メディエイゴ

Computed Tomography(1) (CT) scans(2) are an increasingly(3) used X-ray(4)-based(5) tool for providing a three-dimensional(6) view of a particular organ(7) or tissue(8). The value of CT scanning(9) to diagnose(10) injury(11), cancer(12) and other health problems is undisputed(13). But are these scans being used too frequently(14), in some cases unnecessarily? What are the health consequences(15) of having too many CT scans over the course of(16) a person’s life?

In the Nov. 29 2007 issue(17) of The New England Journal of Medicine, David J. Brenner, Ph.D., and Eric J. Hall, Ph.D., from the Center for Radiological(18) Research at Columbia University Medical Center, argue that the potential(19) carcinogenic effects(20) from using CT scans may be underestimated(21) or overlooked(22). This is of particular concern(23), because perhaps one-third of all CT scans performed in the United States may not be medically(24) necessary, the radiation(25) researchers(26) say.

It is estimated(27) that more than 62 million CT scans per year are currently(28) given in the United States, compared to three million 1980. Because CT scans result in(29) a far larger radiation exposure(30) compared with conventional(31) plain-film(32) X-ray, this has resulted in a marked increase in the average(33) personal radiation exposure in the United States, which has about doubled since 1980, largely because of the increased CT usage(34).

It used to be widely believed that all radiological examinations(35) were essentially(36) harmless(37), because of the small amounts of(38) radiation involved(39), but Drs. Brenner and Hall show that this is unlikely to(40) be true for CT scans.