Cardiac magnetic resonance imaging in normal dogs and two dogs with heart base tumor.

We describe the technique for in vivo cardiac-gated magnetic resonance imaging (MRI) in normal dogs and its application in two dogs with a large right atrial tumor. The dogs with a cardiac tumor were also imaged using contrast-enhanced magnetic resonance angiography (CE-MRA). Cardiac-gated MRI and CE-MRA are both feasible in animals with short acquisition times compatible with breath-hold imaging under anesthesia, and provide detailed two- and three-dimensional (3D) depiction of the cardiac anatomy and great vessels with or without contrast medium. Although cardiac MRI will not replace echocardiography, it is a powerful alternative technique to use when knowledge of the 3D anatomy of the vasculature is required, when precise volume measurements are needed or when myocardial characterization is indicated. As opposed to contrast-enhanced computed tomography angiography, cardiac MRI does not use ionizing radiation or iodinated contrast medium.