Paracardiac Mass Research Articles

"Black blood" T2-weighted inversion-recovery MR imaging of the heart.

To develop a short-inversion-time inversion-recovery (STIR) magnetic resonance imaging pulse sequence for evaluating the myocardium that is relatively free of flow and motion artifact. The authors implemented a breath-hold, cardiac-triggered STIR sequence with preparatory radio-frequency pulses to eliminate signal from flowing blood. A segmented rapid acquisition with relaxation enhancement (turbo spin echo) readout was used, with the inversion-recovery delay adjusted to null fat. The sequence was implemented at 1.0 and 1.5 T and tested in phantoms, five healthy volunteers, and three patients. Phantom studies confirmed the expected behavior of the sequence. In the volunteers, fat-suppressed images of the heart with STIR contrast were generated in a breath-hold period. Blood in the heart chambers was uniformly nulled, and motion artifacts were effectively suppressed. Focal high signal intensity consistent with edema was seen in two patients with acute myocardial infarction; in a third patient, a paracardiac mass was visualized and sharply demarcated relative to normal myocardium. Fast STIR imaging of the heart with effective suppression of flow and motion artifacts was implemented. The approach has much potential for high-contrast imaging in a variety of diseases affecting the heart and mediastinum.

Usefulness of Echocardiography in the Evaluation of Paracardiac Masses

Usefulness of Echocardiography in the Evaluation of Paracardiac Masses

MR Evaluation of the Pericardium

The pericardium is well visualized on magnetic resonance imaging (MRI) because of the superb contrast resolution and multiplanar capability of the technique. This article highlights some of the clinical uses of MRI in evaluating the pericardium and provides comparison with echocardiography and computed tomography (CT) scan. Specific pericardial diseases that are described include pericardial effusion, constrictive pericarditis, neoplastic pericardial disease, congenital abnormalities of the pericardium, and paracardiac masses. The value of MRI in differentiating constrictive pericarditis from restrictive cardiomyopathy is emphasized. The article discusses the impact of newer MRI techniques such as cine MRI on the assessment of pericardial disease.

Imaging of the heart by MRI and PET.

This review article describes the clinical usefulness and future potential of two new methods for the imaging of the heart, which have recently also become available outside research laboratories. These methods are magnetic resonance imaging (MRI) and positron emission tomography (PET). MRI is the most rapidly increasing imaging modality in medicine today. The moving heart forms a challenge to conventionally rather slow MRI-techniques. Techniques based on ECG-gating have been mandatory in making cardiac cine-MRI possible. Even though MRI provides accurate and quantitative information of the heart, conventional methods are time-consuming, confined to special laboratories, and rather expensive. Therefore, the clinical use of cardiac MRI is, in many laboratories, limited to cases in which echocardiography does not provide adequate information (e.g. pulmonary circulation) or when the patient is not willing to have transoesophageal echocardiography for better visibility. MRI is also used instead of or to complement invasive angiography to study large vessels, and it provides excellent information on paracardiac masses. Cardiac MRI is developing rapidly and within the next few years it is likely to have a profound impact on cardiac imaging. This is based on its noninvasive nature and on the comprehensive anatomic (including coronary arteries), functional, flow, perfusion and possibly also metabolic information it has the potential to provide in a manner not comparable to any other imaging method. PET is a nuclear medicine imaging modality that allows quantitative characterization of a variety of physiological and metabolic processes in vivo. Using positron-emitting flow tracers and analogues of metabolic substrates, regional myocardial blood flow, glucose and fatty acid metabolism and oxygen consumption can be studied noninvasively by PET in research as well as in clinical practice. For example, regional myocardial glucose utilization rates can be measured accurately by PET. This allows us to study the effects of nutritional interventions, hormonal and neural effects as well as disease processes on the glucose utilization of the human heart. PET is currently the only technique that permits noninvasive quantification of regional myocardial perfusion in absolute terms. Over the last decade, PET has also emerged as a clinically useful tool to study coronary artery disease and myocardial viability.

Massive thymic hyperplasia: Characterization of a rare mediastinal mass

Thymic hyperplasia is a rare cause of an anterior mediastinal mass in children. True thymic hyperplasia is characterized by massive thymic hypertrophy with retention of normal thymic architecture, and must be distinguished from more commonly seen tumors of the anterior mediastinum. Previous reports of thymic hyperplasia primarily have been descriptive, with minimal analysis of the cellular characteristics of the tumor. To better describe the cellular characteristics of thymic hyperplasia, the authors report on a 10-year-old boy found to have an asymptomatic left paracardiac mass during cardiac evaluation. The mass enlarged rapidly during the following 2 weeks and filled the entire left side of the chest. An open biopsy specimen showed normal thymic architecture. Because of the size and rapid growth of the mass, the authors decided to resect it. Cellular analysis of the mass did not show differences from normal thymic elements. There was conserved thymic architecture. The expression of cell surface markers and the proliferative response of thymocytes to cytokines appeared to be normal. Similarly, a long-term cell culture of the thymocytes did not result in clonal proliferation. Immunohistologic staining of stromal cells showed no striking differences from normal thymic elements. Moreover, immunologic analysis of the patient by standard hematological parameters, lymphocyte subsets, quantitative immunoglobins, and immunoelectrophoresis showed no abnormalities except for lymphocytosis, which resolved after tumor resection. The authors conclude that thymic hyperplasia occurs in immunologically normal children and may exhibit (1) rapid growth with minimal associated symptoms, (2) normal thymic architecture, (3) normal thymocyte and stromal growth characteristics in vitro, and (4) a normal thymocyte response to cytokine stimulation. These data confirm, at a cellular level, the clinical impression that thymic hyperplasia represents benign hypertrophy of the thymus rather than a thymic neoplasm.

Aortocoronary saphenous vein graft aneurysm

An aortocoronary saphenous vein graft aneurysm was diagnosed with computed tomography and selective arteriography in a 79-year-old woman with a history of multiple coronary bypass graft surgeries. Aneurysms of saphenous vein grafts are rare complications of bypass surgery but need to be considered when evaluating bypass patients who present with a mediastinal or paracardiac mass.

Coronary artery aneurysm masquerading as a paracardiac mass on transesophageal echocardiography

Coronary artery aneurysm masquerading as a paracardiac mass on transesophageal echocardiography

Magnetic resonance imaging and spectroscopy of the human heart.

Magnetic resonance imaging and spectroscopy have a great potential both for clinical cardiac diagnostics and for research in cardiac physiology, metabolism and disease. At the present time, cardiac MRI already is the method of choice in several clinical conditions, especially in imaging central vasculature and intra- and paracardiac masses. With the recent development of contrast agents and ability to measure both flow velocities and flow volume, the cardiac MRI is likely to have a profound role in evaluating coronary arterial disease as well as valvular heart disease. The limitations due to long imaging times of cardiac MRI-studies are likely to be overcome with the development of ultrafast imaging techniques in the near future. On the other hand, cardiac MRS is still a research tool, which needs technical improvements before it can be widely utilized in clinical work. However, attempts to this aim are highly justified, when the possibility that MRS will provide metabolic information of the heart is considered and bearing in mind, that MR-magnets with sufficient field strength for MRS are increasingly in use in most modern hospitals. The role of magnetic resonance imaging (MRI) and spectroscopy (MRS) in the evaluation of heart diseases is still evolving. Some clear indications for clinical use of cardiac MRI have already become apparent, whereas cardiac MRS is still confined to research applications. The current paper consists of a review of the role of MRI for cardiovascular diagnosis together with a review of the currents status of cardiac MRS.

Left paracardiac mass caused by dilated pericardiacophrenic vein: report of four cases.

The pericardiacophrenic vein is a possible route of collateral circulation when either the superior or the inferior vena cava is obstructed. When the vein is dilated, it can cause an abnormal appearance on chest radiographs. We describe four such patients. We studied four patients who had abnormalities on conventional chest radiographs due to a grossly dilated pericardiacophrenic vein, confirmed by means of venacavography, CT, or MR imaging. We analyzed the cause of the dilatation and the radiologic findings associated with the dilated pericardiacophrenic vein. The cause of the dilated pericardiacophrenic vein was the membranous obstruction of the inferior vena cava in all four patients. Chest radiographs revealed an undulating vascular shadow (in two cases) or a shadow of several masses (in one case) along the left border of the heart or a poorly defined haziness mimicking a pulmonary parenchymal infiltrate (in one case). A direct communication between the left hepatic vein and the left inferior phrenic vein was seen near their insertion into the inferior vena cava in three cases. Hepatic venous outflow and some of the systemic venous return were directed to this left inferior phrenic-pericardiacophrenic route. When obstruction of the inferior vena cava is clinically suspected and the chest radiograph shows abnormalities at the left paracardiac area, a dilated pericardiacophrenic vein due to obstruction in the suprahepatic portion of the inferior vena cava, most likely a membrane, should be considered in the differential diagnosis.

Right Coronary Artery-Right Atrium Fistula in Primary Angiosarcoma of the Heart

We report a case of angiosarcoma of the heart, manifested as a continuous murmur. Right coronary arteriography disclosed a paracardiac mass with fistulas from the coronary vessel to the right atrium. Histologic study revealed this to be an angiosarcoma with sinusoidal pattern. To our knowledge, this is the first case of this kind of cardiac tumor presenting as a fistula from a coronary artery to the right atrium.

Cardiac masses: signal intensity features on spin-echo, gradient-echo, gadolinium-enhanced spin-echo, and TurboFLASH images.

Fifteen patients with cardiac or paracardiac masses underwent magnetic resonance (MR) imaging with spin-echo (n = 15), cine gradient-echo (n = 15), gadopentetate dimeglumine-enhanced spin-echo (n = 15), and TurboFLASH (fast low-angle shot) (n = 7) sequences. All masses had either histologic confirmation (n = 11) or confirmation with other imaging modalities (n = 4). Myxomas (n = 6) were characterized by an intermediate signal intensity (SI) on spin-echo (n = 6) and low SI on cine gradient-echo (n = 6) images and moderately high-SI contrast enhancement (n = 5). Percent contrast enhancement for myxomas was 57% +/- 11%. Thrombus (n = 4) had intermediate (n = 3) or high (n = 1) SI on spin-echo images and low (n = 2) or intermediate (n = 2) SI on gradient-echo images and did not show substantial contrast enhancement. Postcontrast first-pass TurboFLASH images were useful by clearly demonstrating the nonenhancing mass lesion in a high-SI blood pool. Other cardiac and paracardiac tumors (n = 5) showed variable pre- and postcontrast spin-echo SI; however, no other tumor showed low SI on cine gradient-echo images.

Magnetic resonance imaging of suspected atrial tumors

Two-dimensional echocardiography has become the standard technique for evaluation of cardiac and paracardiac mass lesions. We have used magnetic resonance imaging (MRI) as an independent assessment of cardiac-associated masses in patients with echocardiograms demonstrating sessile atrial tumors. MRI was performed in seven patients, ages 33 to 84, whose echocardiographic diagnoses included left atrial mass (five), right atrial mass (one), and interatrial mass (one). In four of the patients with a diagnosis of left atrial mass, MRI showed extracardiac compression of the atrium, simulating a tumor (hiatal hernia, tortuous descending aorta, bronchogenic cyst). MRI was entirely normal in one patient with an apparent left atrial mass. MRI elucidated extension of an extracavitary mass into the interatrial septum in two patients. One of these patients with an echocardiographic right atrial mass had extension of a lipoma into the interatrial septum without atrial tumor. MRI confirmed the echocardiographic diagnosis of an interatrial mass in the other patient. We conclude that MRI, because of its ability to define anatomic relationships and tissue characteristics, is a powerful noninvasive tool for evaluating suspected cardiac mass lesions. Although echocardiography remains the primary screening test for the detection of cardiac masses, MRI is a more specific modality for precise diagnosis. Correct MRI interpretation may obviate the need for invasive studies or surgery.

Delayed Presentation of Pericardial Pseudocyst Following Blunt Chest Trauma

An unusual presentation of blunt chest trauma is reported. A 21-year-old man presented with symptoms and signs of congestive cardiac failure. 2D echocardiogram showed a thickened pericardium with a mass compressing the right ventricle. CT scan revealed a large mass anterior and to the right of the heart with evidence of pericardial thickening and calcification. However, its delineation from the pericardium and its exact tissue characterization were not possible. Cardiac catheterization showed elevation and equalization of diastolic pressures in all cardiac chambers with characteristic waveforms suggestive of pericardial constriction. The precise definition and characterization of the mass was obtained only on Magnetic Resonance Imaging (MRI) of the chest which showed it to be a solid, well encapsulated, partially calcified mass between the heart and the diaphragm extending anteriorly and to the right of the right ventricle. These findings were confirmed at the time of thoracotomy. Histopathology revealed blood clots and hyalinised fibrous tissue without any evidence of granuloma or malignancy. This report highlights an insiduous, late presentation of blunt chest trauma. It also demonstrates the superiority of MRI over computed X-ray tomography for mediastinal paracardiac masses.

Overview of Cardiovascular Nuclear Magnetic Resonance Imaging

Application of NMR technology to the evaluation of the cardiovascular system is still in its infancy. NMR can frequently yield information equivalent to echocardiography or angiography but cost, long imaging times, and lack of portability have discouraged widespread use. To date, NMR has not replaced standard imaging modalities in the evaluation of most cardiovascular disease states, although it appears to have a unique role in the delineation of great vessel pathology, the evaluation of congenital heart disease, and the delineation of cardiac and paracardiac masses. Appearance of tissue and flowing blood and contrast between structures are highly dependent on magnetic field strength and the imaging pulse sequence used. Published comparisons between NMR and other imaging modalities have to be interpreted and extrapolated with caution, and sensitivity and specificity of NMR imaging in different disease entities should be further validated. With technological improvements, shortening of examination times and data processing times and true three-dimensional imaging may be possible in the near future. Ultimately, however, the clinical importance of NMR will depend on the development of unique applications such as examination of regional cardiac metabolism, noninvasive coronary and peripheral angiography, myocardial perfusion imaging, and improved tissue characterization.

Magnetic resonance imaging of cardiac and paracardiac masses

Magnetic resonance imaging (MRI) with ECG-gated acquisition displays the blood pool as a signal void and thereby provides high contrast differentiation between cardiovascular structures and soft-tissue masses. The role of MRI for the detection and definition of the extent of paracardiac and intracardiac masses is reviewed. The extension of mediastinal, lung, and upper abdominal tumors to the heart and pericardium is depicted favorably by MRI and this attribute is also demonstrated. It is anticipated that MRI will have an increasing role in the evaluation of primary and secondary masses of the heart and pericardium.

Cardiac masses: assessment by MR imaging.

The purpose of this study was to assess the role of MR imaging for evaluating suspected cardiac tumors or paracardiac masses involving the heart. Sixty-one patients with clinical or radiologic evidence of cardiac masses were imaged with ECG-gated MR at 1.5 T (22 patients) or 0.15 T (39 patients). Fifty-one patients had echocardiography previously. Among the tissue diagnoses were myxoma (six); fibroma, rhabdomyoma, plasma cell granuloma, lipomatous hypertrophy of the atrial septum, mesothelioma, and thymoma (two each); and leiomyosarcoma, lymphoma, metastatic carcinoid, melanoma, malignant fibrous histiocytoma, hemangiopericytoma, and lung spindle cell sarcoma (one each). MR imaging demonstrated masses in 50 patients (82%); they were centered in the heart in 32, pericardial in nine, and juxtacardiac in nine. MR imaging provided diagnostic information that affected clinical management or surgical planning in 53 patients (87%), including 11 (18%) in whom cardiac mass was excluded by MR. The ability to provide a global view of cardiac anatomy and other unique capabilities of MR imaging give the procedure an important role in the diagnosis and preoperative assessment of cardiac masses.

Transesophageal Echocardiography: Technique, Anatomic Correlations, Implementation, and Clinical Applications

The introduction of transesophageal echocardiography has provided a new acoustic window to the heart and mediastinum. High-quality images of certain cardiovascular structures [left atrial appendage, thoracic aorta, mitral valvular apparatus, and atrial septum] can be obtained readily (average examination, 15 to 20 minutes). In this article, we discuss the technique of image acquisition, image orientation, and anatomic validation. In addition, we describe our experience with the first 100 awake patients who underwent transesophageal echocardiography at our institution. The procedure was well accepted by the patients and associated with no major complications. The clinical indications for this procedure have included thoracic aortic dissection, prosthetic cardiac valve dysfunction, detection of an intracardiac source of embolism, endocarditis, cardiac and paracardiac masses, and mitral regurgitation. Transesophageal echocardiography also proved to be useful in assessment of critically ill patients in whom standard transthoracic echocardiographic images did not provide complete assessment. In these patients (who had extensive chest trauma, had undergone an operation, or were in an intensive-care unit), rapid assessment of the cardiovascular status at the bedside was possible with transesophageal echocardiography. On the basis of our initial experience, we conclude that transesophageal echocardiography complements standard two-dimensional Doppler and color flow examinations and will considerably improve the care of patients with cardiovascular disorders by providing high-quality unique images.

Systolic antegrade tricuspid blood flow—a sign of severe prosthetic valve stenosis

Cardiac compression is a potentially life-threatening complication of heart surgery. This syndrome often has atypical manifestations, challenging our ability to make a rapid diagnosis and to institute emergent, life-saving treatment. We recently evaluated one such patient who showed cardiac compression caused by an unusual paracardiac mass. The addition of transesophageal echocardiography to the usual transthoracic study may have played more than just a diagnostic role in this case. (J Am Soc Echocardiogr 1998;11:494-6.)

Paracardiac adenopathy: CT evaluation.

To establish the normal CT appearance of lymph nodes in the paracardiac area, we reviewed the CT scans of 50 patients without known malignancy or benign causes of lymphadenopathy. Five patients (10%) showed soft-tissue densities in the paracardiac region. The largest of these measured 3.5 mm. No more than two rounded soft-tissue densities were seen in any of the normal CT studies. Forty-five patients with paracardiac adenopathy were subsequently evaluated. In 27 (60%) of these the masses were due to either carcinoma, sarcoma, or benign disease. In 40%, the cause of paracardiac adenopathy was lymphoma. Features that favor a diagnosis of lymphoma are bilateral disease, multiple nodes, nodes greater than 2 cm in diameter, a lobulated or "matted" appearance, and associated pericardial thickening/effusion. Chest radiographs obtained within 2 weeks of the CT scans in 38 patients revealed only nine cases in which a paracardiac mass could be seen. This study suggests that 1 cm is the upper limit for the diameter of lymph nodes in the paracardiac region, and that paracardiac adenopathy may be caused by a wide variety of nonlymphomatous malignant and benign diseases in addition to lymphoma. Compared with CT, chest radiographs are insensitive for detecting paracardiac lymph node enlargement.

MRI of the abnormal pericardium.

To evaluate the use of MRI in the diagnosis of pericardial disease, 63 patients with pericardial abnormalities or clinically suspected pericardial disease were studied retrospectively. Twenty-three patients had pericardial effusion, 19 patients had pericardial thickening, and 11 patients were referred for evaluation of masses with possible pericardial involvement. The other 10 patients were referred for differentiation of constrictive pericarditis from restrictive cardiomyopathy and eventually were found to have pericardial hematoma or normal pericardium as assessed by MRI. The calculated size of pericardial effusion by MRI showed a good correlation with semiquantitative echocardiographic estimations. MRI could demonstrate fibrinous adhesions in patients with uremic pericarditis. It was also of great value in the differential diagnosis of constrictive pericarditis vs restrictive cardiomyopathy. Pericardial thickness of more than 4 mm was found in patients with constrictive pericarditis. Normal pericardial thickness was demonstrated by MRI in the three patients with restrictive cardiomyopathy. MRI diagnosed hemopericardium correctly as the cause of constrictive symptoms in two patients. Pericardial thickening in patients after cardiac surgery was commonly found by MRI and usually was not associated with clinical signs of constrictive pericarditis. MRI proved to be useful in the diagnosis of pericardial cysts and in the evaluation of paracardiac masses with possible pericardial involvement. MRI is an important technique in the evaluation of the pericardium. It can provide important additional information when diagnosis cannot be made adequately by other noninvasive imaging techniques.