I-Reticular opacities Interlobular septal thickening: Causes :1. Lymphangitic spread of tumour (asymmetrical or symmetrical)2. Pulmonary edema.3. Amyloidosis
Honeycombing – Causes:1. IPF2. Collagen vascular diseases (Rh.A. - scleroderma)3. Drug related fibrosis4. End stage Hypersensitivity pneumonitis5. End Stage Sarcoidosis6. Radiation.7. End stage ARDS
Traction Bronchiectasis Causes : Corkscrewed bronchi1. Non specific in IPF intersitial pneumonia.2. UIP3. Sarcoidosis.4. Hypersensitivity pneumonitis.5. Radiation.6. End stage ARDS
Crazy-paving pattern Combination of GG opacity with interlobular septal thickening. Non specific. Causes : PCP , viral pneumonia ,edema , hemorrhage ,ARDS . If chronic lung disease it is often :alveolar proteinosis
Alveolar Proteinosis Fine reticular pattern + GG opacity
Golden rules for HRCT interpretation. Honeycombing with a basal and subpleural redominance is highly suggestive of UIP.Lung biopsy is rarely performed when HRCT shows these findings. Concentric lower lobe GG opaity without honeycombing suggests NSIP.In a patient with collagen vascular disease ,biopsy is uncommoly performed. Patchy or noular subpleural or peribronchial consolidation is typical of COP. Cystic air spaces or GG opacity may represent LIP.LIP is usually associated with other diseases. Diffuse or centrilobular GG opacity in a smoker is typical of DIP or RB-ILD
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