Inflammation Acute

The Normal Alveolus with an

Intra-alveolar Macrophage to Police the Alveolus

Cellular Makeup of the Normal Alveolus
The diagram shows the lining of the normal alveolus composed of type 1 pneumocyte squamous in nature and the cuboidal cell (type pneumocyte) which rest on a lamina propria, and basement membrane (not shown) shared with the inner endothelial layer of the capillary. Intra-alveolar macrophage lies within the alveolar lumen
Ashley Davidoff
TheCommonVein.net

Lung Injury 
Infection Inflammation or Toxic Injury

Alveolitis
Diagram shows inflammation (red ) in the walls of the alveoli. The increased density in the interalveolar septa results in a ground glass opacity on T scan
Ashley Davidoff TheCommonVein.net
lungs-0736b
Alveolitis
Diagram shows inflammation (red ) in the walls of the alveoli. The increased density in the interalveolar septa results in a ground glass opacity on T scan
Ashley Davidoff TheCommonVein.net
lungs-0736

Within the Alveolus
Basic Cellular Response
Neutrophil Mediated Inflammation
Neutrophils predominate in the first 6 to 24 hours
Monocytes predominate in 24-48 hours
Exudative (acute) phase: 1 – 7 days

Acute Inflammation – The Basics
Ashley Davidoff MD TheCommonVein.net lungs-0698d

Acute Inflammatory Activity in the Alveolus
Cellular Response,
Hyperemia, Edema and Exudation

Early Events in the Pathophysiology of Severe Acute Inflammation
The initial injury results in an acute severe inflammatory response consisting hyperemia , edema with migration initially of neutrophils in the first 6-24 hours followed by monocytes (24-48 hours). The intra -alveolar macrophages are activated.
Ashley Davidoff TheCommonVein.net

Types of Fluid Accumulations in
Acute Inflammatory or Infectious Diseases

Types of Fluid Accumulation in the Alveoli
The acute inflammatory process results in fluid exudation into the alveoli which can take the form of a serous transudate, and exudate or in the form of mucus, and when severe (eg ARDS) can result in tissue and vessel destruction and could be be blood tinged. Infected fluid could be mucoid or purulent. The extent of filling the alveoli results either in a ground glass appearance when partially filled or a consolidation when filled.
Ashley DAvidoff MD TheCommonVein.net
lungs-0701d- lo res

 

Radiology of Fluid in the Alveoli  

Radiology of Ground Glass and and Solid Consolidations – Black White and Gray Densities
An air filled alveolus appears as black, a fluid filled alveolus appears as white and a a half filled alveolus appears as gray
Ashley Davidoff MD TheCommonvein.net lungs-00688b

 

Presenting as Ground Glass Infiltrates
The Alveolus is
Half Filled

Types of Fluid Accumulations and Appearance as Ground Glass Ground Glass Inflammatory Infiltrates – Half Filled Alveoli
Inflammatory fluids half fill the alveolus and will therefore result in ground Glass Infiltrates
Ashley Davidoff MD TheCommonVein.net
lungs-0703d

Imaging Features

COVID 19
The CT scan confirms the presence of confluent extensive ground glass change in the superior segment of the right lower lobe and bilateral, nodular, and peripheral ground glass and opacification in the lower lobes. These findings are consistent with but not diagnostic with the diagnosis of COVID 19. Differential diagnosis however includes other viral pneumonias, allergic alveolitis and other multifocal and organizing pneumonias.
53F ARDS
8months later
53F ARDS
Diffuse Ground Glass Pattern
Ashley Davidoff
TheCommonVein.net
134262

 

Types of Fluid Accumulations Presenting Consolidative Infiltrates
The Alveolus is Totally Filled

Types of Fluid Accumulations and Appearance as Consolidations in Acute Inflammatory or Infectious Diseases
Ashley Davidoff MD TheCommonVein.net
lungs-0705d- lo res

 

 

CXR

diffuse coarse reticular opacities

does not imply irreversible fibrosis,

opacities may resolve

53F ARDS
Diffuse Ground Glass Pattern
Ashley Davidoff
TheCommonVein.net
53F ARDS
Diffuse Ground Glass Pattern
Bibasilar Infiltrates
Ashley Davidoff
TheCommonVein.net 134245
53F ARDS
8months later
53F ARDS
Diffuse Ground Glass Pattern Ashley Davidoff TheCommonVein.net
134262

Post MVA 58M

Acute Exudative Phase

58 MARDS
Diffuse Ground Glass Pattern
Post MVA
Ashley Davidoff
TheCommonVein.net 134269
ARDS
58M Diffuse Ground Glass Pattern Peribronchovascular Infiltrates
Focal Consolidation and Effusion Post MVA
Ashley Davidoff TheCommonVein.net 134273
ARDS
58M Post MVA 3rd Spacing in the Subcutaneous Tissue
Ashley Davidoff TheCommonVein.net 134270

Post MVA 12 Days Later

58M Post MVA ARDS
12 Days later Still Intubated
Ashley Davidoff TheCommonVein.net 134282

 

58M Post MVA ARDS
12 Days later Improved Diffuse Ground Glass Pattern
Ashley Davidoff TheCommonVein.net 134284
58M Post MVA ARDS
12 Days later Improved Diffuse Improved subcutaneous 3rd spacing of fluids
Organized collection in the LUQ
Ashley Davidoff TheCommonVein.net 134281

ARDS – Dominant Central Distribution with Relative Lower Lobe Subpleural Sparing

2 Weeks Earlier

ARDS
79M 2 weeks earlier Cardiomegaly CHF with interstitial edema and complex left effusion
Ashley Davidoff TheCommonVein.net 134304a

2 Weeks Later

ARDS
79M Patchy Diffuse Ground Glass Pattern Dominant – Central Location
Relative Lower Lobes and Subpleural Sparing
Ashley Davidoff TheCommonVein.net 134304
ARDS with diffuse bilateral ground glass and consolidations clinically
79M Patchy Diffuse Ground Glass Pattern Dominant – Central Location
Relative Lower Lobes and Subpleural Sparing
Ashley Davidoff TheCommonVein.net 134294
ARDS
79M
Patchy Diffuse Ground Glass Pattern
Dominant – Central Location
Relative Lower Lobes and Subpleural Sparing
Ashley Davidoff
TheCommonVein.net
134300
ARDS
79M
Patchy Diffuse Ground Glass Pattern
Dominant – Central Location
Relative Lower Lobes and Subpleural Sparing
Ashley Davidoff
TheCommonVein.net
134301

Ground Glass Pattern with Patchy Infiltrates

ARDS
54 year old female with acute respiratory distress syndrome
ARDS-54-f001
ARDS
54 year old female with acute respiratory distress syndrome
Ashley Davidoff MD thecommonvein.net ARDS 54 f002
ARDS
54 year old female with acute respiratory distress syndrome
Ashley Davidoff MD thecommonvein.net ARDS 54 f003

AIP ARDS Immunotherapy Toxicity

AIP ARDS
Pneumonitis in a 65-year-old man with diffuse large B-cell lymphoma after three cycles of rituximab with cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisone (R-CHOP) therapy who presented with new shortness of breath. Axial CT image shows bilateral diffuse GGOs and areas of consolidation in both lungs, with traction bronchiectasis and loss of lung volumes. The findings reflect an AIP/ARDS pattern of pneumonitis related to rituximab. Bilateral pleural effusions were also present. The patient’s condition significantly deteriorated, and he died 1 month after presentation. Autopsy results showed diffuse alveolar damage in the lungs.
Nishino, M et al  Thoracic Complications of Precision Cancer Therapies: A Practical Guide for Radiologists in the New Era of Cancer Care RadioGraphicsVol. 37, No. 5

Diffuse Ground Glass ARDS vs Atypical Pneumonia

ARDS vs Atypical Pneumonia
43F Diffuse Ground Glass Pattern
Ashley Davidoff TheCommonVein.net 117653
ARDS vs Atypical Pneumonia
43F Diffuse Ground Glass Pattern Mosaic Attenuation
Ashley Davidoff TheCommonVein.net 117662

 

ARDS vs Atypical Pneumonia
43F Diffuse Ground Glass Pattern Mosaic Attenuation
Ashley Davidoff TheCommonVein.net 117668
ARDS vs Atypical Pneumonia
43F Diffuse Ground Glass Pattern Mosaic Attenuation                                                                             Ashley Davidoff TheCommonVein.net 117672
ARDS vs Atypical Pneumonia
43F Diffuse Ground Glass Pattern
Ashley Davidoff TheCommonVein.net 117687
Aspiration Pneumonia Pulmonary Edema and DAD
54 year old male alcoholic with seizures presents with diffuse alveolar disease consistent with pulmonary edema (a). CT scan (b) shows bibasilar infiltrates consistent with aspiration.
Follow up CXR 6 months later (c) shows resolution
Ashley Davidoff MD TheCommonVein.net 134455cL01

70F Aspiration and Pneumonia with Crazy Paving

70F Aspiration and Pneumonia with Crazy Paving
Ashley Davidoff MD TheCommonVein.net crazy paving ICU 001
70F Aspiration and Pneumonia with Crazy Paving
Ashley Davidoff MD TheCommonVein.net crazy paving ICU 005
70F Aspiration and Pneumonia with Crazy Paving
Ashley Davidoff MD TheCommonVein.net crazy paving ICU 004
70F Aspiration and Pneumonia with Crazy Paving
Ashley Davidoff MD TheCommonVein.net crazy paving ICU 002
70F Aspiration and Pneumonia with Crazy Paving
Ashley Davidoff MD TheCommonVein.net crazy paving ICU 003

62F-ARDS-post-abdominal-surgery-and-abdominal -abscess-shock

62F-ARDS-
post-abdominal-surgery-and-abdominal -abscess-shock
Ashley Davidoff MD TheCommonVein.net abscess-shock-001
62F-ARDS-
post-abdominal-surgery-and-abdominal -abscess-shock
Ashley Davidoff MD TheCommonVein.net abscess-shock-002

References and Links

Radiopaedia