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.     

杜氏肌营养不良与贝氏肌营养不良常规MRI的对比研究

目的 探讨常规MRI鉴别诊断杜氏肌营养不良（DMD）和贝氏肌营养不良（BMD）的价值。方法 回顾性分析经临床确诊为抗肌萎缩蛋白病697例患者的臀部及大腿肌肉影像学资料,比较DMD与BMD影像学征象的异同。结果 DMD与BMD患者肌肉脂肪浸润的分布规律一致,DMD总体脂肪浸润程度高于BMD（P=0.034）,且以臀大肌、股直肌、缝匠肌为著;肌肉总体水肿程度差异无统计学意义（P=0.065）,但DMD大腿后群肌肉及缝匠肌的水肿明显高于BMD。DMD与BMD患者肌肉萎缩及肥大的选择性受累规律一致,BMD股外侧肌、股中间肌、股内侧肌、半膜肌及股二头肌长头萎缩频率明显高于DMD（P<0.05）;DMD与BMD患者肌肉的肥大改变差异无统计学意义（P>0.05）。结论 常规MRI可鉴别诊断DMD与BMD。     

MRI在肌肉疾病中的临床应用

目的:研究肌肉疾病的MRI表现,评价MRI在肌肉疾病诊断中的应用价值。材料和方法:选择骨盆、双侧大腿及双侧小腿肌肉,对53例经病理活检证实的肌肉疾病患者及4例健康人行MRI检查,进行性肌营养不良症(PMD)31例,其中假肥大型进行性肌营养不良症(Duchenne型PMD,DMD)16例,肢带型PMD 5例,面肩肱型PMD 10例;多发性肌炎(PM)9例;脂质沉积性肌病(LSM)9例;神经源性肌病4例。结果:全部DMD、肢带型PMD及神经源性肌病患者的受累肌肉均表现为短T1、长T2信号;面肩肱型PMD、PM与LSM的受累肌肉表现为两种信号改变:一种为长T1、长T2信号,另一种为短T1、长T2信号。结论:各型神经肌肉疾病具有不同MRI表现;MRI能为临床在肌肉疾病的诊断、鉴别诊断、疗效判断及病情随访中提供客观的资料,并能为临床选取准确的活检部位提供定位。     

急性肌肉拉伤的MRI应用进展

急性肌肉拉伤是一种急性间接肌肉损伤,常见于日常生活和运动中。仅根据临床症状和体格检查难以准确诊断。常规MRI软组织分辨率高,是急性肌肉拉伤诊断和预后评估的重要手段。近年发展的肌肉MR弹性成像、T2弛豫时间图、磁共振扩散加权成像、扩散张量成像和磁共振波谱具有从微观结构、病理和生理层面为急性肌肉拉伤的诊断提供定量、客观依据的潜力。作者对应用于急性肌肉拉伤的各项MRI技术进行综述。     

Left ventricular noncompaction in Duchenne muscular dystrophy

Background

Left ventricular noncompaction (LVNC) describes deep trabeculations in the left ventricular (LV) endocardium and a thinned epicardium. LVNC is seen both as a primary cardiomyopathy and as a secondary finding in other syndromes affecting the myocardium such as neuromuscular disorders. The objective of this study is to define the prevalence of LVNC in the Duchenne Muscular Dystrophy (DMD) population and characterize its relationship to global LV function.

Methods

Cardiac magnetic resonance (CMR) was used to assess ventricular morphology and function in 151 subjects: DMD with ejection fraction (EF) > 55% (n = 66), DMD with EF < 55% (n = 30), primary LVNC (n = 15) and normal controls (n = 40). The non-compacted to compacted (NC/C) ratio was measured in each of the 16 standard myocardial segments. LVNC was defined as a diastolic NC/C ratio > 2.3 for any segment.

Results

LVNC criteria were met by 27/96 DMD patients (prevalence of 28%): 11 had an EF > 55% (prevalence of 16.7%), and 16 had an EF < 55% (prevalence of 53.3%). The median maximum NC/C ratio was 1.8 for DMD with EF > 55%, 2.46 for DMD with EF < 55%, 1.54 for the normal subjects, and 3.69 for primary LVNC patients. Longitudinal data for 78 of the DMD boys demonstrated a mean rate of change in NC/C ratio per year of +0.36.

Conclusion

The high prevalence of LVNC in DMD is associated with decreased LV systolic function that develops over time and may represent muscular degeneration versus compensatory remodeling.     

磁共振波谱和扩散张量成像对多发性硬化的诊断价值

目的：探讨MRI的磁共振波谱和扩散张量成像在多发性硬化（MS）诊断中的应用,并分析较优参数。方法：对32例MS患者和32名健康志愿者（健康对照组）进行头部磁共振波谱和扩散张量成像扫描,分别选取患者的脱髓鞘斑块、表现正常的脑白质（NAWM）区域和对照组相应区域测量氮-乙酰天门冬氨酸（NAA）／肌酸（Cr）比值、胆碱（Cho）／Cr比值、表观扩散系数（ADC）值和部分各向异性（FA）值,并绘制ROC曲线,分别计算其ROC曲线下的面积。结果：在脱髓鞘斑块的ROC曲线图中,NAA／Cr、Cho／Cr、ADC和FA曲线下的面积分别为0．938、0．843、0．975和0．952,提示ADC值是诊断脱髓鞘斑块的最优参数;在NAWM的ROC曲线图中,上述4条曲线下的面积分别为0．722、0．692、0．691和0．657,提示NAA／Cr比值是诊断NAWM存在异常的最优参数。结论：同时应用磁共振波谱和扩散张量成像检查并定量测量其参数值,可以全面评价MS的脱髓鞘斑块和NAWM异常,将会对临床制定治疗方案和判断预后有重要的参考作用。     

磁共振扩散成像技术在轻度认知障碍的研究进展

轻度认知障碍(mild cognitive impairment,MCI)被认为是正常老龄化和阿尔茨海默病(Alzheimer'disease,AD)以及其他类型痴呆的中间状态。给予MCI患者积极的干预治疗,有助于改善认知功能并减缓MCI向AD的转变。因此,寻找MCI诊断和进展监测的敏感影像标记物是非常必要的。磁共振扩散成像技术能够通过描述脑组织中水分子的扩散运动来检测微观结构的变化,可以为MCI的病理机制研究和认知障碍严重程度的评估提供重要的信息。近年来,新型磁共振扩散成像技术的不断发展为MCI的研究提供了额外的价值。作者对扩散张量成像(diffusion tensor imaging,DTI)、扩散峰度成像(diffusion kurtosis imaging,DKI)、自由水扩散磁共振成像(free-water diffusion magnetic resonance imaging,FW diffusion MRI)、神经突方向离散度和密度成像(neurite orientation dispersion and density imaging,NODDI)技术在MCI中的研究进行综述。     

磁共振弥散加权成像及波谱成像评价原发性骨肉瘤恶性程度

目的 探讨DWI和¹H-MRS对不同恶性程度原发性骨肉瘤的诊断价值。方法 回顾性分析41例经病理证实的骨肉瘤患者的DWI和¹H-MRS检查资料。DWI检查中b值分别为0、400、800、1 000、1 500 s/mm²,经后处理获得相应的ADC图,并计算ADC值。对18例MRS谱线稳定的骨肉瘤患者进行分析并获得MRS谱线、胆碱复合物（Cho）、肌酸（Cr）及Cho/Cr值。不同b值下高度和低度恶性骨肉瘤的ADC值比较采用Kruskal-Wallis H检验,Cho/Cr值的比较采用Mann-Whitney U检验。结果 当b值分别为400、800、1000 s/mm²时,高度与低度恶性骨肉瘤的ADC值差异有统计学意义（χ²=6.26、4.37、4.87,P=0.01、0.04、0.03）;而b值为1 500 s/mm²时,高度与低度恶性骨肉瘤ADC值差异无统计学意义（χ²=2.39,P=0.12）。b值为400 s/mm²时,以ADC值诊断高度恶性骨肉瘤的特异度和敏感度为73.30%和72.70%。高、低度恶性骨肉瘤的Cho/Cr值差异有统计学意义（Z=-2.45,P<0.05）。以Cho/Cr诊断高度恶性骨肉瘤的最佳界值为2.21,特异度为75.00%,敏感度为92.90%。结论 ADC值（b值取400 s/mm²）及Cho/Cr值均对诊断原发性骨肉瘤的恶性程度有一定价值。     

Patterns of late gadolinium enhancement in Duchenne muscular dystrophy carriers

Background

This study was designed to assess whether cardiovascular magnetic resonance imaging (CMR) in Duchenne muscular dystrophy carriers (DMDc) may index any cell milieu elements of LV dysfunction and whether this cardiac phenotype may be related to genotype. The null hypothesis was that myocardial fibrosis, assessed by late gadolinium enhancement (LGE), might be similarly accounted for in DMDc and gender and age-matched controls.

Methods

Thirty DMDc patients had CMR and genotyping with 37 gender and age-matched controls. Systolic and diastolic LV function was assessed by 2D-echocardiography.

Results

Absolute and percent LGE were higher in muscular symptomatic (sym) than asymptomatic (asy) DMDc (1.77 ± 0.27 vs 0.76 ± 0.17 ml; F = 19.6, p < 0.0001 and 1.86 ± 0.26% vs 0.68 ± 0.17%, F = 22.1, p < 0.0001, respectively). There was no correlation between LGE and age. LGE was seen most frequently in segments 5 and 6; segment 5 was involved in all asy-DMDc. Subepicardial LGE predominated, compared to the mid-myocardial one (11 out of 14 DMDc). LGE was absent in the subendocardium. No correlations were seen between genotyping (type of mutation, gene region and protein domain), confined to the exon’s study, and cardiac phenotype.

Conclusions

A typical myocardial LGE-pattern location (LV segments 5 and 6) was a common finding in DMDc. LGE was more frequently subepicardial plus midmyocardial in sym-DMDc, with normal LV systolic and diastolic function. No genotype-phenothype correlation was found.     

氢质子波谱在骨肌系统肿瘤诊断中的临床应用

目的：研究骨肌系统良、恶性肿瘤的1H-MRS特点，探讨1H-MRS用于骨肌系统肿瘤诊断与鉴别诊断的可行性及价值。材料与方法：本组研究共40例，良性肿瘤组12例，恶性肿瘤组28例。均行常规MRI扫描及在体1H-MRS检查。26例肿瘤新鲜手术标本行离体1H-MRS检查。观察良、恶性肿瘤组织及正常肌肉在体1H-MRS表现，并与肿瘤标本离体1H-MRS检查结果对照，在工作站上测量Cho/Cr及Lipid/Cr比值并进行统计学分析。分析36例肿瘤的细胞密度，并与肿瘤组织Cho/Cr值作Pearson相关性分析。结果：恶性肿瘤组织Cho/Cr比值明显高于良性肿瘤，Lipid/Cr比值低于良性肿瘤，差异均具有显著性意义（P<0.01）。离体波谱研究显示，与良性肿瘤组织相比，18例恶性肿瘤组织的Cho、Lac与mI峰都明显升高，而Lip、Glc则明显下降，12例恶性肿瘤Ala、Glu、PC、Gly峰增高。在体波谱Cho峰及Lipid峰变化趋势与离体波谱具有较高的一致性。恶性肿瘤平均细胞密度为150/视野，良性肿瘤平均细胞密度为61/视野，两者差异具有显著性意义。肿瘤细胞密度与Cho/Cr值呈明显正相关（r=0.882，P<0.001)。结论：良、恶性骨肌系统肿瘤1H-MRS表现明显不同，在体与离体1H-MRS具有较高的一致性，在体1H-MRS对骨肌系统肿瘤的诊断与鉴别诊断具有较高价值。     

多模态磁共振成像在脑胶质瘤分级诊断及预后评估中的研究进展

脑胶质瘤是中枢神经系统中常见的恶性肿瘤,其具有弥漫性浸润生长的特点,在治疗的过程中具有较大的难度,肿瘤恶性程度高,容易复发、预后较差。多模态磁共振成像技术多用于肿瘤术前的初步诊断,在胶质瘤分级判断以及预测预后方面具有重要的价值。本文就扩散加权磁共振成像、弥散张量磁共振成像、动态磁敏感对比灌注加权成像、动态对比增强磁共振成像、动脉自旋标记成像和磁共振波谱成像等几种多模态磁共振成像技术在脑胶质瘤术前分级诊断及预后评估方面的研究进展进行综述。     

弥散加权成像在软组织脓肿中的诊断价值

目的 探究弥散加权成像(DWI)在软组织脓肿中的诊断价值.方法 搜集我院48例拟诊为软组织脓肿或囊肿患者.病灶的分布部位为:眶周1例,乳房3例,腹腔内13例,肌肉内31例.在其他放射学检查后,在1.5TMR系统中行DWI.在b-1000 DWI上定量测量病灶的信号强度值.行DWI后对所有病例进行穿刺,以穿刺抽吸到脓液作为诊断脓肿的金标准.结果 37例在DWI上呈高信号,其中假阳性结果2例,真阳性结果35例.10例在DWI上呈低信号,其中假阴性2例,真阴性8例.1例脓肿在DWI上未显示,而在增强MRI上显示,此例视为假阴性.DWI对软组织脓肿的敏感性和特异性分别为92.1％、80.0％.结论 DWI在软组织脓肿诊断中有较高的诊断价值,并且是一种可能用于鉴别囊肿和脓肿的重要影像学方法.     

Brain imaging and the effects of caffeine and nicotine

Caffeine and nicotine are the most common psychostimulant drugs used worldwide. Structural neuroimaging findings associated with caffeine and nicotine consumption are limited and primarily reflect the putative relationship between smoking and white matter hyperintensities (WMH), a finding that warrants further appraisal of its clinical implications. The application of newer brain imaging modalities that measure subtle haemodynamic changes or tissue-based chemistry in order to better elucidate brain functional processes, including mechanisms underlying addiction to nicotine and caffeine and the brain functional consequences, provide intriguing findings. Potential influences of caffeine and nicotine on the functional contrast, or metabolic response, to neural activation also necessitates the careful appraisal of the effects that these commonly used drugs may have on the results of functional imaging.     

3.0T磁共振波谱对颞叶癫痫的定侧诊断价值

目的：通过对颞叶癫痫的磁共振波谱研究,探讨3.0T超高场强MRS在颞叶癫痫的定侧诊断价值。方法对40例临床诊断颞叶癫痫患者及20例正常志愿者进行研究,所有实验对象行双侧海马的常规MRI和1H-MRS扫描,MR成像序列为轴位SE T1WI、T2WI,对双侧海马体部进行多体素波谱成像,将正常对照组MRS结果作为标准,评价颞叶癫痫患者MRS代谢物比值特点,分析MRS对颞叶癫痫定侧诊断价值。结果常规MRI诊断海马硬化共21例。癫痫组患侧、健侧与对照组间NAA/（Cho＋ Cr）、NAA/ Cho比值差异均有统计学意义（F分别=12.89、15.73,P均＜0.05）。癫痫组患侧与健侧、患侧与对照组NAA/（Cho＋Cr）、NAA/Cho差异均有统计学意义（q分别=7.32、8.47、7.33、8.47,P均＜0.05）;而癫痫组健侧与对照组差异无统计学意义（q分别=1.13、1.13,P均＞0.05）。结论常规MRI检查对颞叶癫痫的定侧具有一定的价值;3.0T超高场强MRS与常规MRI联合应用可以提高颞叶癫痫定侧的准确性。     

多发性硬化的磁共振波谱研究

目的研究多发性硬化(MS)患者脑内病灶、表现正常脑白质(NAWM)及正常志愿者脑白质的代谢差异,并探讨代谢物浓度比值与临床残疾程度的相关性。方法对32例MS患者和25例正常志愿者进行MRI和质子磁共振波谱(1H MRS)检查,测量各感兴趣区的代谢产物氮-乙酰天冬氨酸(NAA)、肌酸(Cr)及胆碱(Cho)的浓度比率,并分析NAA/Cr及NAA/Cho与扩展残疾状态量表(EDSS)的相关性。结果MS患者的病灶内NAA/Cr及NAA/Cho显著低于NAWM(P<0.001),NAWM的NAA/Cr及NAA/Cho亦显著低于正常对照组(P<0.001)。MS患者病灶和NAWM的NAA/Cr及NAA/Cho与EDSS均无显著相关性。结论1H MRS能检测出MS患者脑部病灶及NAWM的代谢异常,为常规MRI提供补充信息。     

弥散张量成像在脑白质病变中的应用价值初探

ThisstudyperformedacombinedconventionalanddiffusiontensorMRimagingfrom10multiplesclerosis,10multiplelacunarinfarction,3cysticercosis,1angiitis,1morphinistand10healthycontrolvolunteerstoinvestigatedmorphologicandquantitativeindex.1Subjectsandmethods1.1SubjectsTwenty-fivepatientsandtenhealthycontrolvol-unteersunderwentacombinedconventionalanddiffusiontensorMRimagingduringoneyear.Thepatientsincludetenmultiplesclerosis(7womenand3men)whoseagewasfrom17to48years,themediandurationofthediseasewas1yea…     

3.0T 1H-MRS及DTI诊断脑胶质瘤: AA值与FA值的相关性

目的 探讨脑胶质瘤肿瘤外周至肿瘤中心3.0T磁共振氢质子波谱(¹H-MRS)的N-乙酰天门冬氨酸(NAA)值及弥散张量成像(DTI)的各向异性(FA)值的相关性,评价¹H-MRS及DTI对脑胶质瘤的诊断价值。方法 回顾性分析经组织病理学证实的9例低级别(Ⅰ~Ⅱ级)胶质瘤、16例高级别(Ⅲ~Ⅳ级)胶质瘤的常规MRI、DTI及¹H-MRS资料,分析肿瘤不同感兴趣区的部分FA值、NAA与肌酸(Cr)比值、胆碱(Cho)与肌酸(Cr)比值及胆碱(Cho)与NAA的比值,并观察NAA值与FA值的相关性。结果 从肿瘤中心到外周(包括肿瘤邻近脑白质和对侧大脑半球白质)FA和NAA数值持续升高,且两者呈正相关(r=0.90,P<0.05)。低级别、高级别胶质瘤组瘤体的NAA/Cr无明显差异,FA、Cho/Cr和Cho/NAA差异均有统计学意义(P均<0.05)。结论 脑胶质瘤中,从肿瘤外周至肿瘤中心脑胶质瘤对周围组织的浸润程度逐渐增加,而NAA值及FA数值表现为降低趋势,反映了神经元结构和白质纤维的完整性的破坏。肿瘤中心FA、Cho/Cr和Cho/NAA数值对鉴别低级别、高级别胶质瘤具有一定意义。     

Cardiovascular magnetic resonance imaging of myocardial inflammation

Cardiovascular magnetic resonance (CMR) imaging can precisely quantify cardiac size and function, but moreover depict tissue changes that are associated with various forms of myocardial inflammation. Thereby, CMR can often detect myocardial inflammation before contractility is obviously impaired. Various CMR techniques to assess aspects of inflammation including T2-weighted imaging, and early- and late-contrast enhanced T1-weighted imaging, are reviewed regarding technical challenges and clinical usefulness. In this article we discuss the available evidence regarding clinical application of CMR in different forms of myocardial inflammation.     

磁共振弥散张量和波谱成像在缺血性脑小血管疾病中的应用研究

目的探讨磁共振弥散张量成像(diffusion tensor imaging,DTI)联合磁共振波谱成像(magnetic resonance spectroscopy,MRS)对于缺血性脑小血管疾病(small vessel disease,SVD)的影像评估价值。材料与方法对42例缺血性SVD患者进行常规MRI、DTI和MRS扫描,测量病灶及健侧对称正常脑白质区域的平均弥散系数(average diffusion coefficient,DCavg)值、各向异性分数(fractional anisotropy,FA)值,测量病灶及其周围正常脑白质区域的N-乙酰天门冬氨酸(N-acetyl aspartic acid,NAA)、胆碱(choline,Cho)、肌酸(creatine,Cr)、肌醇(myo-inositol,MI)等生化代谢物的浓度值,并计算NAA/Cho、NAA/Cr、Cho/Cr、MI/Cr的比值。将42例SVD患者的缺血性病灶按照影像学显示分组,并对各组上述测量指标进行统计学分析。结果选取42例缺血性SVD患者的42个病灶并分成慢性缺血组(30例)和慢性期梗死灶组(12例)。SVD病灶的DCavg值和FA值分别较健侧镜像区正常脑白质的增高和降低(P0.01),而两组间SVD病灶的DCavg值和FA值差异无统计学意义(P0.05)。SVD病灶的NAA、Cho和Cr的均数都小于周围正常白质(P0.01),而两组间的各项MRS代谢值差异均无统计学意义(P0.05)。Pearson相关性分析,正常脑白质的DCavg值与FA值(r=-0.383,P=0.012)呈负相关,FA值与NAA/Cho(r=0.420,P=0.006)、NAA/Cr(r=0.382,P=0.012)之间均呈正相关,而在SVD病灶组无上述相关性。Spearman相关分析,SVD病灶组的DCavg与高血压呈正相关(r=0.338,P=0.029)。结论对于缺血性SVD,DCavg、FA、NAA、Cho和Cr等检测指标能够共同反映神经髓鞘结构的微观变化及其功能的破坏,联合应用DTI和MRS成像技术对缺血性SVD疾病进行研究,有助于其临床诊断及病理机制的研究。     

磁共振成像与活体波谱在阿尔茨海默病实验及临床研究中的应用

痴呆是当前世界上的流行病之一,阿尔茨海默病是最常见的痴呆类型,其诊断和治疗目前都还非常困难.磁共振成像(MRI)和活体磁共振波谱(MRS)技术相对于其他诊断和研究手段而言,具有其特有的无损伤性和多功能性.随着近年来磁共振成像仪在全世界范围内的广泛普及,磁共振技术在阿尔茨海默病的临床诊断和实验研究中应用发展迅速并日趋广泛.本文综述了磁共振成像和活体磁共振波谱技术近几年来的最新进展及其在阿尔茨海默病研究中的应用,还简述了磁共振在阿尔茨海默病动物模型中的研究.