Testing kits for the SARS-CoV-2, the virus that causes COVID-19, have been in short supply, hard to access, and slow to give results. So, why are chest x-rays not used for COVID-19 screening? Digital x-rays are nearly instantaneous, and many chiropractor and doctor’s office x-ray machines sat unused for most of the early days of the pandemic when testing was particularly hard to come by. It may seem like it would have been a natural solution to the problem, but in March, the American College of Radiology (ACR) recommended against using chest x-ray and CT scans as a COVID-19 screening tool1.
The primary reason behind this recommendation is that it is not a very precise tool for determining if an individual has SARS-CoV-2. An x-ray can only show the presence of an infection, not the virus itself. As we have been learning, many people who have the virus are asymptomatic or have very mild symptoms. Thus, using chest x-rays for screening can lead to false negatives and further spread of the virus. A molecular RT-PCR test will find the SARS-CoV-2 virus even if the patient shows no symptoms.
Secondly, COVID-19 doesn’t have a distinct enough appearance on imaging compared to other infections or pneumonia. So, even if the x-ray images indicated an infection, follow-up testing would need to be done to make a diagnosis. Finally, there is concern that using x-ray equipment on COVID-19 positive patients could have actually increased spread of the disease by contaminating the indoor space and hardware where the imaging equipment is installed.
X-rays and CT scans, however, do play an extremely important role in a patient’s care once they have been diagnosed and are admitted to the hospital where doctors need to monitor their care. They are very effective in showing the severity of the disease and its progression throughout treatment. This is shown in the picture above in x-rays taken over a 72-hour period of the same patient2.
One study used x-rays to link COVID-19 and Racial Disparity3. The authors showed that people of color were admitted to the hospital for COVID-19 treatment with more advanced disease than their white counterparts. This analysis was done using chest x-rays upon admittance to the hospital. X-rays do play a vital role to play in our fight against COVID-19 – just not as a screening tool.