鼻咽癌CT模拟定位增强扫描时间优化研究

Optimization of CT simulated scanning time for nasopharyngeal carcinoma

目的:探讨鼻咽癌CT模拟定位增强扫描最优延迟时间,并分析其影响因素。方法:15例患者造影剂注射30 s开始每隔5 s对蝶骨顶壁至第二颈椎范围重复10次CT扫描。2位及以上副高级放疗医生分别测量增强图像肿瘤最大层面中心的CT值(CT1)及健侧头长肌中心的CT值(CT2),分辨能力指标μ和稳定性指标σ用来描述增强质量,μ最大值(μ_(max))对应时间T为最优增强延迟时间。分析T、μ_(max)、σ值与患者年龄、BMI值、是否高血压、定位前是否行诱导化疗的相关性。结果:最优延迟时间T、最大分辨能力μ_(max)、分辨稳定性指标σ值与患者年龄、BMI值相关性,除σ与年龄相关外(r_(s)=0.52,P=0.047),其他均不相关(P>0.05)。患者是否高血压和定位前是否行诱导化疗对最优延迟时间T有影响,组间比较(U=8.5,P=0.026;U=3.0,P=0.011)。患者是否高血压和定位前是否行诱导化疗与μ_(max)和σ差异无统计学意义(P>0.05)。结论:患者是否高血压和CT模拟定位前是否诱导化疗对延迟时间有一定影响,患者年龄越大增强效果稳定性越差。

Objective:To investigate the optimal delay time of enhanced scanning in simulated localization of nasopharyngeal carcinoma,and to analyze the factors affecting the time.Methods:CT scans were performed 10 times from the parietal wall of the sphenoid to the second cervical vertebra at 5-second intervals in 15 patients.The CT value of the center of the largest layer of the tumor(CT1)and the CT value of the musculi longus capis(CT2)was measured by a senior doctor.The resolution indexμand stability indexσwere used to describe the enhancement quality,and the time T corresponding to theμ_(max)(μ_(max))was the optimal enhancement delay time.The correlation of T,μ_(max)andσvalues with age,BMI,hypertension,and induction chemotherapy before localization was analyzed.Results:The optimal delay time(T),maximum resolutionμ_(max),were not correlated with patient age and BMI(P>0.05),except thatσwas correlated with age(r_(s)=0.52,P=0.047).The optimal delay time(T)was affected by whether the patient was with hypertension or not and whether the patient underwent induction chemotherapy before localization(U=8.5,P=0.026;U=3,P=0.011),μ_(max)andσvalues was not statistically different(P>0.05).Conclusion:Whether the patient is with hypertension or not and whether chemotherapy is induced before CT simulated localization has a certain influence on the delay time.The older the patient is,the less stable the enhancement effect is.