Right ventricular injection study in a dog with a patent ductus arteriosus. In the dextro-phase, the right heart appears normal except for the enlarged pulmonary trunk (PT) and pulmonary arteries which obscure the patent ductus arteriosus.

Left ventricular injection study in the same dog with a patent ductus arteriosus showing the funnel shaped patent ductus arteriosus (PDA). Recirculation through the PDA causes delayed clearance of contrast material.