电子束CT冠状动脉钙化积分和血管造影诊断冠心病的价值

目的对比冠状动脉钙化积分(CCS)和电子束CT血管造影(EBCTA)诊断冠心病的不同价值;探寻造成冠状动脉EBCTA图像不可评估的原因和图像质量影响因素.方法 107例患者同时行常规冠状动脉造影(CCA)、EBCT冠状动脉钙化(非增强扫描)和血管造影(增强扫描).EBCTA采用静脉法单层心电门控增强扫描,诊断在断层和三维重建图像上完成.CCS采用Agatston方法完成.EBCT与CCA结果做双盲法对照研究.结果 7例(6.5%)患者因心跳和呼吸运动伪影而检查失败.CCS和EBCTA诊断冠心病的敏感性分别为79.2%和73.0%(χ2= 0.17,P> 0.05),特异性分别为65.6%和87.6%(χ2=5.32,P< 0.01).ROC(receiver operating characteristic)曲线分析显示EBCTA诊断冠心病的价值优于CCS(χ2=45.09,P< 0.01).EBCTA在冠状动脉左主干三维重建图像质量最好,左回旋支最差(t=11.80,P< 0.001);各支冠状动脉由近段向远段图像质量依次降低 (t=8.69,P< 0.001).不可评估的冠状动脉节段分布在6.5%的左主干,29.5%的左前降支,24.6%左回旋支和11.8%右冠状动脉(χ2=44.65,P< 0.01).结论 EBCTA在显示非钙化性或少量钙化性冠状动脉狭窄方面优于单纯冠状动脉钙化扫描,对于大量钙化性冠状动脉狭窄的诊断并无优势.EBCTA具有中等度的诊断敏感性和较高的特异性和阴性预测值,是临床筛查冠心病较理想的无创影像方法.     

Cost effectiveness of coronary angiography and calcium scoring using CT and stress MRI for diagnosis of coronary artery disease

We compared the cost effectiveness of recent approaches [coronary angiography and calcium scoring using computed tomography (CT) and stress magnetic resonance imaging (MRI)] to the diagnosis of coronary artery disease (CAD) with those of the traditional diagnostic modalities [conventional angiography (CATH), exercise ECG, and stress echocardiography] using a decision tree model. For patients with a 10% to 50% pretest likelihood of coronary artery disease, non-invasive coronary angiography using CT was the most cost effective approach, with costs per correctly identified CAD patient of €4,435 (10% likelihood) to €1,469 (50% likelihood). Only for a pretest likelihood of 30% to 40% was calcium scoring using CT more cost effective than any of the traditional diagnostic modalities, while MRI was not cost effective for any pretest likelihood. At a pretest likelihood of 60%, CT coronary angiography and CATH were equally effective, while CATH was most cost effective for a pretest likelihood of at least 70%. In conclusion, up to a pretest likelihood for coronary artery disease of 50%, CT coronary angiography is the most cost-effective procedure, being superior to the other new modalities and the most commonly used traditional diagnostic modalities. With a very high likelihood for disease (above 60%), CATH is the most effective procedure from the perspective of society.     

CT冠状动脉钙化评分软件工作平台间重复性研究

摘要目的研究3个不同工作站生成的冠状动脉钙化(CAC)评分是否具有可比性,从而得到独立于厂商的结果。材料与方法本研究获得伦理审查委员会和放射防护联盟的批准,每例病人均签署了知情同意书。     

Coronary artery calcium scoring vs. coronary CT angiography for the assessment of occupationally significant coronary artery disease

BackgroundExisting pathways for investigating coronary artery disease (CAD) in individuals undertaking high-hazard employment are currently guided by coronary artery calcium scoring (CACS) or coronary CT angiography (CTA). The optimal pathway has not been established.AimTo compare the diagnostic outcome and occupational recommendations from two differing investigative pathways for the investigation of CAD in a cohort of high-hazard employees.MethodsWe collected CACS and coronary CTA data from three clinics across two Hospitals on 200 consecutive individuals employed in high-hazard occupations to confirm/exclude occupationally significant CAD. High-hazard occupations were grouped into civil/military pilots and aircraft controllers (n ?= ?106); non-pilot aircrew (NPA) (n ?= ?26); and ground-based (military) personnel (GBP) (n ?= ?52). Demographics, referral indications and recommended occupational outcomes between pathways were compared between groups.ResultsThe CACS pathway led to more than double the number of individuals being returned to partial or full employment, compared with the coronary CTA pathway (OR 2.10, [95%CI 1.54–2.85], P ?< ?0.001). This effect was seen in all sub-groups.Of the 177 subjects that would have been returned to full employment using CACS, 21 (11.9%) would have been occupationally restricted on the basis of significant non-calcified plaque disease using coronary CTA (11.4% pilots/controllers; 19.2% non-pilot aircrew, and 7.7% ground-based personnel).ConclusionUsing CACS to determine the presence of occupational CAD risks returning individuals to roles with occupationally significant CAD that may lead to an unacceptably high likelihood of an incapacitating/distracting acute coronary event. Coronary CTA appears to be a more reliable, non-invasive imaging modality for confirming or excluding occupationally significant CAD in high-hazard employees.     

CT coronary calcium scoring with tin filtration using iterative beam-hardening calcium correction reconstruction

ObjectivesTo investigate the diagnostic accuracy of CT coronary artery calcium scoring (CACS) with tin pre-filtration (Sn100 kVp) using iterative beam-hardening correction (IBHC) calcium material reconstruction compared to the standard 120 kVp acquisition.BackgroundThird generation dual-source CT (DSCT) CACS with Sn100 kVp acquisition allows significant dose reduction. However, the Sn100 kVp spectrum is harder with lower contrast compared to 120kVp, resulting in lower calcium score values. Sn100 kVp spectral correction using IBHC-based calcium material reconstruction may restore comparable calcium values.MethodsImage data of 62 patients (56% male, age 63.9 ± 9.2years) who underwent a clinically-indicated CACS acquisition using the standard 120 kVp protocol and an additional Sn100 kVp CACS scan as part of a research study were retrospectively analyzed. Datasets of the Sn100 kVp scans were reconstructed using a dedicated spectral IBHC CACS reconstruction to restore the spectral response of 120 kVp spectra. Agatston scores were derived from 120 kVp and IBHC reconstructed Sn100 kVp studies. Pearson’s correlation coefficient was assessed and Agatston score categories and percentile-based risk categorization were compared.ResultsMedian Agatston scores derived from IBHC Sn100 kVp scans and 120 kVp acquisition were 31.7 and 34.1, respectively (p = 0.057). Pearson‘s correlation coefficient showed excellent correlation between the acquisitions (r = 0.99, p < 0.0001). Agatston score categories and percentile-based cardiac risk categories showed excellent agreement (ĸ = 1.00 and ĸ = 0.99), resulting in a low cardiac risk reclassification of 1.6% with the use of IBHC CACS reconstruction. Image noise was 24.9 ± 3.6HU in IBHC Sn100 kVp and 17.1 ± 3.9HU in 120 kVp scans (p < 0.0001). The dose-length-product was 13.2 ± 3.4 mGy cm with IBHC Sn100 kVp and 59.1 ± 22.9 mGy cm with 120 kVp scans (p < 0.0001), resulting in a significantly lower effective radiation dose (0.19 ± 0.07 mSv vs. 0.83 ± 0.33 mSv, p < 0.0001) for IBHC Sn100 kVp scans.ConclusionLow voltage CACS with tin filtration using a dedicated IBHC CACS material reconstruction algorithm shows excellent correlation and agreement with the standard 120 kVp acquisition regarding Agatston score and cardiac risk categorization, while radiation dose is significantly reduced by 75% to the level of a chest x-ray.     

Feasibility of coronary artery calcium scoring on virtual unenhanced images derived from single-source fast kVp-switching dual-energy coronary CT angiography

BackgroundDual-energy CT technology enables acquisition of virtual unenhanced (VUE) images from contrast-enhanced scans.ObjectiveTo assess the feasibility of coronary artery calcium (CAC) scoring on VUE images derived from fast kVp-switching dual-energy coronary CT angiography.MethodsTwenty-seven patients underwent true noncontrast CAC-scoring CT followed by routine single-energy (120-kVp) and fast kVp-switching dual-energy coronary CT angiography, in a random acquisition order on the same day. We calculated the CAC scores on true noncontrast and VUE images. The image noises and the signal-to-noise and contrast-to-noise ratios of the aorta and coronary arteries were measured on both the single-energy coronary CT angiography images and dual-energy coronary CT angiography images (70 keV virtual monochromatic spectral images). The Pearson correlation coefficient test and paired t test were used for statistical analysis.ResultsExcellent correlation was observed between the CAC scores on the true noncontrast and those on the VUE images (r = 0.88; P < .001). Compared with single-energy coronary CT angiography, dual-energy coronary CT angiography showed significantly reduced image noise and increased signal-to-noise and contrast-to-noise ratios in all regions (all P < .001). The effective dose of dual-energy coronary CT angiography (4.3 ± 0.3 mSv) was significantly lower than that of true noncontrast CAC-scoring CT plus single-energy coronary CT angiography (5.4 ± 0.7 mSv; P < .0001).ConclusionsExcellent correlation was observed between the CAC scores on the VUE images and true noncontrast images. Thus, fast kVp-switching dual-energy coronary CT angiography could allow prediction of the true CAC scores, potentially reducing the total radiation exposure and image acquisition time by obviating the need for true noncontrast CAC-scoring CT.     

Spiral versus electron-beam CT for coronary artery calcium scoring

PURPOSE: To determine differences in coronary artery calcium detection, quantification, and reproducibility, as measured at electron-beam computed tomography (CT) and subsecond spiral CT with retrospective electrocardiogram gating in an asymptomatic adult population. MATERIALS AND METHODS: Seventy subjects asymptomatic for coronary heart disease underwent both electron-beam CT and subsecond spiral CT. In all subjects, two images each were obtained with both scanners. Two experienced readers using three different algorithms scored each of the four scans: one score for the electron-beam CT images and two scores for the spiral CT images. RESULTS: With a 130-HU threshold for the quantification of calcium, there were no significant differences in interscan and interobserver variation in calcium scores between the electron-beam CT and spiral CT images. There was greater interobserver (P <.001) and interscan (P <.03) variation in scores when a 90-HU threshold was used for spiral CT images. With a 130-HU threshold, when calcium scores were used for clinical risk stratification, there was a significant difference between the results obtained with electron-beam CT and those obtained with spiral CT (P <.05). CONCLUSION: Spiral CT has not yet proved to be a feasible alternative to electron-beam CT for coronary artery calcium quantification. There are systematic differences between calcium scores obtained with single-detector array subsecond spiral CT and those obtained with electron-beam CT.     

Multidetector-row cardiac CT: diagnostic value of calcium scoring and CT coronary angiography in patients with symptomatic,but atypical,chest pain

The aim of this study was to investigate the accuracy of multidetector-row cardiac CT (MDCT), calcium scoring (Ca-Sc), and MDCT coronary angiography (MD CTA) in the assessment of coronary atherosclerosis. Thirty-eight patients underwent invasive coronary angiography (CA) and MDCT (collimation 4×1 mm, pitch 1.5 mm, TI 500 ms, 120 kV, 300 mAs, and retrospective ECG-gating). Calcium scoring was calculated for the total coronary artery territory and for RCA, LCA, and LCX separately. The MD CTA served to assess the degree and the localization of stenoses. All findings were compared to invasive coronary angiography. Approximately 68.4% (390 of 570) of all coronary segments could be visualized by MDCT. Correlation coefficient for MD CTA and CA amounted to r=0.58, showing distinct differences for the individual segments. Proximal segments generally showed better correlation (range 0.81–0.77) than medial segments (range 0.91–0.20), distal segments (range 0.55–0.04), or side branches (range 0.76–0.00). Patients with hemodynamically relevant (>75%) stenoses were detected by MD CTA with 72.2% sensitivity (13 of 18) and 100% specificity (20 of 20). For Ca-Sc sensitivity ranged between 94.7% (17 of 18) and 66.7% (12 of 18), specificity between 20% (4 of 20) and 80% (16 of 20) respectively, depending on the prevailing cutoff value. Combination of both methods led to 83.3% sensitivity (15 of 18) and 100% specificity (20 of 20), reaching no level of significance as compared with Ca-Sc (p=0.73) or MD CTA (p=0.23) alone. Calcium scoring as a single method showed highest sensitivity in the detection of coronary atherosclerosis but at the expense of low specificity. In patients with no or moderate calcifications, combination with MD CTA helped to distinctly increase specificity and NPVM. Britten and C. Herzog contributed equally to this study     

冠状动脉CT成像钙化积分扫描噪声与增强扫描噪声的相关性分析

目的：分析冠状动脉CT血管成像（CCTA）中对比增强前后图像噪声值的关系,探讨一种预测CTCA图像噪声的方法,从而为实施个体化剂量管理提供依据。方法：回顾性分析固定各扫描序列曝光参数的82例64层螺旋CT回顾性门控冠状动脉CTA的图像资料,研究钙化积分扫描（CACS）图像噪声（SD1）与对比增强扫描图像噪声（SD2）之间的线性相关性,以及体重指数（BMI）与对比增强扫描图像噪声（SD2）之间的线性相关性,并拟合出直线方程。结果：SD1与SD2之间直线相关系数r=0.94（P〈0.0001）,线性方程为SD2=1.29624×SD1＋1.20457;BMI与SD2之间的直线相关系数r=0.80（P〈0.0001）,线性方程为SD2=1.56067×BMI-10.76970。结论：在CTA各序列的曝光参数不变的情况下,对比增强前后图像噪声值之间存在高度线性相关性。钙化积分扫描噪声比体重指数能更精确地预测增强扫描图像的噪声,从而使基于钙化积分扫描噪声的个体化剂量控制成为可能。     

Effect of calcium scoring scan in reducing scan range and radiation dose in retrospectively ECG-gated CT coronary angiography

目的:探讨使用钙化积分扫描缩短增强扫描范围以降低后门控冠状动脉CTA检查辐射量的临床应用价值.方法:40例患者行冠脉钙化积分及冠脉CTA检查,其增强扫描的实际扫描范围根据钙化积分扫描图像来决定,即冠状动脉树上缘1 cm至心尖部心包影即将消失的层面.并按常规方法在定位像上测量增强扫描的预计扫描范围,即气管隆突下1 cm至心脏下缘2 cm.比较两种扫描范围及相应的辐射剂量的差异.结果:实际扫描范围比预计扫描范围平均缩短(2.09±0.76) cm(t=17.31,P＜0.01),冠状动脉CTA各序列总剂量较常规方法平均减少(1.51±0.87)mSv,差异有极显著性意义(t=10.92,P＜0.01),相当于各序列平均剂量总和的9.20％.结论:使用钙化积分扫描图像能有效缩短增强扫描的范围,从而明显降低冠状动脉CT血管成像的辐射量.     

钙化积分扫描缩短冠脉CTA扫描范围及降低辐射量的作用

目的:探讨使用钙化积分扫描缩短增强扫描范围以降低后门控冠状动脉CTA检查辐射量的临床应用价值。方法:40例患者行冠脉钙化积分及冠脉CTA检查,其增强扫描的实际扫描范围根据钙化积分扫描图像来决定,即冠状动脉树上缘1cm至心尖部心包影即将消失的层面。并按常规方法在定位像上测量增强扫描的预计扫描范围,即气管隆突下1cm至心脏下缘2cm。比较两种扫描范围及相应的辐射剂量的差异。结果:实际扫描范围比预计扫描范围平均缩短(2.09±0.76)cm(t=17.31,P<0.01),冠状动脉CTA各序列总剂量较常规方法平均减少(1.51±0.87)mSv,差异有极显著性意义(t=10.92,P<0.01),相当于各序列平均剂量总和的9.20%。结论:使用钙化积分扫描图像能有效缩短增强扫描的范围,从而明显降低冠状动脉CT血管成像的辐射量。     

Noncalcified atherosclerotic lesions with vulnerable characteristics detected by coronary CT angiography and future coronary events

BackgroundThe ability of coronary CT angiography (CTA) findings such as plaque characteristics to predict future coronary events remains controversial.ObjectiveWe investigated whether noncalcified atherosclerotic lesions (NCALs) detected by coronary CTA were predictive of future coronary events.MethodsA total of 511 patients who underwent coronary CTA were followed for cardiovascular events over a period of 3.3 ± 1.2 years. The primary end point was defined as hard events, including cardiac death, nonfatal myocardial infarction, or unstable angina that required urgent hospitalization. Early elective coronary revascularizations (n = 58) were excluded. The relationship between features of NCALs and outcomes is described.ResultsA total of 15 hard events (2 cardiac deaths, 7 myocardial infarctions, 6 cases of unstable angina that required urgent hospitalization) were documented in the remaining 453 patients with modest risks during a follow-up period of 3.3 ± 1.2 years. For these hard events, a univariate Cox proportional hazard model showed that the hazard ratio for the presence of >50% stenosis was 7.27 (95% CI, 2.62–21.7; P = .0002). Although the presence of NCAL by itself was not statistically significant, NCALs with low attenuation and positive remodeling (low-attenuation plaque [LAP] and positive remodeling [PR]; plaque CT number ≤34 HU and remodeling index ≥1.20) showed an adjusted hazard ratio of 11.2 (95% CI, 3.71–36.7; P < .0001). With C-statistics analysis, when both LAP and PR and >50% stenosis were added, the C-statistic was significantly improved compared with the basal model adjusted for age, sex, and log₂ (Agatston score +1) (0.900 vs 0.704; P = .0018).ConclusionsIdentification of NCALs with LAP and PR characteristics by coronary CTA provides additional prognostic information to coronary stenosis for the prediction of future coronary events.     

钙化积分、CTCA以及两者联合对冠状动脉狭窄的诊断价值

目的:探讨冠状动脉钙化积分(CS)、CT冠状动脉成像(CTCA)以及两者联合对诊断冠状动脉狭窄病变的价值.方法:189例患者均行冠状动脉钙化积分扫描、CT冠状动脉成像以及传统冠状动脉造影(CAG)检查.计算CS、CT-CA以及两者联合诊断冠状动脉病变的符合率,并记录有效X线剂量.结果:189例患者中临床诊断为冠心病156例(82.5％),经冠状动脉造影检测出至少有1支冠状动脉狭窄≥50％.采用钙化积分250分作为诊断阈值,检测冠状动脉狭窄≥50％的敏感度和特异度分别为42.9％(67/156)和96.9％(32/33).CTCA检测冠状动脉狭窄≥50％的敏感度和特异度分别为98.1％(153/156)和72.7％(24/33).CS和CTCA联合时,检测冠状动脉狭窄≥50％的敏感度和特异度分别为96.2％(150/156)和87.9％(29/33).结论:钙化积分对诊断冠状动脉狭窄有着很高的特异度;CTCA对诊断冠状动脉狭窄有着很高的敏感度;CTCA联合钙化积分扫描可提高冠状动脉狭窄的诊断符合率.     

多层螺旋CT冠状动脉钙化积分的临床应用价值探讨

目的 :评价多层螺旋CT冠状动脉钙化积分在冠心病诊断中的临床应用价值。方法 :138例受试者均行多层螺旋CT冠状动脉钙化积分。将冠心病组和无症状组的冠状动脉钙化积分结果对照分析 ,并对其中 2 5例冠心病患者的钙化积分结果与选择性冠脉造影结果对照 ,分析总结多层螺旋CT冠状动脉钙化积分的临床应用价值。结果 :冠心病组的平均钙化积分为 36 0 .5± 5 1.7,无症状组为 87.2 5± 2 7.2 ,两组间差异有显著性意义 (P <0 .0 5 ) ;2 5例行选择性冠状动脉造影(SCA)的结果与多层螺旋CT冠状动脉钙化积分结果对照 ,以积分大于 30 0为阳性 ,小于 30 0为阴性 ,两者之间的差异无显著性意义 (P >0 .0 5 )。结论 :多层螺旋CT冠状动脉钙化积分与冠状动脉狭窄的程度呈正相关 ,定量分析对预测冠状动脉狭窄有较高的敏感性和特异性 ,可作为预测冠状动脉狭窄的无创性筛查手段。     

16层螺旋CT冠状动脉钙化积分的临床分析

目的评价16层螺旋CT冠状动脉钙化积分在冠心病诊断中的临床应用价值。方法 48例患者均行16层螺旋CT冠状动脉钙化积分检查和冠状动脉造影。结果 冠心病组的平均钙化分数为475.5±41.2,与对照组的116.3±21.3差异有统计学意义(P<0.05),冠状动脉造影的结果与16层螺旋CT冠状动脉钙化积分结果对照,以积分>400为阳性,<400为阴性。两者之间的差异无统计学意义(P>0.05)。结论 16层螺旋CT冠状动脉钙化积分分析可以作为冠心病高危人群筛选,高积分值与冠脉狭窄有明显的相关性。     

The accuracy of coronary CT angiography in patients with coronary calcium score above 1000 Agatston Units: Comparison with quantitative coronary angiography

BackgroundHigh amounts of coronary artery calcium (CAC) pose challenges in interpretation of coronary CT angiography (CCTA). The accuracy of stenosis assessment by CCTA in patients with very extensive CAC is uncertain.MethodsRetrospective study was performed including patients who underwent clinically directed CCTA with CAC score >1000 and invasive coronary angiography within 90 days. Segmental stenosis on CCTA was graded by visual inspection with two-observer consensus using categories of 0%, 1–24%, 25–49%, 50–69%, 70–99%, 100% stenosis, or uninterpretable. Blinded quantitative coronary angiography (QCA) was performed on all segments with stenosis ≥25% by CCTA. The primary outcome was vessel-based agreement between CCTA and QCA, using significant stenosis defined by diameter stenosis ≥70%. Secondary analyses on a per-patient basis and inclusive of uninterpretable segments were performed.Results726 segments with stenosis ≥25% in 346 vessels within 119 patients were analyzed. Median coronary calcium score was 1616 (1221–2118). CCTA identification of QCA-based stenosis resulted in a per-vessel sensitivity of 79%, specificity of 75%, positive predictive value (PPV) of 45%, negative predictive value (NPV) of 93%, and accuracy 76% (68 false positive and 15 false negative). Per-patient analysis had sensitivity 94%, specificity 55%, PPV 63%, NPV 92%, and accuracy 72% (30 false-positive and 3 false-negative). Inclusion of uninterpretable segments had variable effect on sensitivity and specificity, depending on whether they are considered as significant or non-significant stenosis.ConclusionsIn patients with very extensive CAC (>1000 Agatston units), CCTA retained a negative predictive value ​> ​90% to identify lack of significant stenosis on a per-vessel and per-patient level, but frequently overestimated stenosis.     

Prevalence of coronary artery disease across the Framingham risk categories: coronary artery calcium scoring and MSCT coronary angiography

Background  Non-invasive assessment of subclinical atherosclerosis by means of coronary artery calcium scoring (CACS) and multi-slice computed tomography (MSCT) coronary angiography could improve patients’ risk stratification. However, data relating observations on CACS and MSCT coronary angiography to traditional risk assessment are scarce. Methods and Results  In 314 consecutive outpatients (54 ± 13 years, 56% males) without known CAD, CACS and 64-slice MSCT coronary angiography were performed. According to the Framingham risk score (FRS), 51% of patients were at low, 24% at intermediate and 25% at high risk, respectively. MSCT angiograms showing atherosclerosis were classified as showing obstructive (≥50% luminal narrowing) CAD or not. Both CACS and MSCT coronary angiography showed a high prevalence of normal coronary arteries in low FRS patients (70% and 61%, respectively). An increase in the prevalence of CACS >400 (4% low vs 19% intermediate vs 36% high), CAD (39% low vs 79% intermediate vs 91% high), and obstructive CAD (15% low vs 43% intermediate vs 58% high) was observed across the FRS categories (P < .0001 for all comparisons). Conclusions  A strong positive relationship exists between FRS and the prevalence and extent of atherosclerosis. Especially in intermediate FRS patients, CACS and MSCT coronary angiography provide useful information on the presence of subclinical atherosclerosis.     

双能量冠状动脉CT成像定量评估冠状动脉钙化

摘要目的评价双能量CT成像应用虚拟非对比增强(VNC)CT序列量化冠状动脉钙化的可行性。材料与方法本研究获得伦理审查委员会的批准,并符合HIPAA规定。所有病人均签署书面知情同意书。对36例病人进行非对比增强CT钙化评分,随后行双能量冠状动脉CT成像。