Roundtable: Can We Reduce CT Radiation in the ER?

  • Share
  • Read Later
Tetra Images / Corbis

Last week, the Medical Insider column explained why doctors have so much trouble managing patients with abdominal pain in the emergency department (ED). Not least among the challenges: the multiplicity of causes of belly pain, the lack of clarity on which tests and treatments are best for which patients, and high cost.

This week we sought solutions — both to these issues and to the questions that readers submitted on's Facebook page over the past week. We put the matter to a roundtable of medical experts — all of whom conduct research or practice emergency medicine firsthand — and what ensued was a lively conversation, an edited version of which appears below.

In their dissection of the issue of belly pain, the single most common reason Americans end up in the ED, our panel members offered illuminating thoughts about the risks of radiation from CT scans, the advantages of electronic medical records and the unintended consequences of policies designed to improve care and reduce cost. They proposed answers to key questions and raised some of their own.

Dr. Zachary F. Meisel, Robert Wood Johnson Foundation clinical scholar and emergency physician at the University of Pennsylvania:

Hi, all:

Thanks for participating in this forum. All of you have unique experience in emergency care, radiology, research on abdominal pain and policies that touch on the way we care for those painful belly-pain cases that we see in the emergency department all the time. I'd like to start this conversation with some questions I have been getting from readers.

Many were concerned about the radiation risks associated with CT scans. How many scans are too many? And do we have any evidence on which emergency patients with belly pain might not need CT?

Dr. Angela Mills, assistant professor of emergency medicine at the University of Pennsylvania:

Patients with a known history of kidney stones who are having their typical symptoms may not need another CT. Ultrasound is also being used more frequently in the evaluation of kidney stones and could be utilized either in the ED or in the outpatient setting when patients see their doctors for follow-up care.

Dr. Brigitte M. Baumann, head of clinical research, department of emergency medicine at Cooper University Hospital:

Yes ... We saw a young woman, mid-20s, who had had her 19th CT to evaluate kidney stones in a local ED. Nineteen CTs over four years is quite a radiation dose in a young woman of childbearing potential.

Dr. Aaron Sodickson, assistant director of emergency radiology, Brigham and Women's Hospital:

I'd like to add some information about approximately how large the risks are thought to be from CT scans of the abdomen, as there is a great deal of confusion about this both by patients and their doctors. While there's a good deal of controversy over exactly how great the risks are for low-level radiation exposure, the most commonly used risk models predict that a single CT scan of the abdomen would increase a patient's risk of cancer by approximately 1 in 1,000 for a 32-year-old woman or a 19-year-old man. These risks increase for younger patients and decrease for older patients.

This increase in risk is on top of the baseline cancer rate of 42% in the U.S. (so that a single scan is expected to increase risk from 42% to 42.1%). For this reason, I become far more concerned about patients who have a large number of scans over time, resulting in more sizable cumulative risk increases. At our institution, we've found that one-third of our patients have had at least five CT scans within the past 20 years, and 5% of our patients have had at least 22 scans. Seven percent of our patients have had enough prior CT imaging to increase their cumulative cancer risk by 1% or more above that baseline 42% rate (if our risk models are correct). These are the patients that need more serious scrutiny of radiation dose.

For the abdominal pain patient who is a newcomer to the ED and has not had much prior radiation exposure, a CT scan that can provide valuable clinical information is often the right choice, especially if it means directing a patient toward a needed surgery, or on the flip side, avoiding a potentially unnecessary surgery.

But we've all seen many patients who come to the ED for recurrent abdominal pain, some of whom carry known diagnoses, some of whom have repeatedly defied diagnosis. In certain scenarios where the clinical question is narrowly focused — is there an obstructing kidney stone or not — we can devise diagnostic algorithms that may allow us to avoid imaging in some of the patients.

Unfortunately, though, most of our abdominal pain patients don't fit neatly into well-defined categories. Their symptoms or clinical findings could be seen in a large variety of conditions, and CT without question provides the greatest survey of all these potential causes. There is not a simple alternative test that uses less radiation: plain X-ray studies are extremely limited in what they can uncover. Ultrasound is a great test for certain focused questions but does not provide the same broad overview as CT, and as a result, a negative or indeterminate ultrasound often leads to a later CT (sometimes increasing cost and delaying care over performing a CT from the start). MRI is finding growing uses in the ED, particularly for pregnant patients, but similarly, it does not perform as well as CT for a broad range of possible diagnoses.

I, too, think we are overimaging. The problem is that it's very difficult to tell ahead of time which patients we can safely not image.

Dr. Ali Raja, associate director for trauma, Brigham and Women's Hospital:

Brigitte and Angela, you're absolutely right — scans for [kidney] stones are some of the most commonly repeated studies. But one of the pitfalls we have to avoid is coming up with protocols that decrease CT utilization without considering the "episode of care," rather than just the ED visit.

For example, if we send the kidney-stone patient home from the ED and have him follow up with a urologist or primary-care doctor, he will likely get that CT anyway. And he now has to make two visits and get charged twice.

At our hospital, we're just finalizing a protocol to decrease overall kidney CT use by working with our radiologists and urologists. That way, when we decide not to scan someone's kidneys in the ED, we can be sure that the urologists would have made the same decision, and we can avoid simply delaying imaging.

Dr. Baumann, Cooper University:

Ali, it's great that you are able to work with the urologists and radiology to come up with such a protocol. I'm sure that will work well for those patients who are able to follow up with the urologists or with their own primary-care physician.

I think the hardest thing is deciding what to do for patients who don't have a primary-care doctor and use the ED for both their primary and urgent-emergent care. At my institution, we have a fairly large population of such patients. One thing that has helped us enormously is our new electronic medical record (EMR). Now we can see how often a patient has come to the ED for a particular complaint, like abdominal pain, and we can also see how many CTs they've had.

Certainly for patients who have had chronic abdominal pain, seeing three CTs documented on the radiology system over the past year or so, we may rethink ordering that fourth CT, particularly if all other testing is normal.

Dr. Mills, University of Pennsylvania:

Yes, I agree. The electronic medical record has helped tremendously, although it may be limited when patients seek care at different institutions. Unfortunately, medical records from other hospitals are often not available on the off-hours or the majority of time we care for patients in the ED. In addition, as patients may not know or report prior imaging studies, the physician may not think to look for this information.

I am currently working with our radiologists to provide emergency physicians with information on prior imaging by using the electronic medical record. We will study if providing this information in real-time [electronically] will better inform medical decisionmaking in abdominal-pain patients.

Dr. Sodickson, Brigham and Women's:

We, too, believe that computer methods can be helpful to display relevant information from the electronic medical record to the doctor ordering a new test. There's a tremendous amount of information available in the EMR that is challenging to digest rapidly when trying to make quick decisions about how best to care for a patient.

We've been working on methods to extract a patient's radiation-dose history from the EMR and to present this to the doctor ordering a new imaging exam. We hope that by better defining the size of the cumulative risks, doctors and patients will be better able to make these risk-benefit decisions. This will generally be reassuring information for patients who have not had a lot of prior imaging (as their risks are very small), and may help to appropriately adjust the threshold for imaging in our frequently imaged patients.

Dr. Baumann, Cooper University:

The other sad piece to this issue is that reimbursement for "thinking" and "counseling patients" is pretty low. Hospitals generate revenue (and keep their doors open) by doing studies and by having the doctors do more tangible things like procedures.

But I think we can make the argument that if we are able to avoid an unnecessary CT, we've helped that patient and allowed for the next patient to leave the waiting room and start their care. Hospitals should endorse this.

Dr. Meisel, University of Pennsylvania:

Guys, I am loving this discussion. Brigitte brings up an important concept related to the financial incentives to do more tests.

So how are we going to incentivize doctors and patients to do the right thing — get the test when it is needed but not too much otherwise?

Dr. Baumann, Cooper University:

This is a really complicated question, and the answer is complicated as well. There will likely be several approaches to reduce unnecessary radiation.

Increased patient education is important. I've found that when patients are given information about the risks, they are able to participate in these decisions as well, and in select cases, a watchful waiting approach may be appropriate.

Increased physician education is also needed: our study demonstrated poor understanding of radiation risk and exposure by both emergency physicians and radiologists. The better we are educated, the better we can make informed decisions for our patients.

Emergency medicine is a risk-averse profession, meaning that our job is based on ruling out conditions that may lead to death or permanent disability. One of the less glamorous aspects of our job is the higher risk of lawsuit when we do miss something.

Finally, I'm not sure if hospitals or the FDA will be using an "incentivize" approach. I suspect that a "dis-incentivize" approach will be more likely, meaning, for physicians who order multiple imaging studies, doctors may end up receiving warnings from regulatory bodies and insurance companies and may be asked to justify why the test was ordered — along the lines of the letters we receive from insurance companies when patients have filled multiple prescriptions from multiple caregivers for narcotics. The future may also hold denials for payment by insurance companies for tests, if they are deemed unnecessary. We see this all the time with hospital admissions.

Dr. Raja, Brigham and Women's:

Brigitte, I think you've hit the nail on the head on all counts. A few more thoughts occurred to me when you mentioned dis-incentivization.

I think that we all agree that we are likely overusing radiation in at least a subset of patients. One strategy that has been used to measure appropriateness in a number of other clinical arenas is the use of publicly reportable quality measures — for example, how often patients with heart attacks are receiving aspirin or what proportion of patients have infections after certain operations. When these quality measures are based on good evidence from the medical literature — for example, aspirin definitely helps in patients with heart attacks — they may very well lead to better outcomes for our patients.

In the world of emergency radiology, there are a number of well-developed clinical decision rules from the U.S. and Canada that many of us are already working to convert into national quality measures. The really good clinical decision rules are designed to look for specific diagnoses: a neck fracture, a head bleed or a blood clot in the lungs, for example, and CTs for patients who don't meet the rules may very well be inappropriate. However, the abdomen simply has too many organs and too many possible diseases for a clinical-decision rule to cover them all, and I think that trying to measure inappropriate abdominal CT use would be a mistake unless we can come up with better evidence.

The danger is that, in an effort to curb utilization, some regulatory bodies may just start measuring overall use of abdominal CTs, rather than whether or not they are appropriate. Some hospitals simply see sicker patients — large trauma, stroke or cancer centers, for example — and may very well get more CTs than smaller hospitals, but the majority of those CTs still may be appropriate because of their sicker patients.

I'd hate to see federal regulations that tried to force doctors to not use abdominal CTs in these sicker patients just to keep their numbers down. We need to keep focusing on developing decision rules to help us decide whether or not CT use is appropriate for certain disease processes rather than just trying to decrease use across the board for everyone.

In the meantime, I still think that the best way to decrease abdominal CT use is to do exactly what Dr. Baumann did with her patient above. We should spend a few minutes talking to our patients, help them to see behind the curtain and understand that their physician really has put a lot of thought into whether or not they should get a CT scan, and then make a decision together. After all, the biggest risks — both of a missed diagnosis and also of the cancer that might develop from the radiation due to an unnecessary CT — are theirs.

Dr. Sodickson, Brigham and Women's

Well said, Ali. It is quite troubling to think about regulating or otherwise curbing utilization without relevant evidence, which, as Ali points out, is quite lacking in the abdomen due to the multitude of possible diagnoses with overlapping clinical presentations. Lacking validated clinical-decision rules, simply setting a target "usual" rate of imaging fails to capture variability in patient mix and other resources, and could well lead to inappropriate under-utilization and harm in patients who need a definitive diagnosis.

Let's be sure not to blur the lines too much between cost control, resource utilization-availability and radiation risk reduction. As we've already discussed, the radiation risks are actually quite small for most patients who have not had much cumulative imaging. It's a different story for frequently imaged and younger patients, in whom we ought to adjust our threshold for imaging when possible.

From a resource-utilization perspective, it is an unfortunate reality that most places have much more limited access to MRI or ultrasound after hours. In an ideal world, our clinical operations and available options would not vary with time of day or day of the week. But this is generally only possible at larger hospitals. Similarly, access to the necessary radiologist expertise for interpretation is often not possible 24/7.

The major drive to curb imaging use comes from the desire to control costs, an important effort when it can be done without causing harm, ideally by eliminating only the "unnecessary" or "inappropriate" exams. Without validated decision rules, this is unfortunately a very challenging task to figure out ahead of time. It's much easier to make a determination that a test was inappropriate after the fact, once the imaging findings and the clinical outcome are known!

Defensive medicine may play an important role here. A 2008 survey by the Mass Medical Society concluded that up to one-third of CT scans in the ED may have been motivated by defensive medicine rather than true medical need. Tort reform and modified patient expectations could help somewhat here, but I'm not holding my breath on either front.

Our fee-for-service reimbursement model also works against genuine efforts to reduce utilization. This has been implicated on a large scale in dramatic rates of excessive imaging in self-referral situations in which physicians own the imaging equipment and benefit financially from the imaging procedures they order. We do need to rethink our reimbursement models so that medical practices can remain financially viable if they do a good job taking care of their patients, even if they opt not to perform tests they do not think are necessary.

How exactly to do this is, of course, the subject of highly controversial and politically charged debates these days.

Dr. Meisel, University of Pennsylvania:

Well, thank you all. This is great. We have a lot of work to do figuring out the best ways to treat our belly-pain patients. But it's clear that smart approaches and evidenced-based policies can work. We just have to make sure that we navigate the minefields so we can take the best possible care of our patients.

Medical Insider, Dr. Meisel's column for, appears every Wednesday.