心脏MR鉴别急性病毒性心肌炎与特发性炎性肌病心肌受累

目的 探讨心脏磁共振(CMR)成像在鉴别急性病毒性心肌炎(AVM)与特发性炎性肌病(IIM)心肌受累中的应用价值.方法 回顾性分析经临床证实的29例ⅡM及24例AVM患者临床及CMR参数.CMR参数包括左心形态功能参数及心肌组织特征成像参数,如初始T1值、T2值、细胞外容积比例(ECV)和延迟强化(LGE).结果 左心...     

心脏MR评估大动脉炎肺动脉受累患者心肌结构及功能受损表现

目的分析临床明确诊断为大动脉炎肺动脉受累(PTA)患者心脏磁共振(CMR)心肌延迟强化(LGE)、心功能参数及组织特征追踪技术(FT)所得的心室心肌整体应变情况, 探讨其心肌结构及功能受损表现。方法回顾性选择2017年1月到2020年12月临床明确诊断为PTA的患者32例和无心肺疾病的健康受试者21名, 且均进行了CMR检查。依据有无肺动脉高压(PAH), 将PTA患者分为PAH组(11例)和非PAH组(21例), 应用Fisher精确检验比较两组PTA患者间心肌LGE表现的差异。进一步应用单因素方差分析或非参数Kruskal-Wallis检验比较PAH组、非PAH组患者和健康对照组心功能参数, 以及左、右心室心肌的整体应变峰值, 并进行组间两两比较。将PAH组上述FT参数值与右心导管检查(RHC)所得的血流动力学参数、经胸超声心动图估测的肺动脉收缩压进行Pearson或Spearman相关性分析。结果 PTA患者存在心肌LGE阳性者23例(71.9 %)。PAH组心室结合部(IP)(11/11)、心肌中层(11/11)或心外膜下(10/11)与非PAH组IP部(11/21)、心肌中层...     

~(15)O-水-可灌注组织分数在陈旧性心肌梗死实验犬研究中的组织化学关系

应用 1 5 O-水 (H2 1 5 O)和 PET监测作协同不全心肌段血流灌注减低区的心肌水 -可灌注组织分数 (PTF)定量研究 ,观察 PTF和可灌注组织指数 (PTI)在犬陈旧性心肌梗死中的组织化学关系。方法 :12条杂种犬实验致心肌梗死 ,1个月后作 PET显像 ,提供 PTF定量参数影像、局部的心肌血流 (MBF)、H2 1 5 O血管外密度、1 5 O-一氧化碳及透射数据集。扫描结束切开心肌 ,将 PET影像直接与相应的心肌切面作比较。结果 :组织化学染色法识别坏死组织的分布与 PTF的缺损符合性较好 ,但与 MBF不一致。PTF与注射 H2 1 5 O大弹丸后获得的心肌…     

超声背向散射技术的基础研究与临床应用

超声组织定征(Ultrasonic tissue characterization,UTC)是采用超声视频法、射频法、声速与声衰减等技术检测组织微病理变化的方法.     

^123I—BMIPP在犬顿抑心肌中的摄取、清除和代谢

目的利用123I-15对碘苯基-3(R，S)甲基十五烷酸(BMIPP)在犬顿抑心肌(SM)中的不匹配分布，探讨其作为诊断SM示踪剂的可能性。方法建立标准犬左回旋支(LCX)顿抑心肌模型(18min结扎后再灌注，n=12)。监测血流动力学和心功能参数。Doppler探头测量ICX血流和局部室壁收缩厚度(WT)。SPEGT显像和组织γ计数法测量局部心肌的BMIPP、201Tl分布和微球灌注(RBF)。测量局部心肌耗氧量、葡萄糖和乳糖利用率。动态测量局部BMIPP摄取与清除。薄层层析法分析BMIPP及其代谢产物。结果心肌顿抑时的血流动力学参数和冠状动脉血流恢复到基础水平，但WT明显低于基础值[(12.9±29.1)％和(66.3±22.4)％，P＜0.01]。离体心脏SPECT显像示，顿抑心肌残留BMIPP[(70±6)％]高于201Tl[(66±6)％，P＜0.05]。SM组织计数则BMIPP[(88.5±6.0)％]和Tl[(85.4±6.7)％]高于RBF[(70.4±10.5)％，P＜0.001]。SM中，201Tl与RBF相关性较好(r=0.67)，而BMIPP与RBF不相关(r=0.11)。虽然SM的局部耗氧量和乳糖利用率低于基础值，但BMIPP代谢产物清除增加。未经代谢的BMIPP摄取和清除均有减低趋势。结论代谢因素对SM的BMIPP残留有明显影响，主要表现为BMIPP摄取减低和其代谢产物清除增加。     

心脏MR在冠状动脉慢血流患者中的初步研究

目的 探讨冠状动脉慢血流(CSF)患者心脏MR(CMR)评价的左室结构功能、心肌静息灌注及心肌应变的改变。方法 回顾性搜集经冠状动脉血流帧数(TFC)诊断为CSF且1周内行CMR检查的患者35例(CSF组),同期纳入健康对照组21例。比较两组间基线资料、左室结构功能参数、静息灌注参数及心肌应变参数的差异,左室结构功能参数包括左室收缩末容积(ESV)、左室舒张末容积(EDV)、左室收缩末容积指数(LVESVi)、心肌质量指数(LVMi)、左室射血分数(LVEF)等;静息灌注参数包括最大上升斜率(upslope)、最大信号强度达峰时间(TTM)、信号强度最大值(SImax);左室心肌应变参数包括径向应变(GRS)、周向应变(GCS)和纵向应变(GLS)。进一步明确TFC与心肌应变参数的相关性。结果 与对照组相比,CSF患者体重指数、低密度脂蛋白胆固醇和甘油三酯水平及高血压患病率增高(P<0.05)。CMR评价的ESV、EDV、LVM、LVESVi、LVMi均较对照组增高,LVEF减低(63.92±7.10 vs 57.37±9.03,P<0.05)。静息心肌灌注显示CSF组SI...     

应变率成像及背向散射积分技术对糖尿病患者心肌局部舒张功能的研究

目的:应用应变率成像(SRI)及背向散射积分技术(IBS)综合评价Ⅱ型糖尿病(DM)患者左室心肌局部舒张功能.方法:应用组织多普勒成像技术(TDI)及背向散射积分(IBS)技术对30例健康成人(对照组)及30例Ⅱ型糖尿病患者(DM组)的左室心肌局部舒张功能进行定量分析.计算局部心肌舒张早期峰值应变率(SRe)、心房收缩期峰值应变率(SRa)、背向散射积分参数(IBS、IBS%、CVIB和CVIB%).应用常规超声心动图检测二尖瓣口血流峰值流速,即舒张早期峰值流速(Ve)和心房收缩期峰值流速(Va),计算Ve与Va的比值.结果:与对照组比较,DM组左室局部心肌舒张早期峰值应变率显著减低,心房收缩期峰值应变率显著增高.心肌背向散射积分参数中IBS和IBS%较对照组显著增高,CVIB和CVIB%显著减低(P<0.05).结论:SRI及IBS技术可以客观评价Ⅱ型糖尿病患者左室局部心肌的舒张功能,为临床制定治疗方案和评估预后提供重要的影像学信息.     

基于MRI定量评估扩张型心肌病心功能及心肌应变的初步研究

目的 探讨心脏磁共振(CMR)组织追踪技术定量评估扩张型心肌病(DCM)患者和健康者双心室心功能及心肌应变参数,并分析临床实验室指标与DCM患者应变参数的相关性。方法 选取33例DCM患者及32例健康者的临床及影像学资料。通过应力分析后处理软件,半自动计算双心室心功能参数、心肌整体纵向、周向、径向应力及各个方向心肌应力率。应用Pearson相关分析实验室指标与应变率的相关性。结果 DCM组的双心室舒张末期、收缩末期容积高于对照组,射血分数及应变力值低于对照组(P <0.05)。DCM组的血清高敏肌钙蛋白T值与右心室整体纵向应力值、乳酸脱氢酶值与左心室收缩期峰值周向应力率、左心室整体纵向应力、肌酸激酶值与右心室收缩期峰值纵向应力率有相关性(P <0.05)。结论 DCM患者双心室心肌收缩功能及收缩应力值均受损,部分心肌酶谱指标与双心室心肌应力参数具有相关性,CMR可显示DCM心肌损伤情况。     

2型糖尿病心肌背向散射积分及左室舒张功能变化的研究

 目的评价2型糖尿病(Diabetes mellitus,DM)患者心肌背向散射积分(Integrated backscatter,IBS)及左室舒张功能的变化.方法用脉冲多普勒超声心动图(Pulsed Doppler echocardiography,PDE)、多普勒组织显像(Dopplertissue imaging,DTI)技术及IBS技术测定40例2型DM患者、20例健康人二尖瓣口和肺静脉血流参数(Ep、Ap、ap)、二尖瓣环运动参数(Vs、Ve、Va)及心肌IBS参数(IBS、IBS%、CVIB).结果DM组Ap、ap、Va增高,Ep/Ap、Ve、Ve/Va降低(P＜0.05);DM组IBS%增高、CVIB减低(P＜0.05).结论2型DM患者早期存在舒张功能异常;DTI测定二尖瓣环运动速度评价左室舒张功能敏感而简便;IBS能早期反映DM患者心肌的组织学改变.     

缺血缺氧在大鼠烧伤后"休克心"中的作用及其机制探讨

目的　探讨缺血缺氧在烧伤后“休克心”中的作用及其机制。　方法　健康成年Wistar大鼠 15 0只 ,分为对照组 (2 5只 )和 30 %TBSAⅢ度烧伤组 (12 5只 ) ,其中烧伤组又分为 1,3,6 ,12和 2 4h组 ,每组 2 5只。检测心肌收缩功能、心肌微血管通透性分值、心肌局部血流量、血浆中心肌肌球蛋白轻链 1(CMLC1)、心肌组织核转录因子 (NF -κB)活性、髓过氧化物酶 (MPO)、TNFαmRNA表达和心肌组织TNFα含量。　结果　伤后 1h ,心肌微血管通透性分值即开始增高 ,2 4h达对照值的 2 .1倍 ;心肌局部血流量显著降低 ,伤后 2 4h仍显著低于对照水平 ;CMLC1增高达对照组的 18.6倍。心肌组织NF -κB活性和TNFαmRNA表达明显增强 ,心肌组织TNFα含量增高。心肌组织MPO活性升高。左心室收缩峰压 (LVSP)、最大左心室等容收缩期中心室内压上升 下降的最大速率 (±dp dtmax)均显著降低 ,而左心室舒张末压 (LVEDP)上升 ,表明心肌收缩功能和舒张功能均减退。　结论　缺血缺氧造成了心肌严重损害 ,心肌组织NF -κB活性明显增强 ,心肌细胞TNFα等促炎因子表达上调是烧伤后“休克心”的重要因素。     

Contrast-enhanced MRI for quantification of myocardial viability.

During the past 10 years substantial advances have taken place in magnetic resonance imaging (MRI) capabilities and in contrast media development. Furthermore, knowledge of in vivo contrast media interactions with surrounding water and distribution into tissue has increased, permitting regional quantification of concentration-time profiles in the myocardium. The combination of these advances has substantially improved the capability of contrast-enhanced MRI characterization of myocardial ischemic injury, including its ability to discriminate viable from nonviable zones. Discrimination of viable from nonviable myocardial subregions is important for patient management and for research applications. This review addresses recent progress toward the goal of defining viable and nonviable myocardium based on MRI detection of contrast media effects. J. Magn. Reson. Imaging 1999;10:694-702.     

Quantitative ultrasonic detection and classification of diffuse liver disease. Comparison with human observer performance

A multiparameter ultrasonic tissue characterization system has been developed and tested on several types of diffuse liver disease. The four tissue characterization parameters used are based on the first and second order statistics of the B-scan image. Performance of the system was evaluated using receiver operating characteristic (ROC) analysis and was compared with the performance of experienced human observers viewing B-scan images. The machine-based multiparameter system achieved an area under the ROC curve (Az) of 0.88 for detection of chronic hepatitis in more than 100 proven cases of the disease. This was dramatically better than the performance of human observers (Az = .64, P less than .05) and compares favorably to the performance of other accepted diagnostic tests such as head CT and the PAP smear. For detection of Gaucher's disease, the Az for the system was .92, whereas for separating hepatitis from Gaucher's disease Az was .84. Human observers also did well at these tasks (P greater than .8) using organomegaly as their major criterion for diagnosing Gaucher's disease. For primary biliary cirrhosis the system Az was .80, for glycogen storage disease Az was .94. These results suggest that use of multiparameter tissue characterization can significantly increase the usefulness of ultrasound for evaluation of diffuse liver disease.     

Quantitative technics in ultrasonic diagnosis

This paper presents techniques for computer-aided analysis of medical ultrasonic images. Methods of image processing, feature extraction and a classification algorithm for tissue characterization are described. Based on these techniques a pattern recognition system for semi-automatic analysis of ultrasonic images has been developed and proved within three clinical studies, which aimed to improve the ultrasound diagnosis of the prostate, the thyroid and the female breast. The results show that computer analysis of ultrasonic images is capable of providing a quantitative diagnosis as well as of differentiating tumor lesions by sonography.     

Técnicas paramétricas de caracterización tisular del miocardio mediante resonancia magnética (parte 1): mapas de T1

The development of myocardial fibrosis is a common process in the appearance of ventricular dysfunction in many heart diseases. Magnetic resonance imaging makes it possible to accurately evaluate the structure and function of the heart, and its role in the macroscopic characterization of myocardial fibrosis by late enhancement techniques has been widely validated clinically. Recent studies have demonstrated that T1-mapping techniques can quantify diffuse myocardial fibrosis and the expansion of the myocardial extracellular space in absolute terms. However, further studies are necessary to validate the usefulness of this technique in the early detection of tissue remodeling at a time when implementing early treatment would improve a patient's prognosis. This article reviews the state of the art for T1 mapping of the myocardium, its clinical applications, and its limitations.     

Current status of viability assessment with positron tomography

Accurate detection of reversible myocardium has great clinical importance, especially in patients being considered for interventional therapy. Positron emission tomography (PET) with fluorine 18-labeled fluorodeoxyglucose (FDG) has been used for this purpose, based on the residual metabolic activity in reversible ischemic areas. Although thallium imaging has been widely used for the evaluation of tissue viability in clinical cardiology, PET-FDG may provide independent values and thus may enhance the accuracy of studies for identifying ischemic myocardium. This review considers the advantages of PET technique, the clinical value of PET-FDG for assessing tissue viability, and the development of other new PET techniques.     

Ultrasonic echo imaging of tissues: instrumentation.

The ultrasonic pulse-echo principle is capable of providing detailed information, of considerable potential diagnostic value, on the structure of soft tissues in relation to pathology, but the present generation of ultrasonic scanners does not fully exploit this possibility. The paper discusses the principal measures necessary to achieve tissue structure visualization and quantitative characterization and describes a clinically functioning system that has been built for this purpose with particular relation to cancer diagnosis. Examples of the application of the system are given in this and an accompanying paper.     

Technetium-labeled heparin: preliminary report of a new radiopharmaceutical with potential for imaging damaged coronary arteries and myocardium

Heparin has been labeled with [99mTc] pertechnetate and its ability to image damaged coronary vessels and myocardium during and following myocardial ischemia has been studied in experimental animals. The data obtained indicate that Tc-99m heparin localizes in damaged myocardium and coronary vessels in canine models of temporary myocardial ischemia and reperfusion and in damaged myocardium during fixed coronary occlusion. Scintigraphic detection of damaged myocardium was possible in both models, but the highest levels of Tc-99m heparin in damaged myocardial tissue were found in those dogs with temporary coronary occlusion and reflow. The data suggest that Tc-99m heparin may be of value as a positive imaging agent when coronary arteries or myocardium are injured and either reperfusion is allowed and/or significant blood flow persists in the damaged area.     

Acute myocardial infarction: contrast-enhanced multi-detector row CT in a porcine model

PURPOSE: To assess the role of contrast material-enhanced retrospectively electrocardiographically (ECG) gated multi-detector row computed tomography (CT) in the detection of acute myocardial infarction in a porcine model of total coronary occlusion. MATERIALS AND METHODS: Seven Yorkshire farm pigs were studied with contrast-enhanced retrospectively ECG-gated multi-detector row CT 3 hours after total occlusion of the distal left anterior descending artery (n = 5) or the second diagonal branch (n = 2). Reformatted short-axis end-systolic and end-diastolic CT data sets were assessed for myocardial perfusion deficits, coronary occlusion, and abnormal myocardial wall motion. Perfusion deficits were compared with microsphere-determined blood flow and triphenyltetrazolium chloride (TTC)-stained tissue samples for infarct assessment by using Bland-Altman analysis and analysis of variance. RESULTS: Myocardial perfusion deficits, occlusion of the left anterior descending artery or second diagonal branch, and akinesis of the infarcted segment were identified in all five animals that completed the study. One animal died, and one data set had nondiagnostic image quality. The CT end-diastolic (mean, 16.1% +/- 4.8 [SD]; range, 8.6%-22.2%) and end-systolic (mean, 17.0% +/- 6.4; range, 8.7%-26.8%) volume of perfusion deficit was similar to that of infarcted tissue at TTC staining (mean, 13.6% +/- 6.0; range, 7.8%-30.9%). Infarcted myocardium at CT demonstrated a 76.1% reduction in microsphere-determined blood flow and a significant reduction of myocardial CT attenuation compared with normal myocardium (P <.01). Myocardial wall motion analysis demonstrated absence of systolic wall thickening in infarcted myocardium. CONCLUSION: Multi-detector row CT with retrospective ECG gating permits the detection and further characterization of acute myocardial infarction in a porcine model of complete coronary occlusion.     

Characterization of radiofrequency ablated myocardium with optical coherence tomography

Certain types of cardiac arrhythmias are best treated with radiofrequency (RF) ablation, in which an electrode is inserted into the targeted area of the myocardium and then RF electrical current is applied to heat and destroy surrounding tissue. The resulting ablation lesion usually consists of a coagulative necrotic core surrounded by a rim region of mixed viable and non-viable cells. The characterization of the RF ablated lesion is of potential clinical importance. Here we aim to elaborate optical coherence tomography (OCT) imaging for the characterization of RF-ablated myocardial tissue. In particular, the underlying principles of OCT and its polarization-sensitive counterpart (PS-OCT) are presented, followed by the knowledge needed to interpret their optical images. Studies focused on real-time monitoring of RF lesion formation in the myocardium using OCT systems are summarized. The design and development of various hybrid probes incorporating both OCT guidance and RF ablation catheters are also discussed. Finally, the challenges related to the transmission of OCT imaging systems to cardiac clinics for real-time monitoring of RF lesions are outlined.     

Thallium scintigraphy of the myocardium. I. Principles and methods

Thallium scintigraphy of myocardium is a diagnostic method of nuclear medicine which enables visualization of well perfused and vital tissue of myocardium by means of 201thallium absorbed by its cells. In the first part of the review the authors present various radiopharmaceuticals having been used in this area. Physical properties are described in greater detail as well as preparation and pharmacokinetics of 201thallium. The method of examination is described in its basic form, but also some special cases of detection and evaluation are presented, such as ECG-synchronised thallium scintigraphy of myocardium and one-photon transaxial tomography.