"When you have a hammer, everything looks like a nail."

Indeed, a golden nail. A New England Journal of Medicine study says that many physicians who own their own X-ray and other imaging equipment order four to four-and-a-half times as many imaging tests as those who refer patients to outside radiologists.Let us bear in mind that these self-referring doctors make money if their patients have their X-rays in their offices, but earn not a penny from X-rays if their patients go elsewhere for those procedures. Now, what we're seeing here is, to some extent, probably just a case of "when something is available, it's easy to use it often," to quote E. Haavi Morreim once again. (He's a philosopher in residence at the University of Tennessee Medical School, and was asked to comment on the Journal report.)

In some cases, it's a matter of physicians commendably wanting to maintain close control of patient diagnosis and care, or of covering themselves from possible lawsuits.

But we suspect that plain old greed lies behind some of this activity, too. The study found that physicians who own their own machines also charge much higher fees than outside radiologists. For example, an average of $54 for an X-ray of a patient with an upper-respiratory ailment, compared to $40 by a radiologist, and $304 per sonogram, compared to $185!

We're not seeking to drum up business for radiologists, who are already among the most highly paid MDs. But these very disturbing figures point out how many physicians' desires for wealth are helping to drive the costs of health care out of control. There is also the natural concern that a few people may be given unsafe levels of X-rays to line some doctors' pockets.

What can be done to bring this under control? First, patients ought to ask their physicians what the costs of such services will be before they submit to these tests, and then find out what an outside radiologist's fee might be. It should be emphasized that this must apply to patients with medical insurance as well. For too long, people with health insurance have persuaded themselves into thinking that they don't really pay for necessary and unnecessary health care, ever-growing deductibles aside.

But they do, through ever-escalating premiums for themselves and their employers - premiums that, among other things, give employers good cause to keep down wage increases. And these astronomical costs hurt poor, uninsured patients the most.

Of course, insurance companies should challenge such fees if they know such imaging can be done more cheaply elsewhere. Government, through its Medicaid and Medicare programs, must also do more to regulate these self-referrals.

Rises in health-care costs continue to exceed inflation. The profits that some physicians are deriving from over-enthusiastic use of their imaging equipment gives some indication why. Patients, government and insurance companies must act together to bring these expenses under control.