Confronted with an unfamiliar respiratory disease with unknown hallmarks, physicians have turned to their colleagues in radiology for clinical clues to help them diagnose and treat coronavirus disease (COVID-19). Early on, hazy areas of increased density, or ground-glass opacity, discernible on the X-rays or CT scans of some patients’ lungs, caught the media’s attention as being sufficient for diagnosing COVID-19. “But there are dozens of things that could cause such areas of inflammation, so it’s not the basis for a diagnosis,” notes William H. Moore, MD, chief of thoracic imaging in NYU Langone Health’s Department of Radiology.

Dr. Moore and his colleagues have found that patients with a ground-glass configuration may actually do better than those whose lungs have denser air spaces. “The central portion of the lungs shown in this 3-D rendering of a CT scan is densely consolidated,” he notes, “suggesting a poor prognosis.” More peripherally, Dr. Moore adds, there are rounded areas of ground-glass opacities. The more disease in the lower lobe, he explains, the worse the outcome may be because that’s where most oxygenation occurs. “This kind of condition is something a radiologist might see once or twice in their career,” says Dr. Moore. “Hopefully, we’ll never see anything like it again.”