Imaging of cardiac and paracardiac masses

Tissue characterization of benign cardiac tumors by cardiac magnetic resonance imaging, a review of core imaging protocol and benign cardiac tumors

Generally, cardiac masses are initially suspected on routine echocardiography. Cardiac magnetic resonance (CMR) imaging is further performed to differentiate tumors from pseudo-tumors and to characterize the cardiac masses based on their appearance on T1/T2-weighted images, detection of perfusion and demonstration of gadolinium-based contrast agent uptake on early and late gadolinium enhancement images. Further evaluation of cardiac masses by CMR is critical because unnecessary surgery can be avoided by better tissue characterization. Different cardiac tissues have different T1 and T2 relaxation times, principally owing to different internal biochemical environments surrounding the protons. In CMR, the signal intensity from a particular tissue depends on its T1 and T2 relaxation times and its proton density. CMR uses this principle to differentiate between various tissue types by weighting images based on their T1 or T2 relaxation times. Generally, tumor cells are larger, edematous, and have associated inflammatory reactions. Higher free water content of the neoplastic cells and other changes in tissue composition lead to prolonged T1/T2 relaxation times and thus an inherent contrast between tumors and normal tissue exists. Overall, these biochemical changes create an environment where different cardiac masses produce different signal intensity on their T1- weighted and T2- weighted images that help to discriminate between them. In this review article, we have provided a detailed description of the core CMR imaging protocol for evaluation of cardiac masses. We have also discussed the basic features of benign cardiac tumors as well as the role of CMR in evaluation and further tissue characterization of these tumors.

Utility of cine MRI in evaluation of cardiovascular invasion by mediastinal masses

BACKGROUND

Accurate imaging assessment of cardiovascular invasion by mediastinal masses is essential for determining surgical feasibility. This can sometimes be difficult on CT owing to limited space available in the mediastinum, resulting in mediastinal masses abutting and indenting adjacent cardiovascular structures. Cine MRI may aid in such situations by demonstrating differential mobility.

AIMS AND OBJECTIVES

To evaluate the role of cine MRI in assessing cardiovascular invasion by mediastinal masses, by evaluating sliding motion and the presence of chemical shift artifact between the mediastinal mass and apposing structures.

MATERIAL AND METHODS

Retrospective study of 44 patients with mediastinal masses, with equivocal involvement of 162 cardiovascular structures on CT scan, in whom cine MRI was done. Involvement on CT was considered equivocal when there was a loss of intervening fat plane and broad surface (>3 cm) or angle (>90°) of contact between the mediastinal mass and cardiovascular structure. The presence of either sliding movement or type 2 chemical shift artifact or both between mass and the cardiovascular structure was considered as no adherence or invasion. The absence of both the parameters was considered as the presence of invasion or adhesion. Imaging findings were correlated with intraoperative findings.

RESULTS

After excluding 25 cardiovascular structures in 7 patients, 137 cardiovascular structures whose involvement was suspected on CT were evaluated in 37 patients with mediastinal masses. In all, 31 cardiovascular structures showed invasion on MRI out of which 28 structures were invaded or adhered intraoperatively and 106 cardiovascular structures showed no invasion on MRI out of which 97 structures were intraoperatively not invaded/adhered. The sensitivity, specificity and accuracy of our study are 75.7%, 97% and 91.2%, respectively.

CONCLUSION

Cine MRI can be used as an effective tool in patients with equivocal cardiovascular invasion by mediastinal masses on CT scans.

Primary Cardiac Tumors: A Retrospective Study

Objectives:

Primary cardiac tumors are rare and account for 0.001 to 0.03% of cardiac lesions. The authors aim to describe the clinical, the microscopic and the therapeutic characteristics of these tumors through a 13-year-experience in order to highlight the diagnostic challenges faced.

Methods:

We report 10 primary cardiac tumors diagnosed in the Departments of Pathology and Thoracic Surgery of the same hospital through a 13-year-period.

Results:

Our study was conducted on 7 women and 3 men. The mean age of the patients was 54.22 years (average, 12 to 79 years). Dyspnea represented the most frequent symptom. Physical examination was normal in all patients. Trans-thoracic ultra-sound examination was performed in all patients. Cardiac MRI allowed localizing the tumors in 2 patients. They were located into the left auricle (6 cases), the right auricle (1 case) and the pericardium (3 cases). The microscopic examination was concluded to myxoma (7 cases), haemangioma (2 cases) and hemangioendothelioma (1 case). Surgical resection was possible in 9 patients. It was impossible in the case of hemangioendothelioma because of the adherence. One death was recorded secondary to postoperative arrhythmia. The other patients presented no complications after a follow-up period ranging from 2 months to 5 years.

Conclusion:

Cardiac tumors are challenging in their diagnosis and management. A positive diagnosis is based on microscopic examination. Surgical treatment plays a key role and is possible in the majority of benign tumors. The prognosis of malignant tumors remains poor even if a complete surgical resection is possible.

Cardiac masses : Experience from a Turkish tertiary center of cardiology

OBJECTIVE

Cardiac masses comprise a category that includes benign, malignant, and nontumoral mass lesions. The present study aims to share the findings relating to cardiac masses observed at our tertiary cardiology hospital in Turkey.

METHODS

The records of patients who presented with cardiac masses and underwent surgery at our institute between 2006 and 2015, and whose tissue samples were sent to a pathology laboratory, were retrospectively reviewed in a consecutive manner.

RESULTS

The study included 228 patients with an average age of 52.5 ± 17.3 years. Of the study's subjects, 95 (41.7%) were male and 133 (58.3%) female. The most commonly observed mass was myxoma in 68 patients (29.8%), of whom 20 (29.4%) were male and 48 (70.6%) female. The second most frequently detected mass was pannus, with 38 cases (16.7%) - 10 (26.3%) in males and 28 (73.7%) in females. The third most common cardiac mass was thrombus (16.2%), with 18 cases of thrombi in men (48.6%) and 19 (51.4%) in women.

CONCLUSION

The most commonly observed cardiac mass was myxoma and most were localized in the left atrium. The second most frequently detected mass was pannus, which was mostly found on mitral mechanical prosthetic valves. Thrombi were the third most prevalent mass and were commonly localized in the right atrium.

MRI assessment of cardiac tumours: part 1, multiparametric imaging protocols and spectrum of appearances of histologically benign lesions

Cardiac magnetic resonance imaging (MRI) is the reference standard technique for assessment and characterization of a suspected cardiac tumour. It provides an unrestricted field of view, high temporal resolution and non-invasive tissue characterization based on multi-parametric assessment of the chemical micro-environment. MRI exploits differences in hydrogen proton density in conjunction with T1 and T2 relaxation properties of different tissues to help differentiation normal from abnormal and benign from malignant lesions. In this article we review specific cardiac MRI techniques, tumour protocol design and the appearance of the spectrum of histologically benign tumours.

Usual and unusual neuroendocrine tumor metastases on (68)Ga-DOTANOC PET/CT: a pictorial review

Neuroendocrine tumors (NETs) are slow-growing indolent tumors that often present with metastatic disease at the outset. They commonly metastasize to lymph nodes, liver, bone, and lungs. However, metastasis to other rare sites may occur. It is important to have clear knowledge of unusual NET metastatic sites because their presence may lead to a more directed investigation. Also, it will be helpful in ruling out incidental second malignancies that might be encountered. The objective of this pictorial article was to provide an illustrative tutorial showing the clinical utility of Ga-labeled somatostatin analog [1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid]-1-NaI3-octreotide (Ga-DOTANOC) PET/CT for imaging usual and unusual metastatic sites in patients with NETs.

MR imaging of cardiac tumors and masses: a review of methods and clinical applications

Cardiac masses are usually first detected at echocardiography. In their further evaluation, cardiac magnetic resonance (MR) imaging has become a highly valuable technique. MR imaging offers incremental value owing to its larger field of view, superior tissue contrast, versatility in image planes, and unique ability to enable discrimination of different tissue characteristics, such as water and fat content, which give rise to particular signal patterns with T1- and T2-weighted techniques. With contrast material-enhanced MR imaging, additional tissue properties such as vascularity and fibrosis can be demonstrated. MR imaging can therefore contribute to the diagnosis of a cardiac mass as well as be used to detail its relationship to other cardiac and extracardiac structures. These assessments are important to plan therapy, such as surgical intervention. In addition, serial MR studies can be used to monitor tumor regression after surgery or chemotherapy. Primary cardiac tumors are very rare; metastases and pseudotumors (eg, thrombus) are much more common. This article provides an overview of cardiac masses and reviews the optimal MR imaging techniques for their assessment.

Primary Cardiac Angiosarcoma in a Young Woman

A 30-year-old woman was admitted to our hospital with severe shortness of breath. A transthoracic echocardiogram showed moderate pericardial effusion with a lesion in the right atrium, confirmed by chest CT scan and cardiac RMN. Pleural and middle lobe involvement occurred within one month. Middle lobe biopsy was performed and pathological examination confirmed the diagnosis of metastatic angiosarcoma. After two months, because of recurrent pleural effusions, chemical pleurodesis was performed. Chemotherapy was started but the patient died four months after the diagnosis. This case highlights the misdiagnosis at initial clinical presentation, available diagnostic approaches and therapeutic options for cardiac angiosarcoma.

Transthoracic echocardiography-guided biopsy of a metastatic endometrial adenocarcinoma in the right atrium: a review of diagnosis and treatment of cardiac masses

We report on a 64-year-old African-American female with a past medical history of an endometrial adenocarcinoma with metastasis to the right atrium. To our knowledge, there have been only four case reports on endometrial carcinoma metastasizing to the right atrium. In our patient, a percutaneous biopsy under fluoroscopic and transthoracic echocardiographic guidance was performed. Histopathologic evaluation of the specimens revealed an adenocarcinoma, consistent with the patient's history of endometrial carcinoma. This report provides a brief review of diagnosis and treatment of cardiac masses.

Benign cardiac tumours: cardiac CT and MRI imaging appearances

Primary benign cardiac tumours are rarely found in clinical practice and are generally evaluated with echocardiography. However, with the increasing usage of helical multislice CT, the initial detection and evaluation of these masses may be made by the radiologist during routine daily practice for other indications. The echocardiographic, CT and cardiac MRI appearances of various benign cardiac tumours and masses are described and illustrated in this review.

Isolated right ventricular intracavitary metastasis of hepatocellular carcinoma in a 74-year-old woman

A 74-year-old woman with a history of chronic hepatitis C and transcatheter arterial chemoembolization for an unresectable hepatocellular carcinoma (HCC) 2 years previously presented with progressive exertional dyspnea of 1 month's duration. Two-dimensional echocardiography revealed a huge right ventricular mass with right atrial and right ventricular outflow tract extension. Palliative resection of the tumor and adjunctive chemotherapy was performed. However, the right ventricular mass recurred 1 month later and the patient died 4 months after the operation. To our knowledge, this is the oldest patient reported with isolated right ventricular intracavitary metastasis of HCC, and this report reemphasizes the lower surgical indication in patients with metastatic cardiac tumors.

Referrals to a dedicated cardiac MRI service: who sends what?

The purpose of this study was to retrospectively evaluate the referral patterns to the authors' cardiac magnetic resonance imaging service in its first 28 months of operation. In late November 2003, the authors' radiology practice established a cardiac magnetic resonance imaging service for a 719-bed teaching hospital and a 247-bed community hospital. Data relevant to referrals were reviewed. Between December 1, 2003, and April 1, 2006, 780 patients were imaged, 556 (71%) at the teaching hospital. Referrals came from 157 physicians in 17 different medical specialties, including adult cardiology (64%), cardiothoracic surgery (15%), pediatric cardiology (8%), internal medicine (6%), and others (7%). Overall, primary indications were function and viability evaluation (29%), aorta and valve assessment (24%), congenital heart disease (17%), arrhythmogenic right ventricular dysplasia exclusion (13%), cardiac masses (9%), pericardial disease (4%), and others (4%). Referrals for function and viability represented a much greater percentage of cases at the community hospital (53%) than at the teaching hospital (19%). The reverse was true for congenital heart disease (7% vs 21%). This study demonstrates that cardiac specialists generate the vast majority of referrals (87%) to the authors' cardiac magnetic resonance imaging service and that there are substantial differences in the referral patterns between a large teaching hospital and a smaller community hospital.

ACR clinical statement on noninvasive cardiac imaging

Coronary artery disease and other acquired and congenital cardiac diseases are major medical and socio-economic problems. Historically, imaging has had a critical role in the diagnosis and evaluation of acquired and congenital cardiac disease. Advances in computed tomography (CT), with multidetector CT and electron beam CT technology, and magnetic resonance (MR) imaging, now make it possible to noninvasively image the coronary arteries, cardiac chambers, valves, myocardium, and pericardium and assess cardiac function, and CT and MR imaging are becoming increasingly important in the evaluation of cardiac disease. Radiologists, because of their extensive experience in CT and MR imaging, have an important role in imaging cardiac patients using these modalities. This clinical statement of the ACR discusses various technical and patient safety issues related to cardiac CT and MR imaging, and it suggests appropriate qualifications for radiologists until such time as ACR practice guidelines for the performance of cardiac CT and cardiac MR imaging are written and approved through the usual ACR process. It stresses that the interpreting physician is responsible for examining not only the cardiac structures of interest but also all the visualized noncardiac structures and must report any clinically relevant abnormalities of these adjacent structures.

Cardiac MRI is Complementary to Echocardiography in the Assessment of Cardiac Masses

Despite the fact that the incidence of cardiac tumors is low, the prompt evaluation and adequate intervention of these is highly important. Although most tumors of the heart are considered histologically benign, there are significant risks associated with these "benign" tumors. These are associated with significant morbidity and mortality due to obstruction of blood flow, alterations of conduction, propagation of arrhythmias, and thromboembolism, depending on their size, location, and nature. With the advent of noninvasive imaging modalities--traditionally echocardiography; but more recently using cross-sectional imaging with cardiac computed tomography and magnetic resonance imaging--cardiac tumors can be optimally assessed providing a greater opportunity for curative treatments by cardiothoracic surgery.

MR imaging of cardiac tumors

Magnetic resonance (MR) imaging is an important tool in the evaluation of cardiac neoplasms. T1-weighted, T2-weighted, and gadolinium-enhanced sequences are used for anatomic definition and tissue characterization, whereas cine gradient-echo imaging is used to assess functional effects. Recent improvements in pulse sequences for cardiac MR imaging have led to superior image quality, with reduced motion artifact and improved signal-to-noise ratio and tissue contrast. Although there is some overlap in the MR imaging appearances of cardiac tumors, particularly of primary malignancies, differences in characteristic locations and features should allow confident differentiation between benign and malignant tumors. Indicators of malignancy at MR imaging are invasive behavior, involvement of the right side of the heart or the pericardium, tissue inhomogeneity, diameter greater than 5 cm, and enhancement after administration of gadolinium contrast material (as a result of higher tissue vascularity). Concomitant pericardial or pleural effusions are rare in benign processes but occur in about 50% of cases of malignant tumors. MR imaging offers improved resolution, a larger field of view, and superior soft-tissue contrast compared with those of echocardiography, suggesting that knowledge of the MR imaging features of cardiac neoplasms is important for accurate diagnosis and management.

Giant coronary artery aneurysm mimicking a compressive cardiac tumor

Giant atheromatous coronary aneurysms mimicking a cardiac tumor remain exceptional. We report the case of a patient who experienced a severe inferior myocardial infarction related to a giant thrombosed coronary aneurysm masquerading a cardiac tumor and compressing right cardiac cavities with mechanical detrimental consequences on tricuspid, mitral and aortic valvular competence. The contribution of imaging was essential to assess diagnosis, understand the physiopathogeny of myocardial and valvular consequences and plan the optimal surgical strategy.

CT and MR imaging findings of malignant cardiac tumors

This article reviews CT and MRI features of malignant cardiac and pericardial tumors, most of which originate from the lung, breast, melanoma, leukemia, or lymphoma through lymphatic, hematogenous, transvenous, and direct pathways. Although echocardiography establishes the diagnosis in most cases, CT and MRI provide additional physical, spatial, and functional information that further aids the evaluation of metastases. For instance, CT provides superior resolution for detecting calcification or fat, while MRI with its direct multiplanar ability more completely characterizes the heart, pericardium, mediastinum, and lungs. MRI also helps elucidate the pathophysiological effects of these tumors on cardiac function through gated cine-loop sequences. Beyond tumor characterization, both modalities can help confirm diagnosis through the addition of contrast, which helps distinguish tumor from myocardium, thrombus, and blood flow artifact. Ultimately, MRI best facilitates surgical planning and posttreatment follow-up in large part because of its unparalleled ability to locate and delimit these tumors.

CT and MR imaging findings of benign cardiac tumors

This imaging review describes the appearance of benign cardiac tumors on CT and MRI. Although rare, benign tumors outnumber their primary malignant counterparts three to one. Since mortality varies directly with invasion, identifying the neoplasm at an early stage helps focus treatment, especially in benign cases, which generally respond well to surgical resection. In adults and children, myxomas and rhabdomyomas, respectively, represent the most common benign tumors, which can be grouped into tissue-specific subtypes, such as rhabdomyomas, fibromas, lipomas, teratomas, etc. Besides their variable prevalence in particular age groups, these tumors also differ with regard to their gender predilection, location, and number. For example, myxomas appear predominantly in women and generally as a solitary mass in the left or right atrium, whereas rhabdomyomas present equally in boys and girls and chiefly as multiple masses in the ventricles. Despite their differences, however, both types share an association with heritable syndromes like the Carney complex for myxomas and tuberous sclerosis for rhabdomyomas. As with all cardiac tumors, echocardiographic findings usually suggest the initial diagnosis but cross-sectional imaging with CT and MRI can help resolve diagnostically challenging cases. For example, with its direct multiplanar capability, excellent contrast resolution, and large field of view, MRI permits a detailed examination of the entire mediastinum, helping to rule out an equivocal mass on echocardiography. Through dynamic techniques, MRI, in addition to morphologic characterization, can depict the pathophysiological effects of these tumors, for instance, with regard to myocardial contraction, valvular function, or blood flow.

Fast interactive real-time magnetic resonance imaging of cardiac masses using spiral gradient echo and radial steady-state free precession sequences

RATIONALE AND OBJECTIVES

Cardiac and respiratory controlled MR-imaging is the gold standard for imaging of cardiac masses. However, this technique may be limited in patients with dyspnoe or arrhythmia. The aim of this study was the evaluation of an interactive MR-approach for the detection and localization of cardiac masses.

METHODS

Interactive real-time spiral gradient-echo (spiralGE) and radial steady-state-free-precession (radialSSFP) MR-imaging was performed during free-breathing and without cardiac triggering in 15 patients with 14 intracardiac or paracardiac masses. Standard cardiac triggered segmented k-space breath-hold steady-state-free-precession cine MR-imaging was used as the reference MR-imaging technique. Two groups of investigators blinded to clinical data were ask to rank image quality and to identify cardiac masses on real-time MR-images.

RESULTS

Image quality was superior using radialSSFP when compared with spiralGE. Using radialSSFP all masses were correctly detected while 6 of 14 masses were missed on spiralGE. Mean real-time MR-imaging time was less than 3 minutes for both techniques.

CONCLUSION

Interactive real-time radialSSFP MR-imaging allows for accurate and fast detection of cardiac masses without the need of cardiac or respiratory triggering.

MR evaluation of cardiac and pericardial malignancy

The accurate evaluation of cardiac masses by MR imaging was established in the infancy of cardiac MR imaging. From its advent, MR imaging was believed to be diagnostically superior to echocardiography in the evaluation of suspected cardiac masses. Though excellent in its assessment of the left side of the heart, echocardiography is limited in its evaluation of the right heart, mediastinum, and paracardiac structures. It is also of limited use in patients with emphysema and chest wall deformities. With the advent of ECG gating, MR imaging's ability to assess the presence and anatomy of cardiac and paracardiac masses was well established by a number of studies. This research also demonstrated MR imaging's capacity to exclude a cardiac mass when the echocardiogram was equivocal.

Role of magnetic resonance imaging for evaluation of tumors in the cardiac region

The aim of this study was to review the role of MRI in the assessment of heart neoplasm, 25 cases with heart neoplasm (10 myxoma, 6 rhabdomyoma, 5 angiosarcoma, 2 mesothelioma, 1 lymphoma, and 1 fibroma) were examined with MRI and echocardiography. Multislice T1- and T2-weighted spin-echo images and static gradient-echo images were taken in appropriate directions with electrocardiogram gating. Gadolinium enhancement was performed in 21 cases. Transthoracic echocardiography was performed in all cases. Except for the 5 patients with rhabdomyoma, the pathological diagnosis was obtained. MRI proved to be useful for tissue characterization of myxoma, angiosarcoma, mesothelioma, and fibroma in cases with tuberous sclerosis. MRI also proved to be useful for detection of the tumor, depiction of contour, relation with other cardiac structures, in cases with myxoma, angiosarcoma, mesothelioma, lymphoma, and fibroma. In the differential diagnosis, MRI provided important information in cases with myxoma, rhabdomyoma, angiosarcoma, and fibroma. In cases with tumors expanding into the mediastinum, such as mesothelioma and fibroma in this report, MRI was useful in determining the location and border. In cases with tumors adjacent to pericardium, MRI was useful in detecting pericardial invasion. Gadolinium enhancement added useful information in cases with myxoma, rhabdomyoma, angiosarcoma, and mesothelioma. The role of MRI with and without Gd enhancement differs somewhat in individual types of heart neoplasm, and adaptation must be considered in each kind of neoplasm. On the other hand, MRI is an essential examination in all cases with a cardiac mass, which has not been diagnosed, since it may provide useful information for the differential diagnosis.