Editor’s Note: This is the first of a two part series on the explosive growth of CAT scanning in American medical care, and what it says about our healthcare system. Part I will focus on the problem, and Part II on possible remedies.

It is not often I can write about the Beatles and bowels in the same column, but here goes. About 40 years ago, flush with cash from selling millions of Beatles records, the British company EMI put a lot of money into research and one of its science-division researchers (and a researcher in Boston working on the same ideas) came up with computed axial tomography, or the CAT Scanner. These super x-ray machines, which take 3-D pictures inside our bodies, have since become just about the hottest thing in American medicine since Viagra.

The blistering increase in the number of Americans getting CAT scanned each year is showing us a lot about what is right and wrong with our health care system, and why it costs so much. There will be about 70 million CAT scans done on Americans this year, almost twice as many as were done on them in 2000. At a price of about $300 to $1,500 per scan, depending on who owns the CAT scanner and the type of scan, the cost is many billions of dollars. A lot of those scans are probably unnecessary, and the story of the overscanning of America is the story of great medical technology running its natural course in our health care system, meaning running amok.

CAT scan use is driven foremost by the fact that CAT scanners can look inside of us. What ails the patient, however, is not all that drives use of CAT scanners; what ails us and our health care system also drives use, including (in no particular order) the following:

. The fact that most of us don’t have to pay directly for our CAT scans, because our insurance picks up the tab. Unless the patient is uninsured or has to pay a deductible, no one ordering, getting, or doing a CAT scanner has any reason not to do it. Most physicians have no “skin” in the decision to spend health care dollars on CAT scans, the patient often does not pay for the test and wants an answer, and hospitals providing CAT scanning services make money on CAT scans. In other words, who cares if we do a lot of CAT scans? Almost no one.

. Fear of the unknown. Most of us hate confusion about what is going on beneath the cloak of our skin, and CAT scans can often either find an answer or rule out the rare but deadly problems that we fear are hiding like cancerous bogey men in our bodies’ closets. Why not check out whatever ails us just in case it might be cancer or something else bad, especially if the test is painless (financially and procedurally)?

. Fear of malpractice suits. Woe to the physician who misses an important diagnosis that could have been found by a simple CAT scan. They are a quick, easy way for physicians to cover their assets, and while there is little downside to ordering a scan, there may be a lot to missing a diagnosis;

. The lack of consistent use by physicians of medical guidelines that tell them when a CAT scan may be unnecessary. There are several such guidelines, especially for CAT scanning of the head after minor trauma or for headache, but most are routinely ignored by practicing physicians.

. Rapid expansion of the number of diagnostic riddles CAT scans can solve. Medical studies in the last 10 years have found CAT scans can rule out appendicitis and thereby keep patients with belly pain that only seems like appendicitis from going unnecessarily to the operating room, rule out blood clots to the lung, replace colonoscopy of the large bowel in some patients, and replace heart catheterization in some patients.

A recent study suggesting CAT scans can find lung cancers when they are smaller and potentially more treatable has some physicians recommending that patients who have smoked cigarettes for more than 15 years have regular CAT scanning of their lungs. That would add millions of CAT scans, and hundreds of millions of dollars in health care costs each year. Before long I am certain to have an ex-smoker in my office asking for a CAT scan for that purpose, and because no group of experts is out there providing me with malpractice cover by saying I should do otherwise, I will be hard pressed to say “No” to that patient.

CAT scanning is a case study in what happens when smart technology is turned loose in the American health care marketplace, where unrestricted demand meets unrestricted supply at a party put on by an aging population and physicians driven by malpractice and other concerns. As a result America is addicted to CAT scans; its patients and physicians addicted to the eradication of uncertainty, its hospitals and other CAT scan owners addicted to the money the scans generate, and all of us addicted to the promise of yet another piece of wizardly technology.

The answer is not to get rid of CAT scanning. Since its invention in the late 1960s CAT scanning has revolutionized medicine because of its ability to look inside the body without invading it, replacing countless exploratory surgeries and other painful and risky diagnostic procedures. Its benefits have outweighed the risks of its considerable radiation exposure and its costs countless times.

The answer is to get rid of unnecessary CAT scans and the likely billions of dollars of unnecessary health care spending that result from them. If patients, physicians, and hospitals cannot do that it will be done for us.

Erik Steele, D.O., a physician in Bangor, is chief medical officer of Eastern Maine Healthcare Systems and is on the staff of several hospital emergency rooms in the region.