64层CT与血管内超声对冠状动脉粥样斑块的定性和定量评估的对照研究

目的 对照血管内超声（intravascular ultrasound,IVUS）评价64层CT对冠状动脉粥样斑块的定性检测和定量分析。方法 2005年7月至10月连续纳入12例拟行PCI的稳定性心绞痛患者进行研究。所有患者术前接受64层CT的冠状动脉成像,术中行三支冠状动脉（左前降支、回旋支和右冠状动脉）的IVUS检查。结果 共对31支血管（左前降支12支,回旋支10支,右冠状动脉9支）,88个节段进行了64层CT和IVUS的对比检查,其中64层CT可评价节段为68个。在IVUS检测到的51个有斑块节段中,64层CT检测出47个（敏感性92％）,在17个IVUS判断为无斑块的节段中,64层CT判断16个为无斑块（特异性94％）。64层CT测量的斑块面积和IVUS测量的斑块面积相关（r=0．53,P〈0．01）,但是高估了斑块面积[（9．09±3．89）mm。比（6．80±2．81）mm^2,P〈0．01]。64层CT在43个IVUS测定的低回声成分中检出30个为低密度成分,平均CT值67．39HU。结论 冠状动脉无严重钙化时,64层CT可准确检测冠状动脉近中段粥样斑块。64层CT测量的斑块面积虽然和IVUS测量结果相关,但准确测量受限。     

16排螺旋CT对冠状动脉斑块的诊断价值

目的探讨16排螺旋CT（16-mulddetector spiral computed tomography,16-MDCT）检测和区分冠状动脉斑块的准确性。方法对2005年8月至2006年3月68例拟诊为冠心病的患者先行16-MDCT检查,4天内再行定量冠状动脉造影（QCA）和血管内超声（IVUS）检查,冠状动脉血管腔直径狭窄（DS）≥50％定义为有意义的狭窄,分别测量斑块的CT密度,单位为CT值（Hounsfield units,HU）,根据冠状动脉斑块的CT值区分斑块性质并作出分类：（1）软斑块：CT值为≤50HU;（2）纤维斑块（中等斑块）：CT值为50—119HU;（3）钙化斑块≥120HU。结果在112段16-MDCT和QCA均诊断为冠状动脉狭窄≥50％的病变中,其敏感性为91．8％（112／122）,特异性为97．8％（556／568）,共96段有意义的狭窄病变纳入研究,分别位于左前降支57段,左回旋支17段,右冠状动脉14段,左主干8段。IVUS发现软斑块21个（21．9％）、纤维斑块36个（37．5％）、钙化斑块38个（39．5％）,混合性斑块（纤维钙化斑块）1个（1．1％）,16-MDCT发现软斑块20个,平均CT值（11±36）HU（-27～42HU）、纤维斑块37个,平均CT值（83±20）Hu（58—105HU）、钙化斑块39个,平均CT值（292±80）HU（167—530HU）,差异有统计学意义（P〈0．05）。结论无创性16排螺旋CT冠状动脉成像技术不仅可诊断冠状动脉狭窄病变,同时对区分钙化斑块及非钙化斑块有较高的诊断价值。     

冠状动脉CT血管成像及血管内超声诊断冠脉钙化病变的比较

目的:比较冠状动脉CT血管成像(CTA)与血管内超声(IVUS)诊断冠状动脉钙化病变的效果。方法:选择经我院临床诊断为冠心病或疑似冠心病患者50例为研究对象,所有患者均行冠状动脉CTA、IVUS检查,观察冠状动脉斑块特征、不同类型斑块CT值,以血管内超声为对照,评估冠状动脉CTA诊断效果。结果:两种检测方法在斑块面积、斑块负荷、管腔面积方面比较差异无统计学意义;钙化斑块CT值明显高于纤维斑块和脂质斑块[(725.68±68.42)Hu比(58.12±7.05)Hu、(60.21±6.78)Hu,P均<0.01];冠状动脉CTA诊断钙化斑块灵敏度、特异性、准确性、阳性预测值、阴性预测值分别为92.86%、92.86%、92.86%、81.25%、97.50%。结论:冠状动脉CT血管成像在冠状动脉钙化病变定性定量检测中,具有较高的诊断效果,可以作为筛查的首选方法。     

64层螺旋CT冠状动脉成像与血管内超声评估冠状动脉临界病变的对比研究

目的评价64层CT冠状动脉成像(SCTCA)对冠状动脉临界病变狭窄程度和斑块性质判断的准确度。方法 50例拟诊或确诊冠心病患者分别行64层SCTCA和血管内超声(IVUS),并以IVUS结果作为标准进行对比分析。结果 64层SCTCA诊断冠状动脉临界狭窄的敏感性、特异性、准确性分别为88.9%、96.6%、94.8%;准确检出了28处脂质斑块中的23处、15处纤维斑块中的12处及11处钙化性斑块中的10处。结论 64层SCTCA评估冠状动脉临界病变具有较高的准确性,值得推广。     

多排螺旋CT对冠状动脉斑块特征评价的精确性与血管内超声的比较

目的:对比血管内超声(IVUS),评价多排螺旋CT(MSCT)判断冠状动脉粥样硬化斑块特征的精确性.方法:连续性入选2007-08-2008-12期间在解放军总医院心内科诊断为冠心病并行MSCT、IVUS检查者,分别利用IVUS、MSCT方法测量同一病变的同一截面的血管截面积(V-CSA)、管腔截面积(L-CSA)、狭窄程度、斑块负荷(BP)、重构指数(RI)等指标;对比IVUS,计算MSCT判断狭窄程度及斑块性质的敏感性、特异性、阳性预测值(PPV)、阴性预测值(NPV).结果:与IVUS对比,MSCT显示冠状动脉粥样硬化斑块的敏感性为98.0%,特异性为90.1%,PPV为93.0%,NPV为97.0%;显示狭窄程度＞50.0%病变的敏感性为96.5%,特异性为97.1%,PPV为98.2%,NPV为94.3%;MSCT与IVUS测量冠状动脉同一病变同一截面下的V-CSA、L-CSA、BP及RI,各指标之间存在明显直线相关关系;MSCT判断脂质斑块的敏感性为88.9%,特异性为84.9%;纤维斑块的敏感性为73.3%,特异性为91.2%;钙化斑块的敏感性为95.7%,特异性为100%.结论:MSCT在诊断冠心病、判断冠状动脉粥样硬化斑块特征方面有较好的精确性,可做为无创性评估易损斑块的手段.     

老年冠心病合并2型糖尿病患者冠状动脉粥样硬化斑块钙化特征

目的探讨老年冠心病合并2型糖尿病患者冠状动脉粥样硬化斑块钙化的总负荷和钙化特征。方法选择稳定性心绞痛患者72例,其中合并2型糖尿病40例(糖尿病组),无糖尿病32例(非糖尿病组)。均行冠状动脉造影,选取一处狭窄50%～70%的斑块进行血管内超声检查。测量斑块钙化弧面积,如果同一斑块内有多个钙化,分别测量每个钙化的弧面积,并将每个弧面积相加得到钙化总负荷,并记录每个斑块内钙化数量。结果与非糖尿病组比较,糖尿病组患者斑块钙化弧面积明显增大,钙化数量明显增多[(1343.0±1007.3)度×mm vs(707.7±589.0)度×mm,(2.4±2.0)个vs(1.4±1.3)个,P<0.05];糖尿病组与非糖尿病组每个钙化弧面积比较差异无统计学意义(P>0.05)。结论老年冠心病合并糖尿病患者冠状动脉钙化负荷更重,这种负荷的加重是由于斑块内钙化数量的增加所致,合并和不合并糖尿病的老年冠心病患者冠状动脉粥样硬化斑块钙化数量相同。     

320排CT在冠状动脉钙化斑块与非钙化斑块狭窄对比研究中的应用

目的按钙化斑块与非钙化斑块进行分类,对照冠状动脉造影(CAG),研究320排CT对冠状动脉粥样硬化斑块狭窄程度判断的准确性、影响因素及解决方法。方法 102名患者行320排CT冠状动脉血管成像(CTA)检查共发现396个冠状动脉斑块,同期行CAG检查,对斑块造成管腔狭窄程度按无、轻、中、重、闭塞5个级别计算两种方法的符合率。按钙化、非钙化斑块分类计算符合率。钙化斑块按钙化阈值>150 HU、>250 HU、>350 HU、>600 HU共4个方案进行计算。结果 CTA显示钙化斑块占68.2%,非钙化斑块占31.8%。6%的斑块为不稳定斑块。7.8%的斑块不导致狭窄。钙化阈值设定>150 HU、>250 HU、>350 HU的符合率测量无明显差异,但>600 HU时有减低。CTA显示冠状动脉斑块性狭窄与CAG符合率为88.4%(非钙化斑块94.4%,钙化斑块85.6%,二者差异显著)。不相符多表现于对钙化斑块狭窄程度的高估。结论与CAG对照,冠状动脉CTA显示斑块狭窄符合率较高(88.4%),其中非钙化斑块狭窄符合率(94.4%)明显高于钙化斑块(85.6%);少数病例存在对钙化斑块狭窄程度的高估。因此CTA在非钙化斑块诊断上具有明显优势,钙化阈值设为>350 HU较合适。     

血管内超声在冠状动脉介入诊治中的运用

目的观察运用血管内超声(Intravascular ultrasound IVUS)测定冠脉病变血管的价值及安全性。方法30例冠心病患者,共46支冠状动脉血管在冠状动脉造影(Coronary angiography CAG)后行IVUS检查。IVUS测量狭窄段血管直径和截面积、斑块性质,与相应部位定量的冠状动脉造影(Quantitative coronary angiographyQCA)的结果比较。结果QCA检出偏心性狭窄25处(54.3%);IVUS检出偏心性狭窄32处(69.6%)(P<0.05)。IVUS发现30处(65.2%)靶血管病变钙化,而CAG检出18处(39.1%)血管病变钙化(P<0.01)。CAG和IVUS检出病变血管直径狭窄率分别为62.15%和74.35%(P<0.01)。46处(100%)靶血管完成IVUS检查,34处血管介入后复查,其中1处IVUS导管无法通过支架,IVUS检出不理想支架释放8处(24.2%)。所有患者随访1个月以上,未发现严重心脏缺血事件。结论IVUS可以准确地识别冠状动脉管腔形态、斑块性质,有助于冠脉介入手术策略的选择,是对CAG的有效补充,IVUS检查本身比较安全。     

血管内超声、64层螺旋CT及定量冠状动脉造影对不稳定性心绞痛患者冠状动脉病变的评价

目的 应用血管内超声(rvos)探讨不稳定性心绞痛(UAP)低、中及高危组患者动脉粥样硬化斑块的特点,评价定量冠状动脉造影(QCA)和64层螺旋CT(MDCT)的诊断价值.方法 采用IVUS、MDCT和QCA分析61例UAP患者(低危组17例,中危组33例,高危组11例)71支病变血管.分析比较3组患者斑块的形态学特点.根据IVUS斑块回声的强度,将斑块分为软斑块、纤维斑块、钙化斑块、混合斑块,计算最小面积处斑块负荷,并分为≤50%、51%～74%及≥75%3类病变.以IVUS结果为标准,评价QCA计算血管狭窄程度的可信性,MDCT诊断3类病变的敏感性和特异性,及对斑块成分诊断的可靠性.结果 QCA可估计低危组和中危组患者的斑块负荷(低危组r=0.768,P<0.01;中危组r=0.721,P<0.01).高危组患者血管重构明显(冠状动脉重构指数=1.21±0.31),QCA低估了IVUS的斑块负荷[分别为(67±14)%、(75±16)%,r=0.551,P<0.01].MDCT对冠状动脉病变有较高的阴性预测值(87.8%-96.3%),但无法区分典型粥样硬化斑块内的纤维帽(kappa=0.245)及脂质核(kappa=0.235).3组患者IVUS斑块特点分析结果表明,随着危险度程度的增加,软斑块比例、血管正性重构程度、血管外弹力膜面积、最小管腔面积、斑块负荷、斑块破裂及血栓发生率逐渐增加.结论 QCA可以相对准确地评价UAP低危和中危组患者的冠状动脉狭窄程度,同时会低估高危组患者的病变程度.MDCT对于冠心病的诊断有非常高的阴性预测值可用于排除冠心病,但是无法可靠地区分粥样硬化斑块内的纤维帽及脂质核.IVUS检查显示软斑块、正性血管重构和最小管腔面积<4mm~2者可能为UAP高危组患者.     

光学相干断层扫描比较不稳定性和稳定性心绞痛患者粥样硬化斑块特征

目的 应用光学相干断层成像(OCT)技术比较不稳定性心绞痛(UAP)和稳定性心绞痛(SAP)患者冠状动脉粥样硬化斑块特征.方法 对临床诊断的23例UAP和24例SAP患者,在完成冠状动脉造影并确诊冠心病后进行OCT检查.根据OCT结果 回顾性比较分析UAP和SAP患者冠状动脉粥样硬化斑块特征,包括富含脂质斑块(≥2个象限的脂质斑块)、斑块纤维帽厚度、薄纤维帽粥样斑块(TCFA)、斑块破裂、钙化和血栓等.结果 47例患者中有44例成功进行OCT检查,包括22例UAP和22例SAP患者.UAP患者冠状动脉富含脂质斑块为91%(20/22),多于SAP患者的73%(16/22),但差异无统计学意义(P=0.741).UAP患者冠状动脉脂质斑块表面纤维帽厚度明显小于SAP患者[(69.5±34.7)μm比(141.1±68.5)μm,P=0.000],纤维帽侵蚀比例为59%(13/22),明显多于SAP患者的9%(2/22,P=0.000);TCFA[73%(16/22)比14%(3/22),P=0.000]和斑块破裂[50%(11/22)比9%(2/22),P=0.003]多于SAP患者.UAP患者冠状动脉斑块表而可见血栓形成多于SAP患者,但差异无统计学意义[27%(6/22)比9%(2/22),P=0.761].在斑块钙化方面,UAP与SAP患者之间差异无统计学意义.结论 OCT技术可清晰显示冠状动脉粥样斑块特征.与SAP患者比较,UAP患者冠状动脉粥样硬化斑块表现为纤维帽更薄、更多的纤维帽侵蚀、更多的破裂斑块和TCFA.     

Characterization of coronary atherosclerotic plaques by multidetector computed tomography

Multidetector computed tomography (MDCT) provides 3-dimensional noninvasive visualization of the coronary arterial tree. We compared MDCT with intravascular ultrasound (IVUS) for assessment of severity of coronary artery stenosis and composition of atherosclerotic plaques in 40 patients (32 men; mean age 52 years, range 33 to 86) with documented coronary artery disease. Cross-sectional images obtained at 10-mm increments were assessed for percent decrease in luminal area. Atherosclerotic plaques were classified by IVUS as soft, fibrous, or calcified. On the matched multidetector computed tomograms, regions of interest of 1 to 3 mm in diameter were placed inside each plaque, and tissue contrast was measured in Hounsfield units. Obstructive coronary artery disease was found in 50 segments by IVUS and 57 segments by MDCT. Sensitivity for detecting obstruction >50% was 86.0% (95% confidence interval 72.6 to 93.7) and specificity was 90.2% (95% confidence interval 83.9 to 94.4). In total, 276 plaques were examined by IVUS and MDCT. There were 188 soft plaques (68.2%), 45 fibrous plaques (16.2%), and 43 calcified plaques (15.5%). Multidetector computed tomographic tissue contrast of soft, fibrous, and calcified plaques were 71.5 +/- 32.1, 116.3 +/- 35.7, and 383.3 +/- 186.1, respectively (p <0.001). Using a cut-off value of 185 HU, 273 of 276 plaques (99%) were correctly classified as calcified or noncalcified plaques. Using a cut-off value of 88 HU, 192 of 233 noncalcified plaques (82%) were correctly classified as fibrous or soft plaques. In conclusion, our data indicate that MDCT can provide important information concerning the composition of atherosclerotic plaques in addition to detecting luminal obstruction.     

Comparison between MDCT and Grayscale IVUS in a Quantitative Analysis of Coronary Lumen in Segments with or without Atherosclerotic Plaques

Background

The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques.

Objectives

We compared 64-slice multidetector computed tomography (MDCT) with gray scale intravascular ultrasound (IVUS) for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease.

Methods

The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient). A coronary plaque was diagnosed in segments with plaque burden > 40%.

Results

At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01). However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions.

Conclusions

In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques.     

Noninvasive tissue characterization of coronary arterial plaque by 16-slice computed tomography in acute coronary syndrome

Noninvasive characterization of coronary plaques is challenging for cardiologists. The authors' goal was to explore the clinical feasibility of newly developed 16-slice computed tomography (CT) in tissue characterization of coronary arterial plaques in patients with acute coronary syndrome. Sixteen patients with acute coronary syndrome underwent 16-slice CT (Aquillion, Toshiba) and coronary arteriography with intravascular ultrasound (IVUS) within 7 days. Twenty-three plaques were classified by IVUS according to plaque echogenicity: 6 soft plaques, 11 intermediate plaques, and 6 calcified plaques. Mean (+/- SD) CT numbers (Hounsfield units [HU]) of these 3 types of plaques were 50.6 +/-14.8 HU, 131 +/-21.0 HU, and 721 +/-231 HU, respectively. Sixteen-slice CT facilitates noninvasive tissue characterization of coronary arterial plaques.     

Atherosclerotic plaque characterization by 0.5-mm-slice multislice computed tomographic imaging.

BACKGROUND: It has been proposed that 0.5-mm-slice multislice computed tomography (MSCT) is a noninvasive tool for the detection of atherosclerotic plaque, but the validity of such an assessment has not been demonstrated by an invasive investigation. The present study was performed to compare the 0.5-mm-slice MSCT density of plaques with intravascular ultrasound (IVUS) findings. METHODS AND RESULTS: Atherosclerotic plaques were characterized in 37 consecutive patients undergoing percutaneous interventions. Based on the IVUS echogenecity, the plaques were classified as soft (n=18), fibrous (n=40) or calcified (n=40). In these 98 plaques, 0.5-mm-slice MSCT plaque density was calculated in 443 regions-of-interest, including 331 lesional foci and 112 luminal cross-sections, and represented as Hounsfield units (HU). MSCT density of the 3 types of plaque was 11+/-12 HU, 78+/-21 HU, and 516 +/-198 HU respectively. Computed tomography density of the (contrast-filled) lumen was 258+/-43 HU. There were statistically highly significant differences in the densitometric characteristics among the 4 groups (soft, fibrous, calcified plaque and lumen) by nonparametric Kruskal-Wallis test (p<0.0001). CONCLUSIONS: The IVUS-based coronary plaque configuration can be accurately identified by 0.5-mm slice MSCT. Noninvasive assessment of plaque characterization will ensure emphasis on the vessel wall beyond the vascular lumen.     

Contrast enhancement of coronary atherosclerotic plaque: a high-resolution, multidetector-row computed tomography study of pressure-perfused, human ex-vivo coronary arteries

OBJECTIVES: The objective of this study was to investigate the effect of contrast injection on atherosclerotic coronary plaque attenuation measured using multidetector-row computed tomography. BACKGROUND: Recent multidetector-row computed tomography studies have described the characterization of coronary atherosclerotic plaque on the basis of Hounsfield unit values. The influence of contrast injection on the attenuation of individual plaque components, however, is unknown. METHODS: Using a pressurized perfusion system, 10 human coronary arteries were examined postmortem with multidetector-row computed tomography and histology. Pre-enhanced, peak-enhanced, and delayed enhanced multidetector-row computed tomography images were acquired during continuous perfusion of the vessel. A total of 37 focal atherosclerotic plaques were identified. Vessel wall attenuation was measured from multidetector-row computed tomography images during all three enhancement phases. On the basis of the histology, plaques were categorized as noncalcified (predominantly fibrous or predominantly fibrofatty), mixed calcified (calcified fibrous or calcified necrotic core), or densely calcified. The mean Hounsfield unit was compared among contrast phases for all plaques and in plaque subgroups. RESULTS: We observed contrast enhancement of atherosclerotic plaques within the vessel wall. For noncalcified plaques including both fibrous and fibrofatty plaques, the mean Hounsfield unit of the vessel wall during and after contrast injection exceeded the mean value before injection (t-test, P<0.002). CONCLUSION: The present study demonstrates that intra-arterial injection of iodinated contrast agent results not only in luminal enhancement but also in atherosclerotic plaque enhancement in pressure-perfused coronary arteries imaged ex vivo. Plaque enhancement should be considered when characterizing plaque components on the basis of Hounsfield unit with multidetector-row computed tomography.     

Intravascular ultrasound assessment of remodelling and reference segment plaque burden in type-2 diabetic patients.

AIMS: Intravascular ultrasound (IVUS) assesses arterial remodelling by comparing the lesion external elastic membrane (EEM) with the reference segments; however, reference segments are rarely disease-free. The aim was to assess lesion and reference segment remodelling and plaque burden in patients with type-2 diabetes mellitus. METHODS AND RESULTS: We used pre-intervention IVUS to study 62 de novo lesions in 43 patients with type-2 diabetes mellitus. The lesion site was the image slice with the smallest lumen cross-sectional area (CSA). The proximal and distal reference segments were the most normal-looking segments within 5 mm proximal and distal to the lesion. Plaque burden was measured as plaque CSA/EEM CSA. The remodelling index was defined as lesion EEM CSA/mean reference EEM CSA. Reference segment plaque burden measured 0.54 +/- 0.09. The majority of lesions (83.9%) had negative remodelling (lesion EEM < reference). Similarly, the slope of the regression line relating EEM to plaque CSA within the lesion was less than the reference substantiating negative remodelling. The reference segment plaque burden correlated inversely with the difference between IVUS lumen and quantitative coronary angiographic artery size [slope = -0.12 (95% CI -0.17 to -0.07); P < 0.001] in all patients with type-2 diabetes mellitus. CONCLUSION: Lesions in type-2 diabetic patients are different from previous reports in non-diabetics. Lesions in type-2 diabetics are characterized by a large reference segment plaque burden and negative lesion site remodelling. These IVUS findings may explain the angiographic appearance of small arteries in diabetic patients.     

Non-invasive assessment of plaque rupture by 64-slice multidetector computed tomography--comparison with intravascular ultrasound

BACKGROUND: Plaque rupture and secondary thrombus formation play key roles in the onset of acute coronary syndrome (ACS). Multidetector computed tomography (MDCT) allows the non-invasive assessment of coronary artery stenosis and plaque properties. In this study, we investigated whether 64-slice MDCT could non-invasively detect a plaque rupture in patients with de novo angina. METHODS AND RESULTS: The study population comprised 67 patients with de novo angina. All patients underwent contrast-enhanced 64-slice MDCT and intravascular ultrasound (IVUS). Patients were divided into a plaque rupture group (n=27) and a non-rupture group (n=40) based on the IVUS. The 64-slice MDCT revealed that the prevalence of an ulcer-like enhancement space (37% vs 5%, p<0.01), a ring-like sign (41% vs 18%, p=0.04), in the plaque rupture group was higher than those in the non-rupture group. Maximum plaque thickness (2.1+/-0.9 mm vs 1.6+/-1.0 mm, p=0.04), outer vessel area (17.6+/-4.9 mm2 vs 13.4+/-5.0 mm2, p<0.01), percentage plaque area (82.3+/-9.1% vs 73.4+/-15.7%, p=0.01), and remodeling index (1.11+/-0.18 vs 1.01+/-0.15, p=0.04) of the plaque rupture group were all significantly larger than those of the non-rupture group. CONCLUSIONS: The 64-slice MDCT can identify differences in lesion morphologies between ruptured plaques and non-ruptured plaques. From our results, the 64-slice MDCT might provide a useful tool for the non-invasive detection of plaque rupture.