Radiology’s Impossible Trinity

Since the advent of teleradiology and the new phase of increased competition it ushered in, the nature of the radiology practice has been evolving. Adding to competitive pressures are macroeconomic factors, including governmental budget deficits and reduced reimbursements. With the aging of the population and with health reform’s addition of millions to the rolls of the insured, the potential demands placed on a practice have never been greater. 

As a result of these two evolving pressures—increasing volume and decreasing per-case payment—practices have tried to become more efficient. This has meant trying to maximize the interpretive productivity of radiologists. For many practices, this has led to criticism from patients, referring clinicians, and hospital administrators regarding the length of patients’ waiting times.

Impossible trinity (trilemma) is a term taken from international monetary theory, which states that it is impossible for a country simultaneously to have an independent monetary policy, a fixed exchange rate, and free capital movement. It is possible to have any two of those three things, but it is never possible to have all three at once. 

The impossible trinity of radiology services states that because only two of three conditions can be present, it is not possible to have limited resources (in terms of radiologists), high-quality care, and short waiting times simultaneously (see figure). The impossible trinity of radiology services is directly analogous to the so-called iron triangle of health care, which places cost, access, and quality on the three sides of the triangle.1,2

Under this concept, an emphasis on one factor (such as quality) necessitates balancing the other two (in this case, cost and access). Translating the iron triangle into the terms of the impossible trinity of radiology service, cost can be understood as limited resources, access relates to patients’ waiting times, and quality relates to both interpretive and noninterpretive services provided by the radiology department. 

The Quality Component

High quality is inherently nebulous, as a term. In this context, however, it includes both the thoroughness of the radiology report and the overall service level (interpretive and noninterpretive).3

For example, a pulmonary-embolism CT report that only answers the question of embolism and covers the basics of the pulmonary findings might be technically adequate. It is of less value, though, than a more detailed dictation (including pertinent negatives about which clinicians typically want to know) would be. 

For example,  is the aorta seen well enough to look for dissection? Furthermore, a radiologist who calls the clinician upon making a new (and potentially unsuspected) diagnosis of malignancy is providing a greater degree of value than a radiologist who simply reports the finding in the dictation—and moves on to the next case—is providing. 

Waiting time refers, broadly, to the length of time that patients must wait to have an imaging exam scheduled, the time that they spend in the department for the imaging study, and the time that elapses before the final report’s approval. Since long waiting times have a negative impact on both patients and referring clinicians, it behooves all practices to be mindful of them. 

Obviously, many factors outside of radiologists’ control affect waiting times (especially time spent in the department). Other factors, such as report-turnaround time, are directly under radiologists’ control. 

Two Conditions

There are two conditions that must be met for the impossible trinity to be true. First, efficiencies must be maximized; second, there must be sufficient volume to stress the system. If departmental efficiencies are not maximized, there is room to improve without additional resources. 

In addition, because numerous factors other than radiologist availability affect patients’ waiting times in the department, a focus on efficient patient transit through the imaging center is a necessity for all institutions. As for the second condition (volume-related stresses), if the caseload is sufficiently limited, the system will have the capacity to absorb additional patients before resource constraints begin to take effect. 

For many practices, today, there is sufficient volume to stress the system, and groups are functioning with limited radiologist resources to reduce expenses in this time of decreasing reimbursement. Inefficiency has been addressed at many practices, and discussions of efficiency are popular in the literature.4 Thus, the two prerequisites for the impossible trinity, volume-related stress and efficiency, are often met. 

This trade-off triangle is neither new nor limited to radiology. For example, a call center (where personnel answer phones to take orders, field questions, or otherwise provide information) must be capable of dealing with volume-related stresses in an efficient and effective fashion. It is thus susceptible to the impossible trinity. The call center must balance quality concerns (adequately handling the customer’s reason for calling), waiting times, and resource limitations (properly trained personnel are costly). 

For many call centers, answering the customer’s questions fully, on the first call, is a priority, placing an emphasis on quality. As this takes longer than hurrying customers through their calls, it means that call centers are forced to balance the two remaining points on the impossible trinity, waiting times and costs. 

Even in a system with volume-related pressures and optimized efficiencies, the solution to poor quality or to long waiting times is not necessarily additional resources. Quality is driven by the radiologist. Without a pool of physicians capable of delivering high-level care, adding resources will not raise the quality level. Furthermore, it is nearly equally important for the radiologists to be able to interpret exams in a timely fashion. 

If the thorough review and dictation of a single, normal chest CT exam takes a radiologist an hour, his or her value is limited. What the impossible trinity indicates is that in a system with volume pressures, even if you have physicians capable of the timely delivery of high-quality care, there will be difficulties with patients’ waiting times if the emphases are placed on quality and on resource limitations.

The Size Advantage

The impossible trinity also helps explain certain advantages held by companies in the teleradiology industry. These companies often have better access to full-time and part-time radiologists (at multiple sites) than a traditional radiology practice has, since the practice typically has a smaller, fixed number of radiologists at one site (or a few). Larger practices, outsourcing or not, are better positioned to provide safety capacity and to tolerate volume spikes than smaller practices are. It is not surprising that these companies market themselves in such a way as to highlight these advantages. 

The Achilles’ heel of teleradiology groups remains the perception of lower quality. As these companies might financially motivate their radiologists to increase throughput (meaning quantity, which is easy to measure), quality (which is more challenging to measure) could become a secondary consideration.

The impossible-trinity concept applies to other areas of medical practice, such as internal-medicine offices. To provide thorough care, for example, the internist must spend time taking a history and examining the patient. Of course, this limits the number of patients seen per day. If the office has a growing, high-volume practice and stable resources, even with maximal efficiencies, it will soon find itself struggling to balance waiting times and care quality. 

The best practices, within radiology or outside it, understand the impossible trinity (even if not by this name) and realize three things:

  • the impossible-trinity concept is true—you can’t have it all;
  • quality is a priority, and in practice management, quality is understood to be patient care (which must always be the top concern); and
  • before adding resources, practices must look for potential system inefficiencies and resource limitations—and must correct those first.

In this time of transition, all radiology departments and practices need to understand that changes are inevitable. Groups that optimally balance the points of the impossible trinity will be better positioned for the challenges to come. 

Richard Heller III, MD, MBA, is chairman of radiology at Advocate Children’s Hospital, Oak Lawn, Illinois, and is a partner with Radiology Imaging Consultants (Harvey, Illinois).


  1. Mehta N, Jha S. The Patient Protection and Affordable Care Act in a nutshell. J Am Coll Radiol. 2012;9(12):877-880.
  2. Carroll A. JAMA Forum — The “Iron Triangle” of Health Care: Access, Cost, and Quality. Published October 3, 2012. Accessed February 5, 2014.
  3. Heller RE 3rd. The total value equation: a suggested framework for understanding value creation in diagnostic radiology. J Am Coll Radiol. 2014;11(1):24-29.
  4. Gunderman RB. The efficiency expert. J Am Coll Radiol. 2013;10(1):63-64.