Imaging under fire

Medical Imaging Tests Drive Up Health Care Costs

November 19, 2008
by Lynn Shapiro, Writer
Bethesda, MD -- A dramatic expansion in the number of magnetic resonance imaging (MRI) and computed tomography (CT) scans since 1995 has led to increased outlays for the federal government and other payers but not necessarily to better health care or reduced mortality, researchers report in a new study published in the November-December issue of the journal Health Affairs. Get details at:

On the other hand, even in managed care settings where there are no particular financial incentives to use imaging, it's difficult to discern which images are worth having and which are not. This creates a real quandary for U.S. policymakers hoping to rein in overall health costs. More information will be needed to determine whether the benefits of these technologies are worth the additional costs.

Between 1995 and 2004, the number of CT and MRI units more than doubled. Using Medicare claims data, Stanford University's Laurence Baker and colleagues from Stanford and Harvard University found that the number of MRI procedures per 1,000 Medicare beneficiaries increased from 0.3 in 1985 to 50 in 1995. By 2003, that number reached 173. CT procedures more than doubled from 1995 to 2005, from 235 per 1,000 beneficiaries to 547.

What's In The Issue? Baker's study is the lead article in the new Health Affairs issue, a thematic volume that looks at the very real benefits, and the equally real costs, of the increasing use of such forms of medical technology as imaging and devices. The issue is supported by grants from the Blue Shield of California Foundation, Medtronic, and Johnson & Johnson. Get more at:

In addition to several articles examining the boom in medical imaging, (, the issue contains articles addressing a variety of questions:
-- What are the costs and benefits of purchasing contract provisions that forbid device purchasers from disclosing the prices they negotiated with manufacturers?
-- How should large health care payers like Medicare determine which new technologies to adopt and what levels of reimbursement to set?
-- How much evidence of effectiveness should be required before new genomic tests or other interventions are allowed onto the marketplace?
The issue also contains articles finding that "consumer-driven" health plans at one large employer attracted disproportionate numbers of younger enrollees with relatively low health expenditures,; that hospital ratings for consumers can often be confusing,; that the capacity of hospitals to respond to mass-casualty events is insufficient and getting worse,; and that the United States continues to spend more on health care than other industrialized nations but often does not achieve better results,

Expanded Use Of Imaging May Make Patients More Informed, But Benefits Are Unclear

Each new CT scanner on the market prompted another 2,224 additional CT procedures per year, adding $685,000 to the yearly Medicare bill, Baker and his colleagues found. Each new MRI unit led to 733 additional MRI procedures, adding $550,000 to Medicare spending annually.

Expanded use of such technology can yield better health outcomes in some cases, but can also produce less tangible benefits such as a patient having more information about a disease or condition. However, it is unclear whether these less tangible benefits justify the costs, the researchers argue. As an example, researchers looked at the use of CT to diagnose conditions affecting the abdominal aorta, particularly abdominal aortic aneurysms. They found that increasing the use of advanced imaging resulted in a few more therapeutic procedures, but that the change was small. The researchers say that the example highlights the challenges of measuring costs and benefits from increased imaging, and that more analysis is needed at the population level.

"We pay for a lot of things that make us happier, but don't necessarily make us healthier," Baker said. "We need to improve our ability to measure the costs and benefits of the dramatic rise in diagnostic imaging we've seen in the past decade."

Explosion In Imaging Rises Among All Patients. The first study to examine use of diagnostic imaging trends in any managed care setting shows how much the use of this technology has exploded in the past decade -- even in a setting where there are no special financial incentives that might encourage providers to use imaging.
Rebecca Smith-Bindman of the University of California, San Francisco, and colleagues at Group Health Cooperative examined the experience of enrollees in that large nonprofit health care system, which provides care and coverage to residents of Washington State.

From 1997 through 2006, use of almost every type of imaging technology increased, including CT scans, MRI, ultrasound, nuclear medicine, x-rays, and arteriography. Annual imaging costs more than doubled from $229 per enrollee in 1997 to $463 per enrollee in 2006. In looking at specific technologies, researchers show that
-- Use of CT, MRI, and ultrasound combined rose significantly from 260 to 478 examinations per thousand enrollees per year
-- CT imaging more than doubled from 81 to 181 exams
-- MRI imaging more than tripled from 22 to 72 exams during the study period.

Cross-sectional imaging studies, which include CT, MRI, and ultrasound, added to existing tests using older technologies instead of replacing them. This pattern is common with the development of new technologies, the authors write. The study looked at how patterns in medical imaging varied by a patient's age, sex, image type, and the technology used. Increased imaging use among every group studied makes it clear that no single group, regardless of age, sex, or disease, can be the single focus of efforts to reduce imaging, the researchers write.

Although it would be ideal to curtail medical imaging by decreasing the use of costly and inappropriate or ineffective imaging, the researchers say that it remains "difficult to identify which imaging tests are most beneficial, and strategies that rely on financial disincentives tend to decrease imaging across the board, instead of selectively reducing unnecessary imaging." More focus should be on studying the cost-effectiveness of these tests and the effect on patient care so that policymakers, payers, and providers can better figure out how best to apply imaging technology, they add.


Health Affairs, published by Project HOPE, is the leading journal of health policy. The peer-reviewed journal appears bimonthly in print with additional online-only papers published weekly as Health Affairs Web Exclusives at The full text of each Health Affairs Web Exclusive is available free of charge to all Web site visitors for a two-week period following posting, after which it will switch to pay-per-view for nonsubscribers. Web Exclusives are supported in part by a grant from the Commonwealth Fund.