65-75bpm心率下大螺距模式冠状动脉CTA舒张期与收缩期图像采集的对比研究

发布时间：2018-04-06 05:34

  本文选题：冠脉CTA　切入点：Force　出处：《浙江大学》2017年硕士论文

【摘要】：目的:研究65-75bpm心率下患者使用Force CT前瞻性触发大螺距(Turbo Flash)螺旋扫描模式舒张期与收缩期不同采集时相的图像质量和辐射剂量。方法:分析60例接受Force CT冠状动脉CTA检查的患者资料,包括25例女性患者和35例男性患者,年龄范围41-82岁,平均年龄63.02±9.33岁,临床确认或怀疑有冠脉疾病。全部病例图像数据均包含齐全的检查时心电图及剂量统计报告。依据冠状动脉CTA检查时预设触发采集期相的不同分病例为两组:A组30例,使用Turbo Flash大螺距舒张期时相采集模式,预设触发采集时相在R-R间期的65%处;B组30例,使用Turbo Flash大螺距收缩期时相采集模式,预设触发采集时相在R-R间期的30%处。1、图像扫描及后处理全部病例均选择Force CT(德国西门子)进行扫描。选择ECG触发Turbo Flash大螺距模式,启用CT系统动态辐射剂量控制CARE Dose 4D技术,手动设定管电压参数值为100kV。扫描完成后各病例的原始数据由计算机系统自动上传到syngo.via工作站,由一名具有丰富心血管影像处理经验的放射科医生运用容积再现成像、曲面重组成像等方法进行影像处理。2、图像质量分析依据美国心脏协会最新提出的冠脉分支分段标准来进行冠脉17节段主观图像质量分析。为避免潜在的偏差,两名富有心血管影像诊断经验的放射科诊断医师在未知分组情况、未知患者采集时心率及心率范围等信息的情况下参照Likert评分法评估冠脉节段的图像质量。依据冠状动脉管腔的CT值、影像噪声等参数计算得出其信噪比和对比噪声比来进行客观图像质量评价。3、辐射剂量计算扫描完成后设备系统自动生成参数报告,包含X线曝光次数、容积CT剂量指数、X线曝光时间、剂量长度乘积等。有效辐射剂量定义为权重因子系数K与剂量长度乘积两个参数的乘积,权重因子系数选择胸部K=0.014mSv/mGy·cm。4、统计学分析本研究选用SPSS 22.0统计软件进行数据统计和分析,选用Student's t-Test(T检验)进行两组病例临床资料(包括性别、年龄、身高、体重、BMI指数等)、有效辐射剂量、信噪比、对比噪声比等的对比。用Kappa一致性检验评估两位放射科评估医师双盲法冠状动脉图像质量评分结果的一致性。P值小于0.05代表差异具有统计学意义。结果:1、冠状动脉图像质量两组60例病例共评价分析779个冠状动脉节段,其中A组为392个冠状动脉节段,B组为387个冠状动脉节段。A组中冠状动脉图像质量最好的节段是第二钝缘支(平均评分为1.00),其次是左冠状动脉主干(平均评分为1.15);图像质量最差的是右冠状动脉中段(平均评分为2.33)。B组中冠状动脉图像质量最好的节段是第二钝缘支(平均评分为1.00),其次是左冠状动脉主干(平均评分为1.35);图像质量显示最差的是左冠脉回旋支远段(平均评分为2.33)。A组中评分为4(不可诊断)的节段有9段(n=9,2.3%),分别为右冠状动脉中段(n=5)、右冠状动脉远段(n=3)、后降支(n=1)。B组中评分为4的节段有19段(n=19,4.9%),分别出现在右冠状动脉近段(n=3)、右冠状动脉中段(n=2)、右冠状动脉远段(n=2)、后降支(n=2)、左室后支(n=2)、左冠状动脉主干(n=1)、左冠状动脉前降支近段(n=1)、左冠状动脉前降支中段(n=1)、第一对角支(n=1)、左冠状动脉回旋支近段(n=1)、第一钝缘支(n=2)、左冠状动脉回旋支中段(n=1)。两组病例按照17节段分段法对冠状动脉分支评价结果表明,A组第一对角支、第一钝缘支、左冠状动脉回旋支近段和中段的图像质量明显优于B组,其余各冠状动脉节段图像质量没有差别。对两名放射科评估医师的主观评分进行一致性检验,检验结果证明二者对图像评价的一致性良好(Kappa=0.816)。两组病例的升主动脉根部、右冠状动脉和左冠状动脉的CT值、影像噪声、信噪比等各项数据对比显示结果没有差别(P0.05)。2、辐射剂量A组患者平均容积CT剂量指数值为3.53,平均剂量长度乘积值为59.82,平均有效辐射剂量值为0.84;B组平均容积CT剂量指数值为3.21,平均剂量长度乘积值为54.78,平均有效辐射剂量值为0.77。两组之间的辐射剂量参数值对比结果显示没有差别(P0.05)。结论:1、Force CT前瞻性大螺距Turbo Flash模式冠脉CTA使用低管电压(100kV)、低造影剂量(40ml)技术,结合ADMIRE迭代重建算法,所得冠脉图像能够达到临床影像诊断的需要,有效辐射剂量小于1mSv。2、患者心率在65-75bpm时行Force CT冠脉CTA,使用大螺距Turbo Flash舒张期采集模式对LCX的显示要优于收缩期采集模式。
[Abstract]:Objective: to trigger a large pitch in patients with Force CT prospective study using 65-75bpm heart rate (Turbo Flash) spiral scan mode diastolic and systolic phase of the acquisition of different image quality and radiation dose. Methods: Patients with 60 patients received Force CT coronary artery CTA examination, including 25 cases of female patients and 35 male patients, age 41-82 years old, the average age of 63.02 + 9.33 years, clinical confirmed or suspected coronary artery disease. All cases were complete image data includes examination of ECG and dose of statistical reports. According to different cases of coronary artery CTA examination preset trigger acquisition phase into two groups: group A 30 cases, Turbo Flash large pitch the diastolic phase acquisition mode, preset trigger acquisition phase at 65% R-R interval; 30 cases in group B, using Turbo Flash pitch systolic phase acquisition mode, preset trigger acquisition phase in R-R interval 30%.1, image scanning and postprocessing of all cases were Force CT (SIEMENS) ECG Turbo Flash scan. High pitch trigger, enable the CARE 4D technology Dose CT system dynamic radiation dose control, voltage parameters manually set the value of the original data for each tube in cases of 100kV. after the scan is complete by the computer system automatically upload to syngo.via workstation, by a rich experience in dealing with cardiovascular imaging radiologists using volume rendering, surface imaging methods such as.2 image processing, based on the analysis of coronary artery branch of the American Heart Association recently proposed new standards for piecewise analysis of 17 segments of coronary subjective image quality. In order to avoid the potential bias, two has the cardiovascular imaging experience in diagnostic radiology, doctors in the unknown group, with unknown acquisition of heart rate and heart rate range Image quality assessment of coronary artery segments according to Likert score information. On the basis of coronary artery CT values, calculated the SNR of objective image quality evaluation of.3 ratio and contrast to noise ratio of image noise and other parameters, automatically generated report parameters after scanning equipment system to calculate the radiation dose, including X-ray exposure times, volume CT dose index, X-ray exposure time and dose length product. The effective radiation dose for the product definition of product weight factor coefficient K and dose length two parameters, K=0.014mSv/mGy and cm.4 choose the weight factor of the chest coefficient analysis in this study using SPSS 22 statistical software for statistical data and statistical analysis, using Student's t-Test (T test) were the clinical data of two cases (including gender, age, height, weight, BMI index), effective radiation dose, SNR, contrast to noise ratio were compared with Ka. PPA consistency test to assess the consistency of Radiology physician assessment.P two double-blind method of coronary artery image quality score was less than 0.05 on behalf of the difference was statistically significant. Results: 1, two cases of coronary artery image quality evaluation and analysis 60 cases of 779 coronary artery segments, which A group of 392 coronary artery segment, segment B group of 387 coronary artery segments of coronary artery in group.A, the best image quality is second obtuse marginal branch (average score 1), followed by the left main coronary artery (average score 1.15); image quality is the worst middle segment of right coronary artery (mean score of 2.33) the image quality of coronary artery in the.B group the best segment is second obtuse marginal branch (average score 1), followed by the left main coronary artery (average score 1.35); image display quality is the worst left circumflex coronary artery distal (Ping Junping 2.33) scores in the.A group 涓，

本文编号：1718211