Intra parenchymal Cystic lung Disease:
Associated GGO:
Associated Nodules:
Multifocal / Diffuse:
LCH: bizarre shaped, thick walled
LAM: round shaped, thin walled
Birt Hogg Dube: oval shaped, thin walled.
Nodular Lung Disease:
Sub pleural nodules: Diffuse - Random pattern:
Sub Pleural Nodules: patchy, subpleural, peribronchovascular, interlobular septa - Perilymphatic pattern:
No subpleural nodules, with Tree and Bud Opacity:
No subpleural nodules, with no tree and bud opacity:
Acute GGO:
Infection - usually atypical Oedema - usually dependent Acute lung injury / ARDS Haemorrhage Aspiration Acute hypersensitivity pneumonitis Acute eosinophilic pneumonia
Chronic GGO:
Hyper sensitivity pneumonitis NSIP DIP / RB LIP / Follicular bronchiolitis Invasive mucinous adenocarcinoma Organising pneumonia Eosinophilic pneumonia Sarcoidosis Lipoid pnuemonia Alveolar proteinosis
Peripheral distribution GGO:
NSIP DIP OP Eosinophilic pneumonia Atypical or viral pneumonia Oedema - usually non cardiogenic.
Patchy geographic GGO with central predominance:
Hypersensitivity pneumonitis RB LIP Follicular bronchiolitis OP Sarcoidosis Alveolar proteinosis
Unilateral / highly asymmetric distribution of GGO:
Invasive pulmonary mucinous adenocarcinoma
Lipoid pneumonia
GGO with mosaic perfusion / air trapping:
Hypersensitivity pneumonitis
Crazy paving
ACUTE:
CHRONIC:
GGO with centrilobular nodules:
Hypersensitivity pneumonitis
RB
Follicular bronchiolitis
Invasive mucinous adenocarcinoma
GGO with signs of fibrosis (honey combing, traction bronchiectasis, irregular reticulation)
NSIP
Hypersensitivity Pneumonitis
Indeterminate UIP.
Peripheral distribution chronic consolidation:
Chronic eosinophilic pneumonia
Organising pneumonia (Polymyositis / dermatomyositis)
COVID
PEs
Causes of organising Pneumonia:
Cryptogenic organising pneumonia Drugs CT disease Toxic Inhalation Immunodeficiencies Graft vs Host.
DDx for organising pneumonia / Atoll sign:
Chronic eosinophilic pneumonia
Hypersensitivity pneumonitis: centrilobular nodules.
Infections - fungal: neutropenia.
Granulomatosis polyangiitis.
Pulmonary infarction: peripheral wedge shaped
Head Cheese Sign:
Hypersensitivity - most likely!
Respiratory bronchiolitis / desquamative interstitial pneumonia
Follicular bronchiolitis / lymphoid interstitial pneumonia
Atypical infections
Sarcoid
2 seperate processes: oedema and asthma.
Upper lobe predominant fibrosis: “ STROLA”C
Sarcoidosis TB Radiation Occupation: pneumoconioses LCH Ankylosing spondylitis Chronic HP
Lower lobe predominant fibrosis:
UIP / Idiopathic pulmonary fibrosis Connective tissue disease Drug fibrosis Asbestosis Hypersensitivity pneumonitis (mid zones, can be diffuse) Chronic aspiration.
Reticulonodular pattern: “VOTE SSSX”
ACUTE:
CHRONIC:
Mid to upper zone bronchiectasis:
CF
ABPA
TB
Lower zone bronchiectasis:
Chronic infection
Aspiration
Immunodeficiency
Primary ciliary dyskinesia
Tree in Bud opacities:
Bacterial infection
mycobacterial infection
Fungal ingection
Viral infection
Cystic fibrosis
ABPA
Primary ciliary dyskineasia
Immunodeficiency
Diffuse panbrochiolitis
Follicular bronchiolitis
Invasive mucinous adenocarcinoma
Aspiration
CT findings of parenchymal lung disease as cause of pulmonary HTN
Fibrosis, emphysema, or cystic lung disease
CT findings of chronic pulmonary thromboembolism as cause of pulmonary HTN:
Pulmonary artery filling defects or occlusion, mosaic perfusion.
CT findings of idiopathic pulmonary HTN:
Dilated main pulmonary artery, centrilobular nodules of GGO