The Cost of High-Tech Medical Imaging

As federal health-care reform bills make their tortuous way through Congress in September, one aspect of medical care that engineers should pay attention to concerns the cost of procedures that use expensive pieces of equipment such as CT-scan X-ray machines and MRI (magnetic resonance imaging) systems. A recent op-ed piece by a group of medical experts pointed out that one reason we have the most expensive health-care system in the world (by many measures), is that we spend a lot of money on high-tech tests that really don't make people healthier. A study of CT scans in Cedar Rapids, Iowa revealed that in the community of 300,000 people, about 52,000 CT scans were administered in only one year. And that's below the national average, which is even worse. One thing that makes it easy to spend that money is the fact that high-end medical equipment is very expensive, both in terms of initial installation and operating costs. Why is that?

From an engineering point of view, medical imaging combines several factors to make a kind of perfect storm of expense. In the case of a CT-scan machine, you are dealing with X-rays, which require precisely controlled high voltages to generate, and a large array of precision detectors. MRI machines don't use X-rays, but instead they need something even more exotic and hard to generate: precisely controlled magnetic fields of tremendous intensity, which can only be produced with superconducting magnets that use liquid helium. Liquid helium is a costly, exotic material that has to be renewed regularly and needs a whole infrastructure to obtain. So even before you have your data, you've spent a lot of money just generating it. Besides that, a lot of intensive computation is needed to produce the images, but with computer and software costs falling these days, the computational aspect is probably the only part of the system that's cheaper than it used to be. Not just anybody can operate a CT-scan or MRI machine: you require highly trained radiologists or technicians who are familiar with safety requirements and the details of how to acquire good images. These people don't come cheap. Finally, every engineer knows that any piece of equipment's price goes up significantly if it is to be used in medicine. There are special safety and other regulations that medical equipment must meet, and the medical-equipment market is a strange and narrow one compared to, for example, consumer electronics. For all these reasons and more, the typical CT scan device goes for between $150,000 and $300,000, while a whole-body MRI machine will set you back more than a megabuck. And that doesn't count maintenance and operating costs.

Considering all this, it doesn't sound like there's much chance to develop really cheap MRI or CT-scan machines operated by the consumer, which after all would be one way to fix the cost problem. The last consumer-operated X-ray machines were the shoe-store fluoroscopes, now banned because they were dangerous, and rightly so. But suppose Congress succeeds in changing the business model of health care, so that we move away from the present system in which each MRI or CT-scan machine is like a piece of factory equipment whose owners are obliged to operate at full capacity in order to recoup their investment. What if we break the connection between the number of procedures and tests done, and the money taken in, so that it is not so direct as it is today? What consequences might this have for the future of high-tech engineering in health care?

For some reason, I find myself thinking about the computers used by the U. S. Postal Service. That agency does use computers, though it was probably not a national leader in pioneering business applications of computers. My impression is that whoever makes the USPS's computers (I'm talking about the little systems the retail clerks use at local post offices) won that contract a long time ago and has jealously guarded it ever since. Innovation and competition is not a big feature of this deal, I suspect. I have no particular complaints about how the Postal Service uses computers, but they could probably do better.

I pick the Postal Service because their near-monopoly status (at least in terms of small-town facilities nationwide) means their revenue is not that sensitive to the amount of money they spend on innovative technologies. Most of us have seen billboards in big cities advertising the latest and greatest medical testing equipment that thus-and-so hospital system has. Those billboards are there for a reason. You don't see billboards advertising the latest computer system that the Postal Service just bought, because it wouldn't make them any more money.

I'm not saying we should leave the present medical system alone, because it's not perfect, and I agree that we probably waste a lot of money on needless procedures that help pay for too many expensive pieces of medical imaging equipment. But every kind of system has advantages and drawbacks. If health-care providers—private and public—can no longer directly recover capital expenses in a fee-for-service way, they will quit spending so much money on high-tech equipment. Maybe that's a good thing, to a degree. But I wouldn't want to go to the opposite extreme that would remind me of a doctor I once went to who prided himself on how long he could keep his semi-antique EKG machine going. The thing was at least thirty years old, and I had to wait an extra five minutes while the tubes warmed up. I felt like I was participating in a historic re-creation of the invention of electrocardiograms, and it did not impress me favorably.

The trick in this aspect of health-care reform is to negotiate the macro-ethics of finding a happy medium between overuse of expensive technology (which is probably where we are now) and underspending to the point that we fall behind the leading edge of technology, depriving some patients of newer procedures simply because we didn't spend the money on them. A thriving technology sector is a delicate thing, and while cost containment is good, we don't want to reduce spending so much that leading-edge medical imaging companies simply decide to leave the market. That would be a loss not only for us in the United States, but worldwide if such companies lead the global market too.

I'm glad I'm not having to make these decisions, but I hope the congressional staffers working on this decide carefully, and are willing to change course if things don't turn out the way they hoped. Any feedback loop that goes through the Congress and the President has a very long delay time, and so we better hope they get it right the first time, because fixing it might take quite a while.

Sources: The article "10 Steps to Better Health Care," in which the statistic on the Cedar Rapids CT scans appears, is from the online edition of the New York Times at http://www.nytimes.com/2009/08/13/opinion/13gawande.html.