What is a MUGA test?

A MUGA (MUltiple Gated Acquisition) scan is a nuclear medicine scan of the heart. It gives an assessment of the pumping function of the heart, as well as the flow of blood through the heart and the proximal aorta. A small amount of radioactive dye is used, and a special imager is used to visualize blood flow.

The weak spot in your father's aorta could be a lot of things. If it's an aneurysm or a dissection of the aorta, that could be very serious. What you do about it really depends on where it is and other health problems. There are many forms of lymphoma and a whole spectrum of prognosis, so that may or may not be an issue in your father's overall health. The weak spot in your father's aorta could be managed just with medicines, but it depends on where it is. Dissections of the aorta in the ascending aorta, the first part right off the heart, are generally treated with surgery unless there's an additional reason not to do surgery, such as another health problem.

Since I don't know the details of your father's case, he really needs to talk to his doctor.