Monckeberg calcification of coronary arteries: a string of pearls

Coronary artery calcium scores are derived from cardiac-gated noncontrast computed tomography scans that are used in cardiac risk stratification. However, an elevated calcium score does not always translate to coronary artery luminal obstruction. Our case demonstrates an extremely high coronary artery calcium score despite nonobstructive coronaries on angiogram.     

心肌灌注显像联合冠状动脉钙化积分诊断冠心病的价值及最新进展

心肌灌注显像（MPI）在冠心病的诊断、危险度分层及预后评价中扮演着越来越重要的角色，冠状动脉钙化积分（CACS）可协助对冠心病患者进行进一步的危险度分层，但两者有各自的局限性和不足。将两者联合应用可以相互弥补不足，为临床提供更多的信息。行SPECT/CT心肌灌注显像时，需进行衰减矫正CT（CTAC）扫描，若采用心电门控的呼气末屏气螺旋CT扫描，则在用于MPI衰减矫正的同时又可用于CACS测定，实现一站式检查，在减少患者辐射剂量的同时又可为临床提供更多的信息。笔者综述了CACS、MPI及两者联合应用的临床价值，并对一站式采集MPI与CACS的最新进展进行了综述。     

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.     

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.     

The use of coronary artery calcium scoring in young adults

Although overall atherosclerotic cardiovascular disease (ASCVD) incidence has been declining in the United States, there is evidence that the incidence of ASCVD events in young adults is increasing. The early initiation of preventive therapies could result in a greater number of life-years saved, and therefore determining the appropriate way to identify high-risk young adults is becoming increasingly important. The coronary artery calcium (CAC) score, an established marker of coronary artery atherosclerosis, can improve discrimination for ASCVD risk beyond established risk prediction tools. Based on abundant evidence, the American College of Cardiology/American Heart Association (ACC/AHA) guidelines currently recommend an approach of using CAC scores as a tool for risk assessment and decision-making regarding drug therapy for primary prevention in middle-aged individuals. However, CAC scoring is not recommended for universal screening in young adults, where its yield and utility for altering clinical decisions are limited. Recent studies have demonstrated the nonnegligible prevalence of CAC and its strong association with ASCVD in young adults, suggesting its potential to reclassify risk and improve selection of young adults most likely to benefit from early preventive therapies. Although convincing clinical trials have not been performed in this population yet, CAC scores should be used selectively in young adults whose ASCVD risk may be sufficiently high to warrant a CAC score assessment. This review summarizes the evidence available regarding CAC scoring in young adults, and discusses an appropriate future role of CAC scores in preventing ASCVD in this population.     

冠状动脉钙化CT检出率及其意义的探讨

我们使用ＥＬＳＣＩＮＴ２４００型全身ＣＴ扫描机，连续对２０５例胸部进行平扫检查，发现冠脉钙化４４例，占２１．５％。５０例４０岁以下者未发现冠脉钙化；１５５例４０岁以上者，冠脉钙化检出率随着年龄增加而增加，其中５８例诊断冠心病，４０例有冠脉钙化；９７例无冠心病者，４例有冠脉钙化。着重探讨冠脉钙化与冠心病的关系，其灵敏度、特异度及阳性予告值分别为６９％、９６％及９１％。ＣＴ检出冠脉钙化虽不很敏感，但却能说明发生冠心病的机率较高，因而仍应将它视为一种重要的非损伤性检查方法。     

Effect of a calcium deblooming algorithm on accuracy of coronary computed tomography angiography

BackgroundCoronary artery calcification is a significant contributor to reduced accuracy of coronary computed tomographic angiography (CTA) in the assessment of coronary artery disease severity. The aim of the current study is to assess the impact of a prototype calcium deblooming algorithm on the diagnostic accuracy of CTA.Methods40 patients referred for invasive catheter angiography underwent CTA and invasive catheter angiography. The CTA were reconstructed using a standard soft tissue kernel (CTA_STAND) and a deblooming algorithm (CTA_DEBLOOM). CTA studies were read with and without the deblooming algorithm blinded to the invasive coronary angiogram findings. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value for the detection of stenosis ≥50% or ≥70% were evaluated using quantitative coronary angiography as the reference standard. Image quality was assessed using a 5-point scale, and the presence of image artifact recorded.ResultsAll studies were diagnostic with 548 segments available for evaluation. Image score was 3.64 ± 0.72 with CTA_DEBLOOM, versus 3.56 ± 0.72 with CTA_STAND (p = 0.38). CTA_DEBLOOM had significantly less calcium blooming artifact than CTA_STAND (12.5% vs. 47.5%, p = 0.001). Based on a 50% stenosis threshold for defining significant disease, the Sensitivity/Specificity/PPV/NPV/Accuracy were 65.9/84.9/27.6/96.6/83.4 for CTA_DEBLOOM and 75.0/81.9/26.6/97.4/81.4 for CTA_STAND using a ≥50% threshold. CTA_DEBLOOM specificity was significantly higher than CTA_STAND (84.9% vs. 81.5%, p = 0.03), with no difference between the algorithms in sensitivity (p = 0.22), or accuracy (p = 0.15). These results remained unchanged when a stenosis threshold of ≥70% was used. Interobserver agreement was fair with both techniques (CTA_DEBLOOM k = 0.38, CTA_STAND k = 0.37).ConclusionIn this proof of concept study, coronary calcification deblooming using a prototype post-processing algorithm is feasible and reduces calcium blooming with an improvement of the specificity of the CTA exam.     

A pooled-analysis of age and sex based coronary artery calcium scores percentiles

BackgroundAge and sex based coronary artery calcium score (CAC) percentiles have been used to improve coronary artery disease (CAD) risk prediction. However, the main limitation of the CACs percentiles currently in use is that they are often based on single studies. We performed a pooled analysis of all available studies that reported on CAC percentiles, in order to develop more generalizable age and sex nomograms.MethodsPubMed/Medline and Embase were searched for studies that reported nomograms of age and sex-based CACs percentiles. Studies were included if they reported data collected among asymptomatic individuals without a history of cardiovascular disease. Absolute CACs for each specific percentile stratum were pooled and new percentiles were generated taking into account the sample size of the study.ResultsWe found 831 studies, of which 12 met the inclusion criteria. Data on CACs percentiles of 134,336 Western and 33,488 Asians were pooled separately, rendering a weighted CACs percentile nomogram available at https://www.calciumscorecalculator.com. Our weighted percentiles differed by up to 24% from the nomograms in use today.ConclusionsOur pooled age and sex based CACs percentiles based on over 155,000 individuals should provide a measure of risk that is more applicable to a wider population than the ones currently in use and hopefully will lead to better risk assessment and treatment decisions.     

多层螺旋CT冠状动脉钙化积分的研究进展

冠状动脉钙化积分对于冠心病的预测有重要的临床价值,随着CT技术发展,多层螺旋CT在冠状动脉钙化检测方面的价值逐渐成为临床研究的热点。本文叙述了多层螺旋CT在冠状动脉钙化积分方面的研究进展。     

The use of computed tomography in the diagnosis of coronary artery bypass graft patency

In a preliminary evaluation of the use of dynamic computed tomography (CT) for the detection of patent aortocoronary bypass grafts, 30 patients were scanned either during the early postoperative peroid or after graft patency was determined by angiography. To visualize the proximal grafts, CT scans were taken through the aortic root following an intravenous bolus injection of contrast medium. Patent bypass grafts to the left anterior descending and right coronary arteries were demonstrated in 77.5%, while posterior grafts to the circumflex and obtuse marginal coronary arteries were detected in 40%. With its pontential for extracting dynamic events, CT scanning provides a new, noninvasive modality for the diagnosis of patent bypass grafts, which heretofore have only been visualized by selective angiography.     

Relationship between the arterial calcification detected in mammography and coronary artery disease

OBJECTIVE: Arterial calcification is frequently encountered in mammography. The frequency of breast arterial calcification (BAC) increases with increasing age. Studies have shown that BAC is seen more frequently among the people who are under the risk of coronary artery diseases (CAD) such as diabetes and hypertension. The objective of this study is to investigate the relationship between the arterial calcification detected in mammography and the CAD. MATERIAL AND METHODS: Screening mammography was performed in 123 women above the age of 40 years who had been examined with coronary angiography for the evaluation of CAD. The presence of BAC, number of affected vessels, and the distribution of calcification in the vessel wall were evaluated in the mammography. Subjects were questioned in terms of the cardiovasculary risk factors. The severity of CAD was evaluated according to the Gensini scoring. In addition, the number of blood vessels with stenosis of more than 50% was used as the vascular score. The correlation between Gensini and the vascular scores, and BAC was statistically evaluated using Mann-Whitney U and Kruskal-Wallis tests. RESULTS: Eighty (65%) of 123 patients had CAD. BAC was detected in the mammography of 49 (39.8%) subjects. The ages and duration of menopause of the cases with BAC were significantly higher than those without BAC (p<0.001). There was an almost significant correlation between the BAC and Gensini scores (p=0.059). There was a significant increase in the frequency of BAC among subjects with more than two vessels with stenosis (p=0.033). CONCLUSION: Frequency of BAC increases with increasing age. BAC is also frequently seen in subjects having severe coronary artery disease. Although increasing age may be a factor increasing the frequency of BAC, BAC may also be an indicator of CAD. Therefore, the mentioning of arterial calcification in mammography reports may be important in warning the clinician in terms of CAD.     

Accuracy of coronary computed tomography angiography vs intravascular ultrasound for evaluation of vessel area

BackgroundWe evaluated the accuracy of commonly used thresholds for vessel area evaluation on coronary CT angiography (CTA) and assessed ability of CTA to image the adventitial border.MethodsWe evaluated 137 paired (coronary CTA and intravascular ultrasound [IVUS]) coronary artery cross-sections in 30 patients. CTA analysis included measurements of external vessel border area defined at Hounsfield unit (HU) thresholds of 0 (presumed adventitia), 50, and 70 (presumed external elastic membrane [EEM]). IVUS analysis included measurements of lumen, EEM, and outer border of the highly echogenic area adjacent to EEM (presumed adventitia area).ResultsHigh correlation was found between CTA and IVUS measurements for EEM areas (R² = 0.65, P < .001 and R² = 0.60, P < .001 for CTA thresholds of 50 and 70 HU, respectively). CTA and IVUS measurements of adventitia areas were significantly correlated (R² = 0.74; P < .001), with no significant difference between the 2 methods (20.2 ± 6.4 mm² vs 19.8 ± 6.4 mm², respectively; P = .278). Cross-sectional coronary lumen radiodensity on CTA images and plaque burden measured on IVUS significantly affected the accuracy of CTA in assessment of the EEM area but not the presumed adventitial area.ConclusionsWe have demonstrated that use of a 50-HU threshold for vessel area determination by CTA led to its significant overestimation, whereas 70-HU threshold was close to that of EEM on IVUS. CTA may accurately delineate the coronary adventitial border by using a 0-HU threshold.     

评估主动脉瓣钙化及二尖瓣钙化是否为冠心病的预测因子

目的 评估主动脉瓣钙化(AVC)及二尖瓣钙化(MAC)是否为冠心病(CAD)的预测因子.方法 研究纳入行冠状动脉CT血管造影(CCTA)患者263例,其中MAC组30例,AVC组82例,MAC+AVC组31例,对照组(None)120例,使用冠状动脉斑块、多支冠状动脉病变、冠状动脉严重狭窄、中重度钙化积分的发生率及冠状动脉病变平均节段数来评估冠状动脉病变累及范围及严重程度.运用Logistic回归分析对MAC、AVC、MAC+AVC与CAD的相关性进行探讨.结果 MAC组、AVC组及MAC+AVC组相对None组在冠状动脉病变累及范围及严重程度均更高,且差异均有统计学意义;对其他传统心血管因素矫正后,AVC组、MAC组及MAC+AVC组与CAD的发生存在独立相关.结论 AVC及MAC是CAD的独立预测因子,常常预示着冠状动脉病变累及范围更广、更严重.     

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。     

降低冠状动脉钙化伪影的CT技术进展

传统冠状动脉CT血管成像（CCTA）可因冠状动脉钙化而降低诊断效能,致使管腔狭窄程度被高估,进而增加不必要的有创性血管造影检查。随着CT空间分辨力提高、新的去伪影算法、双能CT成像技术、冠状动脉减影技术、迭代重建技术及锐利卷积核重建技术的出现与发展,冠状动脉钙化在心脏CT影像上的伪影得以减轻,CT对冠状动脉钙化病人的诊断效能明显提高。就多种降低冠状动脉钙化伪影的CCTA成像技术进展进行综述。     

Association between progression of aortic valve calcification and coronary calcification: assessment by electron beam tomography

RATIONALE AND OBJECTIVES: It has been demonstrated that aortic valve calcification (AVC) shares many similarities with coronary atherosclerosis, including risk factors and pathologic characteristics. We sought to examine the relationship of AVC to coronary artery calcification (CC), to assess whether similar risk factors affect the process in a similar way. MATERIALS AND METHODS: The study included 620 asymptomatic persons (513 men and 107 women, mean age 59 years range [30-82]) who underwent two consecutive electron beam tomography (EBT) scans at least 1 year apart (mean 3.3 years). Calcification scores were obtained by summation of Agatston and volumetric scores. Stabilization of calcium was defined as no increase in score per year or positive percent change in score 1%/year. Of 106 with AVC, 105 (99%) had CC. Sixty-five patients had an AVC >10 on initial scan, and 50 (77%) demonstrated progression on the follow-up scan. Of 394 participants with CC >10 on initial scan, follow-up scans showed CC stabilization in 64 (16.2%) and CC progression in 330 (83.8%). Patients with AVC were significantly older than those with only CC (64.5 versus 56.5 years, P < .0001). The average age of the patient with AVC was 7 years older than the average age with CC. AVC (by volumetric score) progressed more rapidly in patients with diabetes (P = .036) and smoking (P = .042) than those without. RESULTS: We found no difference in the degree of change in the CC scores (by Agatston or volumetric methods) over time between men and women, or in any baseline cardiac risk factor (P > .05 for all measures). In 65 patients with both AVC and CC >10, there was a significant association between progression of AVC and CC (P = .047); the absolute rate of change of AVC was 24.5 +/- 43.2 %/year, and CC was 28.0 +/- 49.1 %/year. CONCLUSION: Virtually all patients with AVC had CC, potentially explaining the coronary risk associated with AVC. There is substantially parallel development between rates of progression of EBT-assessed AVC and CC.     

2016 SCCT/STR guidelines for coronary artery calcium scoring of noncontrast noncardiac chest CT scans: A report of the Society of Cardiovascular Computed Tomography and Society of Thoracic Radiology

The Society of Cardiovascular Computed Tomography (SCCT) and the Society of Thoracic Radiology (STR) have jointly produced this document. Experts in this subject have been selected from both organizations to examine subject-specific data and write this guideline in partnership. A formal literature review, weighing the strength of evidence has been performed. When available, information from studies on cost was considered. Computed tomography (CT) acquisition, CAC scoring methodologies and clinical outcomes are the primary basis for the recommendations in this guideline. This guideline is intended to assist healthcare providers in clinical decision making. The recommendations reflect a consensus after a thorough review of the best available current scientific evidence and practice patterns of experts in the field and are intended to improve patient care while acknowledging that situations arise where additional information may be needed to better inform patient care.     

Quantification of coronary artery stenosis with high-resolution CT in comparison with histopathology in an ex vivo study

Purpose

To investigate the ex vivo performance of high-resolution computed tomography (CT) for quantitative assessment of percentage diameter stenosis in coronary arteries compared to histopathology.

Materials and methods

High-resolution CT was performed in 26 human heart specimens after the injection of iodinated contrast media into the coronary arteries. Coronary artery plaques were visually identified on CT images and the grade of stenosis for each plaque was measured with electronic calipers. All coronary plaques were characterized by histopathology according to the Stary classification, and the percentage of stenosis was measured.

Results

CT depicted 84% (274/326) of all coronary plaques identified by histology. Missed plaques by CT were of Stary type I (n = 31), type II (n = 16), and type III (n = 5). The stenosis degree significantly correlated between CT and histology (r = 0.81, p < 0.001). CT systematically overestimated the stenosis of calcified plaques (mean difference - 11.0 ± 9.5%, p < 0.01) and systematically underestimated the stenosis of non-calcified plaques (mean difference −6.8 ± 10.4%, p < 0.05), while there was no significant difference for mixed-type plaques (mean difference −0.4 ± 11.7%, p = 0.85). There was a significant underestimation of stenosis degree as measured by CT for Stary II plaques (mean difference −14 ± 9%, p < 0.01) and a significant overestimation for Stary VII plaques (mean difference 9 ± 10%, p < 0.05), but there was no significant difference in stenosis degree between both modalities for other plaque types.

Conclusions

High-resolution CT reliably depicts advanced stage coronary plaques with an overall good correlation of stenosis degree compared to histology, however, the degree of stenosis is systematically overestimated in calcified and underestimated in non-calcified plaques.