Interpretation of Imaging Chapter 3: Practical Application in Interstitial Lung Disease (ILD) Care

Watch Chapter 4 here.

Hello, and welcome back to the Interstitial Lung Disease Explainer Video Series. I am Dr Joseph Mammarappallil, a cardiothoracic radiologist at The Duke Medical Center. This series focuses on interpreting high-resolution computed tomography, or HRCT, specifically in diagnosing and characterizing progression in interstitial lung diseases, or ILDs. In this video, you will learn how to recognize key imaging patterns, understand their clinical implications, and integrate radiology findings into multidisciplinary care. 

UIP, NSIP, organizing pneumonia, and LIP each have distinct HRCT patterns, but some cases remain indeterminate. 

Collaborating closely with pulmonology and radiology, whether through formal multidisciplinary review or informal consultation, can further strengthen interpretation and ensure that subtle or overlapping findings are correctly understood in the patient’s full clinical context. 

While HRCT provides essential insights for the diagnosis and monitoring of ILDs, it should be interpreted alongside pulmonary function tests, or PFTs, and the patient’s signs and symptom assessments. 

HRCT findings, combined with changes in forced vital capacity, diffusing capacity of the lung for carbon monoxide, and the patient’s clinical history, provide critical context for detecting disease and assessing progression over time. 

Together, these insights can help guide timely decisions and optimize patient care. 

When you first evaluate a patient with a SARD who is at high risk for ILD, the 2023 ACR and CHEST guidelines recommend obtaining a baseline HRCT. 

This initial HRCT allows you to compare findings over time, identify new abnormalities, and distinguish progression from stable disease. As patients are followed longitudinally, repeating HRCT, along with PFTs and ambulatory desaturation, provides a more complete assessment of changes across both structure and physiology. With a defined baseline and objective follow-up measures, you can recognize subtle progression earlier and make confident, data-driven decisions.

When evaluating HRCT, start by comparing the current scan with the patient’s baseline. Look for new or expanding areas of ground-glass opacity, increased reticulation, or early honeycombing, features that can signal fibrotic progression. Assess whether abnormalities remain stable in extent or distribution, or if there is clear evidence of architectural distortion. Pair these imaging findings with PFT trends and the patient’s symptoms to establish concordance between structural and physiologic data. 

This structured review process ensures that each scan is interpreted in context, providing clarity on whether ILD is stable or evolving. Documenting HRCT findings alongside PFT data and symptom assessment helps build a clear longitudinal record of disease behavior. Over time, this comparison defines the patient’s trajectory and supports confident decision-making. 

The key takeaway is that HRCT brings clarity to the clinical picture of ILD. With the support of multidisciplinary colleagues, even complex scans become manageable. This structured approach not only guides diagnosis and monitoring but also creates a clear clinical story that supports ongoing management decisions. 

ACR – American College of Rheumatology 

ATS – American Thoracic Society 

CHEST – American College of Chest Physicians 

CTD-ILD – Connective Tissue Disease–Related Interstitial Lung Disease 

DLCO – Diffusing Capacity of the Lung for Carbon Monoxide 

ERS – European Respiratory Society 

FVC – Forced Vital Capacity 

GGO – Ground-Glass Opacity 

HRCT – High-Resolution Computed Tomography 

ILD – Interstitial Lung Disease 

IPF – Idiopathic Pulmonary Fibrosis 

JRS – Japanese Respiratory Society 

LIP – Lymphocytic Interstitial Pneumonia 

MDD – Multidisciplinary Discussion 

NSIP – Nonspecific Interstitial Pneumonia 

OP – Organizing Pneumonia 

PFTs – Pulmonary Function Tests 

SARDs – Systemic Autoimmune Rheumatic Diseases 

UIP – Usual Interstitial Pneumonia 

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