A new report details imaging markers that radiologists should look out for in potential coronavirus cases, but warns that experts cannot rely solely on modalities when diagnosing patients.
The brief, published Feb. 4 in Radiology, includes two new case studies on patients infected with 2019-nCoV, focusing on specific chest CT findings consistent with others who have been diagnosed with the illness. Researchers from Mount Sinai Health System in New York say imaging experts are central to responding to this deadly outbreak.
“The radiologist plays a crucial role in the rapid identification and early diagnosis of new cases, which can be of great benefit not only to the patient but to the larger public health surveillance and response systems,” said Michael Chung, MD, with Sinai’s Department of Diagnostic, Interventional and Molecular Radiology, and colleagues in the study.
This is especially true as the number of reported cases continues to climb. The evolving epidemic has claimed more than 400 lives, with some 20,000 cases reported worldwide, according to figures published Feb. 5 in JAMA.
Chung and colleagues looked back at 21 patients with coronavirus admitted to three hospitals in China. Analysis revealed the virus typically shows on CT as bilateral ground-glass and consolidative pulmonary opacities. Additionally, experts should look for nodular opacities, crazy-paving pattern and peripheral distribution of diseases. Chung et al. also found that lung cavitation, discrete pulmonary nodules, pleural effusions and lymphadenopathy are usually absent in those with 2019-nCoV.
Follow-up imaging in seven of eight individuals revealed mild or moderate progression of the disease. These patients are different from other published cases, Chung wrote, in that one initially had normal chest CTs, but developed a solitary nodular ground-glass lesion three days later. This phenomenon may represent the “very first radiographically visible manifestation of disease,” Chung added.
This situation, taken together with a second patient who had a normal follow-up CT four days after her initial exam, reveals imaging results aren’t sufficient for identifying 2019-nCoV.
“This suggests that chest CT lacks complete sensitivity and does not have a perfect negative predictive value,” Chung said. “We can’t rely on CT alone to fully exclude presence of the virus.”
Clinicians should also consider detailed exposure and travel history when looking at potential coronavirus cases, the researchers wrote.