�ݺ�ߣ

APPROACH TO
INTERSTITIAL
LUNG DISEASES

Interstitial Disease vs Air
Space Disease
◦ Interstitial Disease involves the interstitium
located between the alveolar air space and
blood vessels
◦ Air Space Disease involves the alveolar air
sacs, often filled with fluid, cells, tumor, pus
etc.

IMPORTANT CAUSES OF ILD
1. Primary or idiopathic
◦ Idiopathic Pulmonary Fibrosis
◦ Nonspecific interstitial pneumonia (NSIP)
◦ Organising pneumonia (OP)
◦ Respiratory bronchiolitis (RB)
◦ Diffuse alveolar damage (DAD)
◦ Desquamative interstitial pneumonia (DIP)
◦ Lymphocytic interstitial pneumonia (LIP)

Secondary Causes
1.Infectious
◦ Tuberculosis
◦ Bacterial
◦ Fungal
◦ Parasitic
◦ Viral
2. Noninfectious
◦ Hypersensitivity pneumonitis
◦ Pneumoconiosis
◦ Drug induced
◦ Radiation induced
◦ Malignancies

Association with diseases of unknown
aetiology
◦ Sarcoidosis
◦ Connective tissue disorders
◦ Systemic sclerosis
◦ Rheumatoid arthritis
◦ Dermatomyositis,Polymyositis
◦ SLE
◦ Chronic eosinophilic pneumonia

Idiopathic Pulmonary Fibrosis (IPF/UIP)
◦ Defined as progressive fibrosing interstitial pneumonia of
unknown cause. Histo/radio like Usual Interstitial
pneumonia
◦ Histology suggestive of repeated focal damage to alveolar
epithelium.
◦ Usually present in older adult, uncommon before 50 yrs.
◦ Presents with progressive breathlessness and a
nonproductive cough.
◦ Clinical findings-clubbing and fine late inspiratory crepts.

HRCT - TECHNIQUE
◦ Narrow slice thickness (1 mm) at 10 mm intervals.
◦ Image reconstruction with high spatial resolution.
◦ Generally end inspiration views are taken.
◦ One can also take expiration, prone views when
required.
◦ A window width of 1300, window level of -600 HU is
set.
◦ No IV injection of contrast is used.

Fibrosing vs Non Fibrosing ILD
◦ Architectural distortion
◦ Traction bronchiectasis
◦ Irreversible
◦ Loss of volume

INTERSTITIAL LUNG DISEASE HRCT APPROACH.pptx

Common patterns in ILD’s
◦ Honeycombing pattern
◦ Cystic Pattern
◦ Nodular Pattern
◦ Mosaic Pattern
◦ Reticular Interstitial Pattern
◦ Ground glass pattern

Honeycomb pattern
◦ Cystic airspaces
◦ Thick, clearly defined walls
◦ Layered along pleural surface
◦ Pulmonary fibrosis
◦ Seen in :
◦ IPF
◦ Collagen vascular diseases
◦ Asbestosis
◦ *Upper lung - sarcoidosis, HP

Cystic Pattern
◦ Thin walled
◦ Circumscribed
◦ Air filled
◦ Seen in :
◦ Langerhans cell histiocytosis
◦ Lymphangioleiomyomatosis
◦ LIP
◦ Collagen vascular disease
◦ Emphysema

Nodules
◦Perilymphatic
◦Random
◦Centrilobular

Nodular Pattern - Random
◦ Silicosis/Coal worker’s pneumoconiosis
◦ TB/fungal
◦ Metastases

Nodular Pattern – Centrilobular
◦ Subacute hypersensitivity pneumonitis
◦ Respiratory bronchiolitis

Nodular Pattern - Bronchovascular
◦ Lymphoproliferative disorders
◦ Lymphangitic carcinomatosi. p for
◦ Kaposi sarcoma
◦ Sarcoidosis
◦ OP

Mosaic Pattern
◦ Infiltrative disease
◦ Small airways disease
◦ Pulmonary vascular disease

Reticular pattern
◦ Caused by thickened interlobular or
intralobular septa.
◦ infiltration by fibrosis, abnormal cells, or fluid.
◦ Interlobular septal thickening is usually
described as smooth or irregular.
◦ Manifests as a fine reticular pattern on HRCT.
◦ Late stage - honeycombing, characterized by
cystic airspaces surrounded by irregular walls.

Ground glass
◦ is defined as a generalized increase in opacity
◦ that does not obscure pulmonary vessels.
◦ include partial filling of the airspaces,
◦ considerable thickening of the interstitium, or a
combination of the two.

Tree-in-Bud Pattern
◦ Centrilobular dots and linear branching opacities
◦ Bronchiolar dilatation
◦ Bronchiolar impaction
◦ Seen in:
◦ • АВРА
◦ • Cystic fibrosis
◦ • Aspiration
◦ • Diffuse panbronchiolitis

Interlobular septal thickening
◦ Marginates secondary pulmonary lobule
◦ Contains pulmonary veins and lymphatics
◦ Kerley Line

Smooth ILS thickening
◦ • Pulmonary edema
◦ • Infectious pneumonia

�ݺ�ߣ

INTERSTITIAL LUNG DISEASE HRCT APPROACH.pptx

More Related Content

INTERSTITIAL LUNG DISEASE HRCT APPROACH.pptx