Cardiac MRI findings in a dog with a diffuse pericardial mesothelioma and pericardial effusion.

Veterinary cardiac MRI (cMRI) is a relatively new technique. A dog with recurrent pericardial effusion and a questionable right atrial mass lesion on echocardiography underwent cMRI. cMRI provided excellent anatomic information about the heart and surrounding structures and helped to rule out the presence of a focal mass. A diffuse thickening and enhancement of the pericardium was detected. Pericardiectomy was performed and histopathology revealed a diffuse pericardial mesothelioma. This case illustrates the potential of cMRI in the management of patients with pericardial effusion when echocardiographic findings are equivocal and illustrates cMRI findings in a case of diffuse pericardial mesothelioma.