Revolution CT低剂量联合迭代重建技术在冠状动脉成像的临床研究

发布时间：2018-03-31 22:19

本文选题：辐射剂量　切入点：低管电压　出处：《广西医科大学》2017年硕士论文

【摘要】：目的:(1)对比分析revolution CT低管电压(100k Vp)与常规电压(120k Vp)前瞻性心电门控冠状动脉成像的辐射剂量及图像质量,探讨revolution CT不同管电压条件下前门控冠状动脉成像降低辐射剂量的临床应用价值。(2)比较低辐射剂量条件下使用不同权重基于多模型的迭代重建(ASIR-V)在CCTA的图像质量,获取最佳重建参数。材料与方法:本研究收集广西医科大学第一附属医院从2016年11月至2017年2月行CCTA检查患者120例,男性75例,女性45例,年龄33~89岁,平均年龄(60.75±12.14)岁。BMI指数(Body Mass Index,体质指数)范围为18~25 kg/m2。应用美国GE 256排revolution CT扫描,扫描参数及分组如下:组1(100k Vp组):管电压100k Vp,噪声指数12,管电流自动毫安600~720m A,对比剂为非离子碘对比剂(370mg I/ml),组2(120k Vp组):管电压120k Vp,噪声指数12,自动毫安600~720m A,对比剂为非离子碘对比剂(370mg I/ml)。两组进行不同权重ASIR-V重建(0%,20%,40%,60%,80%,100%)。将原始数据传至AW4.6工作站进行图像处理,主要内容包含冠脉VR、曲面重建、冠脉树并进行图像分析。采用4分法评分标准对图像质量进行主观评价。分别测量、记录主动脉根部及两侧冠状动脉主干近段CT值。记录两组图像噪声、信噪比、对比噪声比等客观评价指标。记录两组图像的DLP并计算患者的有效辐射剂量(Effective Radiation Dose,ED)。全部数据使用SPSS 17.0软件进行统计学分析。结果:(1)两组冠状动脉CTA所测节段CT值高于300Hu,图像质量主观评分在2分以及2分以上,可满足临床诊断。100k Vp组的辐射剂量较120k Vp组降低44%,两组间患者所受的ED差异具有统计学意义。两组图像噪声、信噪比、对比噪声比较差异具有统计学意义。(2)100k Vp组在不同权重ASi R-V重建下图像质量主观评分存在统计学差异,P0.05,其中60%及80%ASi R-V重建图像秩次最高,两组差异无统计学意义。(3)20%,40%,60%,80%,100%ASi R-V图像噪声相对于FBP分别降低8%,14%,23%,31%,42%,P0.05。结论:(1)体质指数范围在18~25kg/cm2的患者在低管电压(100k Vp)条件下使用revolution CT行CCTA检查可获得较好的图像质量,并且使患者所受的辐射剂量明显降低。(2)100k Vp条件下60%、80%ASIR-V重建图像具有最高主观评分,图像质量较其他组好,推荐使用60%、80%ASi R-V重建图像。
[Abstract]:Objective to compare and analyze the radiation dose and image quality of revolution CT low-tube voltage of 100kVp and conventional voltage of 120kVp in prospective ECG gated coronary angiography (ECG).To investigate the clinical application value of revolution CT in reducing radiation dose under different tube voltages, we compared the image quality of CCTA with iterative reconstruction of ASIR-V with different weights under low radiation dose.Obtain the best reconstruction parameters.Materials and methods: from November 2016 to February 2017, 120 patients (75 males and 45 females, aged 3389 years) underwent CCTA examination in the first affiliated Hospital of Guangxi Medical University.The average age was 60.75 卤12.14 years old. The BMI index and body Mass index (BMI) ranged from 18 to 25 kg / m2.GE 256 slice revolution CT scan was performed in the United States.The Nonionic iodine contrast agent was 370 mg I / ml 路ml ~ (-1).The two groups were given different weights of ASIR-V reconstruction.The original data is transferred to the AW4.6 workstation for image processing. The main contents include coronary AW4.6, curved surface reconstruction, coronary tree and image analysis.The subjective evaluation of image quality was carried out by using the 4-score method.Ct values of aortic root and proximal coronary artery were measured and recorded.Objective evaluation indexes such as noise, signal-to-noise ratio and contrast noise ratio of two groups of images were recorded.The DLP of the two groups of images was recorded and the effective radiation dose of the patients was calculated.All the data were analyzed by SPSS 17.0 software.Results the CT value of coronary CTA in both groups was higher than 300 Hu.The subjective score of image quality was above 2 points and above 2 points.The radiation dose of the group satisfying the clinical diagnosis of .100kVp was 44% lower than that of the 120kVp group, and the difference of Ed between the two groups was statistically significant.The difference of image noise, signal-to-noise ratio and contrast noise between the two groups was statistically significant. The subjective score of image quality in the 100k VP group with different weights was significantly different (P0.05), among which 60% and 80%ASi R-V images had the highest rank.There was no significant difference between the two groups.Conclusion the patients with body mass index (BMI) in the range of 18~25kg/cm2 can obtain better image quality by using revolution CT to perform CCTA under the condition of low tube voltage of 100kVp.In addition, the radiation dose of the patients was obviously reduced. Under the condition of 100kVP, the reconstruction image of ASIR-V had the highest subjective score, and the image quality was better than that of the other groups. It was recommended to use 60% ASIR-V to reconstruct the image.
【学位授予单位】：广西医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R816.2

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