Interstitial and Occupational Lung Disease Flashcards
Features of pleural plaque on CT
Well defined borders
Associated with ribs
Lower zones mainly
Smooth pleural thickening
Features of asbestosis lung
Pleural plaques Pleural effusion Pleural thickening Folded stele tasks Interstitial lung fibrosis
Holly leaf appearance on cxr
Features of diffuse pleural thickening
Smooth uninterrupted layer of thickened pleura. Extends over one quarter of chest wall
> 3mm thick
8cm cranio caudial
5cm lateral
What is the comet tail sign
Folded or round atelectasis seen in asbestosis. Sub pleural. Bronchi and vessels appear to be drawn into it
HRCT features of asbestosis
Sub pleural branching opacities
Sub pleural curvilinear opacities
Parenchyma bands
Honeycomb change
Simple vs Complicated Pneumoconiosis
Simple: coal pigments 1-5mm no fibrosis
Complicated: coal pigment plus area > 1cm of fibrosis
CXR findings of coal workers pneumoconiosis
Multiple small round opacities. Upper and mid zones
Hilar lymph node enlargement.
Describe caplans syndrome
CWP in rheumatoid patients. Multiple well defined nodules in apices.
Features of silicosis
Small. Sharply defined. Nodules. Perilymphatic. Upper and mid zones. Lymph node calcification. PMF
Features of silicoproteinosis
Centrilobular ground glass nodules. Crazy paving
Features of siderosis
Reticule nodular opacities widespread though out the lung.
Describe the appearances of IPF
Increased risk bronchogenic carcinoma.
CXR: basal bilateral peripheral reticular and small rounded opacities. Lung volume loss.
HTCT: sub pleural cystic air spaces. Honeycombing. Traction Dilatation. Starts posterior lung bases. Mid zone lateral. Upper zone anterior.
Features of non specific interstitial pneumonitis
CXR: mid and lower zone infiltrates
HRCT: symmetrical bilateral ground glass opacity bases. Traction Dilatation. Consolidation.
Features of respiratory Bronchiolitis associated interstitial lung disease.
CXR: patchy ground glass on lower zones.
HRCT: patchy ground glass. Low attenuation centrilobular nodules. Patches of low attenuation die to air trapping.
Features of desquamative interstitial pneumonitis
Patchy ground glass shadowing lower peripheral zones
Features of acute interstitial pneumonitis
CXR: Bilateral patchy air space opacificaton. Air bronchi grams. Sparing the costophrenic angles
HRCT: ground glass. Air space consolidation. Bronchial Dilatation.
Features of cryptogenic organising pneumonia.
Occurs 3months after LRTI
CXR: patchy sub pleural area of consolidation bilaterally. Areas of cavitation
HRCT: consolidation around main bronchi. Ground glass. Multiple nodules. Band opacities. Ring opacities surrounding secondary lobules.
Features of hypersensitivity pneumonitis
Centrilobular nodules. Areas of GGO. Mosaic perfusion.
CXR features of sarcoidosis
Bilateral hilar lymphadenopathy
Differentials:
TB (unilateral)
Lymphoma (anterior mediastinum and paratracheal)
Nodules: upper mid zone
Reticulonodular: nodule plus inter lobar thickening
Airspace consolidation: upper zone
Features of sarcoidosis on HRCT
Bilateral hilar lymphadenopathy
Can compress bronchi causing lobar atelectasis.
Egg shell calcification
HRCT features of sarcoidosis
Irregular small nodules. Around lymph vessels. Bronchi vascular margins. Inter lobule septae. Give a beading appearance to septae.
Feature of Hodgkin’s lymphoma on CXR
Anterior mediastinum lymphadenopathy
Five causes of air space shadowing
Water Pus Blood Cells Protein
Causes of airspace shadowing due to water
Hydrostatic: ccf. Overload. Renal failure
Capillary Leakage: ards
Causes of air space shadowing due to blood
Trauma
Good pastures
Vasculitis
Idiopathic pulmonary haemorrhage
Causes of air space shadowing due to cells
Alveolar cell carcinoma
Lymphoma
Causes of localised air space opacity
Lobar pneumonia
Round pneumonia
Causes of Central diffuse airspace shadowing
Pulmonary odema
Atypical infections
Lymphangitisncarcinonatosa
Alveolar proteinosis
Causes of diffuse peripheral airspace shadowing
Eosinophilic lung disease
COP
Causes of multiple focal airspace shadowing
Alveolar cell carcinoma Lymphoma Pulmonary haemorrhage Wegeners granulomatosis Pulmonary infarcts Alveolar sarcoidosis
Describe the different appearances of kerley lines
Due to thickening of the inter lobular septum.
A lines: Central. few centimeters long
B lines: subpleural 1cm
Causes of inter lobar septal thickening
Raised pulmonary venous pressure: left ventricular failure. Pull odema. Mitral stenosis. Left atrial myxoma. Pulmonary venoocclusive disease.
Tumour: lumphangitis. Sarcoidosis.
Depositis: pneumoconiosis
Describe types of septal thickening and causes
Smooth: pulmonary odema. Lymphangitis
Nodular thickening: sarcoidosis. Lymphangitis
Septal thickening with lung distortion: fibrosis
How do you distinguish between fluid overload post renal transplant and cardiogenic odema.
Normal heart size
Features of Sarcoidosis on CXR and HRCT
Interstitial shadowing middle and upper zones
Nodular septal thickening
Subpleural nodules.
Peribronchovascular thickening
Beading of fissures
Features of Lymphangitis on CXR
Smooth or Nodular septal thickening
Evidence of malignancy: Lung mass Mets Lymphadenopathy Effusions Bone lesions Mastectomy Previous lung surgery
Signs of pulmonary fibrosis on CXR and HRCT
Irregular septal thickening. Honeycombing Volume loss Peripheral and subpleural predominance Asbestos related pleural disease
Emohsema
Irregular septal thickening
Traction bronchiectasis
Ground glass fibrosis
Signs of pneumoconiosis
Septal thickening Lung nodules upper zones Fibrosis Egg shell calcification Progressive massive fibrosis
What are reticular patterns on a CXR ?
Overlapping. Intersecting lines. Resembling a net. Or mesh.
Narrow the differential by noting the zonal distribution and associated signs
Features of established fibrosis on HRCT
Traction bronchiectasis
Honeycombing
Inter lobular septal thickening
Differential for reticular pattern on CXR
IPF CVD fibrosis Asbestosis Drug induced fibrosis Lymphangitis EAA TB fibrosis Sarcoidosis Pneumoconiosis Radiation induced fibrosis
Most common cause of reticular pattern on CXR
IPF
Peripheral and bases reticular pattern
Honeycombing signifies severe disease
How do you distinguish between IPF and CVD fibrosis
Look for associated findings
RD: clavicle erosion. Shoulder disease. Rheumatoid nodules (caseating)
Effusion: RA and SLE. Not SS
Oesophageal Dilatation: SS and Crest
Features of asbestosis on CXR
Lateral pleural plaques
Holly leafs
Calcified plaques
Common drugs causing pulmonary fibrosis and specific feature of amiodarone
Methotrexate. Amiodarone. Bleomycin. Nitrofurantoin.
Amiodarone causes increase attenuation in the liver due to iodine metabolite. Hu 70-94 normal 50-65
Feature of. Extrinsic allergic alveolitis
Chronic. Upper zone reticular
Acute and subacute. Bases
Features of Sarcoidosis vs TB
Common: reticular upper zone pattern. Lymphadenopathy
Difference: sarcoidosis bilateral. Apical sparing.
Features of pneumoconiosis
Upper zone predominance. Reticulonodular.
Silicosis: egg shell calcification
PMR: mass like opacities
Features of radiation induced fibrosis
Lung damage only occurs in field of therapy. Sharp line of demarcation. Previous malignancy history.
General rule for causes of upper and lower zone predominance
Upper: inhaled dust causes where ventilation is greatest; pneumoconiosis. Sarcoidosis. Tb. Ank spond. Chronic eaa. Radiation induced. Histoplasmosis.
Lower: immunological causes where perfusion is better.; IPF. CVD. Asbestosis. Drug induced fibrosis. Chronic aspiration.
CXR differentials for septal lines.
Lymphangitis carinomatosa
Pulmonary odema
CXR differentials for honeycombing
End stage pulmonary fibrosis
Langerhans cell histocytosis
Lymphangioleiomyomatosis
CXR differentials for lymadenopathy
Sarcoidosis Tb Lymphoma Lymphangitis Silicosis
Two causes of mosaicism
Increase filling GGO
Deceased perfusion
How can mosaicism help identify pulmonary embolism
Areas not perfused will be hypo attenuated. Less vascular markings. Compensatory increase in perfused areas. May extend to pulmonary arterial hypertension. Increase in size of pulmonary outflow tract greater than the aorta
Causes of crazy paving?
Alveolar proteinosis
Heart failure
Lymphangitis carcinomatosa
Non specific interstitial pneumonitis
Carcinoma associated with Lymphangitis carcinomatosa
Adenocarcinoma of breast, bronchus, stomach, pancreas, cervix and thyroid
Causes of tree in bud
Mucus plugging
Asthma Aspiration ABPA Bronchiectasis Infectious Bronchiolitis Panbronchiolitis Endobroncial TB
Causes of predominately central consolidation
Cardiac failure
Cancer
PCP
Alveolar proteinosis
Causes of peripheral consolidation
Pneumonias
Poly myosotis
Characteristics of sarcoidosis on HRCT
Subpleural nodules. Peribronchovascular nodules. May coalesce to form consolidation. Beading of fissures. Lymphadenopathy
Difference between UIP and COP
Both have consolidation. GGO. Small nodules.
UIP has added fibrosis
Appearances of EAA
Acute: centrilobular nodules. GGO. Can cause consolidation
Subacute: more upper lobe.
Chronic. Plus fibrosis
Presentations of Bronchioloalveolar cell carcinoma
- Solitary peripheral nodules
- Pneumonic consolidation. 20%. Nodules same lobe
- Multiple 5-6 mm nodules
Features of Chronic eosinophilic pneumonia
Middle aged women
Peripheral consolidation
Resolved with steroids
Area of consolidation moves around lung.
Presentations of Bronchioloalveolar cell carcinoma
- Solitary peripheral nodules
- Pneumonic consolidation. 20%. Nodules same lobe
- Multiple 5-6 mm nodules
Features of acute interstitial pneumonia
Rapidly increasing dyspnoea following ? Viral URTI.
Bilateral GGO
Apical consolidation
Phases:
Exudative-GGO consolidation
Proliferative-traction bronchiectasis
Fibrotic-honeycombing
Half die in 2months
Features of acute interstitial pneumonia
Rapidly increasing dyspnoea following ? Viral URTI.
Bilateral GGO
Apical consolidation
Phases:
Exudative-GGO consolidation
Proliferative-traction bronchiectasis
Fibrotic-honeycombing
Half die in 2months
Three diseases which are primarily cystic in nature
Langerhans cell histopcytosis
Lymphangioleiomyomatoisis
Tuberous sclerosis
Radiological features of Langerhans cell histiocytosis.
Initially Nodular appearance due to granuloma at terminal bronchioles. Progress to cyst. Cyst due to bronchi Dilatation. Varicose bronchi. Extensive lung destruction and bulbous emphysema.
Upper zone predominance. Costophrenic angles are spared.
Clinical features of LAM
Lymphangioleiomyomatosis
Smooth muscle cell proliferation in bronchi and mediastinum.
Women
Childbearing age.
Numerous thin walled cysts uniform distribution surrounded by normal lung no basal sparing. Later stages chylous effusion due to blockage of lymph drainage.
Three mimics of cystic lung disease
Centrilobular emphysema
Para septal emphysema
Cystic bronchiectasis
Pathology of two types of centrilobular emphysema
- Entire parenchyma of secondary lobule destroyed. Septa are intact. Upper zone. Subtle areas of low attenuation. Without any walls
- Destruction spreads over septa. However bronchi vascular bundle traverses the cystic space
How do you distinguish para septal emphysema from cysts
Para septal emphysema produced single later of subpleural and mediastinal cysts. Upper lobe.
Honeycombing. Several layers. Lower zones
How to distinguish cystic bronchiectasis from cysts
Signet ring sign due to dilated bronchiole and adjacent arterioles
Four mechanisms of atelectasis
Relaxation
Cicatrisation
Adhesive
Resorptive
Features of relaxation atelectasis
Due to space occupying process. Adjacent to the lung. Ie pressure increase
Causes: pleural effusion. Pneumothorax. Mass. Gravity
Features of cicatrisation atelectasis
Due to lung fibrosis
Features of adhesive atelectasis
Lack of surfactant. Alveolar collapse.
Ards Pneumonia Pe Smoke inhalation Radiation pneumonitis
GGO
Consolidation. Volume loss
What is the significance of consolidation without air bronchi grams
Suggests bronchial obstruction. Rather than infective consolidation. ? Mass. Golden S sign
Features of Resorptive atelectasis
Bronchus blocked. Air reabsorbed into capillaries.
Two direct signs of atelectasis
Displacement of inter lobar fissures
Crowding of vessels
Indirect signs of atelectasis
Local increase in opacity Elevation of hemidiaphragm Mediastinal displacement Compensatory hyperinflation Displacement of the hilim Crowding of the ribs Absence of an air bronchi gram Absence of the inter lobar artery
Features of right upper line atelectasis on CXR
Elevation of concave minor fissure
Features of left upper lobe atelectasis
On CXR
What is luftsichel sign ?
Veil like opacity over the left lung. Obscured left heart border if linguist region involved.
Air crescent in left upper lobe as upper lobe is pulled down and aerated lower lobe fills space
What’s is the juxtaphrenic peak
Seen in both left and right upper lobe atelectasis
Small triangular opacity medial half of diaphragm. Site of inferior accessory ligament.
Feature of right middle lobe atelectasis
Obscured right heart border
Features of lower lobe atelectasis.
Triangular opacity lower lobe. Blurred diaphragm. Hilum pulled down
Feature of right middle and lower lobe collapse
Obstruction of bronchus intermedia.
combination of middle and lower lobe collapse. Extends to costophrenic angle
Features of segmental atelectasis
No air bronchogram
Linear opacity.
Volume loss.
Need to rule out bronchogenic carcinoma
Features of liner atelectasis
Linear opacity extending to pleural.
Seen in patients with reduced diaphragm movement. Surgery. Acute abdomen.
Feature of rounded atelectasis
Area of folded lung. Occurs adjacent to thickened pleural of any cause. Lung adjacent to thickened pleural becomes atelectic. Produced round oval density.
CXR : bronchi vascular bundle radiates toward in a. Curvilinear fashion
CT: comet tails
On CXR in connective tissue disorders which additional areas should you pay attention to
Joint abnormalities - rheumatoid
Oesophageal Dilatation - scleroderma
Enlarged pulmonary artery - PAH
Soft tissue calcification - dermatomyositis
Difference between UIP and NSIP
UIP - rheumatoid. With honeycombing
NSIP - systemic sclerosis and crest. No honeycombing
Lymphocytic interstitial pneumonitis is associated with which disorders
Sjogrens
AIDs
Primary Biliary Cirrhosis
In SLE patients what are they more at risk of
VTE
Features of systemic sclerosis on CT
Oesophageal Dilatation
Subpleural GGO
Fibrosis
No honeycombing
How do you classify causes of pulmonary haemorrhage
Diffuse
Immunologically mediated
Non immunologically mediated
Immunocompromised
Immune competent
Focal
Causes of focal pulmonary haemorrhage
Chronic bronchitis Tumours Infection Bronchiectasis Local trauma PE Vascular erosis
Cause of immunologically mediated diffuse pulmonary haemorrhage
Good pastures
CVD
SLE
Wegeners
Polyarteritis nodosa
Microscopic polyarteritisCauses of pulmonary haemorrhage in non immunologically mediated immunocompetent
Idiopathic pulmonary haemosiderosis
Drugs
Tumors - angiosarcoma
Haemorrhagic diathesis - antiphospholipid/DIc/TTp
Causes of diffuse pulmonary haemorrhage in immunocompromised patient
Coagulopathy
Infection in the setting of thrombocytopenia
Chemo
Hiv kaposis
Feature of PAH on CXR
Bilateral hilar opacificaton.
Sparing costophrenic angles and apices
Differential for crazy paving
Bronchioalveolar carcinoma Alveolar proteinosis Lipoid pneumonia Ards PCP Pulmonary haemorrhage Sarcoidosis NSIP Organising pneumonia
