Part 2 Radiological Presentation of Infectious Diseases Flashcards
(43 cards)
What are the routes of infection of pneumonia?
> Tracheobronchial tree - most common route
> Hematogenous
> Direct from neighboring organs
What is the most common route of infection in pneumonia?
Tracheobronchial tree
What are the 3 broad imaging findings in pneumonia?
> Consolidation / Lobar pneumonia
> Bronchopneumonia
> Interstitial pneumonia
Consolidation / Lobar pneumonia is caused by what?
> Pneumococcal
> Klebsiella
Bronchopneumonia is caused by what?
> Staphylococcus
> Streptococcus pyogenes
Interstitial pneumonia is caused by what?
> Viral
> Mycoplasma pneumonia
> PCP /Pneumocystis jirovecii pneumonia
Pneumococcal and Klebsiella causes why type of pneumonia?
Consolidation / Lobar pneumonia
Staphylococcus and Streptococcus pyogenes causes what type of pneumonia?
Bronchopneumonia
Viral, Mycoplasma pneumonia, and PCP /Pneumocystis jirovecii pneumonia causes what type of pneumonia?
Interstitial pneumonia
Where does the infection start & spread in consolidation / lobar pneumonia? What part of the lungs does it involve?
> Infection starts in the alveoli and spreads to other alveoli
> It generally involves one whole lobe of the lung.
Where does the infection start & spread in bronchopneumonia?
> Infection starts in the bronchioles, and then it spreads to the alveoli.
Where does the infection start in interstitial pneumonia? What is its effect on the affected tissue?
> Interstitium gets infected and it becomes thickened because of the fluid present in the interstitium.
What is the supporting tissue for blood vessel and lung parenchyma?
Interstitium
What is the insterstitium?
It is the supporting tissue for blood vessel and lung parenchyma.
In consolidation pneumonia, there is replacement of air in alveoli with what?
> Fluid
> Pus
> Debris
In consolidation pneumonia, disease spreads by ___ and ____ through the interalveolar and interbronchiolar spaces.
> Pores of Kuhn
> Channels of Lambert
Opacification continues until it reaches the fissure
Lobar pneumonia
What is the air-bronchogram sign?
Bronchioles remain filled with air (dark appearance)
What do you call it when bronchioles remain filled with air?
Bronchogram sign
How does consolidation pneumonia appear on x-ray?
> Homogenous opacity obscuring the vessels
> Lobar opacification sharply defined at the fissures
> Segmental opacification due to early initiation of antibiotic treatment
> Air bronchograms
> Silhouette sign
> No volume loss
What is the Silhouette sign?
Loss of lung / Soft tissue interface
e.g. You are not able to see the silhouette of the lung and cardiac border because they are appearing on the same density.
Segmental opacification is due to what?
Early initiation of antibiotic treatment
What is the main difference between seeing opacities in lung collapse and consolidation pneumonia?
In consolidation pneumonia, you can see the air bronchogram and you can see that the upper lobe still maintain its size.
In consolidation pneumonia, when there is a patch of opacity in the right lower lung field, how would you know if the lobe affected is the middle or the lower lobe on PA or AP view?
Reference points:
> Costophrenic angles
> Diaphragm
> Right heart border
If you can see the costophrenic angles and diaphragm, but the right heart border is NOT visualized, then this is consolidation pneumonia in the RIGHT MIDDLE LOBE.
But if you did not see the hemidiaphragm on the right side, this infection would have been in the RIGHT LOWER LOBE.
