Magnetic Resonance Imaging in Chronic Chagas' Disease

Background: We studied the correlation among cardiac magnetic resonance imaging (MRI), gallium-67 myocardial uptake, and right ventricular endomyocardial biopsy results in chronic Chagas' disease. To our knowledge, this represents the first attempt to correlate the histological findings with cardiac MRI and gallium-67 myocardial uptake for noninvasive diagnosis of inflammatory activity associated with Chagas' disease. Methods: Ten male patients with cardiomyopathy secondary to Chagas' disease were studied (mean age, 47.7 ± 7 years; congestive heart failure New York Heart Association [NYHA] functional class II [two patients], III [six patients], and IV [two patients]; and mean echocardiographic left ventricular [LV] ejection fraction [EF], 36 ± 6%). The patients underwent right ventricular endomyocardial biopsy, cardiac MRI, and gallium-67 myocardial uptake testing. The results of this group were compared with those of a control group of patients with idiopathic dilated cardiomyopathy who were matched in age (mean age, 46 ± 10 years), LV function (mean echocardiographic EF, 30 ± 4%), and NYHA classification (one patient in class II, five patients in class III, and one patient in class IV). Results: All patients with Chagas' disease showed higher signal intensity on MRI after the administration of gadolinium. The intensity of the septal signal changed from 0.90 ± 0.11 to 1.56 ± 0.19 (P < 0.001). In the control group, there was no difference in signal intensity with gadolinium (mean septal intensity, 0.94 ± 0.12 before and 0.99 ± 0.15 after; NS). On biopsy, eight chagasic patients had evident signs of myocarditis, and two patients had borderline evidence myocarditis. However, only one patient in the control group had a histological diagnosis of borderline myocarditis. Gallium-67 cardiac uptake was positive for myocardial inflammatory process in seven chagasic patients and borderline in one. On the other hand, only one patient in the control group had an uptake that was positive for inflammation, and one had a borderline result. Conclusions: In conclusion, the data from this study strongly suggest that myocarditis is frequently found in Chagas' disease. Cardiac MRI appears to be an accurate and alternative method for the diagnosis of inflammatory process associated with Chagas' disease.     

Cerebral Magnetic Resonance Imaging in Patients with Chronic Liver Disease

Bilateral, symmetrical hyperintensity of the globus pallidus is observed in T₁-weighted cerebral magnetic resonance images in from 52 to 100% of patients with chronic liver disease. No significant relationship exists between the presence of these cerebral changes in image signal intensity and the patients' neuropsychiatric status. However, their presence significantly relates to both the severity of the liver disease and the presence and degree of portal-systemic shunting of blood. This shortening of the T₁-relaxation time is associated with pallidal deposition of manganese most likely reflecting the presence of an adaptive process designed to improve the efficacy of ammonia detoxification by astrocytes. Future studies employing magnetic resonance imaging techniques to obtain information on cerebral function or combined with magnetic resonance spectroscopy to obtain localized biochemical information might further our understanding of the pathogenesis of hepatic encephalopathy in cirrhotic patients.     

Hemitruncus Arteriosus: Cardiac Magnetic Resonance Angiography Findings

Hemitruncus arteriosus (HA) is an uncommon congenital cardiac malformation in which one pulmonary artery branch originates from the ascending aorta. A 2‐month‐old male was referred to our hospital for failure to thrive, cyanosis, and tachypnea. A chest radiograph demonstrated moderate cardiomegaly and peribronchial thickening. Echocardiography demonstrated right atrial and ventricular enlargement and increased gradient (25 mm Hg) in the right pulmonary artery. Cardiac magnetic resonance angiography was performed and clearly revealed typical imaging findings of a right HA which had complex cardiac and vascular anatomy. This case report presents cardiac magnetic resonance angiography findings of HA.     

Defining Myocardial Abnormalities Across the Stages of Chronic Kidney Disease: A Cardiac Magnetic Resonance Imaging Study

ObjectivesA proof of concept cross-sectional study investigating changes in myocardial abnormalities across stages of chronic kidney disease (CKD). Characterizing noninvasive markers of myocardial fibrosis on cardiac magnetic resonance, echocardiography, and correlating with biomarkers of fibrosis, myocardial injury, and functional correlates including exercise tolerance.BackgroundCKD is associated with an increased risk of cardiovascular death. Much of the excess mortality is attributed to uremic cardiomyopathy, defined by increased left ventricular hypertrophy, myocardial dysfunction, and fibrosis. The prevalence of these abnormalities across stages of CKD and their impact on cardiovascular performance is unknown.MethodsA total of 134 nondiabetic, pre-dialysis subjects with CKD stages 2 to 5 without myocardial ischemia underwent cardiac magnetic resonance (1.5-T) including; T₁ mapping (biomarker of diffuse fibrosis), T₂ mapping (edema), late gadolinium enhancement, and assessment of aortic distensibility. Serum biomarkers including collagen turnover (P1NP, P3NP), troponin T, and N-terminal pro–B-type natriuretic peptide were measured. Cardiovascular performance was quantified by bicycle cardiopulmonary exercise testing and echocardiography.ResultsNative myocardial T₁ times increased incrementally from stage 2 to 5 (966 ± 21 ms vs. 994 ± 33 ms; p < 0.001), independent of hypertension and aortic distensibility. Left atrial volume, E/eʹ, N-terminal pro–B-type natriuretic peptide, P1NP, and P3NP increased with CKD stage (p < 0.05), while effort tolerance (% predicted VO₂Peak, %VO₂VT) decreased (p < 0.001). In multivariable linear regression models, estimated glomerular filtration rate was the strongest predictor of native myocardial T₁ time (p < 0.001). Native myocardial T₁ time, left atrial dilatation, and high-sensitivity troponin T were independent predictors of % predicted VO₂Peak (p < 0.001).ConclusionsImaging and serum biomarkers of myocardial fibrosis increase with advancing CKD independent of effects of left ventricular afterload and might be a key intermediary in the development of uremic cardiomyopathy. Further studies are needed to determine whether these changes lead to the increased rates of heart failure and death in CKD. (Left Ventricular Fibrosis in Chronic Kidney Disease [FibroCKD]; NCT03176862)     

心脏核磁共振成像与心内电生理

透视介导的心脏内电生理术一个主要缺点为术中无法正确识别软组织及其与比邻结构关系,然而,心脏核磁共振成像介导的心内电生理术却弥补了这一缺陷.心脏核磁共振成像-心内电生理术不仅可精确地展示出心脏的三维空间形态结构,而且能直接识别心律失常病灶及观察射频消融的疗效,提高复杂心律失常手术成功率及减少并发症有重要作用.因而,心脏核磁共振成像被认为在心内电生理领域具有广泛运用前景.     

Immune Checkpoint Inhibitor Myocarditis With Normal Cardiac Magnetic Resonance Imaging: Importance of Cardiac Biopsy and Early Diagnosis

Immune checkpoint inhibitors (ICIs) have improved the management and the prognosis of patients with cancer but are associated with an increased risk of toxicities that can affect every organ. ICI-associated myocarditis has a low incidence (< 1%) but a high fatality rate (30%-50%). Herein we report a patient treated with ICI admitted for suspicion of myocarditis. Cardiac magnetic resonance imaging (cMRI) was normal. An endomyocardial biopsy (EMB) was in favour of ICI-related myocarditis with cardiac lymphohistiocytic infiltrate. This case highlights the role of a systematic evaluation with electrocardiography and troponin and the potential value of EMB in patients without a suggestive cMRI.     

Classic Images in Cardiac Magnetic Resonance Imaging: A Case-based Atlas Highlighting Current Applications of Cardiac Magnetic Resonance Imaging

There have been tremendous technological advances in noninvasive cardiovascular imaging, offering the clinician unparalleled information from a variety of modalities. Cardiovascular magnetic resonance imaging (MRI) has the advantages of superior spatial resolution, detailed tissue characterization, and accurate quantitative assessment of cardiac structure and function, without the need for radiation exposure. Recent advances in image acquisition and postimage processing have led to clinically validated protocols for myocardial perfusion, late gadolinium enhancement, and coronary angiography. The following collection of images was selected to demonstrate the typical appearance of various cardiovascular conditions using MRI. There is, of course, much heterogeneity in both the phenotypic severity of a given condition as well as its appearance on MRI. This article, while not intended to be a comprehensive collection, aims to serve as an introduction to the current applications of cardiac MRI.     

Evaluation of Adult Congenital Heart Disease by Cardiac Magnetic Resonance Imaging

Cardiovascular magnetic resonance (CMR) imaging plays an essential role in the evaluation and follow‐up of adult congenital heart disease (ACHD), providing safe, high‐resolution imaging of some of the most complex anatomies encountered. Unlimited by acoustic windows and capable of tissue characterization, CMR is devoid of ionizing radiation and provides superior three‐dimensional spatial resolution to transthoracic echocardiography and superior temporal resolution to computed tomography, making it the gold standard for various cardiac and great vessel imaging indications in ACHD. In this state‐of‐the art review, we provide an overview of CMR examination methods and detail the various approaches and classical findings in the more common forms of ACHD. Although this review touches upon technical aspects of CMR imaging in ACHD, it is primarily geared toward the adult congenital caregiver (i.e., clinical, interventional, or surgical), highlighting relevant practical considerations. To enhance the clinical utility of this review, numerous examples with intraoperative correlates are provided to highlight our imaging approaches for various defects. As CMR image acquisition may be time consuming and requires patient collaboration (e.g., intermittent breath holding), a systemic approach is required to maximize efficiency. A thorough knowledge of ACHD anatomy and natural history is essential in maximizing image interpretation. Proficient scanning is further enabled by clearly outlined study objectives with prior documentation of interventional and surgical procedures, where applicable.     

Cardiac Magnetic Resonance Imaging in Peripartum Cardiomyopathy

BackgroundPeripartum cardiomyopathy (PPCM) is a rare life-threatening condition of unclear etiology. Data on the use of cardiac magnetic resonance (CMR) imaging to characterize PPCM are limited. This study was done to assess the role of CMR imaging for the diagnosis and prognostication of patients with PPCM.MethodsMedical records of a tertiary medical center were screened for PPCM patients with CMR imaging done within the past 5 years (2006-2011). Images were reviewed by 2 expert radiologists (blinded to clinical data) using cine sequences for chamber function and size, T2-weighted images for the determination of edema (T2-ratio), and late gadolinium enhancement (LGE) sequences for myocardial tissue characterization.ResultsTen PPCM patients (aged 28 ± 6 years, 90% African American) had a total of 15 CMR examinations: 4 in the acute phase (within 7 days of diagnosis) and 11 during follow-up (median, 12 months; range, 1-72 months). Left ventricular ejection fraction was decreased in all 4 initial scans. Elevated T2 ratio (> 2) seen in 1 patient decreased on follow-up imaging. LGE was seen in 1 of the 4 acute-phase scans and in 4 of the 11 follow-up phase scans. These 4 patients had multiple readmissions because of heart failure exacerbations and persistently low left ventricular ejection fraction on subsequent echo- cardiograms.ConclusionsLGE seems to be associated with a poor prognosis in the setting of PPCM. CMR imaging seems to have promising practical implications in the diagnosis and prognostication of PPCM patients.     

核磁共振成像与心脏起搏器的研究进展

核磁共振成像（MRI）环境可严重影响起搏器功能,从而植入心脏起搏器患者接受MRI检查成为禁忌.为了解决MRI对心脏起搏器产生的危害,MRI兼容性起搏器应运而生 现对MRI与心脏起搏器相互作用、心脏起搏器的改进及MRI兼容性起搏器的类型等方面作一阐述.     

Dermatofibrosarcoma Protuberans: Computed Tomography and Magnetic Resonance Imaging Findings

The aim of this study was to analyze the computed tomography (CT) and magnetic resonance imaging (MRI) findings of dermatofibrosarcoma protuberans (DFSP), with a view to improving the diagnosis of this kind of tumor.A total of 27 cases of histopathologically confirmed DFSP were analyzed retrospectively. Of these, 18 patients underwent a CT scan and 9 patients underwent an MRI. All patients underwent unenhanced and contrast-enhanced examinations; 1 patient underwent multiphrase CT enhancement examination. Imaging characteristics, including location, shape, size, number, edge, and attenuation or intensity of each lesion, both unenhanced and contrast enhanced, were analyzed.Of the 27 cases, 24 were solitary, 2 had 2 nodules, and 1 had multiple confluent tumors. The lesion with multiple confluent tumors was ill defined and irregular; the other lesions were oval or round, well-defined nodules or masses. The unenhanced CT images showed 19 homogenous isodense lesions. There was no calcification in any of the patients. The contrast-enhanced CT images showed intermediate and marked nonhomogeneous enhancement in 13 lesions, intermediate homogeneous enhancement in 4 lesions, and a mild heterogeneous enhancement in 2 lesions. MR T1-weighted images revealed 1 ill-defined and 9 well-defined homogeneous isointense lesions. T2-weighted images showed homogeneous hyperintensity to the muscles in 6 lesions, 3 mild hyperintense lesions with hypointense lesions, and 1 mixed, mild hyperintense and isointense lesion. Contrast-enhanced T1-weighted images demonstrated intermediate and marked nonhomogeneous enhancement in 9 lesions and intermediate homogeneous enhancement in 1 lesion.DFSP is characterized by a subcutaneous well-defined soft tissue nodule or mass on plain CT/MR scans, and shows intermediate-to-marked enhancement on contrast-enhanced CT/MR scans. The imaging findings for DFSP are nonspecific, but may help to define the diagnosis in an appropriate clinical setting.Dermatofibrosarcoma protuberans (DFSP) is a rare low-grade malignant cutaneous tumor. It was first reported by Darier and Ferrand and called “progressive and recurrent skin fibroma” in 1924.¹ In 1925, Hoffman named it as DFSP.² DFSP often occurs in the dermis and subcutaneous layers. Typical DFSP shows superficial skin nodules or masses, and often protrudes from the skin surface. DFSP is often misdiagnosed, especially for larger tumors with deep tissue invasion and atypical manifestations, which often results in improper treatment leading to vulnerability to relapse. DFSP is often superficial; therefore, there are few reports focusing on imaging findings of DFSP.^3–12 Herein, we provide a retrospective review of the imaging findings of 27 cases of DFSP with the aim to improve our knowledge of DFSP.     

Course of Cardiac Magnetic Resonance Imaging Findings in Acute Myocarditis after COVID-19 mRNA Vaccination

Myocarditis is being increasingly reported as a rare complication of coronavirus disease 2019 (COVID-19) mRNA vaccines. We herein report a case of myocarditis following COVID-19 mRNA vaccination in a man. Cardiac magnetic resonance imaging (CMRI) revealed an area of high signal intensity on short T1 inversion recovery (STIR) and late gadolinium enhancement (LGE), which are characteristic of myocarditis. Follow-up CMRI performed six months later revealed improvement in the myocardial edema and LGE findings. CMRI is a useful non-invasive imaging modality for making an initial diagnosis as well as for follow-up in cases of myocarditis after COVID-19 mRNA vaccination.