心脏磁共振延迟强化对尿毒症心肌病的应用初探

目的分析尿毒症患者心脏磁共振(CMR)心肌延迟强化的特征,探讨MRI增强检查对尿毒症心肌病的意义和价值。资料与方法 40例尿毒症患者、10例心肌梗死患者及5例肥厚性心肌病患者分别接受CMR增强检查,分析不同患者延迟强化心肌的特点。结果 CMR延迟增强检查,尿毒症与肥厚性心肌病组与心肌梗死组的延迟强化心肌平均信号强度指数、最大层面延迟强化心肌面积有明显差异(P<0.001)。结论 CMR延迟增强检查尿毒症患者异常强化心肌特点:延迟强化心肌分布在左心室室壁中部,呈局灶性小斑片状,且轻度强化改变,这与肥厚性心肌病有所类似。     

心脏磁共振延迟强化与组织学胶原纤维的关系-移植心脏离体研究

目的 探索心脏磁共振成像(CMR)延迟强化(LGE)评估心肌胶原纤维与人类全心组织学的关系。方法 对22例拟进行心脏移植手术的患者行术前CMR检查,对移植的离体心脏进行16节段取材、苦味酸天狼星红染色后,定量胶原纤维体积分数(CVF)。半自动后处理CMR-LGE序列图像,利用高于远处正常心肌平均信号2～8倍标准差(SD)灰阶阈值法及半峰全宽法计算LGE,用Bland-Altman分析及Pesarson或Spearman相关系数分析LGE与CVF的关系。结果 13例患者出现LGE,各种半自动方法计算LGE与CVF有正相关性,其中6倍SD定量LGE与CVF相关性最好(r=0.783,P=0.02),且二者具有最小偏倚(偏倚：-0.95)。在亚组分析中,缺血性心肌病组半峰全宽法计算LGE与CVF有明显相关性(基于患者：r=0.932,P=0.002),而在非缺血性心肌病中,8倍SD定量LGE与CVF有中等相关性(基于LGE阳性节段：r=0.674,P<0.001)。结论 磁共振LGE技术可无创地检测心肌胶原纤维,半峰全宽法计算缺血性心肌病LGE与组织学胶原纤维最接近,8倍SD计算非缺血...     

急性心肌炎的心脏磁共振延迟强化与左心室功能的关系研究

目的 探讨心脏磁共振延迟强化在急性心肌炎患者心功能受损中的评估价值。方法 选取59例心肌炎患者,分为EF值下降心肌炎组和EF值保留心肌炎组,并招募60例正常志愿者作为对照组,分别评估左心室结构功能、延迟强化,分析延迟强化与左心室EF值的关系,并测试延迟强化对EF值有无下降的鉴别能力。结果 心肌炎组的左心室容积(EDV,ESV)较对照组增加,EF值有下降。EF值保留心肌炎组与对照组相比,尽管EF值保留心肌炎组的左心室容积也更大,但EF值间的差异无统计学意义。相比于EF值保留心肌炎组,EF值下降心肌炎组的PFR更低,左心室容积也是扩张的。而在延迟强范围方面,EF值下降心肌炎组的延迟强化心肌质量和比例都更大。EF值与LGE,LGE%都呈负相关,相关系数分别为-0.67,-0.63。ROC曲线分析结果显示,LGE的诊断效能佳,AUC达到0.96,当LGE的临界值取27.27 g时,敏感性为94%,特异性为88%。结论 心脏磁共振检查能准确评估心肌炎患者是否合并左心室扩张和射血分数下降,而延迟强化范围对急性心肌炎患者心功能受损中鉴别能力较好,有助于对心肌炎患者病情的全面评估。     

心脏磁共振在暴发性心肌炎短期随访中的研究

【摘要】目的：探讨心脏磁共振（CMR）识别及监测暴发性心肌炎患者心肌炎性损伤的价值。方法：19例临床诊断为暴发性心肌炎患者在急性期及随访3个月（愈合期）进行CMR扫描,同期纳入19例正常志愿者作为对照组。CMR序列包括心脏电影、三反转黑血T2WI和延迟增强。测量或计算室间隔厚度、左室心肌质量指数(LVMI)、心肌应变值、水肿比(ER)、延迟强化（LGE）质量等参数。采用Kruskal-Wallis检验比较暴发性心肌炎急性期、愈合期及对照组间各参数的差异。利用ROC曲线分析各参数鉴别急性期和愈合期心肌炎的诊断效能。结果：急性期心肌炎患者的LVMI［64（57,76）g/m2］较愈合期［52（47,63）g/m2］增加（P<0.05）。急性期室间隔厚度［10.5（9,11.3）mm］较愈合期［ 8.3（6.6,9.8）mm］明显增加（P<0.001)。与急性期相比,愈合期心肌ER［1.66（1.43,1.83）vs 2.35（2.1,3.0）］及LGE质量［4.3（1.04,8.75）g vs 14.52（11.4,22.4）g］均明显减低（P均<0.001）。急性期、愈合期收缩期整体峰值圆周应变（GCS）、径向应变（GRS）、纵向应变（GLS）均明显低于对照组（P均<0.001）。LGE质量和心肌ER鉴别急性期和愈合期心肌炎的诊断效能较高,AUC分别为0.809和0.884。结论：CMR可较准确识别和监测暴发性心肌炎患者心肌炎性损伤,心肌ER及LGE质量鉴别急性期与愈合期心肌炎的效能较高。     

儿童肥厚型心肌病磁共振延迟强化特征分析

目的分析肥厚型心肌病（HCM）患儿心脏受累心肌MRI对比剂延迟强化发生率及其与预后的相关性。方法收集2006年1月至2012年1月我院收治的HCM患儿71例,所有患儿均接受心脏MRI检查,并行对比剂增强心肌显像。根据左心室心肌是否存在延迟强化,将患儿分为延迟强化组和非延迟强化组,并进一步分析受累心肌对比剂延迟强化的范围及程度等。应用Kaplan-Meier生存曲线分析两组患儿的预后差别,两组临床数据间的统计分析采用t检验。结果71例HCM患儿中,9例（12.7%）患儿左心室为对称性肥厚,其中2例患儿进展至终末期。52例（73%）患儿出现心肌延迟强化,其延迟强化组患儿左心室质量高于非延迟强化组患儿[（112.7±57.9）g/m2 vs.（70.3±37.4）g/m2],两组间差异有统计学意义（t=2.71,P=0.025）;但两组左室室壁厚度[（19.4±6.3）mm/m2 vs.（18.1±7.9）mm/m2]比较,差异无统计学意义（t=0.69,P=0.513）。HCM患儿随访（2.4±1.6）年显示,心肌延迟强化与不良心血管事件的发生密切相关（χ2=4.77,P=0.029）。结论HCM患儿中,其心肌延迟强化发生率与成人患者接近,并且心肌延迟强化具有判断患儿预后的临床价值。     

磁共振冠状动脉成像的研究进展

随着磁共振设备及其新技术的不断开发和进展,磁共振冠状动脉成像技术已成为显示冠状动脉形态的可靠的无创性影像检查方式。其可以精确显示冠状动脉狭窄部位并评价其血流储备情况,准确评估冠状动脉粥样硬化病变的严重程度,逐渐成为冠心病影像检查的重要方法。随着超高场磁共振设备的临床应用,当前研究主要集中于呼吸及心脏运动伪影抑制、快速数据采集等方面,以期获取高信噪比与高空间分辨力影像。     

磁共振冠状动脉成像的研究进展

随着磁共振设备及其新技术的不断开发和进展,磁共振冠状动脉成像技术已成为显示冠状动脉形态的可靠的无创性影像检查方式。其可以精确显示冠状动脉狭窄部位并评价其血流储备情况,准确评估冠状动脉粥样硬化病变的严重程度,逐渐成为冠心病影像检查的重要方法。随着超高场磁共振设备的临床应用,当前研究主要集中于呼吸及心脏运动伪影抑制、快速数据采集等方面,以期获取高信噪比与高空间分辨力影像。     

心脏磁共振钆延迟增强灰血技术提高心肌梗死检出能力的应用

目的 评估心脏磁共振钆延迟增强（LGE）灰血技术对心肌梗死的检出能力。资料与方法 前瞻性收集2021年1月—2022年1月在华中科技大学同济医学院附属同济医院确诊为心肌梗死或心肌梗死复查患者50例,所有患者均行心脏磁共振LGE亮血和灰血技术扫描,所有图像纳入本次评估范围。使用4点量表法对2种技术的图像质量和心肌梗死检出可信度进行评分,并比较2种技术的整体图像质量和心肌梗死检出可信度。分别比较LGE亮血和灰血技术图像的梗死心肌与左心室血池、梗死心肌与正常心肌、正常心肌和左心室血池的对比率（CR）和对比噪声比（CNR）。2名观察者对LGE灰血和亮血技术图像质量的评价以及CR和CNR的评价均进行一致性分析。结果 LGE灰血与亮血技术图像质量评分差异无统计学意义（t=1.895,P=0.058）,但是LGE灰血技术在心肌梗死检出可信度优于亮血技术（t=5.281,P<0.001）。图像客观定量分析中,与LGE亮血技术比较,LGE灰血技术的梗死心肌/血池的CNR和CR均较高（Z=3.113、3.606,P<0.01）,而梗死心肌/正常心肌的CNR较低（Z=3.06,P=0.002）。...     

心脏MRI在扩张型心肌病中的应用价值

目的 探讨1.5T心脏磁共振成像(CMRI)在扩张型心肌病(DCM)中的应用价值.方法 选取DCM患者45例及健康对照者25例,均进行CMRI检查,通过LGE序列判断左心室有无心肌纤维化将DCM组患者分为LGE(+)组和LGE(-)组,测如下结构及功能参数:LVEDD、LVESD、LVEDV、LVESV、LVEF、LV...     

CMR新技术在心肌纤维化的研究进展及与 LGE-MRI的比较

心肌纤维化（MF）是心室重塑及恶性心律失常发生的根本原因,最终可导致心功能不全、猝死等主要心脏不良事件的发生。延迟增强MRI（LGE-MRI）是既往心肌梗死后局限性MF检测的临床应用标准,而当今T1mapping技术在对心肌弥漫性MF的检测和定量评价中更具优势,心脏功能MRI技术如扩散张量成像（DTI）和扩散加权成像（DWI）无需对比剂即可定量评估心肌微细结构,在MF检测方面亦表现出较大的应用潜能。综述T1mapping、DTI、DWI等技术进展并与LGE-MRI进行比较。     

CMR对扩张性心肌病的应用价值

扩张性心肌病（DCM）的早期诊断及病情监测对其预后非常重要。心脏磁共振（CMR）可以无创性评估心肌的形态、功能及组织特性,有利于DCM的诊断和管理。就延迟钆增强、T₁ mapping、T₂ mapping及CMR特征追踪等CMR技术在DCM的早期诊断、病情监测与评估、预后预测以及鉴别诊断方面的应用价值进行综述。     

Comparison of different quantification methods of late gadolinium enhancement in patients with hypertrophic cardiomyopathy

Aim

There is no consensus regarding the technique of quantification of late gadolinium enhancement (LGE). The aim of the study was to compare different methods of LGE quantification in patients with hypertrophic cardiomyopathy (HCM).

Methods

Cardiac magnetic resonance was performed in 33 patients with HCM. First, LGE was quantified by visual assessment by the team of experienced readers and compared with different thresholding techniques: from 1SD to 6SD above mean signal intensity (SI) of remote myocardium, above 50% of maximal SI of the enhanced area (full-width at half maximum, FWHM) and above peak SI of remote myocardium.

Results

LGE was present in 25 (78%) of patients. The median mass of LGE varied greatly depending on the quantification method used and was highest with the utilization of 1SD threshold [75.5 g, interquartile range (IQR): 63.3-112.3 g] and lowest for FWHM method (8.4 g, IQR: 4.3-13.3 g). There was no difference in mass of LGE as assessed with 6SD threshold and FWHM when compared to visual assessment (p = 0.19 and p = 0.1, respectively); all other thresholding techniques provided significant differences in the median LGE size when compared to visual analysis. Results for all thresholds, except FWHM were significantly correlated with visual assessment with the strongest correlation for 6SD (rho = 0.956, p < 0.0001).

Conclusions

LGE quantification with the use of a threshold of 6SD above the mean SI of the remote myocardium provided the best agreement with visual assessment in patients with HCM.     

心脏淀粉样变性的CMR评估及研究进展

心脏淀粉样变性(CA)是系统性淀粉样变性累及心脏引起心脏损害的一种严重的疾病。心脏磁共振(CMR)具有多方位、多参数、无创、无辐射、高软组织分辨力的检查优势,在CA的早期诊断及不同亚型的鉴别、临床风险分层、治疗后的心肌反应监测、心肌淀粉样蛋白负荷评估和预后评估中具有重要价值。就CMR在CA的心脏形态结构和功能、心肌应变、组织特征评估方面的应用研究进展进行综述。     

Optimizing dose and administration regimen of a high-relaxivity contrast agent for myocardial MRI late gadolinium enhancement

Objectives

To investigate the time-course of late gadolinium enhancement of infarcted myocardium using gadobenate dimeglumine at different dosages and administration regimens.

Materials and methods

After institutional review board approval and informed consent, we studied 13 patients (aged 63 ± 11 years) with chronic myocardial infarction. They underwent two gadobenate dimeglumine-enhanced MR examinations (interval 24–48 h) using short-axis inversion-recovery gradient-echo sequences, with the following two different protocols, in randomized order: 0.05 mmol/kg and imaging at the 2.5th, 5th, 7.5th and 10th minute plus 0.05 mmol/kg and imaging at the 12.5th, 15th, 17.5th and 20th minute; the same as before but using 0.1 mmol/kg for both contrast injections. Contrast-to-noise ratios (CNRs) between infarcted myocardium, non-infarcted myocardium and left ventricle cavity were calculated for each time-point (2.5-min steps). Friedman ANOVA was used for comparing the CNR time-course; Wilcoxon test for comparing CNR at the 10th and the 20th minute.

Results

The CNR between infarcted and non-infarcted myocardium obtained at the 20th minute with 0.05 plus 0.05 mmol/kg resulted significantly higher than that obtained at the 10th minute with 0.05 mmol/kg (P = 0.033) while not significantly different from that obtained at the 10th (0.1 mm/kg) or at the 20th minute with 0.1 plus 0.1 mmol/kg. The CNR between infarcted myocardium and the left ventricle cavity obtained at the 20th minute with 0.05 plus 0.05 mmol/kg resulted significantly higher than all other measured values (P ≤ 0.017).

Conclusion

Using gadobenate dimeglumine, 0.05 plus 0.05 mmol/kg allows for a higher CNR between infarcted myocardium and the left ventricle cavity allowing for reliable assessment of the sub-endocardial infarctions.     

Optimized cardiac magnetic resonance imaging inversion recovery sequence for metal artifact reduction and accurate myocardial scar assessment in patients with cardiac implantable electronic devices

Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) is the gold standard for imaging myocardial viability. An important application of LGE CMR is the assessment of the location and extent of the myocardial scar in patients with ventricular tachycardia (VT), which allows for more accurate identification of the ablation targets. However, a large percentage of patients with VT have cardiac implantable electronic devices (CIEDs), which is a relative contraindication for cardiac magnetic resonance imaging due to safety and image artifact concerns. Previous studies showed that these patients can be safely scanned on 1.5 T scanners provided that an adequate imaging protocol is adopted. Nevertheless, imaging patients with a CIED result in metal artifacts due to the strong frequency off-resonance effects near the device; therefore, the spins in the surrounding myocardium are not completely inverted, and thus give rise to hyperintensity artifacts. These artifacts obscure the myocardial scar tissue and limit the ability to study the correlation between the myocardial scar structure and the electro-anatomical map during catheter ablation. In this study, we developed a modified inversion recovery technique to alleviate the CIED-induced metal artifacts and improve the diagnostic image quality of LGE images in patients with CIEDs without increasing scan time or requiring additional hardware. The developed technique was tested in phantom experiments and in vivo scans, which showed its capability for suppressing the hyperintensity artifacts without compromising myocardium nulling in the resulting LGE images.     

Characterisation of peripartum cardiomyopathy by cardiac magnetic resonance imaging

Peripartum cardiomyopathy (PPCM) is a rare cause of heart failure. Only half of the patients recover normal cardiac function. We assessed the usefulness of magnetic resonance imaging (MRI) and late enhancement imaging to detect myocardial fibrosis in order to predict cardiac function recovery in patients with peripartum cardiomyopathy. Among a consecutive series of 1,037 patients referred for heart failure treatment or prognostic evaluation between 1999 and 2006, eight women had confirmed PPCM. They all underwent echocardiography and cardiac MRI for assessment of left ventricular anatomy, systolic function and detection of myocardial fibrosis through late enhancement imaging. Mean (± SD) baseline left ventricular ejection fraction (LVEF) was 28 ± 4%. After a follow-up of 50 ± 9 months, half the patients recovered normal cardiac function (LVEF = 58 ± 4%) and four did not (LVEF = 35 ± 6%). None of the eight patients exhibited abnormal myocardial late enhancement. No difference in MRI characteristics was observed between the two groups. Patients with PPCM do not exhibit a specific cardiac MRI pattern and particularly no myocardial late enhancement. It suggests that myocardial fibrosis does not play a major role in the limitation of cardiac function recovery after PPCM. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.