多层螺旋CT血管成像显示颈动脉斑块增强与经组织学验证的微血管密度之间的相关性分析

目的应用多层螺旋CT血管成像(MDCTA)可显示颈动脉斑块对比度增强。本研究的目的是探讨颈动脉斑块强化(CPE)与微血管密度之间的相关性。材料与方法本研究经IRB批准。应用16层螺旋CT对29例(男20例,平均63岁)有症状病人进行前瞻性分析,对比剂注射前和注射后均行CT扫描并对斑块强化进行分析。病人行整块颈动脉内膜剥脱术,随后制备组织切片并对微血管进行量化。采用采用Logistic回归分析及ROC曲线分析,并计算曲线下面积。结果 CPE程度和微血管密度之间有显著相关性(P=0.009;ρ=0.553)。ROC曲线分析证实其相关性,10、15、20和25HU的CPE曲线下面积区域分别为0.906、0.735、0.644和0.546。CPE和新生血管形成程度之间差异具有统计学意义(P=0.0003)。结论初步研究结果表明,CPE可能与微血管密度之间存在相关性。组织学分析似乎能表明斑块内新血管形成的程度与CPE的相关性具有统计学意义。     

Association between carotid plaque composition assessed by multidetector computed tomography and cerebral embolism after carotid stenting

Introduction  

We aimed to assess the relationship between atherosclerotic carotid plaque composition analyzed using multidetector computed tomography (MDCT) and the appearance of new ischemic lesions detected by diffusion-weighted images (DWI) after carotid artery stenting (CAS).     

CT and ultrasound in the study of ulcerated carotid plaque compared with surgical results: potentialities and advantages of multidetector row CT angiography

BACKGROUND AND PURPOSE: Ulceration is a severe complication of carotid plaque. The purpose of this study was to evaluate the role and the diagnostic efficacy of multidetector row CT angiography (MDCTA) and ultrasound (US) echo color Doppler (US-ECD) in the study of patients with carotid plaque complicated by ulceration through the comparison with the surgical observation. MATERIALS AND METHODS: From January 2004 to October 2005, 237 patients, for a total of 474 carotid arteries, studied at first with color Doppler US, were analyzed using CT angiography. A total of 103 patients underwent a carotid endarterectomy. We analyzed stenosis degree, plaque composition, and presence of ulcerations. In a second phase, the data were compared with the surgical results when the MDCTA indicated surgical intervention. RESULTS: MDCTA found 31 ulcerations; the surgical confirmation underlined a 93.75% sensitivity and a 98.59% specificity. US-ECD performances were 37.5% and 91.5% for sensitivity and specificity, respectively. The number of patients who showed plaque ulcerations increased with the severity of stenosis. Furthermore, ulcerations of the carotid plaque occurred more often proximal than distal to the point of maximum stenosis, and this trend increased with the severity of the stenosis. We also determined that fatty plaques were more likely to be affected by ulcerations. CONCLUSIONS: The results of our study suggest that MDCTA detects with higher sensitivity and specificity the presence of ulcerated plaque compared with US-ECD, which has been demonstrated to be less effective in this evaluation. Considering the high MDCTA sensitivity and specificity for detection of plaque ulceration, we therefore recommend MDCTA as a useful step for correct presurgical planning.     

Follow-up study on in-stent thrombosis after carotid stenting using multidetector CT angiography

Introduction  The purpose of the present study was to evaluate the role of multidetector three-dimensional computed tomography angiography (3D CTA) for evaluating both the residual arterial lumen and the sequential change in the intraluminal diameter and thrombus formation following carotid artery stenting (CAS). Materials and methods  Twenty consecutive patients consisting of 23 successfully stented carotid arteries were examined by 3D CTA with volume-rendering at 2, 4, 8, 12 weeks and 6, 12 months of follow-up. Results  The eccentric in-stent hypodense area could be detected in ten of 23 (43.5%) carotid arteries at 2 weeks of follow-up, and they then gradually declined until they almost disappeared at 12 weeks. Eccentric in-stent hypodense areas in the acute and subacute phase (up to 12 weeks after CAS) were found in nine out of 16 carotid arteries with longer stents (3 or 4 cm in size) deployed across the carotid bifurcation, whereas no eccentric in-stent hypodense area could be observed in the patients with a short stent (2 cm) deployed only to the internal carotid artery. Seven of the ten observed eccentric hypodense areas presented on the dorsal surface at the carotid bifurcation level. Conclusion  Carotid 3D CTA for evaluating residual lumen and in-stent thrombus formation after CAS is considered to be a useful diagnostic method. To avoid stent occlusion, both the acute and subacute phases following CAS (up to 12 weeks) call for the administration of appropriate anti-platelet therapy and careful observations of the patients.     

Agreement between multi-detector-row CT angiography and US-ECD in quantification of carotid artery stenosis and plaque characterization

Purpose

The purpose of this work was to evaluate the agreement between ultra-sound echo-color Doppler (US-ECD) and multi-detector-row CT angiography (MDCTA) in the quantification of carotid artery stenosis as well as plaque characterization.

Materials and methods

From January 2012 to January 2013 forty-five patients who underwent both MDCTA and US-ECD for the study of carotid arteries, were evaluated (33 males, 12 females; age range 43–70 years; mean age of 59.6 years). For all subjects the following parameters were analyzed: stenosis degree by using the NASCET method, plaque morphology (regular versus irregular), type of the plaque (fatty, mixed and calcified) and presence of ulcerations. Statistical analysis was performed to calculate concordance between the two techniques employed.

Results

The agreement observed in the quantification of carotid artery stenosis was 94.4% with a kappa value of 0.9306 (95% confidence interval of 0.8612–1.0). In the definition of the type of plaque, the observed agreements were 91.1% and the kappa value was 0.8815 (95% confidence interval: 0.7920–0.9709). In the definition of plaque ulceration, the observed agreements were 88.4% but the kappa value was only 0.325 (95% confidence interval: 0.201–0.449). Agreement observed in the evaluation of plaque morphology was 78.3% with a kappa value of 0.513 (95% confidence interval: 0.452–0.574).

Conclusion

We observed a good agreement between US-ECD and MDCTA in the quantification of carotid artery stenosis and the assessment of plaque type. There was, however, a poor agreement in the evaluation of plaque ulceration. The use of US-ECD and MDCTA provides different results in the evaluation of plaque. Our results suggest that information derived from US-ECD should be always critically compared with other diagnostic techniques.     

Effect of patient weight and scanning duration on contrast enhancement during pulmonary multidetector CT angiography

PURPOSE: To retrospectively evaluate the amount of contrast medium required with 16- and 64-section computed tomography (CT) for a given patient weight to achieve desirable contrast enhancement during pulmonary CT angiography. MATERIALS AND METHODS: Institutional review board approval was obtained, and informed consent was not required for this HIPAA-compliant study. Eighty-five patients (35 men, 50 women; range, 22-87 years) who had undergone 16-section (n = 48) or 64-section (n = 37) CT for the detection of pulmonary embolism were retrospectively evaluated. Contrast medium containing 350 mg of iodine per milliliter was injected at a rate of 4 mL/sec. The injected volume corresponded to the injection rate multiplied by the sum of the scanning delay plus the scanning duration, up to 125 mL. The scanning delay was determined with bolus tracking. Contrast enhancement was measured in the main pulmonary artery and the aorta. For each patient, the injected contrast medium volume per body weight index was calculated. Linear regression analysis was performed, and the Wilcoxon signed rank test was used to assess differences between 16- and 64-section CT. RESULTS: A range of patient weights (45.3-153.0 kg) and contrast medium volumes (76-125 mL) were noted. The regression formula indicated that 1.2 mL per kilogram body weight of contrast medium was required to achieve 250 HU. The median scanning duration was shorter for 64-section CT than for 16-section CT (5.7 seconds vs 9.5 seconds, P < .001). Consequently, 64-section CT required 17.6% less contrast medium than did 16-section CT (85.4 mL vs 103.6 mL, P < .001). Median contrast enhancement in the pulmonary artery was 8.9% lower with 64-section CT than with 16-section CT (257.7 HU vs 282.9 HU, P = .11). CONCLUSION: To achieve consistent contrast enhancement during pulmonary CT angiography, the amount of contrast medium can be adjusted to the patient's body weight.     

Atherosclerotic plaque volume and composition in symptomatic carotid arteries assessed with multidetector CT angiography; relationship with severity of stenosis and cardiovascular risk factors

The purpose of this study was to examine the volume and the composition of atherosclerotic plaque in symptomatic carotid arteries and to investigate the relationship between these plaque features and the severity of stenosis and the presence of cardiovascular risk factors. One hundred patients with cerebrovascular symptoms underwent CT angiography. We measured plaque volume (PV) and the relative contribution of plaque components (calcifications, fibrous tissue, and lipid) in the symptomatic artery. The contribution of different components was measured as the number of voxels within defined ranges of HU values (calcification >130 HU, fibrous tissue 60–130 HU, lipid core <60 HU). Fifty-seven patients had atherosclerotic plaque in the symptomatic carotid artery. The severity of stenosis and PV were moderately correlated. Age and smoking were independently related to PV. Patients with hypercholesterolemia had significantly less lipid and more calcium in their plaques than patients without hypercholesterolemia. Other cardiovascular risk factors were not significantly related to PV or plaque composition. Luminal stenosis of the carotid artery partly reflects the amount of atherosclerotic carotid disease. Plaque volume and plaque composition are associated with cardiovascular risk factors.     

Assessment of calcified carotid plaque volume: comparison of contrast-enhanced dual-energy CT angiography and native single-energy CT

OBJECTIVE: The purpose of this study was to compare estimates of calcified plaque volume in the carotid arteries based on contrast-enhanced dual-energy CT angiograms with volume estimates based on native CT scans. CONCLUSION: Detection of hard plaque in the carotid arteries with dual-energy CT angiography was successful in all patients. Estimates of calcified plaque volume based on dual-energy CT angiograms correlated well with those based on native single-energy CT scans but at a lower attenuation threshold (130 HU as opposed to 180 HU) were underestimates compared with those on the native CT scans.     

Higher precontrast CT density of the carotid plaque in the symptomatic patients

Purpose

The purpose of this study was to determine if there is a significant difference in the CT Hounsfield Unit (CTHU) of the carotid atherosclerotic plaque (CAP) on CTpre and CTartery depending on the presence of symptomatology.

Methods

Quantitative analysis of the CTHUs for the CAP was performed in 43 arteries (11 symptomatic arteries, 32 asymptomatic arteries). The CTHUs were measured using the manual ROI method for each CAP. Group differences in the CTHU of the CAP depending on the symptomatology were evaluated by using the independent t-test.

Results

The CTHUs of CAP on CTpre were significantly higher in the symptomatic arteries than those of the asymptomatic arteries (P = 0.036). The CTHUs of CAP on CTartery were not significantly different regardless of symptomatology.

Conclusion

The CTHUs of the CAP on CT_pre may be used as one of the biomarkers to distinguish the vulnerable CAP.     

结直肠癌微血管密度与螺旋CT灌注成像的相关性

目的探讨结直肠癌微血管密度与螺旋CT(SCT)灌注成像的相关性。方法经手术和病理证实的结直肠癌患者37例,水灌肠后行SCT扫描。先行结直肠肿块范围的平扫,选定靶平面后再进行同层动态增强扫描,采用東芝Xpress/SX螺旋CT机自带的灌注功能软件,绘制所选层面的癌灶、靶动脉的感兴趣区的时间密度曲线(TDC)。根据TDC计算病灶的血流灌注量(PF)。癌组织切片经鼠抗人CD34单克隆抗体进行免疫组织化学染色,测定癌组织微血管密度(MVD),将结直肠癌的MVD与血流灌注量进行比较。结果结直肠癌MVD为[87.28±41.18(33.11～173.44)]条/高倍视野,PF为[39.74±10.82(15.60～64.80)]ml·min-1·100g-1。MVD、PF在Dukes分期、浆膜浸润、淋巴结转移比较中差异均无统计学意义(P值均>0.05);MVD、PF随着病理分期的期别升高均有下降趋势,但两者无显著相关性(r=0.18,P>0.05)。结论结直肠癌的MVD与其血流灌注量之间无明显相关性,结直肠癌早期存在高度血管化和高的血流灌注量,SCT灌注成像可能较MVD更好地反映肿瘤的微循环功能。     

肝细胞癌CT灌注参数与微血管密度的相关性研究

目的探讨肝细胞癌(HCC)的CT灌注参数与微血管密度(MVD)之间的相关性。方法以18例行CT灌注扫描检查并经病理及免疫组织化学染色证实的患者为研究对象。CT灌注扫描计算的血供参数包括肝动脉灌流量(HAP)、门静脉灌流量(PVP)、肝总灌流量(TLP)、肝动脉灌流指数(HAI)、门静脉灌流指数(PVI)。病理组织切片经HE及CD34染色,确定癌细胞分化程度及测定组织MVD。分析CT灌注参数与肿瘤恶性程度及MVD之间的相关性。结果18例中,高分化HCC5例,中分化HCC7例,低分化HCC6例。MVD分别为高分化组736个/mm2,中分化组1667个/mm2,低分化组2382个/mm2。各组灌注参数HAP、PVP、TLP、HAI、PVI分别依次为高分化组0478ml·min-1·ml-1、0441ml·min-1·ml-1、0918ml·min-1·ml-1、052、048;中分化组1216ml·min-1·ml-1、0587ml·min-1·ml-1、1803ml·min-1·ml-1、067、033;低分化组1103ml·min-1·ml-1、0473ml·min-1·ml-1、1576ml·min-1·ml-1、071、029。结果表明,高分化HCC的MVD、PVP、TLP、HAI最低,PVI最高(P值均<001);中分化HCC的PVP、TLP最高(P<001);低分化HCC的MVD、HAI最高,PVI最低(P<005)。结论CT灌流指数是反映肿瘤恶性程度及肿瘤血管生成的较好指标。     

Diagnosing carotid stenosis near-occlusion by using CT angiography

BACKGROUND/PURPOSE: Identification of carotid near-occlusion is essential before calculation of percent stenosis because stroke risk is lower than other severe stenosis and the treatment benefit is less. Calculations with reduced distal diameters are fallacious. CT angiography (CTA) is convenient and accurately quantifies internal carotid artery (ICA) stenosis. METHODS: In a blinded protocol, 268 carotid artery CTAs for known or suspected carotid disease were independently evaluated by 2 neuroradiologists. All carotid arteries were measured in millimeters at the narrowest diameter of the stenotic bulb, distal ICA well beyond the tapering bulb, and distal external carotid artery (ECA). Near-occlusions were independently identified, with disagreements settled by consensus meeting. Receiver operating characteristic (ROC) curve analysis defined the threshold values that best predicted near-occlusion according to (1) ICA stenosis, (2) distal ICA, (3) distal ICA: contralateral distal ICA, and (4) distal ICA: ECA. Paired permutations of variables were evaluated. RESULTS: Forty-two near-occlusion distal ICAs were identified. The ROC-derived threshold values determined near-occlusion carotid stenosis with a sensitivity range, 90.2-97.3; specificity, 84.1-89.9; positive predictive value (PPV), 61.3-66.7; and negative predictive value (NPV), 96.7-99.4. Ranges for paired permutations were also determined: sensitivity, 82.9-91.9; specificity, 95.4-96.8; PPV, 78.6-85.7; and NPV, 96.3-98.4. CONCLUSIONS: Threshold values provide guidelines for CTA interpretation when assessing carotid artery disease and the presence of near-occlusion. Ultimate identification of near-occlusion requires the interpreter's judgment, with attention to the following criteria: (1) notable stenosis of the ICA bulb and (2) distal ICA caliber reduction compared with (A) expected size, (B) contralateral ICA, and (C) ipsilateral ECA. Near-occlusion distal ICAs can be reliably identified on CTA.     

Vulnerable plaque: Detection of agreement between multi-detector-row CT angiography and US-ECD

Objectives

The purpose of this work was to evaluate the agreement between ultra-sound echo-color Doppler (US-ECD) and multi-detector-row CT angiography (MDCTA) in the characterization of vulnerable plaque.

Methods

From January 2004 to January 2007 658 patients who underwent both MDCTA and US-ECD for the study of carotid arteries, were retrospectively evaluated (453 males, 205 females). For all subjects the following parameters were analysed: plaque morphology (regular versus irregular), type of the plaque (fatty, mixed and calcified) and presence of ulcerations. Statistical analysis was performed to calculate concordance between the two techniques employed.

Results

In the definition of the type of plaque, the observed agreements were 77.2% and the kappa value was 0.657 (95% confidence interval: 0.615-0.699). The weighted kappa resulted 0.644. In the definition of ulceration plaque, the observed agreements were 88.4% but the kappa value was only 0.325 (95% confidence interval: 0.201-0.449). Agreement observed in the evaluation of plaque morphology was 78.3% with a kappa value of 0.513 (95% confidence interval: 0.452-0.574).

Conclusion

We observed a good agreement between US-ECD and MDCTA in the assessment of plaque type whereas a poor agreement resulted in the evaluation of plaque ulceration. The use of US-ECD and MDCTA provides different results in the evaluation of plaque. Our results suggest that information deriving from US-ECD should be always critically compared with other diagnostic techniques.     

64层CT血管造影诊断颈内动脉狭窄及内膜切除术或支架置入术后随访的价值

目的通过与DSA对比，评价64层容积CT血管造影（CTA）诊断颈内动脉（ICA）狭窄，及其在内膜切除术和支架置入术后随访中的价值。方法同时进行CTA和DSA检查的短暂性脑缺血患者40例，根据北美症状性颈内动脉内膜剥脱术实验（NASCET）的方法，由2名不了解患者情况的放射科主任医生分别对80支颈内动脉进行CTA的曲面重建和DSA测量。以远心端颈内动脉作为参考，以DSA为金标准，以狭窄率50％及70％为界计算CTA敏感度、特异度、阴性预测值和阳性预测值等。内膜切除术和支架置入术前、术后CTA测得的ICA狭窄处直径及横切面面积的比较用配对t检验。结果以狭窄率超过70％为标准，37支血管中35支DSA和CTA检查结果一致（95％），CTA的敏感度、特异度、阴性预测值和阳性预测值分别为97％[95％可信限（CI）为85％-100％]、95％（95％CI为82％-100％）、95％（95％CI为82％-100％）、98％（95％CI为92％-100％）。CTA检测内膜切除术和支架置入术后ICA狭窄处直径及横切面面积较术前有显著增加，差异有统计学意义（P〈0．01）。结论CTA是筛查ICA狭窄的一种有效手段，也可作为ICA内膜剥脱术和支架置入术后随访的首选方法。     

Dual-standard reference values of left ventricular volumetric parameters by multidetector CT angiography

BackgroundThe papillary and trabecular muscles constitute a significant percentage of left ventricular mass and volume. The influence of the papillary and trabecular muscles on left ventricular parameters has not been described with multidetector CT angiography.ObjectiveThe aims of this study are (1) to derive reference values for left ventricular volumetric parameters both including and excluding the papillary and trabecular muscles and (2) to establish the optimal segmentation method for measuring these values.MethodsA total of 179 subjects (mean age, 55.4 ± 9 years; 102 women) without heart disease and at low risk of cardiovascular disease who underwent CT angiography were selected. Left ventricular volumes, myocardial volume, and ejection fraction were measured with epicardial and 2 endocardial trace methods, including and excluding trace for the papillary and trabecular muscles. Values of all parameters obtained by both endocardial trace methods were compared.ResultsSignificant difference between both trace groups for all parameters on both sexes was found (P < .001). Significant differences in precision error of remeasurement were found in the including trace (3.6%) compared with the excluding trace (4.7%; P < .05) and in the epicardial trace (2.2%) compared with both endocardial traces (P < .001).ConclusionThe left ventricular parameters measured by CT angiography were influenced significantly by the trace method by including or excluding the papillary and trabecular muscles. The dual-standard reference values of left ventricular parameters were established, and the optimal segmentation methods were definite in considering the heart size and image quality studied with retrospective and prospective CT angiography.     

多层螺旋CT厚层与薄层图像测量肺密度的一致性研究

目的 探讨多层螺旋CT厚层与薄层重建图像测量肺密度的一致性.方法 本文收集60例健康查体常规胸部CT平扫阴性者数据,年龄21~71岁,按年龄分为21~40岁,41~60岁及60岁以上3组,各组男女各10例,年龄匹配.全部受检者扫描数据均做10 mm层厚及1.5 mm层厚重建,利用Siemens MMWP后处理工作站自带的Pulmo CT软件计算全肺、左肺、左上肺、左中肺、左下肺、右肺、右上肺、右中肺、右下肺、左肺核心、左肺外周、右肺核心、右肺外周各组的厚层及薄层平均肺CT密度值,以Delta=10 HU行H-A检验比较2种重建层厚图像所测结果的一致性,利用B-A 图观察其差异.结果 61岁以上组左肺核心及右肺核心2种层厚肺密度测量结果H-A检验P值分别为0.000 0、0.015 6,余部位及其余2组各部位H-A检验P值均＞0.05,尚不能认为2种层厚重建图像所测平均肺密度值在Delta=10 HU 时具有一致性;B-A图显示3组的全肺平均差值分别为12.900 HU、13.650 HU、14.000 HU,3组中左中肺、右肺、右上肺、右中肺、左肺核心、右肺核心等部位2种结果平均差值均小于相应全肺的平均差值,61岁以上组左上肺平均差值也小于全肺,且差值的95%分布区间较小.结论 2种层厚重建图像所得结果在左中肺、右肺、右上肺、右中肺、左肺核心、右肺核心等部位差异小而且差异值分布范围小,可用这些部位的厚层图像估计肺密度.     

应用多层螺旋CT评价脑缺血症状与颈动脉狭窄关系的研究

目的探讨基于多层螺旋CT血管造影(MDCTA)测量的颈动脉直径和脑血管症状之间的关系,寻找与症状相关的颈动脉狭窄的阈值。方法以接受MDCTA检查的230例可疑颈动脉狭窄患者为研究对象,记录患者有无大脑前循环障碍症状。所有患者均行MDCTA检查测量狭窄颈动脉直径,同时观测动脉粥样硬化斑块类型。利用ROC曲线对症状和狭窄颈动脉直径进行分析确定诊断阈值,利用Logistic多元回归探讨症状与狭窄颈动脉直径、粥样硬化斑块类型和其他变量之间的关系。结果症状组颈动脉直径明显较无症状组小,ROC曲线分析发现曲线下面积为0.720,出现脑缺血症状的最佳预测值为1.6mm,灵敏度为0.734,特异度为0.638。Logistic回归分析证实颈动脉狭窄和软斑块是脑血管症状的独立危险因素。结论利用MDCTA测量颈动脉直径能够较为可靠地预测脑缺血症状,脑缺血症状与颈动脉狭窄和软斑块密切相关,这对于MDCTA在脑卒中防治领域进一步应用具有重要意义。