Imaging of the pulmonary valve in the adults

Abstract

Pulmonary valve is the least imaged of the cardiac valves in adults. This review will address the strengths and the limitations of various imaging modalities that are commonly used for evaluation of pulmonary valve diseases in the adults. Valvular pulmonary stenosis is mostly congenital and pulmonary regurgitation is usually an acquired pulmonary valve disease. Combined pulmonary stenosis and pulmonary regurgitation as sequel to previous surgeries for congenital heart diseases is the most common form of pulmonary valve disease in the adults. Transthoracic echocardiography (TTE) is the first-line imaging for the pulmonary valve, however, TTE pose considerable technical limitations in adults secondary to the body habitus, previous surgeries, and imaging artifacts by the interposed foreign tissue. Transesophageal echocardiography is infrequently used because of farther location of the imaging probe from the pulmonary valve precluding optimal imaging. Cardiac computerized tomography (CT) and cardiac MRI are fast emerging as the most preferred imaging modalities for pulmonary valve diseases in the adults.CT is used to obtain precise anatomic information about the pulmonary valve and the contiguous anatomy such as the right ventricular outflow tract, the distal pulmonary arteries including the coronary arteries. MRI by virtue of its high temporal resolution has the unique advantage of obtaining hemodynamic information related to the pulmonary valve; such as quantification of the pulmonary regurgitation, the right ventricle volumes, mass, and the systolic function. Combined imaging with CT and MRI provide anatomic and hemodynamic information in a variety of pulmonary valve diseases; is useful for understanding of the right ventricle adaptive mechanism and remodeling process, for preprocedure planning during percutaneous pulmonary valve implantation and for surveillance of different pulmonary valve diseases. Multimodality imaging involving a combination of TTE, CT, and (or) MRI are useful to delineate the anatomic and hemodynamic abnormalities associated with different pulmonary valve diseases in the adults.