左心室容积变化特征在高心率患者双源CT冠状动脉造影中的应用研究

发布时间：2018-01-17 03:02

本文关键词：左心室容积变化特征在高心率患者双源CT冠状动脉造影中的应用研究　出处：《苏州大学》2016年硕士论文　论文类型：学位论文

【摘要】：作为一种超低辐射剂量CT冠状动脉造影(coronary computed tomography angiography,CCTA)技术(低至约1m Sv),第二代双源CT所特有的大螺距前瞻性心电门控螺旋扫描模式(prospectively electrocardiogram-triggered high-pitch spiral acquisition mode,flash spiral mode),可在一个心动周期中的250毫秒完成CCTA的扫描。但flash spiral模式通常适用于规则低心率患者,对高心率(心率≥70次/分)患者,其失败率较高。虽然有学者采用30%R-R时相启动扫描的方法,改善了部分患者的CCTA质量,但其总体失败率仍较高,本研究旨在通过分析不同心率患者左心室容积在心动周期中的变化规律,以按心率分组设置flash spiral扫描的最佳启动R-R时相,提高高心率患者的超低辐射剂量CCTA图像质量与检查成功率,拓宽该技术的适检人群。第一部分左心室容积变化特征与双源CT冠脉成像flash spiral模式下启动扫描最佳R-R时相的临床研究目的采用第二代双源CT行冠状动脉造影,分析不同心率的患者左心室容积在心动周期中的变化规律,进而寻找适合flash spiral模式扫描的的最佳启动R-R时相。方法前瞻性选取68例临床怀疑冠心病的患者,按平均心率分为5组,采用回顾性心电门控螺旋扫描模式行冠状动脉造影检查,以5%R-R间期为时间间隔重建0-100%共21个时像周期,利用心功能软件测量左心室容积,绘制不同心率组左心室容积-时间曲线,计算250ms内左心室容积变化速率的平均值,选取容积变化率最小的R-R区间作为flash spiral拟扫描区间,得到不同心率组使用flash spiral模式启动扫描的最佳R-R时相。结果不同心率组患者的左心室容积-时间曲线和左心室容积的变化速率-时间曲线均有其规律,心率越高,250ms内左心室容积变化速率最低的R-R区间越接近前一个R波,使用flash spiral模式启动扫描的最佳R-R间期正性相对值时相越小,心率70次/分、(70~79)次/分、(80~89)次/分、(90~99)次/分、≥100次/分的患者最佳R-R时相分别为60.0%、30.5%、25.8%、23.0%、16.7%。结论通过分析患者左心室容积在心动周期中的变化规律,为临床寻找适合第二代双源CT特有的flash spiral模式扫描的最佳R-R时相提供了指导。第二部分改良的Flash spiral模式冠状动脉造影在高心率患者中的应用研究目的采用基于左心室容积变化规律的改良flash spiral方法,对规则高心率患者(心率≥70次/分)行CCTA检查,并与二代双源常规采用的前瞻性心电门控序列扫描模式(prospectively electrocardiography-gated step-and-shoot mode,SAS mode)比较,探讨改良法在高心率患者CCTA中的临床价值。方法心率≥70次/分且满足入组标准的106例患者随机分为AB两组,A组参照本研究第一部分得到的不同心率组使用flash spiral模式扫描的最佳R-R时相,采用改良的flash spiral模式扫描。B组采用前瞻性心电门控序列扫描,并对A、B两组各心率组的图像质量及患者有效射线剂量进行比较分析。结果1.两组间性别、年龄、BMI、心率比较均无统计学差异(P=0.556,0.164,0.124,0.859)。2.图像质量比较:两组患者均根据心率分为4组,心率(70~79)次/分组和心率(80-89)次/分组的患者,A、B两组间图像质量无统计学差异(P=0.883,0.617);心率(90-99)次/分组和心率≥100次/分组的患者,A、B两组间图像质量有统计学差异(P=0.048,0.044),B组优于A组。3.辐射射线剂量比较:A、B两组射线剂量(DLP、ED)差异均有统计学差异(P均0.001),A组明显低于B组。结论(1)较高心率(70~89次/分)患者采用改良flash spiral模式扫描可以得到与前瞻性心电门控序列扫描相似的、满足诊断要求的图像,且有效射线剂量可以明显减少;(2)但对于心率高于90次/分、心率变异较大的患者,flash spiral模式扫描图像质量欠佳,建议选择前瞻性心电门控序列扫描。
[Abstract]:As a kind of low radiation dose of coronary angiography with CT (coronary computed tomography angiography CCTA (1m) technology to about Sv), the unique second generation dual source CT high pitch prospective ECG gated helical scan mode (prospectively electrocardiogram-triggered high-pitch spiral acquisition mode, flash spiral, mode) in a cardiac cycle 250 milliseconds to complete CCTA scan. But flash spiral model is usually applied to regular low heart rate of the patients, the high heart rate (HR = 70 BPM) patients, the failure rate is high. Although some scholars start scanning method using 30%R-R, improve the patients quality of CCTA, but the overall failure rate is still this study aims to analyze the higher heart rate in patients with left ventricular volume changes during the cardiac cycle, with the best start R-R set flash spiral packet when scanning according to the heart rate By improving the ultra low radiation dose and image quality of CCTA examination in patients with high heart rate success rate, broaden the technology suitable examination population. The first part of left ventricular volume changes and coronary artery imaging with dual source CT flash spiral mode to start scanning at the optimal R-R: clinical study of the second generation dual source CT coronary angiography. Analysis of heart rate in patients with left ventricular volume changes during the cardiac cycle, and then look for flash spiral to start R-R the best scanning phase. Methods a total of 68 patients suspected of coronary heart disease patients, according to the average heart rate divided into 5 groups, using retrospective ECG gated spiral scanning mode for coronary angiography check with 5%R-R interval time interval for reconstruction of 0-100% a total of 21 as a cycle, using left ventricular function measurement software volume rendering, heart rate and left ventricular volume time curve, meter The average rate of change of left ventricular volume in the 250ms value, select the volume change of the minimum rate of R-R interval as flash spiral quasi optimal R-R scanning interval, different heart rate groups using flash spiral mode scanning phase. The heart rate in patients with left ventricular volume time curve and left ventricular volume change rate time curve has its regularity, the heart rate is higher, 250ms R-R interval minimum left ventricular volume change rate is close to the front of a R wave, using the flash spiral mode optimal scan R-R interval is the relative value of phase is small, the heart rate of 70 beats / min / min (70~79), (80~89) / min. (90~99) = 100 / min / min, the patients with the best R-R phase were 60%, 30.5%, 25.8%, 23%, 16.7%. through analysis of left ventricular volume in patients with cardiac changes in the cycle, searching for the second generation dual source CT specific f for clinical The best R-R lash spiral scanning mode phase provides guidance. In the second part, the improved Flash spiral model of coronary angiography in patients with high heart rate to applied research in the modified flash spiral method changes of left ventricular volume based on the rules of patients with high heart rate (heart rate greater than 70 beats / min) and examined by CCTA. With the two generation dual source routine using prospective ECG gated sequence scan mode (prospectively electrocardiography-gated step-and-shoot mode, SAS mode), to explore the improvement method in the high heart rate in patients with CCTA. Methods the heart rate more than 70 BPM and meet the inclusion criteria of 106 patients were randomly divided into two groups of AB, the first part of this study the different heart rate groups using flash spiral scanning mode of the best R-R phase according to the A group, by flash spiral scanning mode of.B modified group using prospective ECG gated sequence Scanning, and the A B, comparative analysis of two groups of heart rate group of patients with image quality and effective radiation dose. The results of 1. between the two groups in gender, age, BMI, heart rate were no statistically significant difference (P=0.556,0.164,0.124,0.859).2. image quality: two groups of patients were divided into 4 groups according to heart rate, heart rate (70~79) time / packet and heart rate (80-89) / group of patients, A, there was no significant difference in B between the two groups of image quality (P=0.883,0.617); heart rate (90-99) and heart rate is more than 100 times / group / subgroup of patients, A, B between the two groups have significant difference in image quality (P=0.048,0.044), B group the radiation dose is better than that of A group.3.: A, B two groups of radiation dose (DLP, ED) were statistically significant difference (P 0.001), A group was significantly lower than that of B group. Conclusion (1) high heart rate (70~89 / min) were treated with modified flash spiral mode scan can be obtained with prospective ECG gated sequence a similar scan, To meet the requirements of image diagnosis, and effective radiation dose can be significantly reduced; (2) but for heart rate more than 90 BPM, heart rate variability in patients with larger flash, spiral scanning mode of poor image quality, recommendations for the selection of prospective ECG gated scanning sequence.

【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R816.2;R541.4

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