Radiologists, pulmonologists to discuss identification of interstitial lung abnormalities

Interstitial lung abnormalities (ILAs) are incidentally identified in up to 10% of patients who undergo CT scan imaging, but radiologists and pulmonologists have been unsure of how to diagnose and manage these patients who are asymptomatic. There is a growing amount of evidence, however, suggesting that ILAs progress over time and are associated with impaired pulmonary function and mortality, according to Joe Mammarappallil, MD, PhD, Associate Professor of Radiology in the Division of Cardiothoracic Imaging at Duke University School of Medicine and Duke University Medical Center.

A panel of experienced radiologists and pulmonologists will discuss the identification and clinical management of ILAs during the CHEST 2025 session Interstitial Lung Abnormalities: Recognition and Risk Stratification at 3:15 pm CT in McCormick Place, Lakeside Center, Room 352. Dr. Mammarappallil will serve as Co-Chair of the session.

“The concept of interstitial lung abnormalities emerged in the early 2010s, initially as a catch-all term for unexplained interstitial changes in [patients who are asymptomatic],” he said. “We’d sometimes see subtle imaging findings that weren’t quite pulmonary fibrosis but didn’t look entirely normal either. We weren’t really sure what to make of them.”

Over the past decade, accumulating evidence has shown that a subset of these findings can progress to clinically significant pulmonary fibrosis, he said, underscoring the importance of early recognition and risk assessment.

Joining Dr. Mammarappallil to discuss the identification and clinical management of ILAs will be session Co-Chair Anthony Esposito, MD, FCCP, Assistant Professor of Medicine, Division of Pulmonary and Critical Care, Northwestern University Feinberg School of Medicine; Sean Callahan, MD, FCCP, Associate Professor of Medicine, Division of Pulmonary Diseases and Critical Care Medicine, University of North Carolina School of Medicine; and Lydia Chelala, MD, Assistant Professor of Radiology, University of Chicago Pritzker School of Medicine.

“In this session, we’ll approach ILA from both sides,” Dr. Mammarappallil said. “Our pulmonology colleagues, Dr. Esposito and Dr. Callahan, will talk about risk stratification because once you’ve identified ILA on a CT [scan], the question becomes, ‘Who is actually at risk?’”

That is where other clinical factors matter, he said, such as family history of pulmonary fibrosis, smoking history, autoimmune disease, and environmental exposures, all of which can push a patient into a higher-risk category.

“On the imaging side, Dr. Chelala and I will walk through how to actually define ILA on CT [scans],” Dr. Mammarappallil said. “We’ll cover not only the typical patterns but also the red herrings—the findings that may look worrisome but aren’t truly ILA, as well as the ones that do point toward progressive fibrosis.”

While many questions remain unanswered, there are early frameworks being developed for management of ILAs, he said.

“The American Thoracic Society and other groups have published early guidelines. The truth is, nobody has all the answers yet, but at least we’re beginning to standardize what we do,” Dr. Mammarappallil said. “We do know that early recognition matters, and that’s where ongoing study of ILAs may be a game changer and allow us to identify, risk-stratify, and ultimately better care for patients who might otherwise progress silently into pulmonary fibrosis.”