This document discusses the mosaic pattern seen on CT scans of the chest. It describes how the pattern shows areas of increased and decreased density that correspond to areas of ground glassing and air trapping, respectively. The black areas represent air trapping and can be seen in conditions like bronchiolitis obliterans, sarcoidosis, and asthma. The white areas represent ground glassing and alveolitis/pneumonitis, seen in diseases like desquamative interstitial pneumonia and nonspecific interstitial pneumonia. The mosaic pattern results from airway disease causing air trapping or alveolitis/pneumonitis causing ground glassing.

2. Mosaic Patternitie
By
Gamal Rabie Agmy , MD , FCCP
Professor of Chest Diseases ,Assiut University

3. Mosiac pattern

4. Where is the pathology ???????
in the areas with increased density
meaning there is ground glass
in the areas with decreased density
meaning there is air trapping

5. Pathology in black areas
Airtrapping: Airway
Disease
Bronchiolitis obliterans (constrictive bronchiolitis)
idiopathic, connective tissue diseases, drug reaction,
after transplantation, after infection
Hypersensitivity pneumonitis
granulomatous inflammation of bronchiolar wall
Sarcoidosis
granulomatous inflammation of bronchiolar wall
Asthma / Bronchiectasis / Airway diseases

6. Airway Disease
what you see……
In inspiration
sharply demarcated areas of seemingly increased
density (normal) and decreased density
demarcation by interlobular septa
In expiration
‘black’ areas remain in volume and density
‘white’ areas decrease in volume and increase in
density
INCREASE IN CONTRAST
DIFFERENCES
AIRTRAPPING

7. Bronchiolitis
obliterans

8. Early Sarcoidosis

9. Chronic
EAA

10. Hypersensitivity pneumonitis
Extr. Allerg. Alveolitis (EAA) HRCT
Morphology
chronic: fibrosis
Intra- / interlobular septal thickening
Irregular interfaces
Traction bronchiectasis
acute - subacute
acinar (centrilobular) unsharp densities
ground glass (patchy - diffuse)

13. Pathology in white Areas
Alveolitis / Pneumonitis
Ground glass
desquamative intertitial pneumoinia (DIP)
nonspecific interstitial pneumonia (NSIP)
organizing pneumonia
In expiration
both areas (white and black) decrease in
volume and increase in density
DECREASE IN CONTRAST
DIFFERENCES

14. DI
P

15. Cellular
NSIP

16. Mosaic Perfusion
Chronic pulmonary embolism
LOOK FOR
Pulmonary hypertension
idiopathic, cardiac disease, pulmonary
disease

17. CTEPH =
Chronic thrombembolic
pulmonary hypertension