SRI对急性前壁STEMI患者心肌存活的早期预测价值

目的探讨应变率成像（SRI）对急性前壁ST段抬高心肌梗死（STEMI）患者心肌存活的早期预测价值。方法行急诊经皮冠状动脉介入术（PCI）的前壁STEMI患者在术后测量室间隔心尖段的SRI指标,当收缩末期应变（SES）≥-7%时则纳入研究,并于6个月后复查,评价急性期SRI指标对心肌存活的预测价值。结果 46例前壁STEMI患者纳入研究,其中25例在6个月时SES〈-7%,我们定义为存活心肌;21例随访时SES≥-7%,我们定义为失活心肌。存活心肌组SES、收缩后应变（SPS）、收缩期应变率（SRS）及舒张早期应变率（SRE）等指标明显优于失活心肌组（P〈0.01）,而收缩后应变率、舒张晚期应变率两组间无明显差异（P〉0.05）。SRS、SRE、SPS、SES均能预测心肌的存活,其中SRS曲线下面积最大（0.803,P〈0.01）,当临界值取-0.31s-1时,其预测存活心肌的敏感性、特异性、阳性预测值、阴性预测值分别为83%、68%、76%、71%。结论在行急诊PCI的前壁STEMI患者中,SRI技术能早期预测受累心肌的存活性。     

分子磁共振成像可准确地确定大脑窦血栓形成

据Stracke CP博士（Stroke，2007，38：1476-1481）报道，使用一种新的纤维蛋白特异性对比剂EP-2104R的分子磁共振成像（MRI），可选择性地确定动物模型的大脑窦静脉血栓形成。     

钆螯合物磁共振成像对比剂的研究进展

在综合文献的基础上,对新型细胞外、肝特异性、网状内皮系统特异性、血池和其它组织特异性钆螯合物磁共振对比剂的研究进展作了较详细的介绍。提示新型组织特异性钆螯合物磁共振对比剂更安全更有效,也是当前钆螯合物磁共振对比剂研究的发展方向。     

磁共振靶向对比剂在淋巴结成像中的研究进展

准确评价淋巴结转移与否关系到对肿瘤患者的分期和预后的判断。目前对淋巴结良恶性诊断的主要依据为淋巴结的大小和形态,正常大小的转移性淋巴结很可能被遗漏,增大的淋巴结是良性增生还是恶性转移也很难鉴别。近年来随着MR特异性对比剂,特别是MR靶向淋巴结对比剂的发展,MR淋巴成像(MR Lymphography,MRL)显示了极为诱人的前景。该文主要介绍MR淋巴靶向对比剂的研究进展。     

几种基于中华小型猪心脏磁共振延时增强图像的心肌梗死体积定量算法的初步比较

目的心脏磁共振(CMR)心肌成像应用钆对比剂延迟强化(LGE)显示冠心病心肌梗死(MI)的价值已得到公认。近年来涌现出多种MI体积的定量方法,但是一直没能达成共识。笔者对比了定量MI体积计算的若干方法在中华小型猪MI模型的应用,以期得到准确度最高的定量MI体积计算方法。方法猪龄3个月中华小型猪6只,行冠状动脉结扎,制作MI模型,1个月后行磁共振扫描(可认为是陈旧MI),随后即取心做TTC染色。运用数学软件MATLAB(2011b)编程对LGE图像先手动勾勒心内膜和心外膜,然后行不同信号强度(SI)阈值(5种倍数标准差:2s、3s、4s、5s、6s)分割,提取MI体积,并与病理切片得到的MI体积进行比较。结果病理切片得到的MI体积为(12.24±4.34)cm3。随着SI阈值增大,5种半自动定量算法得到的MI体积分别为(24.04±6.10)cm3、(17.76±6.41)cm3、(14.29±5.88)cm3、(11.70±5.24)cm3、(9.56±4.73)cm3。采用相关分析显示,TTC染色结果与半自动定量方法得到的结果两两之间的相关系数分别为0.807、0.917、0.952、0.967、0.962。结论 5s半自动定量方法在中华小型猪MI模型MI体积计算中与TTC染色结果相关性好,且无统计学差异。5s是一种行之有效的MI定量方法。     

多普勒组织成像定量评价左室心肌运动异常的价值

目的 运用多普勒组织成像（DTI）技术对急性心肌缺血的检测,探讨其在左室心功能方面的应用价值。方法 对10头开胸的猪结扎左冠状动脉前降支,采用二维超声及DTI对照检测缺血部心肌的运动状况。结果 DTI显示心肌缺血在15s内收缩期、舒张早期运动速度显著降低,心肌色彩暗淡或缺失。而传统超声在结扎1min后才出现显著差异。结论 DTI技术既能通过色彩反映室壁缺血的范围,又能量化其运动速度,可为临床早期评价局部心肌缺血及功能异常提供充分证据。     

一种基于磁共振图像的心肌梗死体积定量算法

目的心脏磁共振(CMR)钆对比剂延迟强化(LGE)图像在诊断冠心病心肌梗死(MI)方面的应用价值已得到公认。MI体积的计算对MI的诊断和治疗有重要意义。笔者在对比了多种定量MI体积计算方法的基础上提出了一种新的基于直方图分布的MI体积计算方法,并以病理切片所得MI体积作为标准进行评价。方法选3个月中华小型猪6只,雌雄不限,体质量20.8~24.1 kg,平均体质量21.5 kg。结扎冠状动脉,用于制备MI模型,1个月后扫描磁共振图像;随即取心脏制备切片并染色。运用数学软件MATLAB(2013b)编程对LGE心脏短轴图像行不同信号强度(SI)阈值分割,包括5s(标准差)阈值法及新算法,提取梗死部分信号,进而计算MI体积,并与染色切片得到的MI体积进行对比。结果病理切片得到的MI体积为(12.24±4.34)cm3。5s阈值法及新算法得到的MI体积分别为(12.54±5.38)cm3、(12.40±4.46)cm3。病理切片所得MI体积与5s阈值法及新算法得到的MI体积之间的相关系数分别为0.967、0.987。结论基于直方图分布的新算法在中华小型猪MI模型MI体积计算中与病理切片所得体积相关性好,且无统计学差异。基于直方图分布的新算法能准确计算MI体积。     

肝硬化相关结节的磁共振表现

肝硬化相关结节是指在肝硬化背景基础上由肝细胞和周围间质增生而形成的结节,有良性与恶性之分,不同性质决定了不同的治疗方法。目前,MRI良好的软组织分辨率及其多种肝脏特异性对比剂的应用使其成为对肝硬化相关结节进行评价的最重要的影像方法。文章就肝硬化相关结节的病理及血液供应、MRI表现、MRI增强扫描及MR弥散加权成像在评价肝硬化相关结节方面作一综述。     

急性心肌梗死的护理体会

心肌梗死（AMI）是由于冠状动脉供血急剧减少或中断，使相应的心肌严重而持久地缺血引起部分心肌坏死。我院2003年12月以来收治AMI 12例，现将护理体会报告如下。     

评价缺血心肌存活的影像学方法及其计算机分析技术

对缺血心肌的存活作出定量评价有助于冠状动脉血流重建术的病人选择和手术预后.介绍了临床上常见的用于心肌存活评价的超声、核素、磁共振等影像学方法,并针对心肌存活评价介绍了心肌图像的计算机配准和融合等技术在这方面的应用.     

Anticardiolipin antibodies are no marker for survived myocardial infarction

Summary Antiphospholipid antibodies — both the lupus anticoagulant and anticardiolipin antibodies — are closely associated with arterial and venous thrombosis. In this prospective trial the IgM- and IgG-anticardiolipin antibodies in serum were determined in acute and chronic coronary artery disease. Seventy-four unselected males (34–87 years, mean 60) were included in the study. All patients underwent coronary angiography; infectious and autoimmune diseases were exclusion criteria. Sixteen patients had coronary artery disease (group A), 34 showed coronary stenoses with prior infarction (B), and 14 had survived an acute myocardial infarction (C), whereas 10 patients revealed no significant coronary narrowing (D; controls). The major risk factors were the same for all groups. Neither the IgM- nor the IgG-anticardiolipin antibody levels showed any significant difference in the four groups. The severity of coronary artery disease did not correlate to these antibodies. Furthermore, no correlation was found between elevated anticardiolipin antibodies and thrombocyte levels. Thus, a higher anticardiolipin level does not appear to be a marker for recurrent cardiovascular events.ACA anticardiolipin antibodies - CAD coronary artery disease - MPL-U/ml IgM phospholipid-units/ml - GPL-U/ml IgG phospholipid-units/ml     

Clinical use of magnetic resonance imaging for the diagnosis of acute myocardial infarction in the survivors of cardiac arrest

The ventricular arrhythmias with underlying coronary artery disease are a leading cause of sudden cardiac death (SCD). While the SCD survivors with proven AMI are considered to be at low risk of SCD recurrence, those without the evidence of AMI represent a high risk group that benefits from implantable cardioverter defibrillator. Therefore, the evaluation of SCD survivors for the presence of acute myocardial infarction (AMI) as a triggering factor of cardiac arrest is essential. In SCD survivors, the use of the standard diagnostic criteria of AMI may be difficult, as both serum cardiac biomarkers and electrocardiogram can be influenced by previous cardiac arrest. A novel technique that may be used for the diagnosis of AMI is magnetic resonance imaging (MRI). We report its use in four patients after cardiopulmonary resuscitation where the diagnosis of AMI could not be definitely established or excluded by means of other diagnostic procedures.     

Studying the imaging features and infarction mechanism of vertebrobasilar dolichoectasia with high-resolution magnetic resonance imaging

The mechanisms underlying ischemic infarction in patients with vertebrobasilar dolichoectasia (VBD) remain unclear. In this study, we retrospectively analyzed the imaging characteristics of high-resolution magnetic resonance imaging (HR-MRI) in patients with VBD to explore the possible mechanisms of ischemic stroke (IS) in patients with VBD. Patients with VBD were recruited from the HR-MRI database between July 2017 and June 2021. HR-MRI was used to evaluate the diameter, bifurcation height, laterality, arterial dissection, and atherosclerotic plaques of the basilar artery (BA). Transcranial Doppler was used to measure the vertebrobasilar mean velocity (Vm), peak systolic velocity (Vs), end-diastolic velocity (Vd), and pulsatile index. Twenty-six patients with VBD were enrolled, of which 15 had IS and 11 did not. The incidence of classical vascular risk factors, including age, sex, hypertension, diabetes, and hypercholesterolemia, did not differ significantly between the two groups. The BA diameters of the stroke group were significantly higher than that of the nonstroke group (6.57 ± 1.00 mm vs. 5.06 ± 0.50 mm, p = 0.000). The height of the BA bifurcation in the stroke and nonstroke groups was statistically significant (p = 0.002). Compared with the nonstroke group, the Vm, Vs, and Vd of the BA in the stroke group were lower, but the difference was not significant. In the 16 patients with atherosclerotic stenosis, 30 atherosclerotic plaques were found in the BA, 18 (60%) in the greater curvature, and 12 (40%) in the lesser curvature. In addition, one artery dissection (on the lesser curvature) and two dissecting aneurysms (on the greater curvature) were found in the BA of three patients, respectively. The BA diameter and bifurcation height are factors related to IS in patients with VBD. The mechanism of stroke in patients with VBD may involve abnormal hemodynamics, artery dissection, and atherosclerosis. HR-MRI is a useful method for evaluating the risk and underlying mechanism of stroke in patients with VBD.     

心脏磁共振T1mapping在评估狗心肌梗死中的作用

目的探讨T1 mapping检测心肌梗死对梗死类型、梗死分期及磁场强度的依赖性。方法建立24只狗的心肌梗死模型(MI),其中出血性心梗(n=15)和非出血性心梗(n=9)。分别在MI的急性和慢性期对全部受试动物进行多参数mapping(T1和T2~*)和晚期钆增强(LGE)扫描。比较不同时期及不同场强下出血梗死区、血肿周围梗死区、非出血性梗死区和非梗塞区(远端心肌)的T1和T2~*值。结果出血性梗死区在急性期和慢性期、1.5T或3.0T均表现为显著的T2~*减低(P0.005)。而梗死区域的平扫T1及其与远端心肌的相对变化显示出对梗塞分期、类型和磁场强度的显着依赖性,急性期各梗死区以及慢性期的血肿周围梗死区和非出血性梗死区在1.5T及3.0T的T1map上均表现出相对远端心肌的高信号(P0.005)。在MI的慢性期,出血性梗死区域的T1在1.5T下低于远端心肌水平(T1%=-9.8±8.6%,P0.005),然而,在3.0T下出血性梗死区域的的T1相对于远端心肌并无显著差异(T1%=-0.6±6.6%,P=0.634)。结论非出血性心梗及急性期出血性心梗依赖T1与正常心肌鉴别,但慢性期出血性心梗的鉴别需要联合T2~*对梗死区域进行空间定位。     

丹参提取物促大鼠心肌梗死后心肌组织血管新生的作用

目的:观察丹参提取物对大鼠心肌梗死后心肌组织血管新生的作用并分析其可能的机制。方法:采用经典的冠状动脉左前降支结扎造模方法成功复制大鼠心肌梗死模型后,随机将大鼠分为模型组以及丹参提取物低(10 mg·kg-1·d-1)、中(20 mg·kg-1·d-1)、高(40 mg·kg-1·d-1)剂量治疗组,另设假手术组大鼠为对照组,各组大鼠数量均为8只。丹参提取物各治疗组给予上述对应的各药物剂量灌胃给药,模型组及对照组大鼠给予等量的生理盐水灌胃,连续饲养4周后应用HE染色、Masson染色和电镜法观察大鼠左心室心肌组织和血管结构病理成分变化,免疫组化染色分析心肌组织中血管内皮生长因子(VEGF)及CD34蛋白的表达变化。结果:组织病理学分析表明,与假手术组相比,模型组大鼠心肌组织形态较为紊乱,部分心肌细胞轮廓消失,坏死心肌组织呈现明显的纤维化,血管不完整,血管超微结构模糊或者消失;丹参提取物治疗之后,新生的血管数量明显增多,且超微结构分析表明,内皮细胞形态相对完整。心肌组织中VEGF及CD34蛋白表达结果证实,模型组较假手术组大鼠表达略有增加,但没有统计学差异;和模型组比较,丹参提取物各治疗组VEGF及CD34蛋白表达明显增多(P0.01)。结论:丹参提取物可明显促进大鼠心肌梗死后心肌组织的血管新生。     

Viable myocardium in reperfused acute myocardial infarction: rest and stress first-pass mr imaging.

Feasibility of identifying viable myocardium in rest and stress magnetic resonance imaging (MRI) was evaluated using 3 hr occlusion and 30 min reperfusion model of left anterior descending (LAD) coronary artery in 12 felines. At rest MRI, viable myocardium confirmed by 2,3,5-triphenyl tetrazolium chloride (TTC)-staining showed rapid signal intensity (SI) rise followed by gradual decline not significantly different from normal myocardium that the two hyperperfused regions were distinguishable only from the hypoperfused nonviable myocardium. At stress MRI, hyperemia induced perfusion change was most pronounced in normal myocardium with earlier and greater peak enhancement followed by brisk 'washout' phase while minimally augmented enhancement in viable myocardium was still in 'washin' phase. From these findings, it was concluded that viable myocardium is identified in rest and stress MRI as redistributing hypo- perfusion compared to persistent hyper-perfusion of the normal myocardium and the persistent hypo-perfusion of the nonviable myocardium.     

Problems with organic materials for magnetic resonance imaging phantoms

Organic liquids are frequently used as magnetic resonance (MR) phantom materials. It is often not appreciated that indirect spin-spin coupling can dramatically affect signal amplitudes in spin-echo experiments. These effects are evidenced in three ways: (1) modulation of spin-echo amplitudes; (2) decrease in measured T2 relaxation times; and (3) dependence of spin-echo modulation and measured T2 values on the echo time (TE) in multiecho Carr-Purcell-Meibroom-Gill experiments. This paper illustrates these effects and warns against the inappropriate use of organic liquids as MR phantoms.     

Large myocardial infarction with myocardium calcium deposits associated with reperfusion injury

The clinical and autopsy findings of a 66-year-old man with myocardial infarction complicated by reperfusion injury are described, highlighting the presence of large myocardium calcium deposits.