Fleischner Society Thoracic Imaging Glossary 2024: Practical Terminology
A practical guide to applying the Fleischner Society's 2024 thoracic imaging terminology consistently in CT interpretation and radiology reports.

The 2024 Fleischner Society glossary standardizes the words used to describe thoracic anatomy, physiology, and imaging abnormalities. Its practical value is consistency: a descriptive term should communicate an observable imaging feature without silently implying an unproven diagnosis. Terms must still be interpreted in the clinical setting and in relation to acquisition technique.
Anatomic foundations
- The acinus is the gas-exchanging unit distal to a terminal bronchiole and is not normally resolved on CT.