Causes of basal fibrosis
- UIP: IPF, RA, asbestos
- NSIP
Upper lobe predominant fibrosis
- End stage sarcoid
- Silicosis
- Chronic HP
Perilymphatic nodules
*Sarcoid (90%),
*Lymphangitic Spread of CA
*Silicosis
Centrilobular nodules
HP
RB ILD
Infection
Random nodules
Miliary TB
*Mets
*Fungal
NSIP
Peribronchial reticulation, traction bronchiectasis, +/- ground glass opacities
LOWER LOBE PREDOMINANCE, SPARES THE PLEURA
Causes- Scleroderma, Dermatomyositis, Mixed connective tissue disease, Drug toxicity
HP
Acute: Extensive ground glass + air trapping
Chronic: Ground glass, peribronchial fibrosis and air trapping, +/- upper lung predominant
3 densities
Causes- HP, drug toxicity
Organising pneumonia
- PERIPHERAL/ PERIBRONCHOVASCULAR distribution
- reverse halo (consolidation around GG)
Causes- idiopathic, Drug toxicity, Connective tissue disorders SLE dermatomyositis
Ground glass nodules
- Disseminated cancer – breast, thyroid, sarcoma, melanoma, prostate, pancreas or lung (miliary)
. - Subacute HP* – centrilobular nodules, ground-glass opacification
- RB ILD – (similar CT appearances to HP but invariably linked to smoking) multiple centrilobular nodules, together with GG opacification, lobular air trapping (on expiratory CT), thickened interlobular septa and limited emphysema.
- Lymphoma*
- Sarcoidosis*
- Viral pneumonia
High density micronodules
- Haemosiderosis – secondary to chronic raised venous pressure (MS), repeated pulmonary haemorrhage or idiopathic
- Silicosis*
- Siderosis
Micronodules
- Miliary tuberculosis – widespread and secondary to haematogenous dissemination.
- Fungal infection – histoplasmosis, coccidioidomycosis.
- Coal miner’s pneumoconiosis* –
- Sarcoidosis* – predominantly upper/mid zones
Tree in bud nodules
Mycobacterium tuberculosis and atypical mycobacteria.
Viral pneumonia.
Aspiration pneumonia.
Pneumocystis pneumonia
- bilateral perihilar (central) airspace opacities
- sparing of the peripheries
- upper lobe pneumatoceles
Immunodeficient/ HIV/ post transplant
Pulmonary hypertension
Group 1: PAH
- Primary pulmonary hypertension > idiopathic or familial, Congenital left-to-right shunts eg. ASD + VSD and shunt reversal (Eisenmenger syndrome).
Group 1 :̍ Pulmonary veno-occlusive disease (PVOD) and pulmonary capillary hemangiomatosis (PCH).
Group 2: Pulmonary venous hypertension.
Left-sided heart disease (left atrial, left ventricular, or mitral/aortic valve disease.
Group 3: Chronic hypoxemia.- COPD, ILD , and sleep apnea
Group 4: Pulmonary HTN due to chronic thromboembolic disease.
Group 5: Pulmonary HTN due to miscellaneous disorders eg. Sarcoidosis,
Compression of pulmonary vessels, which can be due to neoplasm, fibrosing mediastinitis, etc., may cause pulmonary hypertension.
LCH
MID AND UPPER ZONES
Nodules (centrilobular) and cysts
Spares costophernic angles
Complications- cyst rupture> ptx/ pneumomediastinum
end stage pulmonary fibrosis
