IVIM双指数、拉伸指数模型对子宫内膜癌分型的价值

目的 探讨体素内不相干运动（IVIM）双指数、拉伸指数模型各参数在Ⅰ型与Ⅱ型子宫内膜癌（EC）中的鉴别诊断价值。 方法 回顾性分析51例经手术病理证实的Ⅰ型（31例）与Ⅱ型（20例）EC病人的IVIM成像资料。由2名医师在IVIM各参数伪彩图上分别测量慢速表观扩散系数（ADC-slow）、快速表观扩散系数（ADC-fast）、灌注分数（f）、扩散分布指数（DDC）和扩散异质性指数（α）。采用组内相关系数（ICC）评价2名医师测量参数的一致性。采用Fisher确切概率法比较Ⅰ型与Ⅱ型EC的病理类型及分级分期。绘制受试者操作特征（ROC）曲线,分析2组间有统计学差异的参数及其诊断效能。 结果 2名医师所测数据的一致性较好（均ICC≥0.75）。Ⅰ型组的ADC-slow、DDC值均高于Ⅱ型组,ADC-fast值低于Ⅱ型组（均P<0.05）。ADC-slow值为0.500×10^-3 mm²/s时,鉴别Ⅰ型和Ⅱ型EC的AUC为0.926,敏感度、特异度、准确度分别为80.0%、90.3%、86.3%。 结论 双指数模型的参数ADC-slow、ADC-fast值和拉伸指数模型的参数DDC值均有助于鉴别Ⅰ型与Ⅱ型EC,其中ADC-slow值鉴别诊断效能更大。     

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。     

动态CT心肌灌注成像评价猪冠状动脉微循环障碍模型的实验研究

目的:探讨动态CT心肌灌注成像(CT-MPI)定量指标评价猪冠状动脉微循环障碍(CMD)模型的价值。方法:10只实验中华小型猪,麻醉后经股动脉选择性插管,通过导丝缓慢注入左前降支远段1 ml微球混合液(含微球0.5×10⁵/0.5 ml),建立CMD模型。分别于建模前60 min及建模后10 min行CT-MPI静息态和负荷态扫描。测量CT-MPI的定量指标,包括心肌血流量(MBF)、心肌血容量(MBV)。以实验猪建模前后CT-MPI指标的变化为自身参照标准,采用配对样本t检验比较建模前后静息和负荷状态下MBF、MBV的差异。之后处死动物并行病理检查证实CMD心肌节段。结果:8只猪完成实验(2只猪于建模时死亡)。CMD区静息MBF、MBV分别为(98.6±20.9)ml·100 ml^-1·min^-1、(9.0±2.8)ml/100 ml;负荷MBF、MBV分别为(87.6±14.6)ml·100 ml^-1·min^-1、(8.0±1.8)ml/100 ml。CMD区静息和负荷MBF及MBV与非CMD区比较均减低(P<0.001)。HE染色低倍镜下显示损伤心肌与正常心肌并存,高倍镜下显示心肌细胞质黏附,嗜酸性粒细胞增多,心肌细胞排列疏松,细胞核部分出现皱缩以及心肌细胞间质水肿。结论:本研究通过动态CT-MPI评价CMD动物模型,表明CMD心肌节段在静息和负荷状态下的MBF值和MBV值均较造模前明显减低,MBF、MBV变化值可作为动态CT-MPI评价CMD的定量指标。     

基于机器学习方法研究造成缺血特异性狭窄的斑块特征

目的 利用机器学习（ML）方法探讨定量、定性的冠状动脉斑块特征以及血流动力学参数对缺血特异性狭窄血管的影响。 材料与方法 回顾性分析同时行冠状动脉CT血管成像（CCTA）、有创冠状动脉造影（ICA）及FFR测量的255例病人共328支血管的临床及影像资料。以FFR≤0.80作为提示病变特异性缺血的指标,依据FFR值将纳入血管分为非缺血组（FFR>0.80）和缺血组（FFR≤0.80）。测量所有纳入斑块的CCTA参数,包括斑块的定量、定性特征以及血流动力学参数。采用LogitBoost算法建立随机森林模型,通过信息增益排序方法自动选择特征。分类准确度、敏感度以及f1值（分类准确度与敏感度的调和平均值）用以评价随机森林模型对造成缺血特异性狭窄斑块的预测价值,并计算受试者操作特征（ROC）曲线下面积。采用十折分层交叉验证法计算模型的总体分类准确度。 结果 应用ML方法得出,血流动力学参数FFR_CT、ΔFFR_CT是预测缺血特异性狭窄最重要的2个特征,其次是斑块的定量、定性特征,包括脂质斑块体积、斑块弯曲、斑块不规则、非钙化斑块体积、狭窄程度、纤维斑块体积和管腔体积。在排序前10的特征中有9个是CCTA相关参数,只有1个临床参数。采用随机森林模型预测缺血特异性狭窄的分类准确度为0.940,敏感度为0.940,f1值为0.940;预测缺血特异性狭窄的 ROC曲线下面积为0.992,模型的总体分类准确度为0.921±0.047。 结论 ML方法能够很好地预测引起心肌缺血的冠状动脉特异性狭窄病变的斑块特征。     

颅内VW-MRI豆纹动脉成像：大脑中动脉粥样硬化斑块与梗死类型的关系

目的 基于高分辨MR血管壁成像（VW-MRI）技术探讨不同类型脑梗死病人的大脑中动脉（MCA）斑块体积和豆纹动脉（LSA）数量、长度间的关系。方法 回顾性纳入因可疑脑卒中或其他脑血管病行头颅MRI检查的病人58例,均经VW-MRI检查明确诊断。其中,单侧基底节区急性脑梗死病人39例[男28例,女11例,年龄45~75岁,平均（60.92±12.21）岁],根据其MR影像分为大动脉粥样硬化型[较大皮质下梗死（LSI）]组21例和小动脉闭塞型[较小腔隙性梗死（SLI）]组18例;其余19例无急性脑梗死灶且单侧MCA无斑块的病人作为对照组[男8例,女11例,年龄42~81岁,平均（63.84±12.05）岁]。由2名放射科医生统计3组临床资料并测量LSA长度、数量,利用斑块软件测量LSI组和SLI组的MCA M1-2段斑块体积。2组间比较采用独立样本t检验,3组间比较采用单因素方差分析或χ²检验。采用无序多分类logistic回归分析不同梗死类型的影响因素。采用组内相关系数（ICC）评价2名医师测量数据的一致性。结果 3组病人临床资料差异均无统计学意义（均P>0.05）。LSI、SLI和对照组的LSA平均分支长度和分支数量分别为13.48±2.99、15.8±2.71、（16.4±2.69） mm和2.00±0.77、2.78±0.94、（3.11±1.15）支,组间差异均有统计学意义（均P<0.05）。其中,LSI组的分支长度、数量最小（P<0.05）,SLI组和对照组间差异均无统计学意义（均P>0.05）。LSI组的斑块体积大于SLI组[分别为（87.5±17.7） mm³、（75.5±9.4） mm³,t=2.579,P=0.014]。LSA长度越短和分支数越少则LSI型的风险增加,OR（95%CI）值分别为0.665（0.497~0.890）、0.253（0.106~0.604）。2名医师测量斑块体积和长度的一致性较好,ICC分别为0.78和0.84。结论 采用VW-MRI对MCA及LSA成像有助于揭示深穿支梗死类型的发生机制,其中MCA斑块体积及LSA数量和长度是影响脑梗死分型的关键因素。     

双能量CT虚拟去钙技术评价骨质疏松症的价值

目的 评估双能量CT（DECT）虚拟去钙（VNCa）技术定量评价骨质疏松症的应用价值。 方法 回顾性纳入55例慢性腰腿痛病人,其中男29例,女26例,平均年龄（49.8±12.1）岁。所有病人均行腰椎DECT扫描并采集定量CT（QCT）数据。通过修改双能量分析软件中虚拟平扫的配置文件,定量测量对比剂CT值（CM）、常规CT值（rCT）、钙浓度（CaD）及脂肪分数（FF）;利用QCT pro定量分析系统测量椎体的骨密度（BMD）。依据金标准BMD< 80 mg/cm³,将纳入的全部椎体（318个）分为骨质疏松组（OP,87个）和非骨质疏松组（NOP,231个）。采用组内相关系数（ICC）分析2名医师测量数据结果的一致性。采用独立样本t检验比较2组间DECT定量参数的差异。采用Pearson相关分析BMD与DECT定量参数的相关性,并建立多元线性回归模型,将由该模型计算得到的BMD表示为回归BMD（rBMD）,得出决定系数r²和rBMD的方程。以QCT的BMD值作为金标准,采用受试者操作特征（ROC）曲线评价rBMD、CM、CaD、FF的诊断效能。 结果 2名医生测量BMD和DECT定量参数的一致性较好（均ICC>0.75）。OP组的CM、rCT、CaD均低于NOP组,而FF高于NOP组（均P<0.05）。CM、rCT、CaD、FF值与BMD均具有相关性（r分别为0.885、0.947、0.877、-0.492,均P<0.05）。将CM、CaD、FF纳入回归模型计算得出:r²=0.915,rBMD=54.82-0.19×CM+20.03×CaD-1.24×FF。当rBMD的阈值为81.94 mg/cm³时诊断效能最高,其敏感度、特异度、AUC分别为90.04%、91.95%、0.966（0.940~0.983）。 结论 DECT的VNCa技术可作为一种BMD测量的补充方法,从骨矿物质及脂肪含量方面定量评价骨质疏松症。     

基于人工智能的冠状动脉CT血管成像检测阻塞性冠状动脉狭窄效能的研究

目的 以有创冠状动脉造影（ICA）为参考标准,探讨人工智能(AI)辅助的冠状动脉CT血管成像（CCTA）诊断阻塞性冠状动脉狭窄的效能。 方法 回顾性收集行CCTA检查并于3个月内行ICA检查的50例疑患冠状动脉疾病（CAD）的病人,男34例,女16例,平均年龄（61.8±8.5）岁。AI软件、不同年资医师（低/中/高年资）及AI+不同年资医师分别对入组病人CCTA影像进行后处理并解读。将ICA和CCTA上冠状动脉管腔狭窄≥50%定义为阻塞性冠状动脉狭窄。采用Agatston积分法测量病人的钙化积分值,并将病人分为低钙化组（钙化积分<100）和高钙化组（钙化积分≥100）。采用独立样本t检验对AI、医师及AI+医师的图像后处理和解读时间进行两两比较。以ICA为参考标准,分析AI在不同研究水平和高/低钙化组的诊断价值,并比较AI、不同年资医师和AI+不同年资医师的诊断敏感度、特异度、阳性预测值、阴性预测值、准确度及受试者操作特征（ROC）曲线下面积（AUC）。采用Pearson卡方检验或Fisher精确概率检验比较组间差异,采用DeLong检验比较AUC。 结果 50例病人共分析195支血管424个节段。AI和AI+医师的平均后处理和解读时间均低于单独医师诊断的时间（均P<0.05）,AI的时间较低/中/高年资医师分别减少了80%、76.8%和75%;AI+低/中/高年资医师较单独医师分别减少了67%、64%、57.9%。在病人、血管及节段水平,AI诊断阻塞性冠状动脉狭窄的敏感度分别为93.7%、83.1%、67.7%,特异度为50.0%、89.0%、91.0%,准确度为92%、86.7%、85.6%,阳性预测值为97.8%、83.1%、69.8%,阴性预测值为25%、89.0%、90.2%,AUC为0.87、0.89、0.83;在血管及节段水平,AI对低钙化组的特异度高于高钙化组（均P<0.05）。在血管水平,AI诊断的AUC值均低于中/高年资医师（均P<0.05）;其余研究水平,AI与其他不同年资医师诊断的AUC值差异均无统计学意义（均P>0.05）。3种研究水平下,AI+低/中/高年资医师诊断的AUC值与单独不同年资医师诊断的AUC值差异均无统计学意义（均P>0.05）。 结论 AI辅助的CCTA诊断阻塞性冠状动脉狭窄具有较好的诊断效能,且明显缩短后处理时间,可能成为临床医师诊断阻塞性冠状动脉狭窄的有效辅助工具。     

MR多技术扫描检测活性心肌及其和心肌声学造影对比的临床研究

目的 评价MR多技术扫描和心肌声学造影（MCE）在检测心肌灌注、判断心肌存活中的作用。资料与方法 应用MR多技术扫描对36例冠心病患者进行检查,并将结果与冠状动脉造影、MCE结果对照。结果 共有81支冠状动脉狭窄≥70％,狭窄的冠状动脉供血区域为334个（57．99％）节段。MR心肌灌注扫描见268个（46．53％）节段呈缺血改变,MR心肌活性扫描见83个（14．4l％）节段心肌梗死。以冠状动脉造影结果为标准,MR心肌灌注扫描的敏感性为80．2％,特异性为100％,总符合率为88．5％,Kappa值为0．773。定性MCE检查共有202个（35．07％）节段呈缺血改变。以冠状动脉造影结果为标准,定性MCE的敏感性为60．5％,特异性为100％,总符合率为77．1％,Kappa值为0．563。MR心肌灌注扫描所发现的缺血节段比狭窄冠状动脉的供血节段少但无统计学意义（P=0．468）,MCE所发现的缺血节段比狭窄冠状动脉的供血节段少（P=0．000）;MR心肌灌注扫描检出缺血节段比MCE检出的多（P=0．000）。结论 MR多技术扫描可清晰显示心肌缺血或梗死的位置、程度,可重复性好,与冠状动脉造影结果的一致性较高。MCE为临床提供了元创、可重复地准确测定心肌缺血的新方法,但其评价方法具有一定主观性且低估心肌缺血的范围,检查者的经验和检查方法在一定程度上影响其准确性。     

基于第三代双源CT动态心肌灌注成像不同负荷后心率增量者的正常心肌血流量范围

目的:探讨基于第3代双源CT动态心肌灌注成像（CT-MPI）定量的正常心肌血流量（MBF）与负荷后心率增量的关系。方法:回顾性分析2016年10月至2019年11月于上海交通大学附属第六人民医院行动态CT-MPI及冠状动脉CTA（CCTA）检查的冠状动脉正常或冠状动脉轻微狭窄（定义为任一心外膜血管直径狭窄<25%）44...     

激光心肌血管重建术对犬缺血心肌血流量和氧代谢的影响

目的　探讨激光心肌血管重建术（TMLR）对急性缺血心肌血流量和氧代谢的作用与机制。 方法　18只犬随机等分为正常对照组、心肌缺血组、激光治疗组。采用连续型Nd∶YAG激光行TMLR。测左前降支冠状动脉（LAD）结扎前、结扎后30min和60min的心肌血流量（MBF）,动脉血氧含量（C     

Dynamic CT Myocardial Perfusion Imaging in Patients without Obstructive Coronary Artery Disease: Quantification of Myocardial Blood Flow according to Varied Heart Rate Increments after Stress

ObjectiveThe present study aimed to investigate the association between myocardial blood flow (MBF) quantified by dynamic CT myocardial perfusion imaging (CT-MPI) and the increments in heart rate (HR) after stress in patients without obstructive coronary artery disease.Materials and MethodsWe retrospectively included 204 subjects who underwent both dynamic CT-MPI and coronary CT angiography (CCTA). Patients with more than minimal coronary stenosis (diameter ≥ 25%), history of myocardial infarction/revascularization, cardiomyopathy, and microvascular dysfunction were excluded. Global MBF at stress was measured using hybrid deconvolution and maximum slope model. Furthermore, the HR increments after stress were recorded.ResultsThe median radiation dose of dynamic CT-MPI plus CCTA was 5.5 (4.5–6.8) mSv. The median global MBF of all subjects was 156.4 (139.8–180.4) mL/100 mL/min. In subjects with HR increment between 10 to 19 beats per minute (bpm), the global MBF was significantly lower than that of subjects with increment between 20 to 29 bpm (153.3 mL/100 mL/min vs. 171.3 mL/100 mL/min, p = 0.027). This difference became insignificant when the HR increment further increased to ≥ 30 bpm.ConclusionThe global MBF value was associated with the extent of increase in HR after stress. Significantly higher global MBF was seen in subjects with HR increment of ≥ 20 bpm.     

Prognostic value of CT myocardial perfusion imaging and CT-derived fractional flow reserve for major adverse cardiac events in patients with coronary artery disease

ObjectivesThe purpose of this study was to analyze the prognostic value of dynamic CT perfusion imaging (CTP) and CT derived fractional flow reserve (CT-FFR) for major adverse cardiac events (MACE).Methods81 patients from 4 institutions underwent coronary computed tomography angiography (CCTA) with dynamic CTP imaging and CT-FFR analysis. Patients were followed-up at 6, 12, and 18 months after imaging. MACE were defined as cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, or revascularization. CT-FFR was computed for each major coronary artery using an artificial intelligence-based application. CTP studies were analyzed per vessel territory using an index myocardial blood flow, the ratio between territory and global MBF. The prognostic value of CCTA, CT-FFR, and CTP was investigated with a univariate and multivariate Cox proportional hazards regression model.Results243 vessels in 81 patients were interrogated by CCTA with CT-FFR and 243 vessel territories (1296 segments) were evaluated with dynamic CTP imaging. Of the 81 patients, 25 (31%) experienced MACE during follow-up. In univariate analysis, a positive index-MBF resulted in the largest risk for MACE (HR 11.4) compared to CCTA (HR 2.6) and CT-FFR (HR 4.6). In multivariate analysis, including clinical factors, CCTA, CT-FFR, and index-MBF, only index-MBF significantly contributed to the risk of MACE (HR 10.1), unlike CCTA (HR 1.2) and CT-FFR (HR 2.2).ConclusionOur study provides initial evidence that dynamic CTP alone has the highest prognostic value for MACE compared to CCTA and CT-FFR individually or a combination of the three, independent of clinical risk factors.     

Comprehensive morphologic and functional imaging of heart transplant patients: first experience with dynamic perfusion CT

Objectives

We aimed to assess the diagnostic performance of a combined protocol with coronary computed tomography angiography (CCTA) and stress CT perfusion imaging (CTP) in heart transplant patients for comprehensive morphological and functional imaging.

Methods

In this prospective study, 13 patients undergoing routine follow-up 8±6 years after heart transplantation underwent CCTA and dynamic adenosine stress CTP using a third-generation dual-source CT scanner, cardiac magnetic resonance (MR) adenosine stress perfusion imaging at 1.5 T, and catheter coronary angiography. In CCTA stenoses >50% luminal diameter narrowing were noted. Myocardial perfusion deficits were documented in CTP and MR. Quantitative myocardial blood flow (MBF) was calculated with CTP. Left ventricular ejection fraction was determined on cardiac MR cine images. Radiation doses of CT were determined.

Results

One of the 13 patients had to be excluded because of severe motion artifacts. CCTA identified three patients with stenosis >50%, which were confirmed with catheter coronary angiography. CTP showed four patients with stress-induced myocardial hypoperfusion, which were confirmed by MR stress perfusion imaging. Quantitative analysis of global MBF showed lower mean values as compared to known reference values (MBF under stress 125.5 ± 34.5 ml/100 ml/min). Average left ventricular ejection fraction was preserved (56 ± 5%).

Conclusions

In heart transplant patients, a comprehensive CT protocol for the assessment of morphology and function including CCTA and CTP showed good concordance to results from MR perfusion imaging and catheter coronary angiography.

Key Points

? Stress CT perfusion imaging enables the detection of myocardial ischemia ? CT myocardial perfusion imaging can be combined with coronary computed tomography angiography ? Combining perfusion and coronary CT imaging is accurate in heart transplant patients ? CT myocardial perfusion imaging can be performed at a reasonable radiation dose

     

Detection of ischaemic myocardial lesions with coronary CT angiography and adenosine-stress dynamic perfusion imaging using a 128-slice dual-source CT: diagnostic performance in comparison with cardiac MRI

Objective:

We assessed the diagnostic performance of adenosine-stress dynamic CT perfusion (ASDCTP) imaging and coronary CT angiography (CCTA) for the detection of ischaemic myocardial lesions using 128-slice dual-source CT compared with that of 1.5 T cardiac MRI.

Methods:

This prospective study included 33 patients (61±8 years, 82% male) with suspected coronary artery diseases who underwent ASDCTP imaging and adenosine-stress cardiac MRI. Two investigators independently evaluated ASDCTP images in correlation with significant coronary stenosis on CCTA using two different thresholds of 50% and 70% diameter stenosis. Hypoattenuated myocardial lesions on ASDCTP associated with significant coronary stenoses on CCTA were regarded as true perfusion defects. All estimates of diagnostic performance were calculated and compared with those of cardiac MRI.

Results:

With use of a threshold of 50% diameter stenosis on CCTA, the diagnostic estimates per-myocardial segment were as follows: sensitivity, 81% [95% confidence interval (CI): 70–92%]; specificity, 94% (95% CI: 92–96%); and accuracy 93% (95% CI: 91–95%). With use of a threshold of 70%, the diagnostic estimates were as follows: sensitivity, 48% (95% CI: 34–62%); specificity, 99% (95% CI: 98–100%); and accuracy, 94% (95% CI: 92–96%).

Conclusion:

Dynamic CTP using 128-slice dual-source CT enables the assessment of the physiological significance of coronary artery lesions with high diagnostic accuracy in patients with clinically suspected coronary artery disease.

Advances in knowledge:

Combined CCTA and ASDCTP yielded high accuracy in the detection of perfusion defects regardless of the threshold of significant coronary stenosis.It is important to evaluate not only anatomical information about coronary arteries but also physiological information about myocardial perfusion for the precise assessment of coronary artery disease (CAD) [1]. Myocardial perfusion imaging (MPI) can provide haemodynamic information during exercise-induced or pharmacological stress. Single-photon emission tomography (SPECT), cardiac MRI or positron emission tomography (PET) has been extensively used for MPI [2,3]. Moreover, a normal MPI determined using these techniques carries an excellent prognosis with a low rate of cardiac events [4–6].SPECT and PET are limited in their ability to evaluate coronary artery morphology and cardiac structures. By contrast, CT MPI with coronary CT angiography (CCTA) can evaluate not only anatomical structure, including coronary artery morphology, but also myocardial perfusion status. Although radiation dose associated with CT perfusion (CTP) is a concern, recent studies have shown that exposure to radiation can be reduced using different techniques, such as high-pitch helical scan of static CTP, half-scan duration of dynamic CTP and anatomical tube current modulation [7,8]. SPECT is more frequently used than MRI as a reference standard for evaluating the diagnostic accuracy of CTP. However, Jaarsma et al [9] reported that both cardiac MRI and PET showed a significantly higher diagnostic accuracy than SPECT for detection of obstructive CAD. Among several techniques of CTP, adenosine-stress dynamic CTP (ASDCTP) using 128-slice dual-source CT (DSCT) has the advantages of quantitative analysis of myocardial blood flow (MBF) and the use of dynamic data sets [10–14]. There have been 2 previous studies of dynamic CTP using stress perfusion MRI as the reference standard [13,15], but these reports enrolled only 10 patients in the study arm evaluating dynamic CTP.The purpose of this study was to evaluate the diagnostic performance of ASDCTP using a 128-slice DSCT for the detection of myocardial perfusion defects compared with adenosine-stress cardiac MRI.     

Time Efficiency and Diagnostic Accuracy of New Automated Myocardial Perfusion Analysis Software in 320-Row CT Cardiac Imaging

Objective

We aimed to evaluate the time efficiency and diagnostic accuracy of automated myocardial computed tomography perfusion (CTP) image analysis software.

Materials and Methods

320-row CTP was performed in 30 patients, and analyses were conducted independently by three different blinded readers by the use of two recent software releases (version 4.6 and novel version 4.71GR001, Toshiba, Tokyo, Japan). Analysis times were compared, and automated epi- and endocardial contour detection was subjectively rated in five categories (excellent, good, fair, poor and very poor). As semi-quantitative perfusion parameters, myocardial attenuation and transmural perfusion ratio (TPR) were calculated for each myocardial segment and agreement was tested by using the intraclass correlation coefficient (ICC). Conventional coronary angiography served as reference standard.

Results

The analysis time was significantly reduced with the novel automated software version as compared with the former release (Reader 1: 43:08 ± 11:39 min vs. 09:47 ± 04:51 min, Reader 2: 42:07 ± 06:44 min vs. 09:42 ± 02:50 min and Reader 3: 21:38 ± 3:44 min vs. 07:34 ± 02:12 min; p < 0.001 for all). Epi- and endocardial contour detection for the novel software was rated to be significantly better (p < 0.001) than with the former software. ICCs demonstrated strong agreement (≥ 0.75) for myocardial attenuation in 93% and for TPR in 82%. Diagnostic accuracy for the two software versions was not significantly different (p = 0.169) as compared with conventional coronary angiography.

Conclusion

The novel automated CTP analysis software offers enhanced time efficiency with an improvement by a factor of about four, while maintaining diagnostic accuracy.     

Rationale and design of advantage (additional diagnostic value of CT perfusion over coronary CT angiography in stented patients with suspected in-stent restenosis or coronary artery disease progression) prospective study

BackgroundRecent studies demonstrated a significant improvement in the diagnostic performance of coronary CT angiography (CCTA) for the evaluation of in-stent restenosis (ISR). However, coronary stent assessment is still challenging, especially because of beam-hardening artifacts due to metallic stent struts and high atherosclerotic burden of non-stented segments. Adenosine-stress myocardial perfusion assessed by CT (CTP) recently demonstrated to be a feasible and accurate tool for evaluating the functional significance of coronary stenoses in patients with suspected coronary artery disease (CAD). Yet, scarce data are available on the performance of CTP in patients with previous stent implantation.Aim of the studyWe aim to assess the diagnostic performance of CCTA alone, CTP alone and CCTA plus CTP performed with a new scanner generation using quantitative invasive coronary angiography (ICA) and invasive fractional flow reserve (FFR) as standard of reference.MethodsWe will enroll 300 consecutive patients with previous stent implantation, referred for non-emergent and clinically indicated invasive coronary angiography (ICA) due to suspected ISR or progression of CAD in native coronary segments. All patients will be subjected to stress myocardial CTP and a rest CCTA. The first 150 subjects will undergo static CTP scan, while the following 150 patients will undergo dynamic CTP scan. Measurement of invasive FFR will be performed during ICA when clinically indicated.ResultsThe primary study end points will be: 1) assessment of the diagnostic performance (diagnostic rate, sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy) of CCTA, CTP, combined CCTA-CTP and concordant CCTA-CTP vs. ICA as standard of reference in a territory-based and patient-based analysis; 2) assessment of sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CCTA, CTP, combined CCTA-CTP and concordant CCTA-CTP vs. invasive FFR as standard of reference in a territory-based analysis.ConclusionsThe ADVANTAGE study aims to provide an answer to the intriguing question whether the combined anatomical and functional assessment with CCTA plus CTP may have higher diagnostic performance as compared to CCTA alone in identifying stented patients with significant ISR or CAD progression.