Magnetic resonance imaging in right ventricular dysplasia.

Fifteen patients with right ventricular dysplasia were investigated by T1-weighted spin- and gradient-echo pulse sequences, using a protocol that enabled both a subjective analysis of myocardial signal intensity and a quantitative/qualitative analysis of right and left ventricular function. In 8 patients, 3 investigators independently recognized abnormally hyperintense areas in the anatomic sites usually affected by the disease. In 7 of these patients, these areas showed an overlap with a-dyskinetic areas imaged by both magnetic resonance imaging (MRI) and echocardiography. In 1 patient who underwent a cardiac transplant, MRI of the explanted heart showed an excellent correlation between the distribution of the lesions and the in vivo/in vitro features. The data were compared with those from an equivalent sample of patients affected by dilated cardiomyopathy. In the latter patients, no focal hyperintensities were attributed to any anatomic sites in the right ventricule, and no focal a-dyskinetic foci were observed. Furthermore, the 2 groups of patients were significantly different in regard to dimensional and functional quantitative parameters. The results suggest that MRI is useful in integrating echocardiographic data and can be helpful in diagnosing this disease in late stages.     

Magnetic resonance imaging findings in suspected arrhythmogenic right ventricular dysplasia.

INTRODUCTION: Cardiac magnetic resonance imaging (CMRI) has been used to evaluate right ventricular morphology in suspected arrhythmogenic right ventricular cardiomyopathy (ARVC). We report qualitative CMRI findings in patients with suspected ARVD. METHODS: A retrospective review of images in 35 patients referred for CMRI with clinically suspected ARVD. RESULTS: Eleven patients were considered to have alterations on CMRI. In 5 patients a dilated outflow tract and/or right ventricle was identified; a high intramyocardial T1 fat signal was identified in one patient, regional dyskinesia in two patients, and small excavated pouches in 4 patients. Prominent right ventricular trabeculae were present in 4 patients. CONCLUSIONS: CMRI alterations used for diagnosis of ARVC were identified in approximately one-third of patients referred to our center with either clinical suspicion or diagnosis of ARVC.     

Left ventricular haemangioma with papillary endothelial hyperplasia and liver involvement

An intracardiac haemangioma with papillary endothelial hyperplasia (PEH) and liver involvement has not been previously reported in the English literature. This report describes a 65 year old man with a left ventricular haemangioma with PEH coexistent with multiple nodular hepatic haemangiomas. Transthoracic and transoesophageal echocardiography identified a large tumour in the left ventricular cavity with a pedicle connected to the apex. Abdominal sonography also identified multiple hyperechoic hepatic tumours. Magnetic resonance imaging showed hypervascularity of both the cardiac and hepatic lesions. The left ventricular tumour was totally resected and the liver nodules were biopsied. Tissue pathological study showed that both the left ventricular tumour and liver lesions were haemangiomas with PEH. The patient was discharged without complications postoperatively.     

Localized right ventricular structural abnormalities in patients with idiopathic ventricular fibrillation: Magnetic resonance imaging study

Summary Lethal arrhythmias, including ventricular tachycardia and ventricular fibrillation, may occur in the absence of apparent morphological abnormalities. However, a recent study using magnetic resonance imaging (MRI) has suggested that localized, minor structural abnormalities of the right ventricle are responsible for right ventricular outflow tract ventricular tachycardia in a number of patients. We demonstrated regional wall thinning and systolic dyskinesia of the right ventricle by MRI in two patients with idiopathic ventricular fibrillation in whom other cardiac imaging modalities failed to show abnormalities. This finding implies that minor structural abnormalities do exist in patients with so-called idiopathic ventricular fibrillation.     

Magnetic resonance imaging findings in patients meeting task force criteria for arrhythmogenic right ventricular dysplasia

INTRODUCTION: Magnet resonance imaging (MRI) findings in patients meeting Task Force criteria for the diagnosis of arrhythmogenic right ventricular dysplasia (ARVD) have not been systematically described. We report qualitative and quantitative MRI findings in ARVD using state-of-the-art MRI. METHODS AND RESULTS: MRI was performed on 12 patients with ARVD who were prospectively diagnosed using the Task Force criteria. The imaging protocol included breath-hold double inversion recovery spin-echo and gradient-echo images. Ventricular volumes and dimensions were compared to 10 age- and sex-matched normal volunteers. High intramyocardial T1 signal similar to fat signal was observed in 9 (75%) of the 12 patients and in none of the controls. Right ventricular (RV) hypertrophy was seen in 5 (42%) patients, trabecular disarray in 7 (59%), and wall thinning in 3 (25%). Both the RV end-diastolic diameter and the outflow tract area were significantly higher in ARVD patients compared to controls (51.2 vs 43.2 mm, P < 0.01; and 14.5 vs 9.3 cm2, P < 0.01, respectively). ARVD patients had a higher RV end-diastolic volume index and lower RV ejection fraction compared with controls (127.4 vs 87.5, P < 0.01; and 41.6% vs 57%, P < 0.01, respectively). CONCLUSION: High intramyocardial T1 signal indicative of fat is seen in a high percentage (75%) of patients who meet the Task Force criteria for ARVD. Trabecular disarray is seen more frequently than wall thinning and aneurysms. RV dimensions and volumes differ significantly in ARVD compared to controls, indicating a role for quantitative evaluation in the diagnosis of ARVD.     

Evaluation of right ventricular volumes measured by magnetic resonance imaging

Right ventricular volumes were determined in 12 patients with different levels of right and left ventricular function by magnetic resonance imaging (MRI) using an ECG gated multisection technique in planes perpendicular to the diastolic position of the interventricular septum. Right ventricular stroke volume was calculated as the difference between end-diastolic and end-systolic volume and compared to left ventricular stroke volume and to stroke volume determined simultaneously by a classical indicator dilution technique. There was good agreement between right ventricular stroke volume determined by MRI and by the indicator dilution method and between right and left ventricular stroke volume determined by MRI. Thus, MRI gives reliable values not only for left ventricular volumes, but also for right ventricular volumes. By MRI it is possible to obtain volumes from both ventricles simultaneously in a noninvasive way and without exposing the patient to radiation.     

Contrast-enhanced cardiovascular magnetic resonance imaging of right ventricular infarction.

OBJECTIVES: We assessed the role of late enhancement cardiovascular magnetic resonance imaging (LE-CMR) for the diagnosis of right ventricular infarction (RVI). BACKGROUND: Right ventricular infarction occurs in about one-half of patients with inferior myocardial infarction (MI). It is associated with an unfavorable prognosis, but established methods often lack the diagnostic accuracy to detect it. Late enhancement cardiovascular magnetic resonance imaging accurately detects left ventricular MI. METHODS: Thirty-seven patients with acute inferior MI were included. To test for RVI, they prospectively underwent a physical examination, an electrocardiogram (ECG) for ST-segment elevation in the V4r right precordial lead, and an echocardiogram. After coronary reperfusion, LE-CMR was performed for assessing presence and extent of late enhancement in the right ventricular (RV) wall. The LE-CMR data were compared with the other results; interobserver variability was assessed. The LE-CMR was repeated after 13 months. RESULTS: Late enhancement cardiovascular magnetic resonance imaging detected RVI in 21 of 37 (57%) patients with acute inferior MI. Interobserver variability was very good (kappa 0.83); physical exam was positive for RVI in 7 of 37 (19%) patients, V4r ECG in 13 of 37 (35%) patients, and echocardiogram in 6 of 37 (16%) patients. The LE-CMR findings for RVI showed only mild agreement with findings for RVI on physical exam (kappa 0.30), V(4)r ECG (kappa 0.38), and echocardiography (kappa 0.32). Irreversible injury of the RV persisted at 13 months (kappa 0.85). CONCLUSIONS: In patients with acute inferior MI, RVI is more frequently detected by LE-CMR than by current standard diagnostic techniques. Further CMR studies might allow for analyzing its clinical and prognostic relevance.     

Assessment of right ventricular infarction with contrast-enhanced magnetic resonance imaging

OBJECTIVE: Evaluation of contrast-enhanced magnetic resonance imaging to assess right ventricular infarction in patients with acute inferior myocardial infarction. BACKGROUND: Contrast-enhanced magnetic resonance imaging has been used for assessing scar tissue after left ventricular infarction. The value of contrast-enhanced magnetic resonance imaging to assess right ventricular infarction is unknown and was evaluated. METHODS: Consecutive patients (n=18) with first acute inferior infarction were included. Resting electrocardiogram and right-sided electrocardiogram were acquired to assess right ventricular involvement. Resting cine magnetic resonance imaging was performed to evaluate right ventricular function and volumes, whereas the extent of right ventricular scar tissue was assessed by contrast-enhanced magnetic resonance imaging. Cine magnetic resonance imaging was repeated at 6-months follow-up to re-assess right ventricular function and volumes. RESULTS: Sensitivity and specificity of magnetic resonance imaging were 100 and 78%, respectively, to detect right ventricular infarction (using the right-sided electrocardiogram as the gold standard). At 6 months follow-up, patients with scar tissue on contrast-enhanced magnetic resonance imaging showed right ventricular dilatation. Moreover, the extent of right ventricular scar tissue was linearly related to the severity of right ventricular dilatation. CONCLUSIONS: Contrast-enhanced magnetic resonance imaging permits accurate assessment of right ventricular scar tissue. Patients with extensive right ventricular infarction demonstrate right ventricular dilatation at 6 months follow-up.     

磁共振成像在致心律不齐性右室型心肌病的诊断价值

目的回顾性分析27例致心律不齐性右室型心肌病（ARVC）的磁共振成像（MRI）表现,探讨MRI在ARVC的诊断与预后判断中的价值。方法按照1994年WHO关于ARVC的诊断标准,2004年10月至2006年6月共27例临床诊断或病理确诊为ARVC（6例行心脏移植术）,男21例,女6例,平均年龄37．4（15～67）岁。采用1．5T超导MRI扫描仪对心脏形态（脂肪浸润、房室大小）、功能（室壁局部与整体运动功能）、心肌灌注与心肌存活等方面进行综合评价。结果形态学：88．89％（24／27）的病例MRI提示心肌脂肪浸润,62．96％（17／27）右室壁变薄,62．96％（17／27）右室心尖肌小梁明显粗乱,66．67％（18／27）右室流出道扩张,51．85％（14／27）右室心尖扩张,66．67％（18／27）右室下壁及游离壁扩张,40．74％（11／27）合并右房增大。心脏功能：18．52％（5／27）的病例右室局部运动功能异常,70．37％（19／27）整体运动功能异常,右室平均射血分数（EF）35％。40．74％（11／27）的患者合并左室扩大并室壁收缩运动明显减弱。心肌首过灌注示10．52％（2／19）的患者左室受累,36．84％（7／19）的患者左室和右室壁出现异常强化,提示心肌纤维或胶原变性。右室壁强化区域主要位于右室游离壁和右室流出道肌壁,左室则主要位于左室侧壁,少数合并左室心尖或室间隔,5例左室侧壁异常强化经术后病理证实为纤维组织。仅1例表现为右室流出道增宽,但左室心肌显著变薄,收缩运动明显减弱;有3例右室MRI无阳性表现,其中2例左室侧壁室壁变薄并运动异常,延迟显像为异常强化,另1例表现为类似扩张型心肌病样改变。结论MRI高度的软组织对比与多序列成像可对ARVC进行全面诊断与预后评价,但少数以左室异常表现为主而无明显或仅轻微右室异常的病例,MRI易误诊,其左室侧壁段的纤维化为ARVC相对特征表现。右室整体运动异常、广泛纤维脂肪浸润、合并左室扩张并运动异常为其预后不良的指标。     

Findings on magnetic resonance imaging of idiopathic right ventricular outflow tachycardia

We evaluated 20 patients with idiopathic ventricular tachycardia for structural abnormalities using magnetic resonance imaging (MRI) and compared them with 20 controls. Two experienced observers interpreted the MRIs. There were no differences in incidence of qualitative MRI findings in patients compared with controls. These findings do not favor an association between anatomic abnormalities and arrhythmia in these patients.     

Magnetic resonance imaging does not always confirm left ventricular noncompaction

Left ventricular hypertrabeculation/noncompaction (LVHT) is diagnosed echocardiographically or by other imaging techniques, like cardiac magnetic resonance imaging (CMRI). LVHT was diagnosed echocardiographically in a 48-year-old woman with peripheric embolism and a neuromuscular disorder of unknown etiology. The spongiform trabecular meshwork was located in the ventricular lateral and posterior wall. CMRI failed to visualize LVHT and showed only a homogenously thickened structure. The reason for overlooking LVHT on cardiac magnetic resonance imaging might be poor image quality due to movement and respiration artefacts, the fine meshwork, exceeding the resolution capacity of the technique, and the atypical location of LVHT. CMRI does not confirm LVHT in every case on each occasion. This is most likely due to limitations in image resolution of the technique and movement artefacts of the myocardium.     

Magnetic resonance imaging in the assessment of ventricular remodeling and viability

Cardiovascular MRI has effectively become a reference standard for quantifying ventricular volumes and function and for measuring the myocardial scar burden after myocardial infarction. Imaging of late gadolinium enhancement and microvascular obstruction carries strong prognostic information for identifying patients who would benefit from anti-remodeling therapy. The combination of gadolinium enhancement, perfusion, and cine imaging should make MRI the modality of choice in the assessment of left ventricular dysfunction and remodeling. The use of MRI in clinical trials of heart failure could help reduce sample size requirements because of its accuracy and reproducibility. This review describes the use of MRI in assessing ventricular remodeling and viability and summarizes the few studies that have relied on MRI for image-based markers of ventricular remodeling.     

评价致心律失常性右室心肌病右室功能超声指标与磁共振的相关性

目的用目前公认的5个超声指标评价致心律失常性右室心肌病（ARVC）患者的右室功能,研究其与磁共振（MRI）结果的相关性。方法对11例ARVC患者行超声及MRI检查,测量右室功能指标并行相关分析。本研究除了运用传统的心尖四腔心法测量右室面积改变分数（RVFAC 4C）外,增加了胸骨旁右室三腔心切面法测量右室面积改变分数（RVFAC RV 3C）。结果 5个指标中胸骨旁短轴RVFAC RV 3C、三尖瓣环收缩峰值速度、三尖瓣环收缩位移与MRI结果相关,r值分别为0.72、0.65、0.67。结论胸骨旁短轴RVFAC RV3C是评价ARVC患者右室功能的重要指标并且其与MRI测量的结果具有高度的相关性。     

Magnetic resonance imaging in hypertrophied left ventricular myocardium due to amyloidosis

The certain diagnosis of cardiac amyloidosis is only possible with myocardial biopsy, even if echocardiographic studies often show a typical sparkling pattern. Using magnetic resonance imaging (MRI) we examined if there is a specific morphological pattern in patients with amyloidosis compared with patients with hypertrophic cardiomyopathy (LVH). With a 1.0 T magnetom and FISP 2D sequences two patients with biopsy-proven cardiac amyloidosis (AL), two patients with generalized AL and suspected cardiac AL, and five patients with LVH were examined and data were compared with echocardiography. In two cases with cardiac AL, contrast medium (Gd-DTPA) was given and dynamic-turbo-flash-sequences were obtained. In patients with AL, both ventricles were hypertrophied, whereas in the cases of hypertrophy due to other reasons only the left ventricle was hypertrophied. The systolic wall thickening was in all cases of amyloidosis below 30%. In contrast to echocardiography, a myocardial sparkling pattern in amyloidosis was not found with MRI. Even with additional contrast examination we could not differentiate the types of hypertrophy by imaging solely the left ventricular wall. There is no specific myocardial pattern in cardiac amyloidosis neither in standard MRI nor after examination with additional contrast medium, but concomitant right ventricular (RV) and left ventricular (LV) hypertrophy is a typical observation in these patients.Presented at the 37th Annual World Congress, International College of Angiology, Cologne, Germany, June 1996.