From the 2019 HVPAA National Conference
Dr. Alice Yu (Johns Hopkins Department of Radiology), Dr. Yoshimi Anzai (University of Utah), Dr. Pamela Johnson (Johns Hopkins Department of Radiology)
Abdominal CT is one of the leading contributors to medical radiation exposure, and protocols with more than one acquisition can deliver 2-4 times more radiation than a single acquisition. Furthermore, an abdominal CT protocol that includes unenhanced images followed by IV contrast enhanced acquisition(s) (‘CT with and without’) is a higher cost exam than either CT with IV contrast or CT without IV contrast. Nonradiology providers are tasked with selecting from these 3 protocols when ordering an abdominal CT, but traditionally have not received formal education on appropriate indications for abdominal CT with and without IV contrast. The purpose of this study was to evaluate ordering providers’ understanding of when to order abdominal CT with and without IV contrast and simultaneously educate them on appropriate practice.
A survey was created to query ordering providers’ understanding of the the appropriate abdominal CT protocol for 10 clinical scenarios:
- suspect appendicitis
- AAA s/p endovascular repair
- painless gross hematuria
- painless jaundice
- adrenal nodule characterization
- GI bleeding
- severe pancreatitis
- refractory pyelonephritis
- suspect embolic complications of endocarditis
Possible responses for each scenario included:
- CT without oral or IV contrast
- CT with oral contrast CT with oral and IV contrast
- CT with IV contrast only
- CT with and without IV contrast
Correct answers were based on the new ACR Choosing Wisely® recommendation for abdominal CT protocol selection: https://www.choosingwisely.org/clinician-lists/acr-abdominal-ct-with-unenhanced-ct-followed-by-iv-contrast-enhanced-ct/.
Additional questions addressed participants understanding of how abdominal CT with and without contrast is performed and relative exam costs, as well as demographic questions about specialty, level of training and geographic location. After each question, results were immediately available with explanations for questions answered incorrectly and links to relevant ACR Appropriateness Criteria® or Choosing Wisely® resources and/or a JACR article on abdominal CT protocol appropriateness for more information. The IRB of the principle institution acknowledged this as a quality improvement project exempt from approval. The survey was distributed to ordering providers at multiple academic centers in March-April 2018. Performance was correlated with training level and medical specialty.
101 medical providers participated including:
- 39 nonradiology residents (16 surgery, 10 emergency medicine, 10 internal medicine and 3 other)
- 25 radiology residents
- 22 advanced practice providers (nurse practitioner or physician assistant)
- 12 nonradiology attendings
- 3 radiology attendings
The average score was 10.61 out of 14 questions correct for radiology respondents and 6.60/14 for nonradiologists (p<0.0001). The mean score for radiology respondents (10.61) was significantly higher than emergency medicine (7.00, p<0.0001), surgery (7.23, p<0.0001) and medicine providers (5.53, p<0.0001). The mean score for medicine respondents was significantly lower than emergency medicine (5.53 vs. 7.00, p=0.02) and surgery (5.53 vs. 7.23, p=0.03) respondents. Nonradiology faculty average score was significantly lower than radiology residents (6.83 vs 10.48, p<0.0001). Advanced practice providers average score was also lower than radiology residents (5.32 vs 10.48, p<0.0001) and nonradiology residents (5.32 vs 6.74, p=0.02).
Nonradiology medical providers at all levels of experience lack understanding about abdominal CT protocol appropriateness. To perform imaging of the highest quality, safety and value, radiologists must be responsible for appropriate protocol selection for each patient, particularly when CT protocols differ in radiation exposure and cost.