新双源CT低剂量冠状动脉成像临床应用

发布时间：2018-05-09 13:51

本文选题：新双源CT + 冠状动脉　；参考：《郑州大学》2012年硕士论文

【摘要】：第一部分新双源GT Flash扫描在冠状动脉狭窄评估中的初步研究目的探讨新双源CT Flash扫描技术在冠状动脉狭窄诊断中的价值。材料与方法回顾性分析52例应用新双源CT Flash扫描技术行冠状动脉CT血管成像(CTA)患者的影像学资料,并与冠状动脉造影(CAG)检查结果对照,评价其显示冠状动脉狭窄的准确性及有效辐射剂量(mSv)的高低。冠状动脉狭窄程度分为三组,也即轻度狭窄(≤50%)、中度狭窄(50%＜狭窄≤75%)及重度狭窄(＞75%)。根据美国心脏协会(American Heart Association, AHA)的冠状动脉分节标准,从节段水平分析CTA诊断冠状动脉狭窄的敏感性、特异性、阳性预测值、阴性预测值和准确性。对所得结果行配对χ2检验,P0.05认为有统计学意义。结果 Flash CTA对冠状动脉狭窄病变诊断的敏感性、特异性、阳性预测值、阴性预测值和准确性分别为84.3%、95.7%、89.7%、93.2%和92.2%；有效辐射剂量为0.98±0.39mSv。Flash CT和CAG在诊断冠状动脉中、重度狭窄中差异无统计学意义(P值分别为0.344和0.453)；但二者在诊断冠状动脉轻度狭窄中差异有统计学意义(P=0.041)。结论 Flash CTA作为无创性影像学诊断技术,对冠状动脉狭窄的诊断具有较高的应用价值,尤其是对中、重度冠状动脉狭窄的评价,且有效辐射剂量明显降低。第二部分Flash CT (?)低管电压结合IRIS重建技术在超重患者冠状动脉成像中的应用目的探讨Flash CT低管电压结合IRIS重建技术在超重患者冠状动脉成像中的图像质量及辐射剂量。材料与方法 100例体质量指数(BMI)为25.0～30.0kg/m2的患者接受Flash CT检查,按扫描管电压完全随机化分成A(120kVp)、B (100kVp)两组,同时B组图像经IRIS重建获得数据作为C组。A组：50例,管电压120kVp； B组：50例,管电压100kVp；C组：50例,由B组数据进行IRIS重建获得,其一般资料与B组相同。所有患者均采用前门控适应性序列扫描。按血管节段对其图像质量进行分级,分析各个血管节段图像的可评估性。测量主动脉根部、左冠状动脉及右冠状动脉起始部血管腔内CT值、噪声(SD),并计算信噪比(SNR)、对比信噪比(CNR),记录辐射剂量。应用两独立样本t检验比较A、B或A、C两组患者扫描时一般资料及辐射剂量。应用单因素方差分析比较3组图像ROI内的CT值、噪声、SNR、CNR。冠状动脉段图像质量总体评分比较采用秩和检验,应用χ2检验比较不同图像质量评分在3组间的差异。采用Kappa检验判断2名评价者评分的一致性。结果冠状动脉段图像质量总体评分比较3组间差异无统计学意义(H=5.872,P＞0.05)。3组患者优、良图像比较差异有统计学意义(χ2=7.604,P＜0.05)；两两比较A、B两组间差异有统计学意义(χ2=7.534,P＜0.0167),A组优于B组；A、C两组间差异无统计学意义(χ2=1.838,P＞0.0167)。3组患者血管腔强化CT值、噪声、SNR, CNR差异均有统计学意义(P＜0.05)。两两比较,血管腔内CT值B、C两组高于A组；B组噪声最大,CNR最低；C组SNR最高。A、C两组ED分别为(8.6±1.3)mSv和(3.5±0.7)mSv,差异有统计学意义(t=—16.91,P＜0.05)。结论对于超体重患者运用低管电压结合IRIS重建技术进行Flash CT冠状动脉检查能够获得较好的图像质量,同时显著降低辐射剂量。
[Abstract]:Part one preliminary study of new dual source GT Flash scanning in coronary artery stenosis assessment
objective
Objective to explore the value of new dual source CT Flash scanning in the diagnosis of coronary artery stenosis.
Materials and methods
The imaging data of 52 patients with coronary artery CT angiography (CTA) with new dual source CT Flash scan were retrospectively analyzed and compared with the results of coronary angiography (CAG). The accuracy of coronary artery stenosis and the high dose of effective radiation dose (mSv) were evaluated. The degree of coronary stenosis was divided into three groups, that is, mild stenosis (the degree of coronary artery stenosis). Less than 50%), moderate stenosis (50% < 75%) and severe stenosis (> 75%). According to the standard of coronary artery segmental American Heart Association (AHA), the sensitivity, specificity, positive pretest value, negative predictive value and accuracy of CTA diagnosis of coronary artery stenosis were analyzed from segment level. The results were paired chi 2 test, P 0.05 think there is a statistical significance.
Result
The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of Flash CTA for the diagnosis of coronary stenosis were 84.3%, 95.7%, 89.7%, 93.2% and 92.2%, respectively, and the effective radiation dose of 0.98 + 0.39mSv.Flash CT and CAG were not statistically significant in the diagnosis of severe stenosis (P value 0.344 and 0.453 respectively). There was significant difference between the two in the diagnosis of mild coronary artery stenosis (P=0.041).
conclusion
As a noninvasive imaging diagnosis technique, Flash CTA is of high value for the diagnosis of coronary artery stenosis, especially in the middle and severe coronary stenosis, and the effective radiation dose is obviously reduced.
The second part is the application of Flash CT (low) tube voltage combined with IRIS reconstruction in coronary artery imaging of overweight patients.
objective
Objective to investigate the image quality and radiation dose of Flash CT low tube voltage combined with IRIS reconstruction in coronary artery imaging of overweight patients.
Materials and methods
100 patients with body mass index (BMI) of 25 ~ 30.0kg/m2 received Flash CT examination. The scan tube voltage was completely randomized into A (120kVp), B (100kVp) two groups, and B group images were reconstructed by IRIS for.A group in C group: 50 cases, tube voltage, 50 cases, tube voltage, 50 cases. The general data were the same as those in the B group. All the patients were scanned by the anterior gate controlled adaptive sequence. The image quality was graded according to the segment of the vascular segment and the evaluation of each segment image was analyzed. The CT values, noise (SD), and the signal to noise ratio (SNR) were measured in the aorta root, the left coronary artery and the right coronary artery in the starting part of the coronary artery. A contrast signal to noise ratio (CNR) was used to record the radiation dose.
Two independent samples t test was used to compare the general data and radiation dose of A, B, A and C two groups. The single factor variance analysis was used to compare the CT values in the 3 groups of ROI, noise, SNR, and CNR. coronary artery segment image quality overall score was compared with the rank sum test, and the difference between the 3 groups was compared with the x 2 test. Kappa test was used to determine the consistency of the scores of the 2 evaluators.
Result
There was no statistically significant difference between the 3 groups (H=5.872, P > 0.05) in group.3, and there were significant differences in good images (x 2=7.604, P < 0.05), 22 compared to A, B two groups were statistically significant (x 2=7.534, P < 0.0167), A group was superior to B group, and there was no statistical difference between two groups of A and two groups (2 =1.838, P > 0.0167) the vascular cavity enhanced CT value, noise, SNR, CNR difference in group.3 were statistically significant (P < 0.05). 22 compared, the value of CT in the endovascular group was higher than that in the A group; the largest noise in the B group was (8.6 + 1.3) and (3.5 + 0.7) respectively, and the difference was statistically significant (16.91, 0.05).
conclusion
The use of low tube voltage combined with IRIS reconstruction for Flash CT coronary artery examination for patients with super weight can obtain better image quality and significantly lower the radiation dose.

【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R816.2

【参考文献】