New Consensus Aims to Align Post-COVID CT Imaging Practices

Chest CT lung abnormalities after COVID-19 infection tend to stabilize or regress over time, indicating that they are nonprogressive and postinfectious in nature. A new consensus statement aims to standardize CT imaging practices of post–COVID-19 residual lung abnormalities.1

“These include differentiating between persistent residual lung abnormalities from COVID-19—such as ground glass opacity—and any fibrotic alterations, as well as assessing the temporal evolution of these findings. It is essential to distinguish post-COVID-19 residual lung abnormalities from interstitial lung abnormalities (ILA) and interstitial lung diseases (ILD), particularly fibrotic ones, as they have very different clinical implications. Post-COVID-19 abnormalities generally stabilize over time, while ILAs and ILD can progress and have a poor prognosis," investigator Anna Rita Larici, MD, Assistant Professor at Catholic University of the Sacred Heart of Rome, and Clinical Radiologist at the Department of Diagnostic Imaging, Oncological Radiotherapy and Hematology, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, said in a statement.2

Larici and colleagues stated in their paper that residual lung abnormalities on CT scans after COVID-19 respiratory infection may be associated with persistent or progressive respiratory symptoms and frequently correlate with abnormal pulmonary function testing results, which are currently described in varying terms.1

The investigators, which consisted of 21 thoracic radiologists from the European Society of Thoracic Imaging, the Society of Thoracic Radiology, and the Asian Society of Thoracic Radiology put together a multisociety consensus statement, developed with a 2-round survey process. The statement sought to standardize the indication, acquisition, and reporting of post–COVID-19 residual lung abnormalities on CT scans.

"Ours is a best practice guideline, a consensus statement that emerged to promote a uniform approach to the diagnosis of lung changes in CT scans of patients with persistent long COVID symptoms: it guides the radiologist to address clinical practice, like deciding when to perform a chest CT scan (only in cases of persistent symptoms and functional abnormalities), how to perform the CT scan, and when to repeat it, avoiding improper patient management, which would initiate a diagnostic process for pulmonary fibrosis with numerous CT scans and other tests that are unnecessary for long COVID patients; in fact, she concludes, only a very small percentage of patients have permanent post-COVID-19 fibrosis. Although we don’t have definitive estimates, these cases seems to be extremely rare,” Larici said.2

Key recommendations include conducting chest CT scans in patients who have persistent or worsening respiratory symptoms 3 months after infection, with these symptoms lasting for at least 2 months and with no other explanation; utilizing low-dose CT protocols (typically ranging from 1 to 3 mSv) for follow-up CT imaging; applying the Fleischner Society glossary for radiologic terminology; and refraining from using the term “interstitial lung abnormality” to describe post–COVID-19 findings. To avoid mischaracterizing these findings as early signs of interstitial lung disease, the preferred terminology is “post–COVID-19 residual lung abnormality.”

“Using the right name is essential, she explains, in order to refer the patient for appropriate follow-up and avoid misinterpreting post-COVID-19 lung abnormalities as an early manifestation of interstitial lung disease. Therefore, the term ‘post-COVID-19 residual lung abnormalities’ should always be used in these patients, and references to pulmonary fibrosis, which is a very different and, above all, progressive disease, should always be avoided,” Larici said.2

The consensus authors shared their hope that the statement will align clinical practice with research efforts to support accurate and effective patient management amid the evolving landscape of post–COVID-19 care for the large population of affected individuals.

REFERENCES

Yook SH, Kanne JP, Ashizawa K, et al. Best Practice: International Multisociety Consensus Statement for Post–COVID-19 Residual Abnormalities on Chest CT Scans. Radiol. Published online July 22, 2025. doi: 10.1148/radiol.243374

Post-COVID-related lung abnormalities almost always regress. News release. Universita Cattolica del Sacro Cuore. July 22, 2025. https://www.eurekalert.org/news-releases/1091846