MSCT、超声心动图与MRI评价左心功能的比较研究

目的以磁共振成像(MRI)为对照标准,应用64层螺旋CT(MSCT),定量评价左心功能,探讨MSCT和MRI心功能评价指标的相关性及MSCT在冠心病左心功能评价中的应用价值;比较同组病例的超声心动图和心脏MRI的左心功能指标,探讨两种方法心功能指标的相关性。资料与方法临床拟诊冠心病的患者32例(均自愿参加),均行心脏MSCT、MRI和超声心动图检查。结果MSCT和MRI两种方法的心功能指标差异无统计学意义,舒张末期容积(EDV)、收缩末期容积(ESV)、每搏输出量(SV)、左室射血分数(EF)、心肌质量(MM)相关性高(r值=0.78~0.92);超声心动图和MRI两种方法的心功能指标差异亦无统计学意义,EDV和SV相关性高(r值分别为0.63和0.69);ESV和EF值相关性中等或低(r值分别为0.41和0.34)。EDV、ESV均值:MSCT>MRI>超声心动图;SV均值:MSCT>MRI和超声心动图;EF均值:超声心动图>MRI>MSCT。结论MSCT在左心功能定量评价方面准确、可靠,一次MSCT冠状动脉造影检查可以同时评估冠状动脉狭窄情况和左心室功能。超声心动图也具有重要的临床应用价值,但是MSCT用于定量评价左心功能较超声心动图更准确。     

MSCT在左心室功能及冠脉主干径线测定中的应用价值

目的：探讨MSCT成像技术在左心室功能及冠脉径线测量中的应用价值。方法：对28例临床拟诊冠心病的患者进行回顾性心电门控MSCT心脏扫描，分别对左心室容积、室壁厚度、射血分数和室壁收缩增厚率及左、右冠脉主支内径进行测量，MSCT测得结果与超声心动图和数字减影冠脉造影进行对比。结果：MSCT测得的左心室舒张末期容量(EDV)、收缩末期容量(ESV)、射血分数(EV)、心肌收缩末期厚度(EST)、心肌舒张末期厚度(EDT)及室壁增厚率与超声心动图相关性较好，测量结果MSCT略小于超声心动图，但两者相比无显著性差异。MSCT与数字减影冠脉造影左、右冠脉主支内径的测量值间无显著性差异。结论：MSCT在左心室功能及冠脉主干径线测定中具有很高的临床应用价值。     

多层螺旋CT对原发性高血压病心功能相关性研究

目的应用64层螺旋CT对原发性高血压病心功能进行评估,探讨其主要CT表现。方法高血压病例127例,按世界卫生组织高血压诊断标准将其分为高血压Ⅰ、Ⅱ、Ⅲ级组。正常对照组21人。均行多层螺旋CT心脏成像扫描,经心脏分析软件包处理后分别计算出体表面积、左室射血分数、左室舒张末期容积、左室收缩末期容积、每搏输出量、心指数、左室心肌质量等参数,并进行统计学分析。结果高血压病Ⅰ级组46例主要为心肌肥厚改变(P<0.05),高血压病Ⅱ级组38例逐步出现心肌几何构形重构,高血压Ⅲ级组43例心脏离心性重构,心功能减低,左室舒张及收缩末期容积升高,射血分数、每搏输出量、每分输出量、心指数均减低(各组均P<0.05)。结论原发性高血压病心脏改变是从向心性重构到离心性重构,从心功能代偿到失代偿动态过程;64层CT可全面客观评价原发性高血压病心脏功能。     

MRI对肥厚性心肌病解剖及功能评价

目的：探讨MRI对肥厚性心肌病(HCM)解剖及功能评价的临床应用价值。方法：对18例经病史、临床表现、心电图及超声心动图检查(UCG)诊断为HCM的患者，进行MRI扫描，并用ARGUS专用心功能分析软件计算左室心肌质量、左室舒张末期容积和射血分数等参数。比较UCG和MRI检测心脏解剖和功能的作用。结果：①HCM主要累及室间隔及左室前、侧壁，呈非对称性分布。②MRI和UCG在检测左室心肌质量、左室舒张末期容积及射血分数时，2种技术无显著性差异。结论：MRI能全面了解心脏解剖和功能异常，有重要的临床应用价值。     

心脏MR成像:对临床常规用于左心室整体和局部功能评估的心音门控电影成像的评价

目的验证心音门控(PCG)MR电影成像法可用于左心室(LV)功能的评估。方法在本项前瞻性研究中,应用1.5TMR回顾性心音门控和回顾性心电门控的稳态自由进动序列(SSFP),对79例病人进行2次LV的MR电影成像。评估舒张末期容积(EDV)、收缩末期容积(ESV)、每搏输出量     

中华小型猪心肌微循环障碍的影像学研究

目的：MSCT、MRI和SPECT对中华小型猪心肌微循环障碍的显示效果。方法：中华小型猪8只,全部雄性,体重（22．8±0．9）kg。实验猪接受MSCT扫描1次后1周内于前降支中远段注射105直径约100um微球,术后27天行SPECT,28天行造影、MSCT和MRI检查各1次,最后处死动物送病理检查。结果：4只实验猪死亡,其余4只完成所有检查。病理染色未均见梗死。术前与术后28天MSCT扫描测量每搏输出量、收缩末期容积、舒张末期容积和射血分数的差异均无统计学意义（P〉0．05）。术前与术后28天的MSCT扫描测量左室前壁、左室侧壁及室间隔的平均CT值在动脉期、延迟1、3、5和10min自身对照均没有统计学差异。术后28天的左室前壁、左室侧壁及室间隔在MSCT动脉期均未见异常灌注减低区域,延迟扫描也未出现强化;MRI均未见异常灌注减低区域,延迟扫描也未见强化;SPECT扫描示上述区域均未见明显灌注减低区域。结论：MSCT、MRI和SPECT对于没有明显病理染色的梗死区域及心功能变化的微循环障碍显示是受限的。     

MRI评价原发性扩张型心肌病患者左、右心室功能的对照研究

目的:探讨磁共振成像技术在评价原发性扩张型心肌病(IDCM)患者左、右心室功能中的临床应用价值.方法:对42个原发性扩张型心肌病患者行磁共振检查,平均年龄(54.81±13.99)岁;纽约心脏协会(NYHA)心功分级Ⅰ～Ⅱ级者11例,Ⅲ级者16例,Ⅳ级者15例.同时选择44例志愿者作为止常对照组.采用GESign 1.5T超导MR机,应用心脏专用8通道阵列线圈,采用快速稳态进动成像序列(FIESTA)行左、右室短轴电影成像,用argus软件mass analysis分别描记左、右室心内、外膜界面,自动画出左、右室容积-时间变化曲线,测得左、右心窒舒张末期容积参数和功能参数,并对正常志愿者组与患者组临床资料及左、右两侧心室功能数据结果进行比较.结果:两组一般资料结果比较性别和心率差异有统计学意义;患者组与正常对照组的心功能参数差异有统计学意义(P<0.0001),患者组EF、LVPER和LVPFR比正常对照组比较减小,患者组EDV、ESV、LVEDD、LVLAD和MM与正常对照组比较扩大;IDCM组室壁增厚率明显小于正常对照组;患者组临床心功能分级与左室相关良好,与右室心功能部分参数差异有统计学意义.结论:磁共振电影成像可准确测定原发性扩张型心肌病的左、右室心功能参数,重复性好,与NYHA心功能分级有良好的相关性.     

320排CT评价右心室功能的对照研究:与1.5T磁共振心脏成像比较

目的 与1.5T 磁共振成像对比,探讨320排CT心功能扫描模式(cardiac function angiography,CFA)评价右心室心功能的能力.方法 测量分析50例常规就诊患者应用320排CT CFA扫描数据,与心脏核磁共振成像(cardiac MR imaging,CMR)结果对比,统计分析右室射血分数(right ventricular ejection fraction,RVEF)、右心室舒张末期容积(right ventricular end-diastolic volume,RVEDV)、收缩末期容积(right ventricular end- systolic volume,RVESV)、每搏输出量(right ventricular stroke volume,RVSV)、心排血量 (cardiac output,RVCO)各测量值与CMR各测量值的相关性和差异.结果 (1)与CMR结果对照,320排CT对本组的RVEDV、RVESV 、RVEF、RVSV、RVCO各参数测量结果有显著的相关性(n=50,r=0.944～0.990,P＜0.001).除RVEF测量结果差异无显著性意义外,RVEDV、RVESV、RVSV、RVCO均显示有低估.(2)应用CFA技术,平均延迟时间(9.32±1.77) s,平均射线剂量(2.73±0.47) mSv.结论 应用CFA扫描模式,320排CT可以准确描述右心室功能变化.     

MSCT与超声心动图评价成人左心室整体收缩功能的对比研究

目的 与超声心动图对比,探讨MSCT评估左室整体收缩功能与超声心动图的相关性,评价MSCT测量左室整体收缩功能的可行性及准确性.方法 回顾性分析MSCT冠状动脉CTA检查的50例患者的资料,以10％ R-R间期间隔重建图像,测定出左心室舒张末期容积(EDV)、收缩末期容积(ESV)、每搏输出量(SV)、左室射血分数(EF),同时进行超声心动图检查,与超声心动图所测得的相应指标进行相关性分析.结果 10％R-R间期间隔测定的心功能指标与超声心动图检查的各项指标的相关性很高,r在(0.70～0.96)之间,EDV、ESV、SV值:MSCT＞超声心动图,EF值:MSCT≤超声心动图.结论 MSCT冠状动脉造影检查所获得的整体心功能指标数据较准确、可靠,具有较高的临床应用价值,临床可应用10％R-R间期间隔重建图像测定心功能,相对简便快捷.     

多层螺旋CT评估左心室功能的应用进展

左心室功能评估对心脏疾病的诊断、风险分层、治疗及预后分析具有重要意义。心脏CT血管成像(CCTA)作为一种无创性成像技术,目前在心脏疾病的诊断中发挥着越来越重要的作用,它既可评估冠状动脉狭窄,也能获取左心室容积和功能方面的信息。64层及以上的多层螺旋CT(MSCT)可一站式评价冠状动脉和左心室功能,无需对比剂和辐射的重复暴露,心功能分析结果可重复性高,具有较高的临床应用价值。     

Abolition of Respiratory-Motion Artifact in Computed Tomography Coronary Angiography with Ultrafast Examinations: A Comparison Between 64-row and 320-row Multidetector Scanners

Purpose

To compare the incidence of respiratory artifact in computed tomography (CT) coronary angiography performed with 64-row and 320-row multidetector scanners and to assess its effect on coronary evaluability.

Methods

A retrospective review of consecutive coronary angiograms performed on a 64-row multidetector CT from March to April 2007 (group 1: 115 patients, 63 men; mean age [standard deviation] 59.6 ± 12.8 years) and on a 320-row multidetector CT from March to April 2008 (group 2: 169 patients, 89 men; mean [SD] age 57.9 ± 11.6 years). Two cardiac radiologists assessed the occurrence of respiratory artifact and coronary evaluability in studies with respiratory artifacts. Unevaluable coronary segments because of motion at the same anatomical level of the respiratory artifact were considered unevaluable because of this artifact. The association between the occurrence of respiratory artifact and patient biometrics, medication, and scan parameters was examined.

Results

Respiratory artifacts were detected in 9 of the 115 patients from group 1 (7.8%) and in none of the 169 patients from group 2 (P < .001). Group 1 had longer scan times (median, 9.3 seconds; range, 7.5−14.4 seconds) compared with group 2 (median, 1.5 seconds; range, 1.1−3.5 seconds; P < .001). In group 1, 4 patients (3.5%) showed unevaluable coronary segments because of respiratory artifacts, and the CT coronary angiography was repeated in 1 patient (0.9%).

Conclusions

Respiratory artifacts are important in CT coronary angiography performed with 64-row multidetector scanners and impair the diagnostic utility of the examination in up to 3.5% of the studies. These artifacts can be virtually eliminated with a faster scan time provided by 320-row multidetector CT.     

Left ventricular ejection fraction using 64-slice CT coronary angiography and new evaluation software: initial experience

The purpose of this study was to evaluate the feasibility and reliability of software-based quantification of left ventricular function using 64-slice CT coronary angiography. Data were collected from 26 subjects who underwent a 64-slice coronary CT angiography study. Two volumetric data sets at end diastole and end systole were reconstructed from each scan by means of retrospective electrocardiogram gating. Data sets were evaluated with a prototype of now commercially available software (Syngo Circulation I; Siemens Medical Solutions, Erlangen, Germany), which automatically segments the blood volume in the left ventricle after the user defines the mitral valve plane and any point within the ventricle. After segmentation of the blood pool in end systole and end diastole, the software automatically measures end systolic and end diastolic volume and calculates stroke volume and ejection fraction (EF). Two readers processed all CT data sets twice to assess for intra- and inter-observer variation. In addition, CT EF measurements were compared with those obtained by clinical echocardiography. Intra-observer variation for the calculated EF with CT were 13.6% and 15.6% for Readers 1 and 2, respectively. No significant difference in left ventricular functional parameters on CT existed between the readers (p > 0.05). A Bland-Altman plot revealed a slight mean difference between EF measurements on CT and echocardiography, with all differences falling within two standard deviations of the mean in the setting of wide limits of agreement. In conclusion, assessment of left ventricular EF from CT coronary data using the new analysis software is rapid and easy. The software is user-friendly and provides good reproducibility for EF measurements with CT.     

Introduction to coronary imaging with 64-slice computed tomography

The aim of this article is to illustrate the main technical improvements in the last generation of 64-row CT scanners and the possible applications in coronary angiography. In particular, we describe the new physical components (X-ray tube-detectors system) and the general scan and reconstruction parameters. We then define the scan protocols for coronary angiography with the new generation of 64-row CT scanners to enable radiologists to perform a CT study on the basis of the diagnostic possibilities.     

Recurrent coronary artery stenosis: assessment with three-dimensional MR imaging

PURPOSE: To assess the diagnostic value of three-dimensional coronary magnetic resonance (MR) angiography with fat saturation and navigator echo in the setting of restenosis after percutaneous transluminal coronary angioplasty (PTCA). MATERIALS AND METHODS: Thirty consecutive patients who had PTCA and were referred for elective coronary reangiography underwent MR imaging and coronary angiography. The pulse sequence was a cardiac triggered, single-slab, three-dimensional, gradient-echo sequence, employing a spin-echo navigator echo measurement to track the variation of the diaphragm during the scan. The following segments of the coronary arteries were included in this prospective study: left main coronary artery, proximal and middle left anterior descending, proximal and middle left circumflex, proximal and middle right coronary artery, and intermediate branch, if present. The quality of the MR images was graded from 0 to 5. RESULTS: In total, 221 coronary artery segments could be identified. Mean image quality was 3.3. Overall accuracy for segments with an image quality of grade 2 or more was 90%. To achieve a positive predictive value >70% for a significant stenosis/restenosis, only segments with quality >/=3 could be assessed, whereas an acceptable negative predictive value could be achieved for nearly all segments. CONCLUSION: Our preliminary data suggest that MR coronary angiography may be most helpful as a screening test in selected patients to exclude clinically relevant stenoses or to assess restenoses after PTCA or in patients in whose coronary angiography is relatively contraindicated.     

Coronary artery stenosis: direct comparison of four-section multi-detector row CT and 3D navigator MR imaging for detection--initial results

PURPOSE: To prospectively compare the diagnostic accuracy of multi-detector row computed tomography (CT) and of three-dimensional (3D) navigator magnetic resonance (MR) imaging in patients referred for conventional coronary angiography for detection of coronary artery stenosis. MATERIALS AND METHODS: All patients gave written informed consent for the study, which was approved by the local ethics committee. Twenty-seven patients underwent multi-detector row CT and 3D navigator free-breathing MR imaging a mean of 5 days before undergoing invasive coronary angiography. The acquired multi-detector row CT and MR images were graded for the presence of greater than 50% stenosis in vessels larger than 1.5 mm in diameter. The diagnostic accuracies of the two examinations were compared with that of quantitative coronary angiography (QCA) by using the McNemar test. RESULTS: Owing to claustrophobia, MR images were not acquired in one patient; thus, 26 patients were included for analysis. According to QCA findings, 21 of the 26 patients had significant coronary artery disease and 58 (20%) of a total of 294 coronary artery segments larger than 1.5 mm in diameter had significant (>50%) stenosis. Multi-detector row CT had significantly higher sensitivity (46 [79%] of 58 segments) than MR imaging (36 [62%] segments, P < .05) for detection of segments with significant stenosis. Conversely, MR imaging had significantly higher specificity (198 [84%] of 236 segments) than did CT (168 [71%] segments, P < .001) for exclusion of segmental coronary artery stenosis. Both examinations had high negative predictive value for exclusion of segmental stenosis: 93% (168 of 180 segments) for CT and 90% (198 of 220 segments) for MR imaging. The overall diagnostic accuracy of MR imaging (80% [234 of 294 segments]) was significantly higher than that of CT (73% [214 segments], P < .05). CONCLUSION: MR imaging had significantly higher diagnostic accuracy than multi-detector row CT in the evaluation of coronary artery stenosis. Both techniques have high negative predictive value, making them particularly useful for ruling out coronary artery disease in symptomatic patients.     

64排螺旋CT冠状动脉成像注射后延迟时间的影响因素

目的 探讨64排螺旋CT冠状动脉成像中心率、体重指数(BMI)、年龄、性别与冠状动脉CT血管造影(CTA)成像延迟扫描时间的相关性及与冠状动脉达峰CT值的相关性.资料与方法 150例可疑冠心病的受检者,男70例,女80例,年龄最大88岁,最小31岁,平均54岁.所有受检者均行timing bolus扫描技术预测冠状动脉CTA延迟扫描时间,然后行冠状动脉CTA扫描,记录冠状动脉达峰CT值、延迟扫描时间,分析性别、年龄、体重指数、心率与冠状动脉CTA延迟扫描时间及冠状动脉达峰CT值的相关性.结果 体重指数对冠状动脉达峰时间影响差异无统计学意义(P=0.157),性别的标准回归系数为-0.395,对冠状动脉达峰时间影响最大,其次是年龄,影响最小为心率;心率对冠状动脉达峰CT值影响差异无统计学意义(P=0.202),性别标准回归系数为0.462,对冠状动脉达峰CT值影响较大,其次为体重指数,影响最小为年龄.结论 当timing bolus扫描预测冠状动脉CTA达峰延迟扫描时间时,对老年、男性、心率较慢者,应综合考虑,适当增加延迟扫描时间.     

Diagnostic accuracy of 64 multislice CT angiography in the assessment of coronary in-stent restenosis: A meta-analysis

Purpose

The aim of this study was to perform a meta-analysis of the diagnostic accuracy of 64-slice CT angiography for the detection of coronary in-stent restenosis in patients treated with coronary stents when compared to conventional coronary angiography.

Materials and methods

A search of PUBMED/MEDLINE, ProQuest and Cochrane library databases for English literature was performed. Only studies comparing 64-slice CT angiography with conventional coronary angiography for the detection of coronary in-stent restenosis (more than 50% stenosis) were included for analysis. Sensitivity and specificity estimates pooled across studies were tested using a fixed effects model.

Results

Fourteen studies met selection criteria for inclusion in the analysis. The mean value of assessable stents was 89%. Prevalence of in-stent restenosis following coronary stenting was 20% among these studies. Pooled estimates of the sensitivity and specificity of overall 64-slice CT angiography for the detection of coronary in-stent restenosis was 90% (95% CI: 86%, 94%) and 91% (95% CI: 90%, 93%), respectively, based on the evaluation of assessable stents. Diagnostic value of 64-slice CT angiography was found to decrease significantly when the analysis was performed with inclusion of nonassessable segments in five studies, with pooled sensitivity and specificity being 79% (95% CI: 68%, 88%) and 81% (95% CI: 77%, 84%). Stent diameter is the main factor affecting the diagnostic value of 64-slice CT angiography.

Conclusion

Our results showed that 64-slice CT angiography has high diagnostic value (both sensitivity and specificity) for detection of coronary in-stent restenosis based on assessable segments when compared to conventional coronary angiography.     

双源CT低剂量适应性序列扫描对高心率冠状动脉成像的初步研究

目的 研究双源CT低剂量适应性序列扫描技术在高心率患者冠状动脉CTA的应用,并评价其图像质量.方法 将72例心率70次/min(bpm)以上行冠状动脉CTA检查的患者按扫描方式分为2组.A组40例行适应性序列扫描.B组32例行常规回顾性心电门控螺旋扫描.对2组扫描的冠状动脉分别做图像处理,应用秩和检验比较2组患者冠状动脉段图像质量总体评分,应用两独立样本t检验比较2组患者辐射剂量.结果 A组评价501段冠状动脉,B组评价400段冠状动脉.可评价的冠状动脉段图像质量评分平均秩次,A组为475.42,B组为420.41,2组间比较差异有统计学意义(Z=-3.509,P=0.000).平均有效剂量A组为(6.2±0.9)mSv,B组为(14.7 ±1.9)mSv,2组间差异有统计学意义(t=-27.011,P=0.000).结论 适应性序列扫描对高心率患者冠状动脉CTA检查具有可行性,该技术能显著降低辐射剂量而保证诊断所需图像质量.     

Diagnostic performance of multidetector CT angiography for assessment of coronary artery disease: meta-analysis

PURPOSE: To review the literature on the diagnostic performance of multidetector computed tomographic (CT) angiography for assessment of symptomatic coronary artery disease, with conventional coronary angiography as the reference standard. MATERIALS AND METHODS: A PubMed and manual search of the literature published between January 1998 and May 2006 on use of multidetector CT angiography compared with coronary angiography in patients with symptomatic coronary artery disease was performed. Summary estimates of diagnostic odds ratio, sensitivity, and specificity were calculated. Random-effects models were used to compare the diagnostic performance of four-, 16-, and 64-detector CT angiographic units, and the proportion of nonassessable coronary arterial segments was evaluated. RESULTS: Fifty-four studies were included in the meta-analysis: 22 studies with four-detector CT angiography, 26 with 16-detector CT angiography, and six with 64-detector CT angiography. The pooled sensitivity and specificity for detecting a greater than 50% stenosis per segment were 0.93 (95% confidence interval [CI]: 0.88, 0.97) and 0.96 (95% CI: 0.96, 0.97) for 64-detector CT angiography, 0.83 (95% CI: 0.76, 0.90) and 0.96 (95% CI: 0.95, 0.97) for 16-detector CT angiography, and 0.84 (95% CI: 0.81, 0.88) and 0.93 (95% CI: 0.91, 0.95) for four-detector CT angiography, respectively. Results of regression analysis indicated that the diagnostic performance significantly improved with the newer generations of multidetector CT scanners (64- and 16-detector vs four-detector units), adjusted for exclusion of nonassessable segments, and contrast agent concentration used (P < .05). Simultaneously, the nonassessable proportion of segments significantly decreased with the newer generations of multidetector CT scanners, adjusted for heart rate, prevalence of significant disease, and mean age. CONCLUSION: With the newer generations of multidetector CT scanners, the diagnostic performance for the assessment of coronary artery disease has significantly improved, and the proportion of nonassessable segments has decreased.     

Intraindividual comparison of 3D coronary MR angiography and coronary CT angiography

RATIONALE AND OBJECTIVES: To compare the diagnostic value of magnetic resonance (MR) and computed tomography (CT) for the detection of coronary artery disease (CAD) with special regard to calcifications. MATERIALS AND METHODS: Twenty-seven patients with known CAD were examined with a targeted, navigator-gated, free-breathing, steady-state free precession MR angiography sequence (repetition time = 5.6 milliseconds, echo time = 2.8 milliseconds, flip angle 110 degrees ) and 16-slice coronary CT angiography. Segment-based sensitivity, specificity, and accuracy for the detection of stenoses larger than 50% were determined as defined by the gold standard catheter coronary angiography along with the subjective image quality (Grade 1-4). The degree of calcifications in each segment was quantified using a standard calcium scoring tool. RESULTS: Of 115 possible segments, 7% had to be excluded in MR imaging because of poor image quality. In CT, 3% were nondiagnostic because of image quality and 15% were not evaluable because of calcifications. Values for the detection of relevant coronary artery stenoses in the evaluated segments were: sensitivity: MR imaging 85% versus CT 96%; specificity: 88% versus 96%; accuracy: 87% versus. 96%. Average subjective image quality was 1.8 for MR imaging and 1.6 for CT. Of the 15% of segments that had to be excluded from CT evaluation because of calcifications, MR imaging provided the correct diagnosis segments in 67%. CONCLUSIONS: CT provided a better image quality with superior accuracy for the detection of CAD. Despite its overall inferiority, MR imaging proved to be helpful method in interpreting coronary stenosis in severely calcified segments.