There seems to be a bit of disconnect on what medical examinations in general, and flight physicals for airmen do. They are not preventive health, but regulatory with the intent to answer the question: Will this airman be healthy enough to fly safely for the next 6 months, 12 months, 2 years, 5 years?
Much of our preventive annual exams (non-FAA) exams are focused on improving health and diagnosing common problems. Heart disease and cancer and diabetes are most common, but there are others that do happen. Some of them we catch by knowing personal or family history, and take a special look. Some we catch on routine and inexpensive lab tests. Some we miss because it is simply too expensive or invasive or the tests themselves can cause harm.
Where the consequences disease and the risk of a disease is high, CTs are used. Low Dose CT scans for smokers to diagnose early (potentially) curable lung cancer are a key example, but routine use in everyone without reason would potentially increase the risk and expense to the population with little gain.
An example is a fit airman carrying a Class I medical with current EKG demonstrating excellent cardiac health in his mid 40s with a regular training regimen, bicycling, downhill skiing, running were his activities. One warm summer day walking in town with his family, he died in his tracks from a ruptured aneurism. This could have just as easily happened several days later when he was on his trans-oceanic airliner headed to the EU. Or it could have happened on his way home on the interstate with the cruise control set. This type of event takes seconds and is mostly fatal. The USPHTF recommendations are not to screen for AAA until 65-70 and only in males, and even then they report a low probability of a positive result.
The FAAās medical certification program has been questioned, sometimes appropriately, other times not. But the reality is that medical events are rarely the proximate cause of aviation accidents. They are not designed to catch health events, but to insure you meet FAA/regulatory criteria to fly your missions for the duration of the certificate.
The family doctor is the one who manages your overall heath. People with cancer, still die of heart attacks despite extensive diagnostic testing and work ups before they begin their treatments. I might be one of the higher risk not because I have any known or potentially detectable medical problems, but because I fly a lot of time solo, and maybe half of that is night or ifr. Then it doesnāt matter if Iām flying the King Air or the J3 on amphib floats. Class I medical or not.