Reproducibility of quantitative plaque measurement in advanced coronary artery disease

BackgroundThe ability to characterize and to quantify the extent of coronary artery disease has the potential to improve the prognostic capability of coronary computed tomography angiography. Although reproducible techniques have been described in those with mild coronary disease, this has yet to be assessed in patients with advanced disease.MethodsTwenty patients with known multivessel disease underwent repeated computed tomography coronary angiography, 2 weeks apart. Coronary artery segments were analysed using semi-automated software by two trained observers to determine intraobserver, interobserver and interscan reproducibility.ResultsOverall, 149 coronary arterial segments were analysed. There was excellent intraobserver and interobserver agreement for all plaque volume measurements (Lin’s coefficient 0.95 to 1.0). There were no substantial interscan differences (P ?> ?0.05 for all) for total (2063 ?± ?1246 ?mm³, mean of differences ?35.6 ?mm³), non-calcified (1795 ?± ?910 ?mm³, mean of differences ?4.3 ?mm³), calcified (298 ?± ?425 ?mm³, mean of differences ?31.3 ?mm³) and low-attenuation (13 ?± ?13 ?mm³, mean of differences ?2.6 ?mm³) plaque volumes. Interscan agreement was highest for total and noncalcified plaque volumes. Calcified and low-attenuation plaque (?236.6 to 174 ?mm³ and -15.8 to 10.5 ?mm³ respectively) had relatively wider 95% limits of agreement reflecting the lower absolute plaque volumes.ConclusionIn the presence of advanced coronary disease, semi-automated plaque quantification provides excellent reproducibility, particularly for total and non-calcified plaque volumes. This approach has major potential to assess change in disease over time and optimize risk stratification in patients with established coronary artery disease.     

64层螺旋CT冠状动脉粥样硬化斑块稳定性分析

目的探讨64层螺旋CT冠状动脉成像在判别冠心病不同类型间斑块性质方面的价值。方法经冠状动脉造影(CAG)证实明确诊断为冠心病的患者126例,行64层螺旋CT冠状动脉成像,并对主要冠状动脉狭窄节段数、狭窄程度以及斑块性质进行比较。结果本组患者冠状动脉评估节段数368个,其中狭窄节段195个(35.4%)。狭窄<50%共98个节段,狭窄50%～75%共71个节段,狭窄>75%共26个节段(左前降支中段、近段、后降支中段、左回旋支近段),其中完全闭塞2个(右冠状动脉近段以远、左回旋支中段以远)。软斑块46个(27.3%),纤维斑块42个(31.5%),混合斑块78个(29.5%),钙化斑块93个(12.6%)。对应斑块测量的CT值分别为软斑块(17±26)HU,纤维斑块(97±35)HU,钙化斑块(489±195)HU。结论 64层螺旋CT冠状动脉成像有助于显示斑块性质。     

Coronary plaque imaging by coronary computed tomography angiography

Coronary computed tomography angiography (CTA) has become the useful noninvasive imaging modality alternative to the invasive coronary angiography for detecting coronary artery stenoses in patients with suspected coronary artery disease (CAD). With the development of technical aspects of coronary CTA, clinical practice and research are increasingly shifting toward defining the clinical implication of plaque morphology and patients outcomes by coronary CTA. In this review we discuss the coronary plaque morphology estimated by CTA beyond coronary angiography including the comparison to the currently available other imaging modalities used to examine morphological characteristics of the atherosclerotic plaque. Furthermore, this review underlies the value of a combined assessment of coronary anatomy and myocardial perfusion in patients with CAD, and adds to an increasing body of evidence suggesting an added diagnostic value when combining both modalities. We hope that an integrated, multi-modality imaging approach will become the gold standard for noninvasive evaluation of coronary plaque morphology and outcome data in clinical practice.     

64排CTA对冠状动脉埋藏式走行的诊断价值

目的:探讨64排128层螺旋CT对先天性冠状动脉起源异常及埋藏式走行的诊断价值。方法:回顾性分析25例冠脉起源异常患者的64排128层CT冠脉血管成像及冠脉血管造影(CAG)资料。CT检查资料采用容积再现(VR)、曲面重组(MPR)及最大密度投影(MIP)等方法进行图像后处理,观察冠状动脉的起源及走行,并与CAG的结果进行对照。结果:MSCTA显示25例患者均为冠状动脉起源于相反主动脉窦开口,16例(16/25)为右冠状动脉起自左冠状窦,其中6例为右冠状动脉走行于主动脉与肺动脉-右室流出道之间,呈埋藏式走行;9例为左冠状动脉起源于右冠状窦,其中2例为左冠状动脉走行于主动脉与肺动脉-右室流出道之间,呈埋藏式走行。8例埋藏式走行的冠状动脉中7例冠脉与主动脉间夹角<45°,7例管腔狭窄>50%。25例患者中CAG仅正确诊断冠脉起源异常22例,漏诊2例、误诊1例,8例冠脉埋藏式走行均未能提示。结论:64排128层CTA对冠脉起源异常及冠脉埋藏式走行的诊断准确性高,优于冠状动脉造影检查。     

64排容积CT在冠状动脉成像中的临床应用

 目的 探讨64排容积CT在冠状动脉成像的临床应用及意义.方法 56例临床诊断及可疑诊断冠心病患者包括冠脉搭桥术后2例、PTCA术后6例,采用回顾性心电门控技术行64排容积CT冠脉成像检查,在不同心电相位窗利用多种后处理技术行冠状动脉重建并分析其病变,12例诊断为冠脉中重度狭窄的患者行选择性冠状动脉造影.结果 56例中心率＜75次/min的冠脉重建相位窗多数位于心动周期R波后75%,心率＞75次/min冠脉重建相位窗多数位于心动周期R波后45%,56例成功显示冠脉各主干(左主干、左前降支、左回旋支、右冠)221支,显示率98%;直径大于2 mm的分支(后降支、左室后支、对角支、钝缘支、窦房结支、圆锥支)237支;64排容积CT诊断冠状动脉中重度狭窄患者12例行选择性冠脉造影,11例结果同64排容积CT.结论 64排容积CT下的冠脉造影成像检查是一种安全、准确、经济的检查方法,可以作为可疑冠心病及冠心病的筛选普查及术后复查的首选方法.     

Smoking and obesity predict high-risk plaque by coronary CTA in low coronary artery calcium score (CACS)

BackgroundThe AHA recommends statins in patients with CACS>100 AU. However in patients with low CACS (1–99 AU), no clear statement is provided, leaving the clinician in a grey-zone. High-risk plaque (HRP) criteria by coronary CTA are novel imaging biomarkers indicating a higher a-priori cardiovascular (CV) risk, which could help for decision-making. Therefore the objective of our study was to identify which CV-risk factors predict HRP in patients with low CACS 1–99.Methods1003 symptomatic patients with low-to-intermediate risk, a clinical indication for coronary computed tomography angiography (CCTA) and who had a coronary artery calcium score (CACS) between 1 and 99 AU, were enrolled. CCTA analysis included: stenosis severity and HRP-criteria: low-attenuation plaque (LAP <30HU, <60HU and <90HU) napkin-ring-sign, spotty calcification and positive remodeling. Multivariate regression models were created for predicting HRP-criteria by the major 5 cardiovascular risk factors (CVRF) (smoking, arterial hypertension, positive family history, dyslipidemia, diabetes) and obesity (BMI>25 ​kg/m²).Results304 (33.5%) were smokers. 20.4% of smokers had HRP compared with only 14.9% of non-smokers (p ​= ​0.045). Male gender was associated with HRP (p ​< ​0.001).Smoking but not the other 5 CVRF had the most associations with HRP-criteria (LAP<60HU/≥2 criteria:OR 1.59; 95%CI:1.07–2.35), LAP<90HU (OR 1.57; 95%CI:1.01–2.43), Napkin-Ring-Sign (OR 1.78; 95%CI:1.02–3.1) and positive remodelling (OR 1.54; 95%CI:1.09–2.19). Smoking predicted fibrofatty LAP<90HU in males only. Obesity predicted LAP<60HU in both females and males.ConclusionsIn patients with low CACS 1-99AU, male gender, smoking and obesity, but not the other CVRF predict HRP. These patients would rather benefit from intensification of primary CV-prevention measures such as statins.     

Volumetric coronary angiography using the 256-detector row computed tomography scanner: comparison in vivo and in vitro with porcine models

Purpose: To investigate the feasibility of volumetric cine imaging in human cardiac studies by comparing in vivo and in vitro coronary angiography using a 256-detector row computed tomography (CT) without ECG gating.

Material and Methods: The left and right coronary arteries of two domestic pigs were scanned in vivo and in vitro in cine mode using the 256-detector row CT. The device scanned approximately 100 mm in the cranio-caudal direction with one rotation, with a slice thickness of 0.5 mm.

Results: The coronary arteries could be observed to the third-degree branches in vitro, but could be visualized clearly only to the proximal portion (first-degree or second-degree branches) in vivo.

Conclusion: Application of cardiac volumetric cine imaging with 256-detector row CT may be a promising means of obtaining diagnostic information and has potential for adoption to human studies.     

Cardiac CT angiography after coronary artery surgery in children using 64-slice CT scan

Objective

The purpose of this study was to compare the diagnostic accuracy of 64-slice CT with that of invasive angiography in the detection of graft and/or coronary angioplasty stenosis in children who had undergone coronary artery surgery.

Population and methods

Fifteen consecutive children (8 male and 7 female; age 9.2 ± 6.1 years) underwent 64-slice CT because of chest pain or ECG changes mean 4.8 ± 3.7 years after surgical coronary artery surgery; 10 patients had coronary angioplasty using a patch from the saphenous vein, four had mammary artery bypass, and one had saphenous vein bypass. Six main segments of the coronary arteries and all the bypass graft considered as a single segment were analyzed and compared with invasive angiography used as the reference standard.

Results

CT correctly identified the four children with coronary angioplasty and mammary graft lesions that were confirmed by conventional angiography: one patient had a significant stenosis (>50% stenosis) at the mammary bypass graft anastomosis site; three other had non-significant stenosis (<50% stenosis) including a mild lesion of the saphenous vein patch in two patients and a mild lesion at the anastomosis site of the mammary bypass in one. All segments identified as normal by CT in the other 11 children were also found to be normal by conventional angiography.

Conclusion

In centers expert in this technique, 64-slice CT scanning is a promising, rapid, and useful diagnostic technique for evaluating both coronary angioplasty and bypass graft lesions in children who had undergone coronary artery surgery.     

Impact of age on coronary artery plaque progression and clinical outcome: A PARADIGM substudy

BackgroundThe association of age with coronary plaque dynamics is not well characterized by coronary computed tomography angiography (CCTA).MethodsFrom a multinational registry of patients who underwent serial CCTA, 1153 subjects (61 ± 5 years old, 61.1% male) were analyzed. Annualized volume changes of total, fibrous, fibrofatty, necrotic core, and dense calcification plaque components of the whole heart were compared by age quartile groups. Clinical events, a composite of all-cause death, acute coronary syndrome, and any revascularization after 30 days of the initial CCTA, were also analyzed. Random forest analysis was used to define the relative importance of age on plaque progression.ResultsWith a 3.3-years’ median interval between the two CCTA, the median annual volume changes of total plaque in each age quartile group was 7.8, 10.5, 10.8, and 12.1 mm³/year and for dense calcification, 2.5, 4.6, 5.4, and 7.1 mm³/year, both of which demonstrated a tendency to increase by age (p-for-trend = 0.001 and < 0.001, respectively). However, this tendency was not observed in any other plaque components. The annual volume changes of total plaque and dense calcification were also significantly different in the propensity score-matched lowest age quartile group versus the other age groups as was the composite clinical event (log-rank p = 0.003). In random forest analysis, age had comparable importance in the total plaque volume progression as other traditional factors.ConclusionsThe rate of whole-heart plaque progression and dense calcification increases depending on age. Age is a significant factor in plaque growth, the importance of which is comparable to other traditional risk factors.Clinical trial registrationURL: http://www.clinicaltrials.gov. Unique identifiers: NCT02803411.     

64层探测器CT冠状动脉成像依据不同心率的最佳重建方案

目的:探讨64层螺旋CT冠状动脉成像不同心率下冠状动脉各节段血管的最佳重建时相。方法:对61例患者行64层螺旋CT冠状动脉成像,扫描后原始数据分别按R-R间期30%、35%、40%、45%、50%、60%、70%、75%的相位进行后处理重组,按扫描期间平均心率分组,Ⅰ组30例,心率70次/min;Ⅱ组31例,心率≥70次/min。分析不同心率组不同R-R时相对各支冠状动脉血管的显示情况。结果:Ⅰ组的所有的冠状动脉节段可以在单一的75%相位上获得最佳图像质量;Ⅱ组的所有冠状动脉可以在单一的45%或40%的相位上获得最佳图像质量,多时相重建并不能显著提高图像质量。结论:随着64层螺旋CT时间分辨率的充分发展,所有冠状动脉节段能在一个重建时相得到有诊断价值的图像,多时相重建并不能显著提高图像质量。     

64层MDCT评价冠脉粥样硬化斑块的准确性:与IVUS对照研究

目的:评价64层MDCT在判断冠脉粥样硬化斑块性质及测量血管大小、斑块负担的应用价值。方法:14例患者经MDCT显示的位于冠脉近、中段的粥样硬化斑块作为研究对象,在斑块的最大层面测量斑块的CT值,根据CT值将斑块分类。并测量、计算最小管腔面积、血管外膜面积,斑块面积、斑块负荷。以IVUS为金标准,分别计算MDCT判断斑块性质的敏感性、特异性及各类斑块的平均CT值,并对血管测量进行统计学分析。结果:14例患者粥样硬化斑块25个,软斑块11个,纤维斑块7个,钙化斑块7个,平均CT值分别为49±32HU,93±23HU,1138±350HU。MDCT对脂质、纤维和钙化斑块诊断的敏感性和特异性分别为90.9%和92.9%;85.7%和94.4%;100%和100%。MDCT测量的管腔面积、血管面积、斑块面积、斑块负荷高于IVUS测量的结果,但两者之间没有统计学差异。结论:64层MDCT是一种准确无创的诊断和测量冠脉粥样硬化斑块的工具。     

Plaque imaging with CT coronary angiography: Effect of intra-vascular attenuation on plaque type classification

AIM:To assess the attenuation of non-calcified atherosclerotic coronary artery plaques with computed tomography coronary angiography(CTCA).METHODS:Four hundred consecutive patients underwent CTCA(Group 1:200 patients,Sensation 64 Cardiac,Siemens;Group 2:200 patients,VCT GE Healthcare,with either Iomeprol 400 or Iodixanol 320,respectively) for suspected coronary artery disease(CAD).CTCA was performed using standard protocols.Image quality(score 0-3),plaque(within the accessible non-calcified component of each non-calcified/mixed plaque) and coronary lumen attenuation were measured.Data were compared on a per-segment/perplaque basis.Plaques were classified as fibrous vs lipid rich based on different attenuation thresholds.A P < 0.05 was considered significant.RESULTS:In 468 atherosclerotic plaques in Group 1 and 644 in Group 2,average image quality was 2.96 ± 0.19 in Group 1 and 2.93 ± 0.25 in Group 2(P ≥ 0.05).Coronary lumen attenuation was 367 ± 85 Hounsfield units(HU) in Group 1 and 327 ± 73 HU in Group 2(P < 0.05);non-calcified plaque attenuation was 48 ± 23 HU in Group 1 and 39 ± 21 HU in Group 2(P < 0.05).Overall signal to noise ratio was 15.6 ± 4.7 in Group 1 and 21.2 ± 7.7 in Group 2(P < 0.01).CONCLUSION:Higher intra-vascular attenuation modifies significantly the attenuation of non-calcified coronary plaques.This results in a more difficult characterization between lipid rich vs fibrous type.     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

目的 探讨64层螺旋CT调整螺距对冠状动脉成像图像质量的影响。方法 对566例患者进行64层螺旋CT心脏冠状动脉成像,以容积再现(VR)、最大密度投影(MIP) 和曲面重组(CPR)等技术行冠状动脉三维成像,以心率≤50、51~70、71~80 及≥80次/min分为4组,每组随机分为常规组及修改组,采用常规螺距及修订螺距扫描,评价图像质量,分析其影响。结果 4组组间冠状动脉成像优良率差异有统计学意义(P＜0.05),各组间不同螺距图像质量差异有统计学意义(P<0.01)。对心率较快(71~80 次/min)或(≥80 次/min)但心率整齐,更改螺距能有效提高图像质量,达到诊断目的。结论 64层螺旋CT冠状动脉成像通过调整螺距能有效提高心率较快时图像质量,达到优化诊断的效果。