New Imaging Recommendations for Suspected COVID-19

Viral testing remains the only specific method of diagnosis. Confirmation with the viral test is required, even if radiologic findings are suggestive of COVID-19 on CXR or CT.
• For the initial diagnostic testing for suspected COVID-19 infection, the CDC recommends collecting and testing specimens from the upper respiratory tract (via nasopharyngeal and oropharyngeal swabs) or from the lower respiratory tract when available for viral testing.
• The findings on chest imaging in COVID-19 are not specific, and overlap with other infections, including influenza, H1N1, SARS and MERS. Being in the midst of the current flu season with a much higher prevalence of influenza in the U.S. than COVID-19, further limits the specificity of CT.

Additionally, there are issues related to infection control in health care facilities, including the use of imaging equipment. Primary care and other medical providers are attempting to limit visits of patients with suspected influenza or COVID-19 to health care facilities. In addition to environmental cleaning and decontamination of rooms occupied by a patient with suspected or known COVID-19 infection, air-flow within fixed radiography or CT scanner rooms should be considered before imaging the next patient. Depending on the air exchange rates, rooms may need to be unavailable for approximately one hour after imaging infected patients.

Based on these concerns, the ACR recommends:

1. CT should not be used to screen for or as a first-line test to diagnose COVID-19
2. CT should be used sparingly and reserved for hospitalized, symptomatic patients with specific clinical indications for CT. Appropriate infection control procedures should be followed before scanning subsequent patients.
3. Facilities may consider deploying portable radiography units in ambulatory care facilities for use when CXRs are considered medically necessary. The surfaces of these machines can be easily cleaned, avoiding the need to bring patients into radiography rooms.
4. Radiologists should familiarize themselves with the CT appearance of COVID-19 infection in order to be able to identify findings consistent with infection in patients imaged for other reasons.

Related Links:
American College of Radiology