I'd bet you either know someone who's had a CAT scan or you've had one.

That is how popular and effective it is.

CAT stands for Computed Axial Tomography, and it has revolutionized medical imaging by giving doctors a three dimensional image of the internal structures of the body.

The number of CAT scans performed has soared from about 3 million in 1980 to 62 million in 2007. But now there is serious concern we may be overusing it.

Not only are CAT scans expensive, but for some people, they may be a health hazard.

The scans expose patients to radiation, which breaks down our DNA and can lead to mutations and chromosomal abnormalities. CAT scans have fifty times the radiation of x-rays.

Here is a shocking comparison: the dose of radiation from three to four abdominal CAT scans is equal to the radiation survivors of the Atomic-Bomb received who were only one to two miles from Ground Zero.

Perhaps you think it's uncommon for someone to get 3-4 CAT scans in a lifetime. But a study showed nearly all patients having their abdomen or pelvis imaged undergo more than one CAT scan in the same day.

Nearly a third have at least three scans, and an alarming seven percent have more than five scans.

The estimate now is that up to two percent of all cancers in the US may be caused by CAT scans. And some believe around 29-thousand future cancers could be related to the scans performed in the US in 2007 alone.

The Food and Drug Administration has recommended that CAT scan technicians record the radiation dose so that a patient's lifetime exposure may be tracked.

Other recommendations include encouraging doctors to use other imaging tools like MRIs and Ultrasounds and that patients avoid unnecessary scans by keeping their own records.