Contribution of Cardiac MRI in the Diagnosis of Acute Myocarditis

Objective: To describe the MRI abnormalities observed in acute myocarditis. Materials and Methods: Retrospective cross-sectional study with a descriptive aim, carried out at the North Franche-Comte Hospital, over a period of 12 months, from January 2021 to December 2021. It covered all patients who received an MRI of heart disease and were diagnosed with myocarditis. The diagnosis of myocarditis was retained in all patients on the basis of two arguments: a T2 PSIR hyper signal and a late enhancement at 15 min in T1 PSIR with gadolinium. Results: Myocarditis was diagnosed in 20 patients out of a total of 214 who performed cardiac MRI, i.e. 10.30% of cases. The average age was 33.7 ± 14.3 with extremes of 17 and 69 years. We observed a male predominance with 11 men (55%) for 9 women (45%) or a sex ratio of 1.2. Clinical suspicion of myocarditis and acute coronary syndrome were the main indications for MRI. The lesion sites were subepicardial (95%) and/or intramural (30%), respecting the subendocardium, interesting for the majority, segments 12 (anterolateral) in 50% and/or 11 (inferolateral) in 43% of cases. Global hypokinesia was observed in 30% of patients associated with a decrease in LVEF. There was no cardiac volume abnormality or valvular abnormality. Conclusion: Cardiac MRI is nowadays the most efficient non-invasive imaging in the diagnosis of acute myocarditis. The diagnosis of myocarditis was made on 2 pathognomonic signs, namely a T2 STIR hyper signal and late enhancement at 15 min in T1 PSIR after injection of gadolinium. The morphology and lesion locations were in agreement with those described in previous studies. Global hypokinesia and pericardial effusion were observed in some patients. On the other hand, there was neither valvular anomaly, nor cardiac volume anomaly.

Detection of Left Ventricular Cavity from Cardiac MRI Images Using Faster R-CNN

The automatic localization of the left ventricle(LV)in short-axis magnetic resonance(MR)images is a required step to process cardiac images using convolutional neural networks for the extraction of a region of interest(ROI).The precise extraction of the LV’s ROI from cardiac MRI images is crucial for detecting heart disorders via cardiac segmentation or registration.Nevertheless,this task appears to be intricate due to the diversities in the size and shape of the LV and the scattering of surrounding tissues across different slices.Thus,this study proposed a region-based convolutional network(Faster R-CNN)for the LV localization from short-axis cardiac MRI images using a region proposal network(RPN)integrated with deep feature classification and regression.Themodel was trained using images with corresponding bounding boxes(labels)around the LV,and various experiments were applied to select the appropriate layers and set the suitable hyper-parameters.The experimental findings showthat the proposed modelwas adequate,with accuracy,precision,recall,and F1 score values of 0.91,0.94,0.95,and 0.95,respectively.This model also allows the cropping of the detected area of LV,which is vital in reducing the computational cost and time during segmentation and classification procedures.Therefore,itwould be an ideal model and clinically applicable for diagnosing cardiac diseases.

Primary Cardiac Involvement in Scleroderma and Role of Cardiac MRI

Systemic sclerosis (scleroderma) is a connective tissue disease characterized by vascular dysfunction and fibrosis that can affect multiple organ systems. We present case of primary cardiac involvement and the diagnostic role of cardiac MRI. Cardiovascular magnetic resonance imaging (MRI) is an accurate, quantitative method for the non-invasive assessment of myocardial perfusion. The presence of clinically apparent myocardial involvement in scleroderma portends a very poor prognosis. One study of US veterans found that clinical cardiac disease in scleroderma was associated with a 70% mortality rate at five years. Management of heart failure and conduction system abnormalities in scleroderma is similar to other cardiac disease. It includes afterload reduction, beta-blockade, defibrillator placement, etc. Patients with reduced cardiac function and normal coronary arteries may benefit from increased immune suppresion.

Noninvasive Diagnosis of Cardiac Amyloidosis by MRI and Echochardiography

This study described the radiological features on echocardiography and MRI specific to cardiac amyloidosis confirmed on biopsy. Eleven cases of biopsy-proven cardiac amyloidosis were retrospectively reviewed in this study. All patients underwent biopsy, cardiac MRI and echocardiography. The main echocardiography and MRI findings were as follows: diffuse ventricular and septum wall thickening, atrial enlargement, pericardial effusion, restricted left ventricular (LV) systolic and diastolic function, characteristic granular sparkling of myocardium. MRI revealed a characteristic pattern of global subendocardial late enhancement, extending in varying degrees into the neighboring myocardium. The findings agreed with the infiltration distribution of amyloid protein. Typical abnormalities seen on echocardiography and MRI should have important diagnostic and prognostic value of cardiac amyloidosis. MRI should be considered in the diagnosis of cardiac amyloidosis if echocardiographic features are suspicious.

心脏MRI预测扩张性心肌病中心脏猝死风险的临床研究

目的本研究旨在确定心脏MRI心肌组织特征预测心源性猝死(sudden cardiac death,SCD)的相关因素,并探讨非缺血性扩张型心肌病(dilated cardiomyopathy,DCM)的SCD分层算法。方法纳入了在2020年1月至2021年12月期间接受心脏MRI检查的非缺血型扩张型心肌病成人患者。与SCD相关的事件包括SCD、适当的植入性心律转复除颤器休克和心脏骤停后的复苏。竞争风险回归分析和Kaplan-Meier分析用于确定心肌组织特征与预后的关系。结果858名参与者中,70名(8%)参与者在中位数33.0个月的随访中经历了SCD相关事件。在多变量竞争风险分析中,晚期Gd增强(LGE)(危险比[HR],1.87;95%CI:1.07,3.27;P=0.03)、自然T1(每10毫秒增加一次:HR,1.07;95%CI:1.04,1.11;P<0.001)和细胞外体积分数(每增加3%:HR,1.26;95%CI:1.11,1.44;P<0.001)是调整收缩压、房颤和左心室射血分数后SCD相关事件的独立预测因素。结合本地T1和LGE制定了SCD风险分层类别。自然T1值高于平均值(1382毫秒)4或以上的参与者每年SCD相关事件的发生率最高,为9.3%,而天然T1值为2,低于平均值(1292毫秒)且LGE为负值的参与者的SCD相关事件发生率最低,为0.6%。这一类别具有良好的预测能力(C=0.74),可用于区分SCD风险和竞争性心力衰竭风险。结论来自心脏MRI的心肌组织特征是非缺血性扩张型心肌病患者心源性猝死(SCD)相关事件的独立预测因子,可用于根据不同的SCD风险类别对参与者进行分层。

Nonlinear profile order for three-dimensional hybrid radial acquisition applied to self-gated free-breathing cardiac cine MRI

This paper presents a nonlinear profile order scheme for three-dimensional（3D） hybrid radial acquisition applied to self-gated, free-breathing cardiac cine magnetic resonance imaging（MRI）. In self-gated, free-breathing cardiac cine MRI,respiratory and cardiac motions are unpredictable during acquisition, especially for retrospective reconstruction. Therefore,the non-uniformity of the k-space distribution is an issue of great concern during retrospective self-gated reconstruction. A nonlinear profile order with varying azimuthal increments was provided and compared with the existing golden ratio-based profile order. Optimal parameter values for the nonlinear formula were chosen based on simulations. The two profile orders were compared in terms of the k-space distribution and phantom and human image results. An approximately uniform distribution was obtained based on the nonlinear profile order for persons with various heart rates and breathing patterns.The nonlinear profile order provides more stable profile distributions and fewer streaking artifacts in phantom images. In a comparison of human cardiac cine images, the nonlinear profile order provided results comparable to those provided by the golden ratio-based profile order, and the images were suitable for diagnosis. In conclusion, the nonlinear profile order scheme was demonstrated to be insensitive to various motion patterns and more useful for retrospective reconstruction.

Integrated Assessment of Cardiac PET/MRI: Co-Registered PET and MRI Polar Plots by Mutual MR-Based Segmentation of the Left Ventricular Myocardium

Background: In the present study, we sought to describe a procedure for the creation of co-registered positron emission tomography (PET) and magnetic resonance imaging (MRI) polar plots of cardiac PET/MRI examinations, validate the resulting plots against available standard methods in patients with myocardial infarction and provide examples that demonstrate the advantage of the novel approach over existing standards. Methods: Co-registered LGE and PET short-axis images were transformed into polar maps based on a radial sampling pattern. LGE was automatically detected using an automated thresholding algorithm (ATA). In 20 PET/MRI examinations in patients with acute myocardial infarction, agreement between manual LGE assessment and the ATA classification was calculated. Also agreement between MRI-segmentation based PET polar plots and standard PET polar plots (created with the Corridor4DM software package) was assessed. Results: No statistically significant difference in infarct sizes between manual and ATA segmentation was found (p = 0.12). Both methods were highly correlated (Pearson’s r = 0.96, p Conclusion: A straightforward software approach for the creation of co-registered PET and MRI polar plots was described and successfully demonstrated in PET/MRI studies of myocardial infarction and inflammation.

MRI影像组学用于心脏疾病的诊断价值及其研究进展

影像组学是一种基于医学影像数据的分析方法,传统的心脏磁共振扫描序列与其相结合可以从原始数据中获取定量空间数据,能够更加精准诊断心脏疾病的类型、严重程度和进展情况。基于此,本文就MRI影像组学在心脏疾病的诊断方面已体现的价值及不同序列MRI影像组学用于心脏疾病的研究进展进行综述。

原发性心脏血管肉瘤CT、MRI影像学特征及其诊断效能分析

目的分析原发性心脏血管肉瘤CT、MRI影像学特征及其诊断效能。方法回顾性选取2020年1月至2023年5月开封市中心医院及河南大学淮河医院经病理诊断为原发性心脏血管肉瘤患者52例的临床影像学资料进行分析,以病理检查为金标准,比较CT、MRI对原发性心脏血管肉瘤检出的正确率。结果CT对原发性心脏血管肉瘤检出的正确率为73.08%,MRI正确率为78.85%,二者对比无明显差异(P>0.05)。52例患者中,CT检查发现26例为右心房占位,7例为右心室占位,5例仅表现为大量心包积液,14例未发现明显异常;MRI检查发现38例表现为右心房占位,3例表现为为纵隔占位,11例未发现明显异常。结论原发性心脏血管肉瘤的早期诊断、治疗有赖于多种影像学的辅助诊断,CT检查和心脏MRI对原发性心脏血管肉瘤具有一定的诊断价值,可以为早期诊断和临床治疗提供参考。

心肌炎儿童MRI表现及心功能生化cTnT、pro-BNP浓度异常的关系研究

目的分析心肌炎儿童MRI表现及心功能生化cTnT、pro-BNP浓度异常的关系。方法选取2022年1月至2022年12月期间我院收治的64例心肌炎患儿作为观察组,收集同期在我院接受健康体检结果正常儿童36例作为对照组,所有对象均接受MRI检查,并对血清心肌肌钙蛋白T(cTnT)和N端脑钠肽前体(pro-BNP)进行检测,参考临床诊断结果,分析MRI在心肌炎儿童中的诊断价值及不同心功能生化cTnT、pro-BNP浓度MRI检出情况。结果心脏MRI诊断中42例为阳性,58例为阴性,灵敏度为62.50%,特异度为94.44%,准确率为74.00%,心肌炎心脏MRI诊断约登指数=0.57,kappa值=0.503,吻合度一般;心肌炎患儿cTnT水平达到140 ng/L以上,pro-BNP达到614 ng/L以上检出率明显比cTnT水平低于140 ng/L和pro-BNP水平低于614 ng/L高(P<0.05)。结论通过心脏MRI可以准确检查心肌炎,特别是cTnT、pro-BNP浓度越高的患儿,心脏MRI检出率更高。

基于对比学习的非对称编解码结构的心脏MRI分割研究

全监督方法在心脏磁共振成像(MRI)分割任务中的成功依赖于大规模标记数据集,然而由于患者隐私及人工标注困难等问题,心脏MRI标注数据规模较小,使全监督方法面临挑战。基于半监督的对比学习方法,设计双分支编码与单分支解码的心脏MRI分割网络CPCL-Net,引入图像和像素的联合对比损失,提升了模型对数据样本的特征表达能力。为了增强CPCL-Net对Hard负样本的分割精度,设计动态自适应加权模块(DAWM),利用生成的α和β权重因子评估样本级别和像素级别的训练贡献度,使模型分割精度得到大幅提升。基于自动心脏诊断挑战赛(ACDC)数据集的实验结果表明,该网络模型仅利用少量标注样本即可获得较高的分割精度,缓解了心脏MRI高质量标注样本不足导致的分割精度低下问题,并且在标注样本规模相同的情况下,对心脏左心室、右心室、心肌等部位的分割精度分别为86.17%、85.52%、84.55%,优于现有的4种典型半监督分割模型以及经典的对比学习框架Sim-CLR,有效缓解了全监督分割模型对样本规模的依赖及过拟合问题。

原发性心脏心包肿瘤的MRI诊断

目的 评价MRI在原发性心脏心包肿瘤诊断中的价值。资料与方法 回顾分析 14例经手术病理或临床证实的原发性心脏心包肿瘤的MRI表现 ,并与UCG检查结果比较。结果 除 1例右心房粘液瘤漏诊、1例定位错误外 ,其余定位和良恶性定性均正确 ,10例术前组织学定性正确。与MRI比较 ,UCG另有 3例定位定性错误。结论 MRI对心腔内肿瘤不仅定位准确 ,还多可定性 ;对肌壁肿瘤的良、恶性区别也有重要价值 ;对心包肿瘤多因其好发部位与特殊信号诊断不难。

二维斑点追踪技术与心脏MRI评估肺动脉高压患者右心功能的对比研究

目的对比分析二维斑点追踪(2D-STI)技术与心脏MRI在评估肺动脉高压(PH)患者右心功能中的价值。方法选取我院经右心导管确诊且资料完整的77例PH患者(PH组)和77例健康志愿者(对照组),使用2D-STI测量两组右室游离壁纵向应变(RVLSrw)、右房储备功能(RASr)、右房管道功能(RASc)和右房泵功能(RASp),使用心脏MRI检测右室射血分数(RVEF)、舒张末期容积指数(EDVI)、收缩末期容积指数(ESVI)、每搏输出量指数(SVI)、心指数(CI)、心肌质量(MM)及心肌质量指数(MMI);分析心脏MRI指标与2D-STI指标之间的相关性;绘制受试者工作特征(ROC)曲线分析不同指标评估PH患者右心功能的诊断效能。结果①心脏MRI检查显示,PH组RVEF、EDVI、ESVI与对照组比较差异均有统计学意义(均P<0.05);②2D-STI检查显示,PH组RVLSrw、RASr、RASc与对照组比较差异均有统计学意义(均P<0.05);③相关性分析显示,RVEF、ESVI与RVLSrw、RASr、RASc均呈正相关(均P<0.05),EDVI与RVLSrw、RASr均呈正相关(均P<0.05);④ROC曲线分析显示,RVEF、EDVI、ESVI、RVLSrw、RASr、RASc评估PH患者右心功能的曲线下面积分别为0.756、0.739、0.820、0.725、0.957、0.659,敏感性分别为49.4%、48.1%、66.2%、92.2%、92.2%、100%,特异性分别为100%、100%、100%、49.4%、88.3%、33.8%。结论2D-STI技术较心脏MRI能更准确地评估PH患者右心功能,可为临床治疗提供参考依据。

心肌声学造影联合心脏MRI对肥厚性心肌病的诊断价值

目的探讨心肌声学造影联合心脏MRI对肥厚性心肌病的诊断价值。方法选取95例肥厚性心肌病患者(观察组)和95例健康体检者(对照组),两组均行心肌声学造影和心脏MRI检查,比较两组左室射血分数(LVEF)、左室舒张末期内径(LVEDD)、舒张早期与晚期峰值流速的比值(E/A)、舒张晚期运动速度(Am)、二尖瓣舒张早期血流峰值流速(E)、左室心肌质量指数(LVMMI)、心指数(CI)、左室高峰射血率(LVCO)、左室收缩末期容积指数(LVESVI)、左室每搏输出量指数(LVSVI)的差异。绘制受试者工作特征(ROC)曲线分析心肌声学造影、心脏MRI检查及其联合对肥厚性心肌病的诊断效能,计算曲线下面积(AUC)。结果心肌声学造影检查显示,观察组LVMMI、CI、LVCO、LVESVI均高于对照组(均P<0.05),E/A、Am、E、LVSVI均低于对照组(均P<0.05);心脏MRI检查显示,观察组LVMMI、CI、LVCO、LVESVI均高于对照组,LVSVI、E/A、Am、E均低于对照组(均P<0.05)。两种检查方法测得的Am和LVSVI比较,差异均有统计学意义(均P<0.05)。ROC曲线分析结果显示,心肌声学造影和心脏MRI诊断肥厚性心肌病的AUC分别为0.865和0.932,敏感性、特异性、准确率分别为92.90%、80.00%、91.58%和96.47%、90.00%、95.79%,两者联合应用的AUC为0.994,敏感性、特异性、准确率分别为98.82%、100%、98.95%,均高于其单独应用(均P<0.05)。结论心肌声学造影联合心脏MRI诊断肥厚性心肌病具有较好的应用价值,能为临床提供参考依据。

原发左室型扩张型心肌病左心功能MRI评价

目的 用电影MRI评价原发扩张型心肌病患者的心功能。方法 用电影磁共振技术对 2 4个原发扩张型心肌病患者和 12个正常志愿者几个左心功能指标进行测量 ,并将测量结果进行比较。结果 患者组左心室容量及左房内径明显大于正常对照组 ,而射血分数、短轴缩短率及室壁增厚率明显小于正常对照组。结论 电影MR技术能准确和可重复地评价原发扩张型心肌病患者的左心功能。

基于椭圆约束分割心脏MRI图像的水平集模型

针对左心室外轮廓类似椭圆的特点,提出了基于椭圆约束的水平集模型,该模型在Chan and Vese模型的基础上增加椭圆形状约束项,来控制曲线的演化,将水平集的演化曲线作为对轮廓新的位置预测,并用椭圆对预测结果进行修正,把预测结果和修正结果分别作为新的水平集曲线和椭圆信息,直到曲线停止演化。实验表明,该方法能够有效地分割心脏外轮廓。

超声与MRI在胎儿心脏畸形筛查中的应用研究

目的探讨超声与MRI在胎儿心脏畸形筛查中的对比和联合应用价值。方法第一阶段选取39例经超声检查确诊为心脏畸形胎儿行MRI扫查,以超声切面图为模板创建出与之相对应的MRI标准断层图,计算并比较图像获取成功率;第二阶段选取57例胎儿心脏畸形可疑病例,以标准切面图或断层图为基础,分别行单独超声、单独MRI及两者联合诊断,并将其结果与尸检或出生后随访结果进行分析,比较单独超声、单独MRI及两者联合诊断胎儿心脏畸形的符合率。结果第一阶段39例心脏畸形病例中,38例获得标准超声切面图,图像获取成功率97.44%;以标准超声切面图为模板,32例应用MRI成功创建了标准切面图,图像获取成功率82.05%,差异有统计学意义(χ~2=5.014,P<0.05)。第二阶段57例可疑心脏畸形胎儿中,超声与MRI联合诊断胎儿心脏畸形的符合率为98.24%,高于单独超声和单独MRI诊断符合率(85.96%、70.18%),差异均有统计学意义(χ~2=3.95,P<0.05;χ~2=14.21,P<0.01);单独MRI的诊断符合率明显低于单独超声,差异有统计学意义(χ~2=4.15,P<0.05)。结论超声与MRI联合诊断的符合率明显高于单独超声或MRI诊断,能有效提高胎儿心脏畸形筛查的检出率和准确性。

MRI对法乐氏四联症的诊断价值

目的：探讨ＭＲＩ对法乐氏（Ｆａｌｏｔ）四联症的诊断价值，并与超声心动图和心血管造影比较。方法：８例Ｆａｌｏｔ四联症ＭＲＩ、超声心动图与手术结果比较。结果：ＭＲＩ和超声心动图显示心内结构相似，但ＭＲＩ可很好显示主肺动脉发育不良和左右肺动脉分支狭窄。结论：ＭＲＩ能显示Ｆａｌｏｔ四联症全部畸形情况。对主肺动脉和分支观察优于超声心动图。

MRI在主动脉缩窄诊断中的应用价值

目的 探讨MRI诊断先天性主动脉缩窄的价值。方法 采用一般回顾性分析。全组共11例患者，均经手术证实，年龄4．16岁。对所有患儿常规行SE序列成像，其中3例兼做电影MRI。结果 11例均显示了主动脉缩窄及缩窄的程度、形态，并显示了缩窄处与左锁骨下动脉的关系。9例（81．8％）MRI显示为局限性膜状或嵴状狭窄，2例（18．2％）呈长管状狭窄。3例cine MRI均能显示狭窄段。合并畸形有：4例同时伴有动脉导管未闭和室间隔缺损，5例合并有动脉导管未闭，1例合并室间隔缺损。结论 MRI作为一种无创性检查技术，能相当准确地对主动脉缩窄进行诊断，并能同时显示合并的胸部大血管异常。

原发性心脏肿瘤的MRI诊断

目的 :探讨原发性心脏肿瘤的MRI特征性表现以及诊断价值。方法 :经手术病理证实的原发性心脏肿瘤 14例 ,良性10例 ,恶性 4例。结果 :良性肿瘤 10例 ,定位、定性诊断全部正确。恶性肿瘤 4例 ,定位诊断正确 3例 ,良、恶性诊断正确 3例 ,不同性质的恶性肿瘤定性诊断正确 1例。MRI充分显示了心脏肿瘤的形态、大小、部位 ,累及的心腔及范围 ,尤其是其组织特定性可对脂肪瘤、纤维瘤等作出明确的定性诊断。结论 :MRI检查对心脏肿瘤敏感性高 ,可显示心脏、心包全貌以及与周围结构的关系 ,对心脏肿瘤的定位、定性诊断准确率高 ,但对不同性质恶性肿瘤之间的鉴别有一定困难。