Some EPs err on the side of ordering imaging tests because they do not want to miss something — or be sued for malpractice.

“Many radiologists attribute increasing volumes of imaging studies to defensive medicine ordering practices,” says Alexander Villalobos, MD, a diagnostic radiology resident at Emory University School of Medicine in Atlanta.

Villalobos and colleagues set out to answer the compelling (and controversial) question: “Does the litigation environment affect the way doctors order imaging tests?”1

“Before our study, no one had thoroughly evaluated the multiyear impact of the malpractice environment on imaging practice patterns at a national or even regional level,” Villalobos offers.

Researchers analyzed advanced Medicare imaging use and paid malpractice claims, examining claims data for a 5% sample of Medicare beneficiaries from 2004 to 2016 and the National Practitioner Data Bank. For every 1% increase in the number of paid malpractice claims, there was a corresponding 0.20% increase in advanced imaging use.

The increase might seem small, but it amounts to much additional imaging. One paid malpractice claim was associated with an average of 1,389 additional advanced imaging exams in the subsequent year, and that is just in the Medicare population, Villalobos reports.

“Imaging utilization in the ED setting has grown considerably, and disproportionately, compared to other sites of service,” Villalobos notes.2,3

The authors of one study found that cervical spine imaging for Medicare patients in EDs more than tripled between 1994 and 2012.4 Radiography declined by 27% during this period, but CT scans increased dramatically — more than 8,000%.

“While our recent paper shows that part of this increase in CT utilization is driven by the litigation environment, it is more likely that improved access, scanning efficiency, and overall outcomes have predominantly driven this huge increase,” Villalobos notes.

Another study revealed the use of advanced imaging (defined as CT scans or MRIs) increased significantly from 1996 to 2014. For patients with a headache, the percentage increased from 17.5% to 33.3%. For those with urinary calculus, the percentage increased from 0% to 48.5%.5

All this advanced ED imaging is adding to, rather than replacing, other imaging modalities. Radiography and ultrasound use rates remained grossly unchanged within this period.5

“Advanced imaging has significantly increased in the ED setting, and its use has unfortunately not been displaced by similar decrease in the utilization of non-advanced imaging,” Villalobos laments.

Many ED patients undergo both non-advanced imaging and advanced imaging. An example would be a patient who comes to the ED with minor trauma to the neck. The EP may decide to obtain a CT of the cervical-spine (C-spine) without contrast first, and it clearly shows no acute fracture or traumatic malalignment of the C-spine.

This might be unnecessary. It is unlikely to add more information about an acute fracture or traumatic malalignment than what the CT C-spine without contrast has provided. “One could argue that a flexion and extension C-spine radiograph may be worth pursuing after a CT C-spine without contrast to evaluate for more subtle pathologies,” Villalobos offers.

The work by Villalobos and colleagues suggest defensive medicine is driving at least some of the surge in ED imaging. “It is our hope that highlighting the impact of medical malpractice on actual physician practice patterns will be beneficial to the design of targeted policy and delivery system interventions aimed at helping control the ED imaging volume and costs,” Villalobos says.

Several clinical decision algorithms have been created to curb the unnecessary use of imaging, such as the National Emergency X-Radiography Utilization Study and the Canadian C-Spine Rule.6

Potentially medically inappropriate CT C-spine scans decreased from 45% to 22% after a clinical decision-making tool was added to the EHR and ED clinicians were educated on the criteria.7

“Nevertheless, clinical decision support systems are not widely implemented into daily clinical practice at this time, or at least not as wide of a scale as it should be,” Villalobos says.

EPs may perceive the information provided by the tools is not valid, relevant, or convenient to use. “Many physicians and researchers are working on understanding the reasons for why physicians are not adopting clinical decision support systems as much as they should,” Villalobos says.

Villalobos suggests EPs become aware of all available tools for imaging use decision-making. It is not only software that can be consulted. Simply getting to know the radiology group can help reduce unnecessary imaging. Radiologists might note that a prior study can answer the EP’s clinical question.

“Sometimes, radiologists can save you time and your patients money by recommending a single study that answers multiple clinical questions at once,” Villalobos adds.


  1. Villalobos A, Horný M, Hughes DR, Duszak R Jr. Associations over time between paid medical malpractice claims and imaging utilization in the United States. J Am Coll Radiol 2020; Aug 19:S1546-1440(20)30788-2. doi: 10.1016/j.jacr.2020.04.035. [Online ahead of print].
  2. Selvarajan SK, Levin DC, Parker L. The increasing use of emergency department imaging in the United States: Is it appropriate? AJR Am J Roentgenol 2019;213:W180-W184.
  3. Levin DC, Rao VM, Parker L, Frangos AJ. Continued growth in emergency department imaging is bucking the overall trends. J Am Coll Radiol 2014;11:1044-1047.
  4. Gan G, Harkey P, Hemingway J, et al. Changing utilization patterns of cervical spine imaging in the emergency department: Perspectives from two decades of national Medicare claims. J Am Coll Radiol 2016;13:644-648.
  5. Rosenkrantz AB, Hanna TN, Babb JS, Duszak R Jr. Changes in emergency department imaging: Perspectives from national patient surveys over two decades. J Am Coll Radiol 2017;14:1282-1290.
  6. Saragiotto BT, Maher CG, Lin CWC, et al. Canadian C-Spine Rule and the National Emergency X-Radiography Utilization Study (NEXUS) for detecting clinically important cervical spine injury following blunt trauma. Cochrane Database Syst Rev 2018:CD012989.
  7. Baker M, Jaeger C, Hafley C, Waymack J. Appropriate CT cervical spine utilisation in the emergency department. BMJ Open Qual 2020;9:e000844.