Introduction:
Cardiac tumors show a cumulative prevalence of 0.002 to 0.3 percent, as detected through an autopsy. Primary cardiac tumors can be histologically both benign and malignant types. Metastatic involvement of the heart is 30 times more common than primary cardiac tumors.
Primary cardiac tumors are generally rare, with different histological types. The imaging features can help distinguish between benign and malignant cardiac tumors. The most widely used imaging technique for the evaluation of cardiac tumors is transthoracic echocardiography. However, for visualizing extracardiac extension, the use of transthoracic echocardiography is not considered optimal for evaluating malignant cardiac masses.
Today, magnetic resonance imaging (MRI) is the technique of choice for evaluating cardiac tumors. High contrast resolution and multiplanar capability help in specific diagnosis and proper evaluation of myocardial infiltration, extracardiac extension, and involvement of pericardium. Currently, multidetector computed tomography (MDCT) has been used highly for cardiac imaging. The short image acquisition time for multidetector computed tomography (MDCT) is helpful in cardiac imaging as compared with the use of magnetic resonance imaging (MRI).
What Are the Radiographic Features of Rare Primary Cardiac Tumors?
Different radiographic features are observed in different techniques of imaging:
1. Echocardiography: Transthoracic echocardiography (TTE) is initially used for diagnosing intracardiac masses, which helps in the delineation of the degree of mobility, location, dimensions, and any associated disruption of cardiac structure and function. The pericardial extension can also be described through this method.
Transthoracic evaluation has certain limitations, including inherent anatomic barriers and reduced visualization of several relevant structures like the great vessels. It might be further limited by patient-specific factors, like chest wall abnormalities, prior surgeries or dressings, body build, and hyperinflated lungs. Transesophageal echocardiography is especially utilized for evaluating the masses that are related to a valvular apparatus.
It is good for imaging structures inside the atria. It is particularly useful for describing the origin or attachment site of masses, which are usually difficult with a transthoracic approach.
3-dimensional echocardiography (3DE) is frequently employed for the following reasons:
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Its ability to provide a detailed anatomical relationship of masses.
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Provide a good description of mass shape and dimensions.
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Additional descriptions or details of subtle structural elements inside the mass which cannot be diagnosed otherwise, such as subtle internal trabeculation.
Contrast agents used in sonography might also provide additional diagnosis, helping in the assessment of the vascularity present within a mass along with the relative abundance or lack of perfusion. Typical features of benign tumors include:
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Qualitatively small amounts of microbubbles circulate throughout the mass.
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Lacking the hypervascularity associated with malignancy.
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Appears to have a lesser degree of enhancement to the adjacent myocardium.
Intra-cavitary masses can also be identified as their presence is indicated by a filling defect inside the relevant cardiac chamber.
2. Magnetic Resonance Imaging: Cardiac magnetic resonance imaging (CMR) helps in both qualitative and quantitative features identification of the mass that has to be diagnosed along with cardiac structure, function, and adjacent structures. Salient features to be diagnosed on cardiac magnetic resonance imaging include:
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Shape or size, location, involvement of adjacent anatomical structures.
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Absence or presence along with degree or pattern of late gadolinium (a silvery-white metal) enhancement.
3. Computed Tomography: Since metastases are common in primary tumors, computed tomography (CT) of the abdomen, chest, and pelvis might be considered to identify a primary source of malignancy, with common reasons including:
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Hematologic malignancy (lymphoma, leukemia, hematogenous seeding from melanoma might occur).
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Lung cancer.
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Renal cell carcinoma.
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Esophageal cancer.
Computed tomography might be used to diagnose cardiac masses in coronary vessels and helps in the identification of extra-cardiac progress of a tumor in adjacent structures. Contrast enhancement helps to identify the vascular nature of the mass, and fat or calcifications are seen well with computed tomography.
What Is Multidetector Computed Tomography Technique?
Multidetector computed tomography technique involves the administration of intravenous contrast, and material volumetric data of the heart were collected from a 64-slice multidetector computed tomography (MDCT) scanner. 65 millimeters of a nonionic contrast material was injected at a rate of 4 millimeters/liter with the use of a dual-syringe power injector.
After the injection of contrast material, an injection of 30 ml of mixed normal saline and contrast medium (20 % contrast medium and 80 % normal saline) at 3 ml/second is administered. A real-time bolus tracking method was used with an area of interest in the ascending aorta.
By using helical computed tomography, gating the cardiac images to the electrocardiogram (ECG) might be accomplished by reconstructing or scanning raw data at the point of least cardiac motion.
The use of electrocardiogram-gated multidetector computed tomography (MDCT) has better soft tissue contrast than echocardiography and can definitively characterize fatty content and calcifications. A wide field of view with multidetector computed tomography (MDCT) allows for the assessment of the extent of a cardiac malignancy. It helps detect metastatic lesions. However, the role of multidetector computed tomography (MDCT) in the evaluation of cardiac tumors has not been described properly in the literature.
Conclusion:
Multidetector computed tomography and magnetic resonance imaging (MRI) might be used for differentiating benign and malignant cardiac masses. Multidetector computed tomography (MDCT) is useful for evaluating the calcification and fat content inside a cardiac mass and the high spatial resolution of MDCT for describing tiny lesions. MDCT is helpful in staging malignant tumors. The good contrast resolution with the use of MRI helps in the characterization of fibromas (noncancerous growths or tumors involving the fibrous connective tissue) and hemangiomas (a commonly occurring vascular birthmark consisting of extra blood vessels in the skin).
The homogeneity of a mass as a result of compact cellularity might be characterized by lymphoma. Acquisition of post contrast sequences helps a good identification of tumor vascularity and might be used to determine tumor borders. MRI has an essential role in identifying thrombi from cardiac tumors. Apart from the characteristics of a tumor, a preoperative imaging assessment of cardiac tumors using multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) might help to identify tumor resectability and helps to plan the reconstruction of the cardiac chambers.
