双源CT冠状动脉造影在冠状动脉狭窄中的诊断价值

<正>选择性冠状动脉造影(CAG)一直被认为是确诊冠状动脉狭窄和病变的"金标准",但其属于有创检查,存在并发症,且费用较高而难以被大多数患者所接受。随着CT影像技术的发展,多排螺旋CT冠状动脉成像在临床中应用越来越多,双源CT(DSCT)时间分辨率高、成像不受心率影响,且属于无创检查,受到广大医务人员的认可。本文通过比较CAG和DSCT冠状动脉造影,探讨DSCT冠状动脉造影在诊断冠状动脉狭窄中     

SSF技术在高心率和心率波动受检者CCTA中的应用价值

目的探讨SSF技术在改善高心率(心率70次/min)和心率波动受检者冠状动脉成像质量中的临床应用价值。方法选取66例高心率和心率波动受检者进行冠脉CT血管成像扫描后,分别得到A、B两组图像,其中A组图像采用标准重建,B组图像采用SSF重建,并将检查结果进行对比,分析两组之间冠状动脉图像质量差异。结果除了左主干显示无明显差异外,其余冠状动脉节段B组图像质量均优于A组(P0.05),右冠状动脉S2、S3段及回旋支S10段图像质量明显改善;随着心率增加,A、B两组图像质量均有下降,二者之间无统计学意义(P0.05)。结论 SSF技术可以改善高心率及心率不稳病人的冠状动脉成像质量,满足临床诊断需求,拓宽了受检者临床检查范围,让冠状动脉CTA检查成为真正意义上的冠状动脉病变首选筛查手段,为冠心病临床诊断提供有价值的影像学信息。     

心率及心率波动对256层CT回顾性心电门控冠状动脉成像质量的影响简

目的 探讨心率及心率波动对256层计算机断层扫描（computerized tomography,CT）冠状动脉成像图像质量的影响.方法 150例疑为冠状动脉粥样硬化性心脏病（冠心病）的患者行256层CT回顾性心电门控冠状动脉检查,对直径＞1.5 mm的冠状动脉节段进行评分.根据平均心率分为3组：A组,心率＜65次/min;B组,65次/min～80次/min;C组,心率≥80次/min.比较不同心率组间的图像质量,采用Pearson相关分析方法分析平均心率及心率波动对图像质量的影响,并采用线性回归方程确定需进行干预的心率临界点.结果 在最佳重组时相上,可满足诊断要求的图像占97.9％.冠状动脉总体、右冠状动脉、左前降支及左旋支的图像质量评分与心率显著相关,相关系数分别为0.473、0.425、0.409、0.413（P均＜0.001）,冠状动脉图像质量与心率波动无明显相关（P＞0.05）.不同心率组间冠状动脉图像质量比较,差异有统计学意义（P＜0.05）.当心率＜83.1次/min时,可获得优良的图像质量,而为获取满足临床诊断要求的图像,心率应＜119.1次/min.心率＜65次/min时,舒张期重建的图像质量佳;心率＞71次/min时,收缩期重建的图像质量佳.结论 心率波动对256层CT同顾性心电门控冠状动脉图像质量无显著影响,但心率仍是影响图像质量的一个重要因素;降低心率有助于提高图像质量.     

心率波动对冠状动脉运动及64层螺旋CT冠状动脉成像质量的影响

目的探讨心率波动对冠状动脉运动及64层螺旋CT冠状动脉成像质量的影响。方法选取本院;临床中请多层螺旋CT冠状动脉成像（MSCTCA）且同意参加试验者34例为试验组,根据两次扫描心率变化分为三组,A组：≤5次／minBMP,B组：6～10次／minBMP,C组：〉10次／minBMP。分别测量心脏收缩末期和舒张末期右冠状动脉和左前降支间的距离,计算两次扫描的距离变化差。回顾性收集同期64SCTCA资料完整者137例为临床组,根据心率波动程度分成三组：Ⅰ组：0～2次／minBMP,Ⅱ组：3～6次／minBMP,Ⅲ组：〉7次／minBMP。按5分法评价不同心率波动情况下的图像质量。结果试验组两次扫描右冠状动脉与左前降支的间距差以舒展期变化较大,同收缩期比较差异有统计学意义（P〈0．05）;心率变化越大,距离的变化值也越大（P〈0．05）。临床组137例患者共有83．2％冠状动脉图像质量可满足诊断要求。不同心率波动组间冠状动脉图像质量有显著差异,心率变化越小图像质量越好（P〈0．05）。结论心率波动时数据匹配错误是导致图像质量降低的根本因素,稳定心率有助于提高图像质量。     

心率变化对256层螺旋CT冠状动脉成像质量的影响

目的探讨心率变化对256层螺旋CT冠状动脉成像质量的影响。方法对95例临床怀疑或确诊为冠心病的患者行256层螺旋CT冠状动脉造影检查,入选患者按照心率不同分为3组:第一组为心率≤75次/min,第二组心率为76～100次/min,第三组为心率100次/min。分别对每组图像质量进行评价。结果第一组的图像质量优良率为97.6%,能够满足诊断率为98.6%,第二组图像质量优良率为96.9%,能够满足诊断率为98.5%,第三组图像质量优良率为94.3%,能够满足诊断率为96.8%。结论 256层螺旋CT对高心率的适应性有了明显提高。     

冠状动脉CT成像中心率波动幅度对SSF算法冠状动脉重建图像质量的影响

目的探究冠状动脉CT成像中心率波动幅度对冠状动脉运动追踪技术(SSF)算法冠状动脉重建图像质量的影响。方法选取2015年7月至2017年7月于海南省第三人民医院心血管内科行CT扫描的284例患者作为研究对象,按照心率波动幅度进行分组,3～5次/min为观察组A组,6～8次/min为观察组B组,2次/min以下与无明显心率波动为对照组,比较不同冠状动脉节段下的图像质量。结果与对照组比较,观察组A组的优良率无统计学差异(P0.05),观察组B组的优良率有统计学意义(P0.05),且右冠状动脉图像质量的优良率低于左冠状动脉优良率。结论 SSF能够改善冠状动脉CT图像质量。     

心率及心律对256层螺旋CT冠状动脉CT血管造影图像质量的影响

目的探讨心率及心律对256层螺旋CT冠状动脉(以下简称为冠脉)CT血管造影(CTA)图像质量及诊断结果的影响。方法选择该院冠脉疾病患者610例,均经256层螺旋CT行冠脉CTA诊断,其中580例患者心律整齐,有76例患者同意接受选择性冠状动脉造影(CAG)诊断,根据心率由低到高将580例心律整齐者分成Ⅰ组、Ⅱ组、Ⅲ组、Ⅳ组;另将心率≤80次/min的537例患者根据采集周期中心律变化幅度由低到高划分成A组、B组、C组。对比不同心率组的冠脉图像质量,分析采集周期中患者心率及心律变化的幅度与图像质量的联系,比较不同心率及心律变化幅度的CAG及CTA诊断结果。结果患者心率越低,则CTA图像质量优良率也越高,但其诊断的敏感度、准确度与心率变化幅度无明显相关性(r=-0.145,P=0.128;r=-0.128,P=0.220);心律变化的幅度越低,则CTA图像质量优良率也越高,但其诊断敏感度、准确度与心率变化幅度也无明显相关性(r=-0.241,P=0.097;r=-0.208,P=0.142)。结论冠脉疾病患者的心率及心律越低,则CTA图像质量也越高,但其变化对于256层螺旋CT冠脉CTA诊断并无明显的影响,因此CTA对心血管疾病诊断价值较高。     

应用心电编辑在CT冠状动脉成像中降低心率异常及屏气不良影响的初步探讨

<正> 64层螺旋CT时间分辨率和空间分辨率的提高,使无创性CT冠状动脉成像技术日臻成熟和完善,并逐渐被临床认可。影响CT冠状动脉成像的图像质量主要因素包括扫描时被检查者的心率、心律、呼吸运动伪影及冠状动脉管壁的钙化、右心房高密度对比剂等。对于检查过程中因心率异常造成的错层伪影及运动伪影,常用的解决方法是使用心电编辑软件。国内外近年有各种研究证实,心电编辑功能能够提高心率异常患者CT冠状动脉成像的图像质量。本研究旨在探讨应用心电编辑的方法消除或降低心率异常及屏气不良对CT冠状动脉成像的图像质量的影响。     

双源CT冠状动脉造影前瞻性呼吸控制的护理干预探讨

正伴随双源CT(dual source computed tomography,DSCT)的推出和广泛应用于心血管造影成像,实现了无明显心率限制的心脏冠状动脉无创性造影检查。DSCT虽然无需严格控制心率,但仍有影响冠脉成像质量的因素,呼吸运动控制不当,可成为导致产生伪影的最常见因素[1]。因此,如何控制好CT造影过程呼吸的方式和保证达到屏气良好的目的,成为护理工作者对冠状动脉检查前期重点关注和护理干预的     

双源CT评价冠状动脉支架内再狭窄的意义

目的:通过双源CT(DSCT)与选择性冠状动脉造影(CAG)对支架评估的对比分析,探讨DSCT对冠状动脉支架内再狭窄的诊断意义。方法:42例同期行双源CT冠状动脉血管成像及选择性CAG检查的患者,分析比较DSCT诊断支架内再狭窄的敏感性、特异性及准确性。结果:①DSCT按病例数诊断支架内再狭窄的敏感性86.7%、特异性96.2%、阳性预测值92.9%、阴性预测值92.6%、准确性92.7%。②DSCT按支架数诊断支架内再狭窄的敏感性76.5%、特异性95.1%、阳性预测值86.7%、阴性预测值90.7%、准确性89.7%。③DSCT与CAG比较,诊断支架内再狭窄的差异无统计学意义。④DSCT对直径≥3.0mm支架的再狭窄检出的阳性预测值、特异性、敏感性均优于直径3.0mm支架。结论:双源CT在诊断支架内再狭窄方面接近CAG,可作为支架内再狭窄的评估手段之一。     

窄窗扫描技术在高心率患者320排CT冠状动脉成像中的应用研究

目的：探讨高心律患者320排CT冠状动脉成像使用前瞻性心电门控窄窗扫描技术对图像质量和辐射剂量的影响。方法80例心率在80~100次/min的患者随机分成观察组和对照组。观察组按R- R间期30％～50％进行前瞻性窄窗扫描3个心动周期,对照组按R- R间期30％～80％进行常规扫描3个心动周期,冠状动脉节段图像质量采用4级评分法评分,辐射剂量值由设备自动计算。结果可评价血管段和优良率两组间差异无统计学意义（P＞0.05）。冠状动脉总节段、右冠状动脉（RCA）、左冠状动脉主干（LM）、左前降支（LAD）和旋支（LCX）的质量评分两组间差异无统计学意义（P＞0.05）。观察组的RCA和LCX与心律波动呈中等程度负相关（r =0.41、0.47）。观察组和对照组平均辐射剂量分别为（7.63±3.29）和（12.85±2.71）mSv,差异有统计学意义（t=1.384,P＜0.05）。结论窄窗扫描技术可应用在心律波动不大的高心率患者,能明显降低辐射剂量而不影响图像质量。     

Dual-Source Computed Tomographic Coronary Angiography: Image Quality and Stenosis Diagnosis in Patients with High Heart Rates

We sought to evaluate prospectively the effects of heart rate and heart-rate variability on dual-source computed tomographic coronary image quality in patients whose heart rates were high, and to determine retrospectively the accuracy of dual-source computed tomographic diagnosis of coronary artery stenosis in the same patients.We compared image quality and diagnostic accuracy in 40 patients whose heart rates exceeded 70 beats/min with the same data in 40 patients whose heart rates were 70 beats/min or slower. In both groups, we analyzed 1,133 coronary arterial segments. Five hundred forty-five segments (97.7%) in low-heart-rate patients and 539 segments (93.7%) in high-heart-rate patients were of diagnostic image quality. We considered P < 0.05 to be statistically significant. No statistically significant differences between the groups were found in diagnostic-image quality scores of total segments or of any coronary artery, nor were any significant differences found between the groups in the accurate diagnosis of angiographically significant stenosis.Calcification was the chief factor that affected diagnostic accuracy. In high-heart-rate patients, heart-rate variability was significantly related to the diagnostic image quality of all segments (P = 0.001) and of the left circumflex coronary artery (P = 0.016). Heart-rate variability of more than 5 beats/min most strongly contributed to an inability to evaluate segments in both groups. When heart rates rose, the optimal reconstruction window shifted from diastole to systole.The image quality of dual-source computed tomographic coronary angiography at high heart rates enables sufficient diagnosis of stenosis, although variability of heart rates significantly deteriorates image quality.Key words: Artifacts, coronary angiography/methods, coronary stenosis/diagnosis/radiography, diastole/physiology, heart rate/physiology, image processing, computer-assisted, prospective studies, radiographic image interpretation, computer-assisted, sensitivity and specificity, systole/physiology, technology assessment, biomedical, tomography, spiral computed/instrumentation/methods/standardsDuring the past few years, noninvasive coronary angiography upon multidetector-row computed tomography (MDCT) has rapidly progressed and has shown promise with regard to the detection and quantification of coronary artery stenosis.^1–4 However, despite the increase in temporal resolution from 16- to 64-detector-row computed tomography (CT), coronary CT angiography remains sensitive to motion artifacts, which occur especially at higher heart rates.^2,5–7 Results of a study³ of 64-detector-row CT coronary angiography showed a nonsignificant tendency toward lower image quality at higher mean heart rates, and a significant negative relation between image quality and heart-rate variability. In order to reduce motion artifacts, it has been proposed that patients be administered oral β-blocker medication for heart-rate control, even when 64-detector-row CT is to be used.^8–11 In most studies that have involved 16- or 64-detector-row CT, the target for scanning has been maintained at heart rates slower than 70 or even 60 beats/min, so that good-quality images of coronary arteries could be obtained. The requirement to premedicate patients with β-blocker drugs in order to achieve a sufficiently low heart rate for scanning has been considered a major limitation surrounding the clinical use of MDCT coronary angiography.Dual-source CT (DSCT) coronary angiography incorporates 2 X-ray tubes and 2 detectors that are mounted onto a rotating gantry, with an angular offset of 90°.¹² The DSCT system affords a high temporal resolution of 83 ms in monosegment reconstruction mode. In contrast with single-source CT systems that rely on multisegment reconstruction techniques, temporal resolution upon DSCT is independent of heart rate. Initial studies have shown that DSCT enables the study of coronary arteries with excellent diagnostic quality in all patients, independent of heart rate—thus obviating the need to premedicate patients with β-blockers.^12–15 We believed that the effects of heart rate and heart-rate variability on image quality, diagnostic accuracy, and optimal reconstruction windows merited further evaluation in patients whose heart rates exceeded 70 beats/min.The aim of this study was to evaluate prospectively the effect of heart rate and heart-rate variability on DSCT image quality in patients who had high heart rates, and to determine retrospectively the accuracy of DSCT in the diagnosis of coronary artery stenosis, using invasive coronary angiography as the reference standard.     

老年患者双源CT冠状动脉成像的研究

目的 探讨老年患者采用双源CT冠状动脉成像的图像质量和诊断冠状动脉病变的特点. 方法 200例临床怀疑冠心病者,检查前均未口服倍他乐克准备.分为老年组126例,年龄60～91岁,对照组例74例,年龄38～59岁.比较两组患者的临床特征、平扫及增强扫描的平均心率和屏气时间、平均钙化积分值、图像质量评价及冠状动脉狭窄情况. 结果与对照组比较,老年组胸闷、胸痛、高血压、糖尿病、高血脂和陈旧心肌梗死的发生率明显高于对照组,平均钙化积分值、<50%及≥50%狭窄数均高于对照组(均P<0.01).老年组平扫及增强扫描的平均心率和屏气时间与对照组比较差异无统计学意义,老年组图像质量为1级、2级和3级的冠状动脉节段分别为96.5%、2.3%和1.2%,与对照组(97.1%、2.0%和0.9%)比较,差异无统计学意义(均P>0.05).结论 双源CT冠状动脉成像是一种无创、安伞、简便的方法.在无需口服倍他乐克准备的情况下获得满意的冠状动脉各节段图像,可做为老年患者冠心病常规检查有效方法之一.     

心房颤动对双源CT冠状动脉血管成像的影响

目的探讨心房颤动（房颤）平均心室率、心率波动和心率变异性对冠状动脉CT血管成像（CTA）图像质量的影响。方法87例房颤患者和107例心律正常者进行了双源CT冠状动脉血管成像。平均心室率、心率波动和心率变异性与图像质量之间的关系采用相关分析和线性回归分析判断,各分段图像质量之间的差别采用卡方检验和非参数检验。结果房颤组共1218段血管纳入分析,达到诊断标准的血管共1038段（85．2％）。房颤组的平均心室率为（90．1±22．0）次／min,心率波动为（55．8±34．3）次／min,心率变异性为0．55±0．29,均高于对照组（P〈0．01）。部分动脉图像质量与平均心率无关（P〉0．05）。除左主干外,心率波动与其他分段图像质量呈负相关（P〈0．01）。心率变异性与所有分段图像质量呈负相关（0．01〈P〈0．05和P〈0．01）。左主干和回旋支近段高质量图像百分率较高,而后降支和钝缘支图像质量较差。结论双源CT能对大多数房颤患者冠状动脉进行评价,其获得的各近段动脉图像质量高于远段动脉。心率波动对房颤冠状动脉CTA图像质量起主导影响作用。     

Influence of heart rate on the diagnostic accuracy of dual-source computed tomography coronary angiography.

OBJECTIVES: We evaluated the influence of heart rate on image quality and diagnostic accuracy of dual-source computed tomography (DSCT) coronary angiography. BACKGROUND: Multidetector computed tomography (MDCT) coronary angiography has demonstrated an inverse relationship between heart rate and image quality. Dual-source CT provides a higher temporal resolution. METHODS: One hundred patients were studied by DSCT (DEFINITION, Siemens Medical Solutions, Forchheim, Germany). A contrast-enhanced volume dataset was acquired (two tubes, 120 kV, 400 mAs/rot, collimation 64 x 0.6 mm). Datasets were evaluated concerning the presence of significant coronary stenoses and validated against invasive coronary angiography. RESULTS: In 44 patients with a heart rate > or =65 beats/min, 566 of 616 coronary segments were evaluable (92%), whereas in 56 patients with a heart rate <65 beats/min, 777 of 778 coronary segments were evaluable (100%, p < 0.001). On a per-patient basis, 93% of patients (> or =65 beats/min) and 100% of patients (<65 beats/min) were considered evaluable. By classifying unevaluable segments as positive for stenosis, per-patient sensitivity was 95% (19 of 20) for heart rates > or =65 beats/min and 100% (22 of 22) for heart rates <65 beats/min. Specificity was 87% (21 of 24) versus 76% (26 of 34), and overall diagnostic accuracy was 91% (40 of 44) versus 86% (48 of 56). None of these differences were statistically significant. Similarly, no difference in diagnostic accuracy was found in per-vessel and -segment analyses. CONCLUSIONS: In 100 patients studied without beta-blocker pre-medication, DSCT demonstrated slightly lower per-segment evaluability for high heart rates but no decrease in diagnostic accuracy for the detection of coronary artery stenoses.     

双源CT不同扫描模式下患者冠脉图像质量评分及接受有效辐射剂量的研究

目的 研究双源CT不同扫描模式下患者冠脉图像质量评分及患者接受的有效辐射剂量.方法 50例患者被纳入研究,男性36例,女性14例,平均年龄（68.2±9.4）岁,心率＜60次/min,心率稳定,BMI为22.5～24.9 kg/m2.所有研究对象均在第1个月的第1天和第15天两次行不同扫描模式双源螺旋CT（DSCT）：A组为100/sn 100 kV,B组为80/sn 120 kV.研究两组的冠脉图像质量及患者接受的有效辐射剂量.结果 A组Ⅰ级图像数量（52％）低于B组（70％）,且差异具有统计学意义（P＜0.01）.B组的图像比A组的图像质量高,但都可以进行诊断.从性别上来看,无论100 kV还是120 kV,高螺距冠脉图像的有效辐射剂量暴露量女性均值高于男性均值,但100 kV的辐射剂量暴露低于120 kV.结论 Flash双源CT（100/sn100kV）在获得满意图像质量的同时可以减低辐射剂量.     

Influence of Balloon Angioplasty on Heart Rate Variability in Patients with Coronary Artery Disease

We assessed the influence of elective balloon angioplasty on heart rate variability (HRV) in patients with coronary artery disease. In 62 patients (41 men and 21 women, aged 33 to 69), two 6-minute electrocardiographic recordings were performed 2 hours apart. Patients were divided into three groups: group A (26 patients) underwent balloon angioplasty; group B (14 patients) underwent coronary angiography alone, and group C (22 patients) served as controls. There was a statistically significant decrease in time and frequency domain measurements in group A patients after successful balloon angioplasty (P < 0.05). The logarithm of the high frequency decreased in group B patients after coronary angiography alone (P < 0.05). HRV did not change in group C. There was no correlation with lesion location. We conclude that in patients with coronary arterial disease, successful balloon angioplasty is associated with an immediate decrease in HRV in time and frequency domains regardless of the artery involved. Coronary angiography alone is associated with an early decrease in the logarithm of the high frequency domain measurement of HRV. These changes may be due to procedure-related factors, patient characteristics, and microvascular derangements. A delayed improvement in HRV after balloon angioplasty is not addressed by the present study and warrants further evaluation.     

Comparison of diagnostic accuracy and radiation dose between prospective triggering and retrospective gated coronary angiography by dual-source computed tomography

The purpose of this study was to evaluate and compare the diagnostic accuracy and radiation dose of dual-source computed tomographic (DSCT) coronary angiography for assessment of coronary artery disease using prospective electrocardiographic triggering and retrospective electrocardiographically (ECG) gated spiral scans. One hundred sixteen patients who had undergone dual-source computed tomography and conventional coronary angiography were enrolled in this study. Fifty-four patients were scanned using retrospective ECG-gated protocols (group 1) and 62 patients using prospective ECG-triggered protocols (group 2). Diagnostic accuracy, image quality, and effective dose were compared between groups 1 and 2. Conventional coronary angiography was used as the reference standard. In total 1,709 (98.2%) coronary segments in the 116 patients were assessable with adequate image quality. Sensitivities and specificities of diagnosing coronary heart disease (≥50% stenosis) in a patient-based analysis of DSCT data were 93.3% and 88.9% in group 1 and 96.4% and 85.7% in group 2, respectively (p=0.973 and 0.761). In vessel-based analysis, sensitivities and specificities were 77.4% and 94.1% in group 1 and 79.6% and 92.3% in group 2 (p=0.983 and 0.985). Overall averaged image quality scores (using 1- to 4-point scale) in groups 1 and 2 were 3.3 ± 0.4 and 3.5 ± 0.9, respectively (p=0.268). Prevalence of good (score 3.0) and excellent (score 4.0) image qualities of coronary vessels were 95.4% in group 1 and 92.4% in group 2 (p = 0.861). Effective doses were 8.82 ± 3.50 mSv (range 3.92 to 15.36) in group 1 and 2.95 ± 1.39 mSv (range 0.99 to 6.06) in group 2 (p<0.001). In conclusion, DSCT prospective ECG-triggered coronary angiography has equivalent image quality and diagnostic value compared to that of retrospective ECG-gated scans. Radiation dose was significantly decreased using prospective electrocardiographic triggering.