新型磁共振对典型及早期致心律失常性右室心肌病诊断价值的探讨

目的 用有黑血技术的新型磁共振（MRI）对典型致心律失常性右室心肌病（ARVC）进行检查，以确定新型MRI诊断ARVC的特异性和敏感性，并通过对确诊的ARVC患的一级亲属行MRI检查，以探讨MRI对早期ARVC的诊断价值。方法 10例ARVC患（除1例猝死首诊外）及其7个家系的54名成员全部接受询问病史，体检，心电图，心脏超声等检查；10例临床患均接受MRI检查，分析和确定其影响特征及诊断条件，在此基础上对部分家系成员行MRI检查以发现早期ARVC患。结果 临床患有阵发性室性心动过速（8／8），晕厥（9／10），心力衰竭（3／10）和猝死（3／10）。心电图均有左束支传导阻滞型阵发性室性心动过速，心室晚电位（VLP）均阳性（8／8）。MRI检查显示临床患均有明显右心室（RV）扩大及室壁广泛强信号，经压脂处理后心肌信号呈岛状或连续中断，为特征性纤维脂肪替代影像，患均有RV运动减低或室壁瘤形成，部分伴左心室受累（3／8）。家系筛选发现8例异常，拟诊为早期ARVC，2例有心电图异常，2例VLP阳性。MRI显示，8例心室壁均有局限性纤维脂肪病的影像改变，4例有RV扩大，2例可疑扩大，6例RV心尖部血流淤滞现象。结论 带黑血技术的新型MRI是目前诊断ARVC和早期ARVC的最具特异性和敏感性的检查手段。

Diagnosis of typical and early arrhythmogenic right ventricular cardiomyopathy by novel magnetic resonance imaging

Objective To evaluate the sensitivity and specificity of a novel magnetic resonance imaging (MRI) with black blood technique in diagnosing arrhythmogenic right ventricular cardiomyopathy (ARVC) and to explore the possibility of early diagnosis. Methods Ten ARVC patients and 54 members of the 7 ARVC pedigrees received medical history inquiring, physical examination, electrocardiography (ECG) and ultrasound cardiography (UCG) tests. The 10 ARVC cases then underwent the novel MRI with black blood technique. MRI properties and diagnostic imaging conditions for ARVC were analyzed and defined. And then the first grade relatives of the ARVC patients received the MRI test to find early ARVC based on the MRI diagnostic conditions. Results Clinical or typical ARVC patients had paroxysmal ventricular tachycardia ( 8/8), syncope (9/10), heart failure (3/10), and sudden death (3/10). ECG showed left bundle branch block-shaped VT and positive late potentials (8/8). MRI showed that all the patients have enlarged right ventricle (10/10) and strong signal in right ventricle wall. Myocardial signal in right ventricle became islands-like or discontinuous after nulling fat, which is the characteristic imaging of fibrofatty tissue replacement. The patients had lowered right ventricle activity (9/9), right ventricle aneurysm formation and left ventricle involvement (3/8). Screening of pedigrees showed abnormal in 8 members and early ARVC was diagnosed. Two of them have abnormal ECG, 2 had positive ventricle late potential. MRI showed RV enlargement in 4 cases, suspicious enlargement in 2 and detention of blood flow near the apical part of RV in 6 . Characteristic imaging of fibrofatty tissue replacement in RV wall was found in all the 8 cases with the triple-IR FSE. Conclusion The MRI with black blood technique is the most specific and sensitive method for diagnosis of ARVC and ARVC in earlier period.