Elizabeth Cohen: Body-scanning basics

CNN's Elizabeth Cohen

(CNN) -- Businesses increasingly are promoting expensive full-body scans, which they say will detect the earliest signs of disease. But are these procedures worth the money?

CNN Medical Correspondent Elizabeth Cohen told CNN's Bill Hemmer what the experts are saying about it.

COHEN: This procedure is making news because later this week Atlanta Braves announcer Skip Caray is going to have an angioplasty because he had one of these scans, didn't have any symptoms, but they found that one of his arteries was 96 percent blocked.

So why did he have the scan if he had no symptoms? Well, because his colleague, Hall of Fame pitcher Don Sutton, got himself a scan for his 57th birthday, found that he had kidney cancer, and he recently had a kidney removed. But what exactly is this scan, and what does it do?

Well, what this scan does is it sends radiation through your body at various angles, and it can take basically slices of your body and takes many, many pictures, and it can find all sorts of illnesses for which you don't have symptoms.

It can see what your arteries are doing; it can find cancers; it can find aneurysms. There are the stories that we just told you, about Sutton and Caray, where they found diseases that they didn't know existed. So you might be asking yourself, "Well, gosh, if you're willing to dish out the $700 to $1,000 to have one of these, why not have it?"

Well, the American College of Radiology says, "We don't think people should be getting these." And they basically have two reasons. One, you're exposing yourself to radiation, albeit a small amount. The other reason is that there are no studies that prove that these work, and what they sometimes do is they find small things that seem like they might be harmful, but they actually turn out to be harmless.

So yes, there are stories like Caray and Sutton, but there are also stories of people where they said, "You know what, you really need to get this checked out. We found this spot on your lung." It turns out to be nothing, and that patient worries and has to have weeks and weeks of sometimes very expensive tests just to show that it was nothing.

Now, bottom line, if you do still decide that you want to have a scan, you want to look for one where a board-certified radiologist is looking at your scan, and also ask how much experience that radiologist has reading CAT scans.

HEMMER: Good advice. You threw out a price figure there. Does insurance cover this?

COHEN: Usually not, because insurance companies don't pay for fishing expeditions. I mean, if you seem perfectly fine, they're not going to just pay for you to have this scan. If, for example, you have had some symptoms, let's say, in your abdomen, and the doctor wants you to get this scan of your abdomen, insurance usually would pay for that, but they are not going to pay for these full body scans.

HEMMER: What about this scan in terms of completeness? Does it find everything and anything that may be wrong inside of the human body?

COHEN: It doesn't find everything, and that is really important for people to keep in mind. Because when you see these pictures, you think, gosh, they have looked into every nook and cranny of my body, what could it have missed?

Well, you know what, it is not going to find high blood pressure. It is not going to find high cholesterol levels; it is not going to find infection; it is not going to find an abnormal heart rhythm, which sometimes is the reason why people have heart attacks. You need to go to your doctor for that. So the scan does not find everything.