的 比较不同的剂量胶片分析软件对同一台伽玛刀验证胶片的分析结果,分析产生差异的原因,探讨伽玛刀检测和结果分析过程中质量保证与质量控制的方法和措施.方法 分别用Kodak EDR2和GAFCHROMIC(R)EBT胶片对"月亮神"伽玛刀和"伽玛星"伽玛刀进行检测验证,验证胶片用EPSON PERFECTION V750 PRO胶片扫描仪扫描成剂量分析软件要求的图像格式,用Robot Knife Adjuvant 1.09伽玛刀剂量场测量分析与验证系统和Fas-09 1.0伽玛刀射野分析软件对"月亮神"伽玛刀检测结果进行分析,用Fas-09 1.0伽玛刀射野分析软件和MATLAB 7.0对"伽玛星"伽玛刀检测结果进行分析,比较其结果差异.结果 Robot Knife Adjuvant伽玛刀剂量场测量分析与验证系统和Fas-09伽玛刀射野分析软件对"月亮神"伽玛刀照射野尺寸(半高宽)与标称值最大偏差的分析结果显示两者差异无统计学意义(t=-2.133,P＞0.05),对不同尺寸准直器的照射野半影宽度的分析结果表明两者差异有统计学意义(t=-8.154,P＜0.05).Fas-09伽玛刀射野分析软件和MATLAB对"伽玛星"伽玛刀照射野尺寸与标称值最大偏差的分析结果显示两者差异无统计学意义(t=-1.384,P＞0.05),但根据国家标准,对于φ4 mm准直器的检测结果,两种软件结论不同:Fas-09伽玛刀射野分析软件的结论是不合格,MATLAB的结论是合格;对不同尺寸准直器的照射野半影宽度的分析结果表明两者差异有统计学意义(t=3.074,P＜0.05).用Fas-09伽玛刀射野分析软件对图像进行处理,处理前后照射野尺寸与标称值最大偏差的检测结果差异无统计学意义(t=0.647,P＞0.05),照射野半影宽度的检测结果差异无统计学意义(t=-0.627,P＞0.05).结论 不同的胶片剂量分析软件对同一套伽玛刀验证胶片的分析结果有一定差异,其差异根据国家标准可能会得出不同的结论.

Abstract：

Objective To compare the analytical result of different kinds of film dose analysis software for the same gamma knife,analyze the reasons of difference caused,and explore the measurements and means for quality control and quality assurance during testing gamma knife and analyzing its result.Methods To test the Moon Deity gamma knife with Kodak EDR2 film and γ-Star gamma knife with GAFCHROMIC(R) EBT film,respectively.All the validation films are scanned to proper imagine format for dose analysis software by EPSON PERFECTION V750 PRO scanner.Then imagines of Moon Deity gamma knife are analyzed with Robot Knife Adjuvant 1.09 and Fas-09 1.0,and imagines of γ-Star gamma knife with Fas-09 and MATLAB 7.0.Results There is no significant difference in the maximum deviation of radiation field size ( Full Width at Half Maximum,FWHM) and its nominal value between Robot Knife Adjuvant and Fas-09 for Moon Deity gamma knife (t = -2.133,P ＞0.05).The analysis on the radiation field' s penumbra region width of collimators which have different sizes indicated that the differences are significant (t = - 8.154,P ＜ 0.05 ).There is no significant difference in the maximum deviation of FWHM and its nominal value between Fas-09 and MATLAB for γ-Star gamma knife ( t = - 1.384,P ＞0.05 ).However,following national standards,analysis of φ4 mm width of collimators can obtain different results according to the two kinds software,and the result of Fas-09 is not qualified while MATLAB is qualified.The analysis on the radiation field' s penumbra region width of collimators which have different sizes indicates that the differences are significant ( t = 3.074,P ＜ 0.05 ).The imagines are processed with Fas-09.The analysis of imagine in the pre-and the post-processing indicates that there is no significant difference in the maximum deviation of FWHM and its nominal value ( t = 0.647,P ＞ 0.05 ),and the analytical result of the radiation field' s penumbra region width indicates that there is no significant difference as well ( t = -0.627,P ＞ 0.05 ).Conclusion The study shows that different kinds of film dose analysis software may have some differences in analysis of the same gamma knife validation film,and the results may lead to the different decisions in accordance with national standard.     

某医院γ射线头部立体定向外科治疗放射卫生防护检测与评价

目的 检测与评价某医院γ射线头部立体定向外科治疗(γ-刀)的放射卫生防护情况,保证其剂量学参数和防护安全性能符合有关标准和要求.方法 依据X、γ射线头部立体定向外科治疗放射卫生防护标准(GBZ 168-2005)对γ-刀进行检测与评价.结果 γ-刀剂量学参数:焦点剂量率为2.39 Gy/min,焦点计划剂量与实测剂量的相对偏差为2.3%,机械中心与照射野中心的距离为0.19～0.41 mm,照射野尺寸与标称值偏差为0.11～1.12 mm,照射野半影宽度为2.86～4.12 mm;防护安全性能:治疗室周围辐射水平为0.06～0.20 μGy/h,安全连锁及通风装置工作正常.结论 γ-刀剂量学参数和防护安全性能符合有关标准要求.     

一台国产γ刀装置的剂量学参数检测及质量保证

γ刀因其治疗肿瘤精度高,对人体正常组织辐射损伤小而被广泛应用于肿瘤放射治疗领域.γ刀的剂量偏差、定位精度和半影、半高宽等剂量学参数直接影响到治疗效果.笔者将某医院γ刀的剂量学参数检测结果报道如下.