To learn a step-by-step approach for narrowing the differential diagnosis of diffuse ground glass opacification (GGO). To identify differentiating clinical and radiologic features that point to the most probable differential diagnosis.
Diffuse GGO is a commonly encountered pattern in CT scans of the lung and can prove to be a very time-consuming finding,
as there are many possible differential diagnoses (1).
Following a step-by-step approach can help to narrow down the differentials,
as we will show in this exhibit.
Findings and procedure details
Pathophysiology of GGO on CT scans Ground glass opacifications are one of the most commonly encountered pulmonary patterns in chest CTs.
The underlying mechanism is an increase in density caused by a partial filling or collapse of the alveoli or the thickening of the interstitial tissue (Fig.
1). Alveoli may fill with: Transudate (pulmonary edema,
inflammatory reaction) Aspirated material Hyaline (ARDS) Mucins (mucinous adenocarcinoma of the lung,
pulmonary alveolar proteinosis) Pus Blood...
Three questions guide the differential diagnosis of diffuse GGO: Is it a pathology? Is the GGO acute or chronic? What is the patient's medical history? Followed by the review of imaging findings regarding: Spatial and temporal distribution of GGO Ancillary imaging findings
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Ground-glass opacity at CT: the ABCs.
AJR American journal of roentgenology.
1997;169(2):355-67. (2) Müller NL,
Lee KS et-al.
Imaging of pulmonary infections.
Lippincott Williams & Wilkins.
(2007) ISBN:078177232X. (3) Collins,
and Eric J.
Chest Radiology: The Essentials.
Lippincott Williams & Wilkins. (4) Elicker,
Fundamentals of High-Resolution Lung CT: Common Findings,