For cardiologists, they must complete their education with at least three years of course in undergraduate schools with knowledge of the basic sciences. Afterwards, they will have to go on and complete four years of medical school. Then when they complete their time in medical school they will be required to complete another two to six years of the studies in internal medicine. The programs for internal medicine are paid and allow them to acquire experience by supervision of a licensed physician. In order to practice, all cardiologists must be licensed. Cardiologists have to take the United States Medical Licensing Examination (USMLE), and to do this they must have a degree from a credited medical school. The American Board of Internal Medicine (ABIM) offers certification in the subspecialties of cardiology. For example, clinical cardiac electrophysiology and cardiovascular diseases. To become certified by ABIM, cardiologists must become certified in internal medicine and must pass a written exam. Being a very difficult career to achieve, the field cardiology has problems in as well. One of the major issues in cardiology, called "radiation issue" is a consideration for possible deterministic effects, such as skin injuries, and long term cancer risks because of the ionizing radiation testing. About ten years ago the "radiation issue" was brought upon, which has to do with ionizing radiation testing. This issue had came upon by individual patient's, societal, and bioethical