CAJ | 학술논문

　　目的通过冠状动脉体模实验，探讨斑块性质和血管管径对64排CT冠状动脉成像血管狭窄显示准确性影响。方法使用心脏动态体模建立不同类型冠状动脉体外模型，模拟血管管径分别为2.5、3.0、3.5、4.0 mm，管腔内对比剂浓度设置为（346±13.6）Hu 。模拟斑块CT值为（14±9.6） Hu和（712±15.1）Hu，用以模拟软斑块和钙化斑块，模拟狭窄程度分别为25%、50%、75%。使用64排螺旋CT行回顾性心电门控扫描，选择75%R-R间期单扇区重建。使用AW4.2工作站进行多平面重组（Multiplanar Reformation， MPR）获得模拟冠状动脉最佳长轴位影像，在每段模拟血管狭窄影像上各选取10个位置测量管径和计算狭窄程度平均值。应用单样本t检验比较模拟血管影像管径和狭窄程度与模型数据之间差别，应用独立样本t 检验进行两者间比较，用ANOVA进行多组数据的比较。结果经单样本 t 检验及方差分析显示，各组不同管径及狭窄的绝对测量值均与标准值存在统计学差异。软斑块组狭窄的相对测量值（狭窄率）与标准值的差异无统计学意义，相同狭窄程度、不同管径之间的差异均无统计学意义。测量所得钙化组狭窄率与标准值存在显著性差异，相同狭窄程度、不同管径之间均存在显著性差异。经独立样本 t 检验分析，软斑块与钙化组之间的绝对和相对测量值均有显著性差异，钙化组测量值高估了狭窄程度。结论64排CT冠状动脉成像能够评价血管相对狭窄程度，但对钙化斑块的评价存在高估。
　　목적통과관상동맥체모실험，탐토반괴성질화혈관관경대64배CT관상동맥성상혈관협착현시준학성영향。방법사용심장동태체모건립불동류형관상동맥체외모형，모의혈관관경분별위2.5、3.0、3.5、4.0 mm，관강내대비제농도설치위（346±13.6）Hu 。모의반괴CT치위（14±9.6） Hu화（712±15.1）Hu，용이모의연반괴화개화반괴，모의협착정도분별위25%、50%、75%。사용64배라선CT행회고성심전문공소묘，선택75%R-R간기단선구중건。사용AW4.2공작참진행다평면중조（Multiplanar Reformation， MPR）획득모의관상동맥최가장축위영상，재매단모의혈관협착영상상각선취10개위치측량관경화계산협착정도평균치。응용단양본t검험비교모의혈관영상관경화협착정도여모형수거지간차별，응용독립양본t 검험진행량자간비교，용ANOVA진행다조수거적비교。결과경단양본 t 검험급방차분석현시，각조불동관경급협착적절대측량치균여표준치존재통계학차이。연반괴조협착적상대측량치（협착솔）여표준치적차이무통계학의의，상동협착정도、불동관경지간적차이균무통계학의의。측량소득개화조협착솔여표준치존재현저성차이，상동협착정도、불동관경지간균존재현저성차이。경독립양본 t 검험분석，연반괴여개화조지간적절대화상대측량치균유현저성차이，개화조측량치고고료협착정도。결론64배CT관상동맥성상능구평개혈관상대협착정도，단대개화반괴적평개존재고고。
Objective To evaluate the effect of vessel diameter and plaque nature on the accuracy of stenosis measurement in 64-row CT coronary angiography by conducting experiments with a cardiac phantom. Methods By adopting an adjustable pulsating cardiac phantom, different models of the simulated coronary arteries are established. Simulate vascular diameters of these models are 2.5 mm, 3.0 mm, 3.5 mm and 4.0 mm respectively.The concentration of contrast medium in vascular lumen of these models is (346±13.6) Hu. CT values of simulated plaques used to simulate soft plaques and calcified plaques are (14±9.6) Hu and (712±15.1) Hu and stenosis degrees of these plaques are 25%, 50% and 75% respectively. Retrospective ECG gating is scanned by Lightspeed VCT, and Half reconstruction is performed at 75% R-R interval. All data are sent to AW4.2 workstation for multiplanar reformation (MPR) to obtain the best longitudinal section. Calibers and stenosis degrees of 10 random sections on stenosis images of simulation vessels are measured. One-sample t test is used to evaluate the accuracy of calibers and stenosis degrees. The two groups of different plaques are compared by using independent-samples t test. The data of multiple groups are compared by ANOVA(analysis of variance). Results of one-sample t test and ANOVA shows that the absolute measure value of all groups with different calibers and stenosis degrees has statistics difference with the standard value. In the group of soft plaques, there is no statistics difference between the measured relative stenosis degrees with the standard value,nor between the measured relative degrees among different calibers. However, in the group of calcified plaques, statistical differences are found in these comparisons of independent-samples t test shows that there are statistical difference between the absolute and relative measured values between the groups of soft and calcified plaques.The stenosis degree was exaggerated in calcified plaques. Conclusion Relative stenosis degree of coronary arteries can be measured with 64-row CT coronary angiography. However, the stenosis degree is exaggerated in calcified plaques.