Evaluation of plaque texture by means of multislice computed tomography in patients with acute coronary syndrome and stable angina.

BACKGROUND: In the present study, multislice spiral computed tomography (MSCT), which allows non-invasive assessment of coronary artery plaque, was used to compare the CT density of plaque between patients with acute coronary syndrome (acs) and those with stable angina (sa). METHODS AND RESULTS: MSCT was performed in 20 patients with ACS (17 with acute myocardial infarction, 3 with unstable angina) and 22 patients with SA. The presence of the plaque was defined on the basis of multiplanar reformation and axial images. At least 4 regions of interest were then placed within the plaque and the minimum CT density was measured and expressed as Hounsfield units (HU). The number of plaques did not differ between the 2 groups, but the minimum CT density was significantly lower in patients with ACS (25+/-15 HU) than in those with SA (71+/-16 HU, range 46-101 HU, p<0.001). Similarly, the minimum plaque density was significantly lower in the culprit coronary segment (26+/-16 HU) than in the non-culprit segment (48+/-17 HU) in 15 ACS patients with multiple plaques. CONCLUSION: MSCT can potentially differentiate vulnerable from stable plaque in patients with coronary artery disease, although long-term, prospective analysis is needed to establish the conclusion.     

Efficacy of multislice computed tomography for the detection of acute coronary syndrome in the emergency department.

BACKGROUND: The diagnosis of acute coronary syndrome (ACS), especially non-ST-elevation myocardial infarction and unstable angina in the emergency department (ED) still remains a challenge. Multislice computed tomography (MSCT) allows assessment of not only coronary artery stenoses and occlusions, but also assessment of coronary artery plaques and myocardial perfusion status. METHODS AND RESULTS: MSCT was performed in 31 patients who were admitted to the ED because of chest pain persisting at least 30 min and non-diagnostic ECG changes and normal serum enzyme concentrations. Using MSCT, ACS was defined by coronary artery stenosis > or = 75% accompanied by computed tomography (CT)-low-density plaques, and/or by the presence of myocardial perfusion defects. ACS was confirmed by coronary stenosis > or = 75% by coronary angiography and/or subsequent elevation of troponin I concentration. In total, 22 patients were diagnosed as having ACS. MSCT detected stenoses with CT-low-density plaques in 21 and non-transmural myocardial perfusion defect in 3 patients. There was 1 false-positive and 1 false-negative result. The sensitivity and specificity of MSCT to identify ACS was 95.5% and 88.9%, respectively. CONCLUSION: MSCT provides diagnostic operating characteristics suitable for triage of patients with ACS in the ED.     

Differences in plaque composition and distribution in stable coronary artery disease versus acute coronary syndromes; non-invasive evaluation with multi-slice computed tomography

BACKGROUND: Plaque composition rather than degree of luminal narrowing may be predictive of acute coronary syndromes (ACS). The purpose of the study was to compare plaque composition and distribution with multi-slice computed tomography (MSCT) between patients presenting with either stable coronary artery disease (CAD) or ACS. METHODS: MSCT was performed in 22 and 24 patients presenting with ACS or stable CAD, respectively. Coronary lesions were classified as calcified, non-calcified or mixed while signal intensity (SI) was measured. RESULTS: In patients with stable CAD, the majority of lesions were calcified (89%). In patients with ACS, less calcifications were observed with a greater proportion of non-calcified (18%) or mixed (36%) lesions (P<0.001). Accordingly, mean SI of plaques was significantly less in ACS (320+/-201 HU versus 620+/-256 HU in stable CAD, P<0.001). Dividing lesions in the ACS group according to culprit versus non-culprit vessel location resulted in no significant difference in average SI between these two groups while still lower as compared to stable CAD (P<0.001). CONCLUSIONS: In patients with ACS, significantly less calcifications were present as compared to stable CAD. Moreover, even in non-culprit vessels, multiple non-calcified plaques were detected, indicating diffuse rather than focal atherosclerosis in ACS.     

Multislice computed tomographic characteristics of coronary lesions in acute coronary syndromes.

OBJECTIVES: To evaluate the feasibility of noninvasive assessment of the characteristics of disrupted atherosclerotic plaques, the authors interrogated the culprit lesions in acute coronary syndromes (ACS) by multislice computed tomography (CT). BACKGROUND: Disrupted atherosclerotic plaques responsible for ACS histopathologically demonstrate large lipid cores and positive vascular remodeling. It is expected that plaques vulnerable to rupture should bear similar imaging signatures by CT. METHODS: Either 0.5-mm x 16-slice or 64-slice CT was performed in 38 patients with ACS and compared with 33 patients with stable angina pectoris (SAP) before percutaneous coronary intervention. The coronary plaques in ACS and SAP were evaluated for the CT plaque characteristics, including vessel remodeling, consistency of noncalcified plaque (NCP <30 HU or 30 HU 相似文献   

Noninvasive detection and evaluation of atherosclerotic coronary plaques with multislice computed tomography

OBJECTIVES: The aim of the present study was to evaluate the accuracy in determining coronary lesion configuration by multislice computed tomography (MSCT). The results were compared with the findings of intracoronary ultrasound (ICUS). BACKGROUND: The risk of acute coronary syndromes caused by plaque disruption and thrombosis depends on plaque composition rather than stenosis severity. Thus, the reliable noninvasive assessment of plaque configuration would constitute an important step forward for risk stratification in patients with known or suspected coronary artery disease. Just recently, MSCT scanners became available for general purpose scanning. Due to improved spatial and temporal resolution, this new technology holds promise to allow for differentiation of coronary lesion configuration. METHODS: The ICUS and MSCT scans (Somatom Volume Zoom, Siemens, Forchheim, Germany) were performed in 15 patients. Plaque composition was analyzed according to ICUS (plaque echogenity: soft, intermediate, calcified) and MSCT criteria (plaque density expressed by Hounsfield units [HU]). RESULTS: Thirty-four plaques were analyzed. With ICUS, the plaques were classified as soft (n = 12), intermediate (n = 5) and calcified (n = 17). Using MSCT, soft plaques had a density of 14 +/- 26 HU (range -42 to +47 HU), intermediate plaques of 91 +/- 21 HU (61 to 112 HU) and calcified plaques of 419 +/- 194 HU (126 to 736 HU). Nonparametric Kruskal-Wallis test revealed a significant difference of plaque density among the three groups (p < 0.0001). CONCLUSIONS: Our results indicate that coronary lesion configuration might be correctly differentiated by MSCT. Since also rupture-prone soft plaques can be detected by MSCT, this noninvasive method might become an important diagnostic tool for risk stratification in the near future.     

Detection of atherosclerotic coronary artery plaques by multislice spiral computed tomography in patients with acute coronary syndrome: report of 2 cases.

Multislice spiral computed tomography (MSCT) is a new non-invasive imaging technique for detecting coronary artery disease. It allows direct visualization of not only the lumen of the coronary arteries, but also plaque within the artery. Identification of soft plaques is of the utmost importance in the therapeutic decision making for patients with acute coronary syndrome (ACS), including acute myocardial infarction and unstable angina pectoris. MSCT detected coronary artery soft plaques in 2 cases of ACS.     

Relationship between high sensitive C-reactive protein and coronary plaque component in patients with acute coronary syndrome: Virtual Histology study

OBJECTIVES: Elevated circulating C-reactive protein (CRP)is commonly observed in patients with acute coronary syndrome(ACS), suggesting enhanced inflammation in vulnerable plaques. However, few data are available on the relationship between the levels of CRP and the histological composition of coronary plaque. We investigated the relationship between plasma high sensitive CRP level and coronary plaque component with Virtual Histology intravascular ultrasound (VH-IVUS). METHODS: Twenty eight patients with ACS and 37 patients with non-ACS were enrolled in the study. Plasma high sensitve CRP levels were measured before catheterization. A total of 125 lesions (ACS; 24 culprit lesions, 30 non-culprit lesions, non-ACS; 34 culprit lesions, 37 non-culprit lesions)underwent IVUS volumetric investigation, and the volume of plaque and media were calculated. Spectral analysis of IVUS radiofrequency data was performed with VH software, and plaque and media were classified into fibrous, fibro-fatty, dense calcium, and necrotic core elements. RESULTS: Although the plasma high sensitive CRP level in patients with ACS was higher than that in those with non-ACS (0.26 +/- 0.2 vs 0.15 +/- 0.17 mg/dl, p < 0.05), necrotic core volume was not different between the two groups(11.7 +/- 7.3 vs 12.3 +/- 7.2mm3/cm, p = 0.71). There was a positive correlation between high sensitve CRP and necrotic core volume in patients with ACS, not only in culprit lesions (p = 0.0004, r2 = 0.564) but also in non-culprit lesions (p = 0.0008, r2 = 0.473), whereas patients with non-ACS showed no correlations. CONCLUSIONS: IVUS spectral analysis revealed that elevated plasma high sensitve CRP level was correlated with necrotic core volume in patients with ACS, both in culprit and non-culprit lesions, suggesting enhanced vascular inflammation.     

多层螺旋CT评价急性冠状动脉综合征及稳定性心绞痛患者斑块特征的作用

目的利用多层螺旋CT评价急性冠状动脉综合征(ACS)及稳定性心绞痛(SAP)患者冠状动脉病变的差异。方法连续性入选诊断为ACS及SAP、并于介入治疗前72h内行多层螺旋CT检查的患者45例,将诊断为ACS的31例作为ACS组,诊断为SAP的14例作为SAP组,将ACS组的病变分为罪犯病变和非罪犯病变,SAP组的病变定义为稳定病变;比较冠状动脉病变性质。结果 2组共有60处病变,ACS组40处,SAP组20处;ACS组罪犯病变非钙化斑块和脂质斑块比例明显高于同组非罪犯病变及SAP组的稳定病变(96.8%vs 55.6%vs 20.0%,83.3%vs 40.0%vs 25.0%,P<0.01);ACS组罪犯病变的血管截面积、斑块面积、重构指数、斑块的偏心指数明显高于同组的非罪犯病变及SAP组的稳定病变(P<0.05)。结论多层螺旋CT作为无创的影像学工具,可识别ACS与SAP患者冠状动脉斑块病变的差异。     

Prognostic value of non-obstructive CT low-dense coronary artery plaques detected by multislice computed tomography.

BACKGROUND: The prognostic value of non-obstructive, CT low-dense plaques (CTLDP) on multislice computed tomography (MSCT) for the prediction of nonfatal acute myocardial infarction (AMI), unstable angina (UA) and cardiac death has not yet been defined. METHODS AND RESULTS: In the present study 810 patients who underwent MSCT and had non-obstructive coronary artery disease were followed up for the occurrence of AMI, UA and cardiac death. Non-obstructive CTLDP were defined as plaques with a CT density <68 Hounsfield units, accompanied by mild to moderate coronary artery stenosis (25-75%). Patients were followed-up for 1,062+/-544 days for the occurrence of (1) acute coronary syndrome (ACS) including nonfatal AMI and UA, and (2) cardiac death. CTLDP were detected in 189 patients (23.3%). The annual event rate of AMI, UA, ACS and cardiac death was 0.91%, 0.91%, 1.82% and 0.36%, respectively, in patients with CTLDP and 0.10%, 0.55%, 0.66% and 0.21%, respectively, in patients without CTLDP. The event rate of ACS was significantly higher in patients with CTLDP than in those without CTLDP (p<0.001). Multivariate Cox proportional regression analysis revealed that previous MI and the presence of CTLDP were independent predictors of ACS. CONCLUSION: Non-obstructive CTLDP detected by MSCT yield prognostic information toward the identification of ACS.     

多层螺旋计算机断层扫描血管造影对冠状动脉易损斑块的检测作用

目的 评价多层螺旋计算机断层扫描（computed tomography,CT）血管造影（multislice computed tomography angiography,MSCTA）检测冠状动脉易损斑块的可靠性,建立急性冠脉综合征积分（score system of acute coronary syndromes,SACS）,用于评估冠状动脉粥样硬化性心脏病（冠心病）患者危险分层.方法 研究20例非急性冠脉综合征及41例急性冠脉综合征且冠状动脉MSCTA发现斑块的患者,比较两组斑块CT值、重构指数（RI）等指标,进而构建急性冠脉综合征发病风险预测模型.结果 两组病变血管99支,可分析斑块1 17个,非急性冠脉综合征组36个,以钙化斑块为主（88.9％,32/36）;急性冠脉综合征组81个,以脂质斑块为主（37.0％,30/81）.两组正性重构比例比较,差异有统计学意义（61.1％ vs.32.1％,P＜0.01）;负性重构比例比较,差异有统计学意义（25.0％vs.19.8％,P＜0.01）.由RI建立SACS,所得模型为：SACS=0.003PA＋2.255RI-4.22,预测准确率为76.9％（P＜0.01）,受试者工作曲线下面积为0.815（P＜0.01）.结论 急性冠脉综合征患者冠状动脉斑块多为脂质斑块,以正性重构为主,SACS对急性冠脉综合征发病具有较高的预测价值,有助于临床指导冠心病危险分层及早期干预.     

Presence and severity of Chlamydia pneumoniae and Cytomegalovirus infection in coronary plaques are associated with acute coronary syndromes

Although an association between Chlamydia pneumoniae (Cpn) or Cytomegalovirus (CMV) infection and coronary atherosclerosis has been reported, such an association is less clear for acute coronary syndromes (ACS). The purpose of this study was to investigate the pathogenic roles of Cpn and CMV infection of coronary plaques in ACS. We divided 38 coronary plaque specimens obtained from 38 patients who underwent directional coronary atherectomy or thrombectomy into an ACS group (n = 21) and a non-ACS group (n = 17). Cpn and CMV in specimens were stained using immunohistochemical techniques and analyzed quantitatively. The detection rate for either Cpn- or CMV-positive cells in ACS patients was slightly higher compared with non-ACS patients. Detection rates for both Cpn- and CMV-positive cells were significantly higher in ACS patients than in non-ACS patients (P = 0.010). Furthermore, the density of Cpn- and CMV-positive cells in plaques was significantly higher in ACS patients than in non-ACS patients (P < 0.003). The results indicate that the presence and severity of Cpn and CMV infection in coronary plaques are greater in patients with ACS compared with non-ACS patients. We conclude that infection with Cpn and CMV in coronary plaques may be involved in the pathogenesis of ACS.     

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.     

Assessing culprit lesions and active complex lesions in patients with early acute myocardial infarction by multidetector computed tomography

BACKGROUND: Accurate, non-invasive characterization of culprit lesions in patients after acute myocardial infarction (AMI) remains challenging. In this prospective study, multidetector row computed tomography (MDCT) is used to assess culprit and active complex lesions in patients early after AMI. METHODS AND RESULTS: We enrolled 103 patients with first non ST-elevation AMI who underwent 64-slices MDCT and conventional coronary angiography (CCAG). The definition of culprit lesion, stable non-culprit lesions and non-culprit active complex lesions was based on the findings of CCAG. The lesions were analyzed with MDCT data. In culprit lesions (n=103), luminal artery stenosis, remodeling index, plaque area and burden were significantly higher than non-culprit lesions (n=129). Multivariate discriminant analysis showed that MDCT density could discriminate culprit from non-culprit lesions. Receiver-operator characteristic curve analysis identified the optimal cutoff value of lesion density for discrimination between culprit and non-culprit lesion as 49.6 Hounsfield units (HU); this value was associated with a sensitivity, specificity and accuracy of 88.4%, 87.4%, and 87.9%, respectively. The MDCT in the stable non-culprit lesions (81.8+/-15.5 HU) was significantly higher than that in culprit lesions or non-culprit active complex lesions (33.2+/-13.8 and 48.3+/-15.7 HU, p<0.001). CONCLUSIONS: MDCT can predict culprit lesions in patients early after AMI, and identify multiple complex lesions.     

Prognostic value of multislice computed tomography coronary angiography in patients with known or suspected coronary artery disease.

OBJECTIVES: This study sought to determine the prognostic value of multislice computed tomography (MSCT) coronary angiography in patients with known or suspected coronary artery disease (CAD). BACKGROUND: It is expected that MSCT will be used increasingly as an alternative imaging modality in the diagnosis of patients with suspected CAD. Data on the prognostic value of MSCT, however, are currently not available. METHODS: A total of 100 patients (73 men, age 59 +/- 12 years) who were referred for further cardiac evaluation due to suspicion of significant CAD underwent additional MSCT coronary angiography to evaluate the presence and severity of CAD. Patients were followed up for the occurrence of: 1) cardiac death, 2) nonfatal myocardial infarction, 3) unstable angina requiring hospitalization, and 4) revascularization. RESULTS: Coronary plaques were detected in 80 (80%) patients. During a mean follow-up of 16 months, 33 events occurred in 26 patients. In patients with normal coronary arteries on MSCT, the first-year event rate was 0% versus 30% in patients with any evidence of CAD on MSCT. The observed event rate was highest in the presence of obstructive lesions (63%) and when obstructive lesions were located in the left main (LM)/left anterior descending (LAD) coronary arteries (77%). Nonetheless, an elevated event rate was also observed in patients with nonobstructive CAD (8%). In multivariate analysis, significant predictors of events were the presence of CAD, obstructive CAD, obstructive CAD in LM/LAD, number of segments with plaques, number of segments with obstructive plaques, and number of segments with mixed plaques. CONCLUSIONS: Multislice computed tomography coronary angiography provides independent prognostic information over baseline clinical risk factors in patients with known and suspected CAD. An excellent prognosis was noted in patients with a normal MSCT.     

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.     

Diagnostic value of CT angiography in coronary arteries stenosis detection

BACKGROUND: Noninvasive imaging of coronary arteries is very important. CT angiography (multislice computed tomography and electron beam computed tomography -- MSCT and EBT) is most reliable method for noninvasive coronary visualization. PURPOSE: The aim of our study was to evaluate the diagnostic value of CT angiography in coronary arteries stenoses detection in patients with coronary arteries disease (CAD). MATERIALS AND METHODS: 140 patients with CAD who underwent EBT (n=97) or 4-slice CT (n=43) coronary angiography and conventional coronary angiography as a gold standard were included in the study. RESULTS: Sensitivity and specificity of CT angiography in coronary stenoses detection (proximal and mid segments) were 86% and 97%, respectively. Positive and negative predictive values were 90% and 96%, respectively. Overall accuracy was 95%. 6.2% of coronary segments were excluded from the study because of unsatisfactory image quality. CONCLUSIONS: CT angiography is noninvasive method for coronary stenoses detection with high sensitivity and specificity. Nevertheless EBT and 4-slice CT angiography can not replace conventional coronary angiography because of lower temporal and spatial resolution, artifacts in patients with arrhythmias and huge coronary calcification.     

Differences in plaque composition and distribution in stable coronary artery disease versus acute coronary syndromes; non‐invasive evaluation with multi‐slice computed tomography

Background: Plaque composition rather than degree of luminal narrowing may be predictive of acute coronary syndromes (ACS). The purpose of the study was to compare plaque composition and distribution with multi‐slice computed tomography (MSCT) between patients presenting with either stable coronary artery disease (CAD) or ACS. Methods: MSCT was performed in 22 and 24 patients presenting with ACS or stable CAD, respectively. Coronary lesions were classified as calcified, non‐calcified or mixed while signal intensity (SI) was measured. Results: In patients with stable CAD, the majority of lesions were calcified (89%). In patients with ACS, less calcifications were observed with a greater proportion of non‐calcified (18%) or mixed (36%) lesions (P<0.001). Accordingly, mean SI of plaques was significantly less in ACS (320±201?HU versus 620±256?HU in stable CAD, P<0.001). Dividing lesions in the ACS group according to culprit versus non‐culprit vessel location resulted in no significant difference in average SI between these two groups while still lower as compared to stable CAD (P<0.001). Conclusions: In patients with ACS, significantly less calcifications were present as compared to stable CAD. Moreover, even in non‐culprit vessels, multiple non‐calcified plaques were detected, indicating diffuse rather than focal atherosclerosis in ACS.     

多层螺旋CT在急性冠状动脉综合征诊断中的应用

急性冠状动脉综合征(ACS)是在动脉粥样硬化的基础上,斑块破裂、表面破损或裂纹引起血栓形成,导致冠状动脉不完全或完全闭塞,使心肌发生缺血或不同程度坏死的一组临床综合征。多层螺旋CT是一种新的无创性影像诊断技术,近年来临床已使用该技术检测冠状动脉狭窄和钙化,多层螺旋CT不仅可以评价冠状动脉狭窄或闭塞,还可以评价冠状动脉斑块的性质和心肌血流灌注情况。本文综述多层螺旋CT在ACS诊断中的作用。     

Role of coronary CT angiography in asymptomatic patients with type 2 diabetes mellitus

Diabetic patients with coronary artery disease are often asymptomatic, making appropriate care of such patients difficult. The purpose of this study was to investigate the prevalence of coronary lesions in asymptomatic diabetic patients. Coronary computed tomography (CT) angiography was performed in 120 consecutive diabetic patients (90 of whom were men, mean age 65, mean HbA1c 7.2%). Images from patients whose coronary artery calcium scores (CAC scores) were less than 400 were subjected to stenosis and plaque analysis. Significant stenosis was defined as coronary artery stenosis > 70%. High-risk plaque was defined as plaque having both a CT density < 30 Hounsfield Units (HU) and showing positive remodeling. Significant stenoses were identified in 30.5% of the patients. High-risk plaques were identified in 17.1% of the patients. Less than half of the high-risk plaques were obstructive plaques. There was a statistically significant association between significant stenosis and high-risk plaque by chi-square test (P = 0.022). We found significant stenosis even in patients whose CAC score = 0 at a rate of 5.0%. Using univariate logistic-regression analysis, we found that coronary risk factors associated with significant stenosis and high-risk plaque were dyslipidemia (P = 0.033) and current smoking (P = 0.030), respectively. We report for the first time, the prevalence of high-risk plaques in the arteries of patients with asymptomatic diabetes, as assessed by coronary CT angiography.     

Evaluation of coronary artery remodeling in patients with acute coronary syndrome and stable angina by multislice computed tomography.

BACKGROUND: Multislice computed tomography (MSCT) was used to evaluate coronary artery remodeling in patients with acute coronary syndrome (ACS) and stable angina (SA). METHODS AND RESULTS: MSCT was performed in 31 patients with ACS and 26 patients with SA and intravascular ultrasound (IVUS) was performed in 28 of these 57 patients. In both the MSCT and IVUS analyses, coronary artery remodeling was assessed by the remodeling index (RI): RI >1.10 was defined as positive coronary artery remodeling (PCAR) and RI <0.95 was defined as negative coronary artery remodeling (NCAR). The RI assessed by MSCT closely correlated with that of IVUS (r=0.86, n=28). The vessel area at the region of maximum luminal narrowing was also comparable between the MSCT and IVUS measurements (r=0.92). PCAR was present in 19 patients (61.3%) with ACS, but in none of the patients with SA (p<0.0001). However, NCAR was present in only 1 patient with ACS (3.2%), but was present in 18 patients (62.9%) with SA. The RI was significantly larger in patients with ACS (1.19+/-0.18) than in those with SA (0.89+/-0.10, p<0.0001). CONCLUSION: MSCT accurately assesses coronary artery remodeling.