心脏磁共振T1Mapping定量分析重度主动脉瓣反流心肌纤维化程度的价值

【目的】探讨心脏磁共振(CMR)纵向弛豫时间定量(T1 mapping)技术评估重度主动脉瓣反流(AR)心肌纤维化程度的价值。【方法】选择2018年1月至2020年11月在本院进行CMR成像检查的28例重度AR患者(观察组),选择同期在本院行CMR检查,未发现器质性心脏病者为对照组。比较两组左心室心肌质量(LVMM)、左心室舒张末期容积指数(LVEDVi)、左心室收缩末期容积指数(LVESVi)、左心室每搏输出量容积指数(LVSVi)及左心室射血分数(LVEF)等结构、功能参数及心肌T1值、细胞外间质容积分数(ECV)值,并采用Pearson系数进行相关性分析。【结果】观察组LVEF低于对照组,LVEDVi、LVESVi、LVSVi、LVMM均高于对照组,差异有统计学意义(P<0.05)。延迟强化方面,观察组中有15例患者出现对比剂延迟增强(LGE),对照组中未发现LGE,组间差异有统计学意义(P<0.05)。左心室心肌纤维化方面,观察组初始T1值、ECV均高于对照组,增强后T1值低于对照组,差异有统计学意义(P<0.05)。Pearson相关系数分析显示,初始T1值、ECV值与LVEF呈负相关关系(r=-0.403、-0.400,均P<0.05);增强后T1值与LVEF无明显相关性(r=0.419,P=0.052>0.05)。【结论】CMR T1 mapping技术可反映重度AR患者心肌纤维化程度,且患者心肌纤维化程度与早期心脏重构和左心室收缩功能障碍相关。     

T1 mapping技术用于心脏疾病危险分层及预后评估研究进展

近年心脏MR(CMR)技术快速发展,在心脏疾病中的应用越来越受到重视。T1 mapping成像技术可量化评价心肌组织T1弛豫时间,在评价心肌组织学特征和定量分析方面具有较大潜力,可为判断多种心脏疾病的预后提供有价值的信息。本文就T1 mapping技术在心脏疾病危险分层及预后评估中的研究进展进行综述。     

T1-mapping序列在心肌梗死定量分析中的临床应用

目的分析T1-mapping序列显示心肌受损的模式和定量分析心肌梗死的范围和程度。方法收集50例心肌梗死患者作为试验组,20例健康志愿者为对照组。用1.5T磁共振进行心脏扫描。扫描序列包括磁共振黑血反转恢复成像技术(T2WI-STIR)、首过灌注、延迟强化、心肌电影和T1-mapping序列。对比分析T1-mapping与常规序列显示心肌病变范围和灵敏度。结果试验组心肌T1值与对照组相比差异具有统计学意义[(1 220.0±50.0)ms vs.(981.0±23.0)ms,P0.05],T1-mapping显示受累心肌病变范围比T2WI-STIR更准确。T1-mapping能敏感显示局灶性心肌梗死,特别对早期心内膜下心肌梗死显示较清楚。T1-mapping与T2WI-STIR比较,其显示心肌梗死灵敏度、阳性预测值均较高,但其特异度相对较低。结论 T1-mapping序列不使用对比剂可准确显示病变心肌范围并可进行定量分析,对局灶性心肌梗死显示更有优势。     

磁共振成像在糖尿病心肌病心肌评价中的进展

糖尿病心肌病是引起糖尿病患者心力衰竭的主要原因之一。通过磁共振结构和功能成像技术可准确评估糖尿病心肌病的病理学变化,现已应用于糖尿病心肌病临床治疗的疗效评估中。评估糖尿病心肌病的MRI技术主要包括电影成像、MRS、T1 Mapping等。本文主要对MRI技术在糖尿病心肌病心肌评价方面的应用进展进行综述。     

维持性血液透析患者心脏磁共振初始T1 mapping表现及相关因素分析

目的应用心脏磁共振(cardiovascular magnetic resonance imaging,CMRI)初始T1mapping技术探究维持性血液透析(maintenance hemodialysis,MHD)患者的心肌纤维化病变,并探寻MHD患者心肌纤维化病变的相关因素。方法选取32例MHD患者行CMRI检查,并收集动态血压数据及各项化验结果,另选取14例健康志愿者作为对照组,行CMRI检查。探究两组人群心肌初始T1值的差异,及MHD患者初始T1值的改变与动态血压指标、各项实验室化验结果之间是否存在相关性。结果 MHD组患者心脏初始T1值高于对照组(1208.9±90.9ms比1134.5±28.1ms),差异具有统计学意义(F=4.270,P=0.045),MHD组患者左室基底段[(1213.1±89.1)ms]、室中段[(1200.6±89.8)ms]、远段[(1213.1±10.3)ms]初始T1值之间无显著性差异(F=0.186,P=0.831)。MHD组患者心脏初始T1值与全段甲状旁腺素水平呈正相关(r=0.418,P=0.017),与三酰甘油水平呈负相关(r=-0.366,P=0.039);初始T1值与44h平均收缩压、44h平均舒张压、收缩压变异和舒张压变异之间均不存在线性相关关系(r_1=0.204,P_1=0.320;r_2=0.316,P_2=0.208;r_3=0.259,P_3=0.402;r_4=0.135,P_4=0.662)。MHD患者心脏初始T1值与左室舒张末期容积/体表面积、左室收缩末期容积/体表面积、左室质量指数呈正相关(r_1=0.528,P_1=0.014;r_2=0.506,P_2=0.019;r_3=0.600,P_3=0.005),与射血分数(ejection fraction,EF)呈负相关(r=-0.551,P=0.010),与心脏指数无线性关系(r=-0.210,P=0.357)。结论 MHD患者心肌初始T1值较健康人高,提示其心肌纤维化程度重,初始T1值大小与心脏结构、功能指标关联密切,全段甲状旁腺素、三酰甘油可能在MHD患者心肌纤维化的发生、发展过程中起重要作用。     

MRI对儿童急性骨感染的诊断价值

目的：评价MRI对儿童急性骨感染的诊断价值。材料与方法：经临床手术证实的儿童急性骨感染9例，回顾性分析其MRI表现。结果：9例病变部位T1、T2值均明显延长，T1加权像上呈低、稍低或中等信号强度，T2加权像上病变区是高信号。5例做了重T2加权像（HT2WI），骨感染病变显示更明显。结论：MRI能清楚显示儿童急性骨感染的病变部位、大小、范围及软组织受累情况，结合临床能做出定性诊断。     

心脏磁共振T1 mapping和组织追踪技术在左心室肥厚相关疾病中的鉴别诊断价值

目的 使用心脏磁共振(cardiac magnetic resonance, CMR)T1 mapping及组织追踪(tissue tracking, TT)技术鉴别心肌淀粉样变性(cardiac amyloidosis, CA)、肥厚型心肌病(hypertrophic cardiomyopathy, HCM)及高血压性心脏病(hypertensive heart disease, HHD)等左室肥厚相关疾病。材料与方法 回顾性分析HCM、CA和HHD各20例(三组合称病例组)相关临床和CMR资料,纳入25名健康志愿者作为健康对照(healthy control, HC)组。使用单因素方差分析及Kruskal-Wallis检验比较四组间心肌初始T1值、整体和各节段心肌的纵向应变(longitudinal strain, LS)、周向应变(circumferential strain, CS)、径向应变(radial strain, RS),相对心尖应变(relative apical sparing of strain, RAS)等定量参数。结果 CA组的初始T1值[(1473.05±...     

体素内不相干运动成像

传统的MR成像技术主要依赖于组织的自旋质子密度、T1值、T2值或T2*值等属性的差异,DWI与之不同,它主要取决于组织中水分子的运动。DWI量化分析可以提供常规MRI无法提供的信息,ADC值测量有助于区分病变的良恶性,预测和监控放化疗对恶性肿瘤的疗效等;对于生物组织而言,水分子的运动主要有两方面:其一,水分子的扩散运动,即布     

食管肿瘤扩散加权成像序列参数优化及相关影像病理对照研究

目的探讨食管肿瘤磁共振扩散成像的技术可行性和b值的选择,比较扩散成像与食管钡餐造影、CT、T2WI在显示病变长度方面的差异.方法食管肿瘤32例,进行常规MRI及DWI横断面扫描b=200、300、500、800、1000s/mm2,分别测定图像SIR和CNR并与常规T2WI图像进行比较.测量食管肿瘤病变的扩散信号强度,分别计算ADC值,选择合适的b值.在DWI图像上测量病变长度,与食管钡餐造影、CT、T2WI及手术切除病理大体标本显示的病变长度进行比较.结果不同b值DWI图像与常规T2WI比较,SIR无显著性差异(P＞0.05),b值为200、300、500 s/mm2时,DWI图像CNR与T2WI有显著性差异(P＜0.05).b值200、300、500 s/mm2DWI图像的SIR和CNR与b值选择800、1000s/mm2时有显著性差异(P＜0.05),b值选择500 s/mm2较为合适.b值500 s/mm2磁共振扩散加权图像显示病变长度与病理结果、食管钡餐造影及T2WI图像无显著性差异(P＞0.05).结论应用8通道阵列线圈结合ASSET技术一次屏气扫描,b值采用500 s/mm2可以获得较为满意的食管肿瘤扩散图像,DWI测量的病变长度与手术切除病理大体标本无显著性差异;DWI与钡餐造影和MRI T2WI在显示病变长度方面有较好的对应关系.     

自然组织谐波成像技术的初步临床应用

本文采用组织谐波成像技术，对５２例因肥胖、肋间隙狭窄、胸廓畸形、肺气过多及老龄等原因致常规二维图像显示欠清晰的心脏病患者进行了检查。结果表明组织谐波成像能明显增强心肌与心内膜显示，提高对细小病变的分辨力，有助于了解心包积液的物理性状和扩张型心肌病、受压腔静脉的血流状态。同传统基波成像技术相比，组织谐波成像能获取更多的诊断信息，提高诊断正确率。     

Assessment of myocardial changes in athletes with native T1 mapping and cardiac functional evaluation using 3 T MRI

Intensive physical exercise leads to increases in left ventricular muscle mass and wall thickness. Cardiac magnetic resonance imaging allows the assessment of functional and morphological changes in an athlete’s heart. In addition, a native T1 mapping technique has been suggested as a non-contrast method to detect myocardial fibrosis. The aim of this study was to show the correlation between athletes’ cardiac modifications and myocardial fibrosis with a native T1 mapping technique. A total of 41 healthy non-athletic control subjects and 46 athletes underwent CMR imaging. After the functional and morphological assessments, native T1 mapping was performed in all subjects using 3.0 T magnetic resonance imaging. Most of the CMR findings were significantly higher in athletes who had ≥5 years of sports activity when compared with non-athletic controls and athletes who had <5 years of sports activity. Significantly higher results were shown in native T1 values in athletes who had <5 years of sports activity, but there were no significant differences in the left ventricular end-diastolic volume, left ventricular end-diastolic mass, or interventricular septal wall thickness between non-athletic controls and athletes who had <5 years of sports activity. The native T1 mapping technique has the potential to discriminate myocardial fibrotic changes in athletes when compared to a normal myocardium. The T1 mapping method might be a feasible technique to evaluate athletes because it does not involve contrast, is non-invasive and allows for easy evaluation of myocardial remodeling.     

Oedema‐fibrosis in Duchenne Muscular Dystrophy: Role of cardiovascular magnetic resonance imaging

Duchenne muscular dystrophy (DMD) is an X‐linked muscle disorder characterized by progressive, irreversible loss of cardiac and skeletal muscular function. Muscular enlargement in DMD is attributed to oedema, due to the increased cytoplasmic Na+ concentration. The aim of this review was to present the current experience and emphasize the role of cardiovascular magnetic resonance (CMR) in the diagnosis of this condition. DMD patients' survival depends on ventilatory assistance, as respiratory muscle dysfunction was the most common cause of death in the past. Currently, due to improved ventilatory assistance, cardiomyopathy has become the main cause of death, even though clinically overt heart failure may be absent. CMR is the technique of choice to assess the pathophysiologic phenomena taking place in DMD, such as myocardial oedema and subepicardial fibrosis. The classic index to assess oedema is the T2‐weighted short‐tau inversion recovery (T2w‐STIR), as it suppresses the signal from flowing blood and resident fat and enhances sensitivity to tissue fluid. Furthermore, CMR is the most reliable technique to detect and quantify fibrosis in DMD. Recently, the new indices T2, T1 mapping (native and postcontrast) and the extracellular volume (ECV) allow a more accurate approach of myocardial oedema and fibrosis. To conclude, the assessment of cardiac oedema and subepicardial fibrosis in the inferolateral wall of the left heart ventricle are the most important early finding in DMD with preserved ventricular function, and CMR, using both the classic and the new indices, is the best technique to detect and monitor these lesions.     

心脏MRI诊断肌营养不良心肌病研究进展

肌营养不良症是一类包含多种亚型的异质性疾病,表现为控制运动的骨骼肌进行性无力和变性,Duchenne肌营养不良和Becker肌营养不良是最常见的两种类型。肌营养不良症可累及心肌,心脏相关疾病已成为患者死亡的首要原因,利用有效检查手段早期发现心脏受累,对改善患者预后具有重要价值。心脏MRI技术,包括延迟强化、T2加权黑血序列、T2 mapping、增强前T1 mapping、细胞外容积及心肌应力等手段可在病变早期发现心脏损伤,为早期干预治疗提供有力证据;并可精准定量测量左心室容积、左心室射血分数等指标,在标准化治疗和新方案评估等方面具有显著优势。本文对心脏MRI诊断肌营养不良心肌损伤中的研究进展进行综述。     

Myocardial T1 mapping and extracellular volume quantification: a Society for Cardiovascular Magnetic Resonance (SCMR) and CMR Working Group of the European Society of Cardiology consensus statement

Rapid innovations in cardiovascular magnetic resonance (CMR) now permit the routine acquisition of quantitative measures of myocardial and blood T1 which are key tissue characteristics. These capabilities introduce a new frontier in cardiology, enabling the practitioner/investigator to quantify biologically important myocardial properties that otherwise can be difficult to ascertain clinically. CMR may be able to track biologically important changes in the myocardium by: a) native T1 that reflects myocardial disease involving the myocyte and interstitium without use of gadolinium based contrast agents (GBCA), or b) the extracellular volume fraction (ECV)–a direct GBCA-based measurement of the size of the extracellular space, reflecting interstitial disease. The latter technique attempts to dichotomize the myocardium into its cellular and interstitial components with estimates expressed as volume fractions. This document provides recommendations for clinical and research T1 and ECV measurement, based on published evidence when available and expert consensus when not. We address site preparation, scan type, scan planning and acquisition, quality control, visualisation and analysis, technical development. We also address controversies in the field. While ECV and native T1 mapping appear destined to affect clinical decision making, they lack multi-centre application and face significant challenges, which demand a community-wide approach among stakeholders. At present, ECV and native T1 mapping appear sufficiently robust for many diseases; yet more research is required before a large-scale application for clinical decision-making can be recommended.     

B1场校正T1 mapping测量肺癌初始T1值的可重复性及其与表观弥散系数和Ki-67表达的相关性

目的 观察B1场校正MR纵向弛豫时间成像(T1 mapping)测量肺癌初始T1值的可重复性及其与弥散加权成像(DWI)定量参数表观弥散系数(ADC)及Ki-67表达的相关性。方法 收集36例经穿刺活检或手术病理确诊的肺癌患者,包括33例单发及3例多发共39个病灶;采集胸部B1场校正T1 mapping及DWI,以免疫组织化学检测方法评估病灶组织Ki-67表达水平。由2名影像科医师(观察者A、B)独立测量病灶初始T1值和ADC,评估观察者内及观察者间测量T1值的一致性及其差异,分析肺癌初始T1值、ADC及Ki-67表达的相关性。结果 观察者A所测肺癌初始T1值为(1 436.38±222.26)ms及(1 449.58±229.98)ms,差异无统计学意义(t=-0.960,P=0.343);观察者B所测肺癌初始T1值为(1 461.30±236.44)ms,与观察者A差异无统计学意义(t=-1.532,P=0.134);观察者内[组内相关系数(ICC)=0.963,95%CI(0.928,0.980)]与观察者间[ICC=0.948,95%CI(0.901,0.973)]测量肺癌初始...     

Performance of native and contrast-enhanced T1 mapping to detect myocardial damage in patients with suspected myocarditis: a head-to-head comparison of different cardiovascular magnetic resonance techniques

Myocardial T1 mapping is a novel technique that has proven to be superior to standard imaging for differentiation between healthy individuals in acute myocarditis. Aim of this study was comparison of T1 mapping with a clinical biomarker. We retrospectively investigated 171 patients undergoing cardiovascular magnetic resonance (CMR) examination with suspected myocarditis by performing native and contrast enhanced T1-mapping. Additionally, T2w and T1w images and late gadolinium enhancement sequences (LGE) were utilized for myocardial evaluation; Lake Louise Criteria comprise T1w, T2w and LGE imaging in a score. Reference for positive myocarditis diagnosis was a ten-fold increase of troponin level above normal (0.14 ng/ml). Native T1 and extracellular volume (ECV) showed good association with relevant troponin elevations. Area under the curve (AUC) was 81% (p?=?0.0001) for native T1 with an optimal threshold of 979 ms and 86% (p?<?0.0001) for ECV with an optimal cutoff of 32.4%. AUC for T2w imaging (T2-signal intensity ratio to skeletal muscle) was 77% (p?=?0.0003). AUC for T2w imaging (T2-signal intensity compared to remote myocardium) was 69% (p?=?0.012). Additionally, we found positive correlation for native T1 and ECV with the Lake Louise Criteria (r?=?0.44, p?=?0.0001 for native T1 and r?=?0.45, p?=?0.0001 for ECV). Correlated to troponin as biomarker, ECV and native T1 mapping perform at least equally well in comparison to established CMR-techniques LGE, T2w imaging and the combined Lake Louise Criteria in detecting acute myocardial damage. Normal ECV values rule out myocardial damage with very high certainty. T1 mapping qualifies for further prospective evaluations to evolve as a separate biomarker.     

T1 mapping评价扩张型心肌病心肌纤维化

目的探讨T1 mapping评价扩张型心肌病(DCM)心肌纤维化的应用价值。方法对32例DCM患者(DCM组)和16名健康体检者(对照组)行T1mapping和延迟钆增强(LGE)扫描。根据DCM患者是否存在LGE分为LGE(+)亚组和LGE(-)亚组。根据LGE形态和区域,将LGE(+)亚组心肌分为线状LGE区、斑片状LGE区、弥漫性LGE区及远程区(正常心肌区)。分别测量对照组、DCM组、线状LGE区、斑片状LGE区、弥漫性LGE区、远程区T1值,并进行统计学分析。结果 DCM组T1值[(1332.55±61.34)ms]明显高于对照组[(1222.52±45.59)ms,P<0.001]。对照组心肌T1值与线状LGE区[(1359.44±77.93)ms]、斑片状LGE区[(1456.49±110.27)ms]、弥漫性LGE区[(1524.17±52.30)ms]及远程区[(1329.11±64.12)ms]比较,差异均有统计学意义(P均<0.001)。LGE(+)亚组T1值[(1341.35±65.01)ms]与LGE(-)亚组[(1310.06±45.57)ms]差异无统计学意义(P=0.199)。LGE和T1mapping成像诊断DCM组心肌纤维化的ROC曲线下面积分别为0.84、0.95。结论 T1mapping评价DCM心肌纤维化具有较高的应用价值。     

T1 mapping定量技术在慢性心肌缺血模型猪的初步应用研究

目的采用心脏磁共振T1 mapping技术,检测正常猪及其在慢性心肌缺血造模后的心肌T1定量值,为心肌缺血诊断提供新的定量参数,探索T1mapping技术分析判断慢性心肌缺血或梗死的可行性。材料与方法选取13只中华小型猪,于冠脉左前降支近中段手术植入蛋白缩窄环,4 w后建成慢性心肌缺血小型猪模型;于造模前后行3.0 T心脏磁共振扫描(cardiac magnetic resonance,CMR),在短轴位的心尖、乳头肌水平层面行T1 mapping扫描,分别在增强前后测定左心室壁感兴趣区的心肌T1定量值,应用独立样本t检验,统计分析比较造模前后、增强前后T1值的差异。结果 12只正常猪完成了造模前磁共振检查,所有层面平扫心肌平均T1值为(1108.9±10.5)ms,其中心尖部心肌平均T1值为(1050.2±16.7)ms,乳头肌层心肌平均T1值为(1139.7±54.4)ms,两个层面平均T1值差异有统计学意义(P0.05);11只慢性心肌缺血模型猪完成了CMR扫描,心尖部心肌平均T1值为(1210.6±94.2)ms,比造模前升高,差异有统计学意义(P0.05);乳头肌层心肌平均T1值为(1236.0±114.3)ms,与造模前差异无统计学意义(P0.05);但是,乳头肌层的前壁、前间壁与其造模前后的平均T1 mapping的差异具有统计学意义(P值分别为0.017和0.006)。结论左室前壁、前间壁为前降支供血区,T1 mapping在造模前后差异具有统计学意义(P0.05),因此,此技术对诊断心肌慢性缺血或梗死有定量参考价值。     

磁共振T1 mapping成像评价肥厚型和扩张型心肌病弥漫性心肌纤维化

目的 探讨磁共振纵向弛豫时间定量(T1 mapping)成像评价肥厚型心肌病(HCM)和扩张型心肌病(DCM)心肌纤维化的价值,及心肌纤维化与左心室射血分数的关系。方法 收集经临床诊断证实的30例HCM患者(HCM组)、27例DCM患者(DCM)和符合纳入标准的33例患者(对照组)。对所有受检者均行心脏电影成像、对比增强前、后T1 mapping成像、延迟对比增强(LGE)成像。测量不同受检者增强前、后左心室平均T1值及心功能参数并进行统计学分析,分析心肌平均T1值与心功能指标的相关性。结果 HCM组22例(22/30,73.33%)患者存在延迟强化,DCM组15例(15/27,55.56%)患者存在延迟强化,对照组无延迟强化。比增强前,HCM组[(1294.79±85.22)ms]、DCM组[(1312.88±59.57)ms]左心室心肌T1值均较对照组[(1266.56±57.33)ms]显著增加(P均<0.05);对比增强后,HCM组[(491.31±121.59)ms]、DCM组[(466.77±126.34)ms]左心室心肌T1均值较对照组[(534.09±92.73)]显著减低(P均<0.05)。HCM患者左心室心肌增强前T1值与左心室射血分数呈负相关(r=-0.58,P<0.05),增强后T1值与其呈正相关(r=0.59,P<0.05);DCM患者左心室心肌增强前T1值与左心室射血分数呈负相关(r=-0.55,P<0.05),增强后T1值与其呈正相关(r=0.51,P<0.05)。结论 HCM和DCM患者心肌纤维化与心功能相关;T1 mapping成像有助于评价HCM和DCM患者心肌纤维化。