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。     

基于冠状动脉CT血管成像定量钙化负荷的可行性研究

目的 探讨冠状动脉CT血管成像（CCTA）一站式计算冠状动脉钙化积分（CCTA-CS）和体积积分（CCTA-VS）的可行性,并分析其与心电门控CT平扫测得标准积分（CACS、VS）的相关性。 方法 本研究回顾性连续纳入1 075例受试者,男447例,女628例,平均年龄（56.79±9.49）岁。全部受试者均行包括门控CT平扫和CCTA的常规冠状动脉CT检查,测量CACS、VS、CCTA-CS和CCTA-VS。选择CACS与CCTA-CS均不为0的影像数据进行分析。采用组内相关系数（ICC）评估2名观察者间及观察者内测量CCTA-CS和CCTA-VS的一致性。采用线性相关分析与Bland-Altman检验分析CCTA与门控CT平扫所测评分的相关性与一致性。根据CACS对受试者进行心血管病危险度分层,并采用Kruskal-Wallis H检验比较多组间的CCTA-CS与CCTA-VS。采用二元Logistic回归分析影响钙化积分的危险因素。采用独立样本t检验比较CCTA和常规冠状动脉CT检查的有效辐射剂量（ED）。 结果 CACS和CCTA-CS不为0的受试者共437例。2名观察者间和观察者内测量的CCTA-CS和CCTA-VS的一致性均较好（均ICC>0.960）。CCTA-CS与CACS、CCTA-VS与VS均呈较好的正相关（r²=0.98、0.96,均P<0.05）。Bland-Altman检验结果显示CCTA与门控CT平扫所测评分间的一致性较高。不同危险分层病人的CCTA-CS和CCTA-VS差异均有统计学意义（均P<0.05）。Logistic回归分析显示高血压、糖尿病、高脂血症、吸烟史、脑血管病均为CACS、CCTA-CS的危险因素。CCTA检查的ED低于常规冠状动脉CT检查,Flash扫描可减少21.2%,Sequence扫描可减少18.6%。 结论 CCTA一站式测量可以精确定量钙化,测得的CCTA-CS、CCTA-VS与标准积分有较好的相关性,且能有效降低辐射剂量。     

Association between socioeconomic position and coronary artery calcium score in patients with symptoms suggestive of obstructive coronary artery disease

AimLow socioeconomic-position (SEP) is associated with increased prevalence of cardiovascular disease. Whether this is caused by earlier development of atherosclerotic calcifications is not well understood. This study aimed to investigate the association between SEP and coronary artery calcium score (CACS) in a population presenting with symptoms suggestive of obstructive coronary artery disease.MethodsWe included 50,561 patients (mean age 57 ​± ​11, 53% women) from a national registry undergoing coronary computed tomography angiography (CTA) from 2008 to 2019. CACS was used as outcome in categories; 1–399 and ​≥ ​400 in regression analyses. SEP was obtained from central registries and defined as mean personal income and length of education.ResultsThe number of risk factors were negatively associated with income and education among both men and women. The adjusted OR of having a CACS≥400 was 1.67(1.50–1.86) among women with <10 years of education compared to >13 years. For men the corresponding OR was 1.03(0.91–1.16).For women with low income the adjusted OR of CACS ≥400 was 2.29(1.96–2.69) using high income as a reference. For men the corresponding OR was 1.13(0.99–1.29).ConclusionIn patients referred for coronary CTA we found an increased level of risk factors among men and women with short education and low income. Among women with longer education and a higher income we demonstrated a lower CACS compared to other women and men. Socioeconomic differences seem to affect the development of CACS beyond what can be explained by traditional risk factors. Part of the observed result may be due to referral bias.ClinicalTrials.gov identifierNone.     

心肌灌注显像与冠状动脉钙化积分对冠心病风险评估的研究现状及相互关系

冠心病是严重威胁人类健康的常见病和多发病.早期诊断冠心病,无创、准确地进行心脏不良事件的风险评估并及时干预,是亟待解决的临床问题.风险评估模型对于心脏风险评估的有效性虽已被众多临床试验所证实,但仍有局限性.心肌灌注显像及冠状动脉钙化积分以及两者结合,为冠心病诊断及心脏风险的评估提供了新的思路.     

CT低剂量技术在冠状动脉钙化积分检查中的应用现状与新进展

冠状动脉钙化积分(CACS)是无创性评估心血管风险分层及冠心病发生、发展和预后的一项重要指标,可以辅助临床治疗策略的选择制定。遵从辐射防护最优化原则(ALARA),可以采用直接方法(降低管电流、管电压,自动管电流调制技术)、间接方法(大螺距、迭代重建技术),以及直接在冠状动脉CT血管成像、双能CT虚拟平扫和非心电门控胸部CT平扫影像上测量CACS,从而降低该检查辐射剂量,并可准确、可重复地测量CACS,进行心血管风险分层。     

CT-SYNTAX评分在复杂冠状动脉疾病心肌血运重建决策中的应用进展

复杂冠状动脉疾病（CAD）心肌血运重建治疗策略的选择是临床医师关注的问题,基于有创冠状动脉造影（ICA）的SYNTAX评分是当前重要的临床指导依据。随着冠状动脉CT血管成像（CCTA）的普及,基于CCTA的SYNTAX评分（CT-SYNTAX）成为研究热点。基于CCTA的血流储备分数（FFR_CT）可提供CAD的功能学信息,实现了CT-SYNTAX评分从解剖学向功能学的提升。就CT-SYNTAX评分在复杂CAD病人治疗策略中应用的研究进展予以综述。     

Using a genetic risk score to calculate the optimal age for an individual to undergo coronary artery calcium screening

BackgroundGenetic risk scores (GRSs) have been associated with CHD events and coronary artery calcium (CAC). We sought to evaluate the ability of a GRS to improve CAC as a screening test.MethodsUsing the results of the most recent genome-wide association studies, we calculated a GRS in 6660 individuals from the Multi-Ethnic Study of Atherosclerosis and used it to determine the optimal age for an individual to undergo CAC screening.ResultsThis 157-SNP GRS was predictive of non-zero CAC in individuals aged 44–54 and improved the positive yield of CAC as a screening test in this age group. The GRS was predictive of CAC in the entire multi-ethnic cohort and in each self-identified ethnic group (European American, Chinese American, African American, and Hispanic American) assessed individually. Given a specified target yield rate of non-zero CAC, an equation was derived to calculate an individual's optimal age to undergo CAC screening. In addition, a “direct-to-consumer” GRS consisting of only risk SNPs or their proxies that are directly genotyped on the 23andMe v5 chip (102-SNP GRS) was assessed in the European American population and was predictive of non-zero CAC in younger individuals.ConclusionA GRS is associated with non-zero CAC in a multi-ethnic cohort and can be used to calculate the age of a person's first calcium scan, given a target threshold for CAC discovery. Furthermore, an inexpensive and widely available “direct-to-consumer” GRS was found to be a viable option to calculate the optimal age for CAC screening.     

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.     

CT冠状动脉成像与钙化积分评价可疑冠心病患者预后

目的 探讨CT冠状动脉成像（CTCA）与钙化积分（CACS）对可疑冠心病患者预后的预测价值.方法 对150例可疑冠心病患者行前瞻性分析.所有患者均接受320排动态容积CT扫描,分析CTCA以及CACS结果,分析并对照CTCA以及CACS判断患者预后的价值.结果 85例患者CTCA发现非阻塞性冠状动脉病变（管腔狭窄≤50％）,38例患者发现阻塞性冠状动脉病变（管腔狭窄＞50％）,27例患者冠状动脉未发现异常.54例患者钙化积分在0～10之间,47例患者钙化积分在11～400之间,49例患者钙化积分大于400.冠状动脉狭窄程度、斑块的类型及钙化积分大小均为患者终点事件发生的危险因素（OR＝5.254,95％ CI=2.095-13.176,P＜0.001; OR=6.877,95％CI＝1.372-14.033,P＜0.001;OR=2.976,95％CI=1.437-6.614,P＝0.003）.冠状动脉狭窄程度、斑块类型对患者预后有显著影响（OR=3.725,95％CI=1.379-10.062,P=0.007;OR=4.283,95％CI=1.992-12.254,P＝0.002）.结论 CTCA和CACS对可疑冠心病患者预后有较高的预测价值,CTCA对患者的预后的预测价值优于CACS.     

Coronary artery calcium score on low-dose computed tomography for lung cancer screening

AIM: To evaluate the feasibility of coronary artery calcium score (CACS) on low-dose non-gated chest CT (ngCCT).METHODS: Sixty consecutive individuals (30 males; 73 ± 7 years) scheduled for risk stratification by means of unenhanced ECG-triggered cardiac computed tomography (gCCT) underwent additional unenhanced ngCCT. All CT scans were performed on a 64-slice CT scanner (Somatom Sensation 64 Cardiac, Siemens, Germany). CACS was calculated using conventional methods/scores (Volume, Mass, Agatston) as previously described in literature. The CACS value obtained were compared. The Mayo Clinic classification was used to stratify cardiovascular risk based on Agatston CACS. Differences and correlations between the two methods were compared. A P-value < 0.05 was considered significant.RESULTS: Mean CACS values were significantly higher for gCCT as compared to ngCCT (Volume: 418 ± 747 vs 332 ± 597; Mass: 89 ± 151 vs 78 ± 141; Agatston: 481 ± 854 vs 428 ± 776; P < 0.05). The correlation between the two values was always very high (Volume: r = 0.95; Mass: r = 0.97; Agatston: r = 0.98). Of the 6 patients with 0 Agatston score on gCCT, 2 (33%) showed an Agatston score > 0 in the ngCCT. Of the 3 patients with 1-10 Agatston score on gCCT, 1 (33%) showed an Agatston score of 0 in the ngCCT. Overall, 23 (38%) patients were reclassified in a different cardiovascular risk category, mostly (18/23; 78%) shifting to a lower risk in the ngCCT. The estimated radiation dose was significantly higher for gCCT (DLP 115.8 ± 50.7 vs 83.8 ± 16.3; Effective dose 1.6 ± 0.7 mSv vs 1.2 ± 0.2 mSv; P < 0.01).CONCLUSION: CACS assessment is feasible on ngCCT; the variability of CACS values and the associated re-stratification of patients in cardiovascular risk groups should be taken into account.     

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.     

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。     

Calcium score of small coronary calcifications on multidetector computed tomography: Results from a static phantom study

Introduction

Multi detector computed tomography (MDCT) underestimates the coronary calcium score as compared to electron beam tomography (EBT). Therefore clinical risk stratification based on MDCT calcium scoring may be inaccurate. The aim of this study was to assess the feasibility of a new phantom which enables establishment of a calcium scoring protocol for MDCT that yields a calcium score comparable to the EBT values and to the physical mass.

Materials and methods

A phantom containing 100 small calcifications ranging from 0.5 to 2.0 mm was scanned on EBT using a standard coronary calcium protocol. In addition, the phantom was scanned on a 320-row MDCT scanner using different scanning, reconstruction and scoring parameters (tube voltage 80–135 kV, slice thickness 0.5–3.0 mm, reconstruction kernel FC11–FC15 and threshold 110–150 HU). The Agatston and mass score of both modalities was compared and the influence of the parameters was assessed.

Results

On EBT the Agatston and mass scores were between 0 and 20, and 0 and 3 mg, respectively. On MDCT the Agatston and mass scores were between 0 and 20, and 0 and 4 mg, respectively. All parameters showed an influence on the calcium score. The Agatston score on MDCT differed 52% between the 80 and 135 kV, 65% between 0.5 and 3.0 mm and 48% between FC11 and FC15. More calcifications were detected with a lower tube voltage, a smaller slice thickness, a sharper kernel and a lower threshold. Based on these observations an acquisition protocol with a tube voltage of 100 kV and two reconstructions protocols were defined with a FC12 reconstruction kernel; one with a slice thickness of 3.0 mm and a one with a slice thickness of 0.5 mm. This protocol yielded an Agatston score as close to the EBT as possible, but also a mass score as close to the physical phantom value as possible, respectively.

Conclusion

With the new phantom one acquisition protocol and two reconstruction protocols can be defined which produces Agatston scores comparable to EBT values and to the physical mass.     

Practical tips and tricks in cardiovascular computed tomography: Non-contrast “heartscans”—beyond the calcium score

The Agatston total coronary artery calcium (CAC) score, derived from a non-contrast CT scan of the heart (also known as the “heartscan”) in asymptomatic and symptomatic patients, has been shown to provide incremental and independent assessment to conventional risk factors based upon literally hundreds of studies published from around the world. However, recent data have emerged to indicate that there is additional information which can be derived from a “heartscan” beyond the calcium score. These include recent data on the applicability across ethnic sub-groups, prognostication in the elderly, defining “heart age” versus chronological age for individual risk stratification, evaluating CAC distribution in addition to total CAC score, and looking beyond the coronary arteries regarding left ventricular size, arotic root/thoracic aorta diameter, and epicardial fat.     

The association between carotid calcium on dental panoramic radiographs and coronary calcium score on chest computerized tomography

Objectives:Coronary artery calcium measured by CT predicts future coronary events. Similarly, carotid artery calcium on dental panoramic radiographs has been associated with increased cardiovascular events. Pre-procedural assessment of candidates for valve replacement in our institution includes panoramic radiographs and chest tomography. We aimed to assess the association of carotid calcium on panoramic radiographs with coronary artery calcium on chest tomography.Methods:Paired pre-procedural panoramic radiographs and chest tomography scans were done in 177 consecutive patients between October 2016 and October 2017. Carotid calcium was quantified using NIH’s ImageJ. Coronary artery calcium was quantified by the Agatston score using Philips Intellispace portal, v. 8.0.1.20640.Results:Carotid calcium maximal intensity, area and perimeter were higher among patients with high coronary artery calcium. Non-zero carotid calcium was found in half of patients with high coronary artery calcium, doubling prevalence of low coronary artery calcium.Conclusion:Carotid calcium identified in panoramic radiographs was associated with high coronary artery calcium. Awareness of carotid calcium recognized by dental practitioners in low-cost, low radiation and commonly done panoramic radiographs may be useful to identify patients at risk of coronary disease with potential future cardiovascular events.     

冠状动脉钙化积分评价冠状动脉弹性的研究

目的 探讨冠状动脉钙化积分(CS)与冠状动脉弹性之间的相关性以及冠状动脉CS评价冠状动脉弹性的可行性.方法 选择冠心病患者30例,其主要病变位于左前降支.对照组为疑似冠心病(如胸闷、胸痛)但冠状动脉造影检查未见明显狭窄者30例行CT血管造影(CTA)检查,2组年龄均＜55岁.应用冠状动脉CTA测量和计算所有研究对象左前降支的弹性指标——弹性系数值(D value),并对其钙化灶进行峰值计分,应用计算机工作站直接进行计算得到CS,分析弹性系数值和CS之间的相关性.结果 病例组左前降支弹性小于对照组,差异具有统计学意义(P＜0.05).病例组左前降支血管的CS平均为337.52±84.43,大于对照组的平均值154.56±62.54,差异有统计学意义(P＜0.01).Pearson相关性分析显示病例组和对照组左前降支血管的CS与弹性系数值都在0.01水平上显著相关,相关系数分别为-0.884和-0.991,为负相关.结论 CS与冠状动脉血管弹性呈现良好的负相关关系,当CS增大时,该血管的弹性下降.CS评价冠状动脉弹性具有可行性,可为临床上冠状动脉弹性的评价提供参考.     

Validation of the Coronary Artery Calcium Data and Reporting System (CAC-DRS): Dual importance of CAC score and CAC distribution from the Coronary Artery Calcium (CAC) consortium

BackgroundThe Coronary Artery Calcium Data and Reporting System (CAC-DRS), which takes into account the Agatston score category (A) and the number of calcified vessels (N) has not yet been validated in terms of its prognostic significance.MethodsWe included 54,678 patients from the CAC Consortium, a large retrospective clinical cohort of asymptomatic individuals free of baseline cardiovascular disease (CVD). CAC-DRS groups were derived from routine, cardiac-gated CAC scans. Cox proportional hazards regression models, adjusted for traditional CVD risk factors, were used to assess the association between CAC-DRS groups and CHD, CVD, and all-cause mortality. CAC-DRS was then compared to CAC score groups and regional CAC distribution using area under the curve (AUC) analysis.ResultsThe study population had a mean age of 54.2 ± 10.7, 34.4% female, and mean ASCVD score 7.3% ± 9.0. Over a mean follow-up of 12 ± 4 years, a total of 2,469 deaths (including 398 CHD deaths and 762 CVD deaths) were recorded. There was a graded risk for CHD, CVD and all-cause mortality with increasing CAC-DRS groups ranging from an all-cause mortality rate of 1.2 per 1,000 person-years for A0 to 15.4 per 1,000 person-years for A3/N4. In multivariable-adjusted models, those with CAC-DRS A3/N4 had significantly higher risk for CHD mortality (HR 5.9 (95% CI 3.6–9.9), CVD mortality (HR4.0 (95% CI 2.8–5.7), and all-cause mortality a (HR 2.5 (95% CI 2.1–3.0) compared to CAC-DRS A0. CAC-DRS had higher AUC than CAC score groups (0.762 vs 0.754, P < 0.001) and CAC distribution (0.762 vs 0.748, P < 0.001).ConclusionThe CAC-DRS system, combining the Agatston score and the number of vessels with CAC provides better stratification of risk for CHD, CVD, and all-cause death than the Agatston score alone. These prognostic data strongly support new SCCT guidelines recommending the use CAC-DRS scoring.     

Overestimation of pretest probability of coronary artery disease by Duke clinical score in patients undergoing coronary CT angiography in a Japanese population

BackgroundThe Duke clinical score (DCS) is commonly used to estimate the pretest probability of coronary artery disease (CAD). However, the criterion was developed in a population undergoing catheter angiography.ObjectiveTo test the hypothesis that DCS overestimates the CAD probability when applied to patients evaluated with coronary CT angiography (CCTA). A second objective is to compute an adjustment of the calculated DCS to apply to this population.MethodsThe DCS was calculated for the 3996 consecutive CCTA studies (February 2009 to April 2013) performed for symptomatic patients with no known CAD. Performance of the DCS for the detection of CAD was evaluated by the area under the receiver operating characteristic curve. Using the training cohort (n = 2789), a linear regression line between the calculated probability and the observed prevalence of CAD identified a modified DCS cutoff for a better risk categorization; this was internally validated by a separate cohort (n = 1207).ResultsThe DCS showed a good discrimination (area under the receiver operating characteristic curve = 0.71) for the detection of CAD (prevalence = 23.3%). The calibration analysis showed an overall 2.4-fold overestimation by DCS with a DCS < 23% corresponding to the low-risk category (ie, observed prevalence of CAD < 10%). There was no appropriate DCS cutoff to define high-risk category (ie, prevalence > 90%). The validation cohort showed a prevalence of 9.4% when DCS < 23% was used to define low risk.ConclusionAmong patients who underwent CCTA, DCS overestimated the pretest probability by at least 2-fold; the DCS < 23% should define the lower risk probability. The DCS poorly identifies high-risk population and thus development of new CCTA-based criteria is warranted.     

冠状动脉CTA钙化积分与炎性因子及斑块稳定相关性分析

目的 探讨冠状动脉CTA钙化积分(coronary CTA calcification score,CACS)与冠心病患者斑块稳定性指标与血清炎性因子的关系.方法选取本院收治的冠心病患者共136例,将全部患者根据冠状动脉病变程度的不同可分为单支病变组49例,两支病变组68例与三支病变组19例.结果 与单支病变组相比,两...