Almost 60% of Chest X-Rays ‘Normal,’ May Be Inadequate in COVID-19

Among cases of confirmed COVID-19, 58.3% of chest x-rays read as “normal,” with 89% reading as either normal or “mild,” reported Michael Weinstock, MD, of Wexner Medical Center at The Ohio State University in Columbus, and colleagues, in the Journal of Urgent Care Medicine.
The authors described their study as “the largest observational study to date” to examine “plain film radiographic findings” among patients with COVID-19, adding that earlier studies have focused predominantly on CT imaging, but “cost and practical considerations” limit that imaging modality’s use among patients in ambulatory care settings.

Weinstock noted because most COVID-19 patients do not have severe illness, this is likely the population clinicians will be seeing, where their symptoms are severe enough to seek care.
“These patients are going to present to their primary care physician, or urgent care or an emergency department [ED]; they’re part of the ‘walking wounded.’ We were surprised when we started looking at it, because there was almost no data in ambulatory patients … but most patients assessed are going to be in this population,” he told MedPage Today.
Researchers examined data from a large urgent care company in the greater New York City area, focusing on patients who tested positive for SARS-CoV-2, the virus that causes COVID-19, who also underwent a chest x-ray from March 9 to March 24. Eleven board-certified radiologists who knew they were reading images from COVID-19 patients reviewed the chest x-rays and classified the findings as normal, mild, moderate, or severe disease.

Overall, 636 chest x-rays were reviewed. Patients ranged in age from 18 to 90, and 57% were men. Over three-quarters of patients were ages 30-70.
The authors noted that, of the approximately 42% of chest x-rays reading as abnormal, 195 demonstrated mild disease, 65 had moderate disease, and five had severe disease. Most common descriptive findings were interstitial changes (23.7%) and ground glass opacities (19%). About a third of these abnormalities were in the lower lobe, though a quarter were multifocal and about 21% were bilateral. Effusions and lymphadenopathy were uncommon, they added.
Interestingly, researchers noted original readings from medical records classified about 74% of the original chest x-rays as “normal.” When they were re-read for this study, 97 were changed to abnormal, though two patients with an initial finding of “possible pneumonia” were changed to “normal,” they noted.
Limitations to the data include its retrospective and observational nature, and that only a single chest x-ray series was obtained for each patient, meaning it was impossible to determine if patients developed radiographic findings as the illness progressed. They also noted a lack of underlying health histories or basic chest x-rays to identify chronic pulmonary conditions. Finally, the radiologists were not blinded to the fact the patients had been diagnosed with COVID-19, which may have impacted their classification of the images.

Weinstock shared an anecdote about treating a patient in the ED with longer term, concerning medical conditions and symptoms of COVID-19, who was tested for the illness, but the test wouldn’t be back for a few days.
“We did a chest x-ray and it came back negative. If that patient had severe symptoms, that shouldn’t be reassuring to us,” he said.

Disclosures

Weinstock disclosed serving as senior editor, clinical at the Journal of Urgent Care Medicine.

Primary Source

The Journal of Urgent Care Medicine

Source Reference: Weinstock MB, et al “Chest x-ray findings in 636 ambulatory patients with COVID-19 presenting to an urgent care center: A normal chest x-ray is no guarantee” Journal of Urgent Care Medicine 2020.

https://www.medpagetoday.com/infectiousdisease/covid19/85985