Gary Culpan

HR-6000U Justification, Optimisation and Interpretation

in Medical Imaging

Chest X-ray Interstitial Lung Diseases

Gary Culpan

Secondary pulmonary lobule

Gary Culpan

Review and

relate to

specimen

Secondary

pulmonary

lobule

Gary Culpan

The Lung Intersitium

Connective tissue matrix

Surrounds and supports lung

Axial (broncho-arterial)

Peripheral (septal)

Parenchymal (alveolar)

Gary Culpan

Gary Culpan

Gary Culpan

Gary Culpan

Causes of Interstitial Lung Abnormalities

Dusts Organic - EAA Inorganic - Asbestos,

Silica

Drugs Sarcoid Connective Tissue

Diseases RA, Scleroderma

Vasculitis Tumour Infection

Histiocytosis

Neurofibromatosis

Tuberous Sclerosis

Lymphangiolyomatosis

IDIOPATHIC

EAA = extrinsic allergic alveolitis

Gary Culpan

Clues from clinical information Onset

Acute

Chronic

Pyrexia

Other system involvement

History of exposure to dust

Current drug treatments

Immunosuppression Due to disease or treatment

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Plain film patterns due to Interstitial Lung Disease

Septal thickening

Ground Glass

Nodular

Reticular

Reticulo-nodular

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Plain Radiograph Clues

Distribution Upper, Mid or Lower Zone

Volume Loss Yes or No

Pleural Fluid Yes or No

Other clues eg Joint erosions, dilated oesophagus, pleural

plaques

Gary Culpan

Which test?

Investigation of suspected Interstitial Lung Disease

CXR is important and useful first line investigation

HRCT is the definitive test

Gary Culpan

Causes of Septal Thickening

Heart Failure

Sarcoid

Lymphangitis carcinomatosis

Infection

Pneumoconiosis

Alveolar Proteinosis

Gary Culpan Kerley lines

Gary Culpan

Kerley B lines

Seen at lung bases

Periphery of lung Horizontal Right angles to

pleura Up to 1 cm long Represent

interlobular septa Caused by fluid or

infiltrate within the interstitium

Gary Culpan

Sarcoid

Increased interstitial pattern

Increased soft tissue densities at both hila due to enlarged lymph nodes

Gary Culpan

CT appearances

Gary Culpan

Gary Culpan

Gary Culpan

Sarcoidosis Findings

Symmetrical Bilateral Perihilar

lymphadenopathy Granulomas Lymphatic or

perilymphatic distribution

Interstitial

May progress to fibrosis

Best seen on HRCT

Gary Culpan

Lymphadenopathy

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Interstitial infiltrate

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Gary Culpan

Ground Glass opacity

Generalised increased density of lung No loss of the underlying lung markings

Better seen on CT than CXR Usually implies combination of

interstitial and alveolar pathology

Gary Culpan

Causes of ground glass opacity

Infection Bronchopneumonia, viral infections,

P carinii pneumonia, or M Pneumoniae

Pulmonary oedema

Chronic infiltrative diseases Hypersensitivity pneumonitis

Alveolar proteinosis

Gary Culpan

Example

Overall increase in lung density

Normal lung markings still visible

Not obscured

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Gary Culpan

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Gary Culpan

Nodular opacities

Sarcoidosis

Pneumoconiosis

Hypersensitivity pneumonitis Extrinsic Allergic Alveolitis (EAA)

Ill defined

TB miliary (2mm or less)

Gary Culpan

Reticular shadows

Fine lines seen throughout the lungs

Related pathologies Sarcoidosis

Chronic EAA

Fibrosis end stage

Cystic conditions

Gary Culpan

Causes of Interstitial Changes with Preserved Lung Volumes

Combination of Fibrosis and Emphysema

Pathology involved Eosinophilic granuloma (Histiocytosis X,

pulmonary Langerhans cell histiocytosis X) Neurofibromatosis Tuberous Sclerosis Lymphangiolyomatosis

Eosinophilic granuloma

Epidemiologically related to tobacco smoking

Chiefly affects young adults

Primarily occurring in the third or fourth decades of life

Gary Culpan

Chest radiograph in a 30-year-old woman who presented with shortness of breath and a palpable swelling over the right parietal region

CXR shows an interstitial lung pattern with a honeycomb appearance in the upper zones

Gary Culpan

Neurofibromatosis Common manifestation is fibrosing alveolitis or

interstitial pulmonary fibrosis

Does not appear until adulthood

Occurs in 20% of patients with the disease who are over 30 years old

Characteristic radiographic findings include linear, interstitial density and large upper lobe bullae

This combination limits the differential diagnosis Pathological examination demonstrates alveolar wall thickening

progressing to fibrosis and lung destruction

Gary Culpan

Tuberous sclerosis complex (TSC) and lymphangioleiomyomatosis (LAM)

Patients develop progressive replacement of the lung parenchyma with multiple cysts

Process is identical in both diseases Genetic analysis has shown that proliferative bronchiolar

smooth muscle in tuberous sclerosis-related LAM is monoclonal metastasis from a coexisting renal angiomyolipoma

There have been cases of TSC-related LAM recurring following lung transplant

Gary Culpan

Gary Culpan

Reticular shadowing

Fine lines

Throughout lungs

Gary Culpan

Causes of Interstitial changes with Volume Loss in Upper Zones

Sarcoid

TB

Pneumoconiosis

EAA (chronic)

Previous Radiation

Ankylosing Spondylitis

Aspergillosis

Gary Culpan

Gary Culpan

Gary Culpan

Gary Culpan

Nodular opacities

Fine nodules

Throughout lungs

Gary Culpan

Causes of Interstitial Changes with Volume Loss - Peripheral

and Basal

Asbestosis

Connective Tissue Diseases

Drugs

Idiopathic

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Pleural plaques

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Gary Culpan

Asbestosis

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Idiopathic Interstitial Pneumonias

Classification: Idiopathic Pulmonary Fibrosis (IPF)

AKA Usual Interstitial Pneumonia (UIP)

Non Specific Interstitial Pneumonia (NSIP)

Desquamative Interstitial Pneumonia (DIP)

Acute Interstitial Pneumonia (AIP)

Lymphocytic Interstitial Pneumonia (LIP)

Cryptogenic Organising Pneumonia (COP)

AKA Bronchiolitis Obliterans Organising Pneumonia (BOOP)

Diagnosis based on HRCT features and Pathology

Gary Culpan

IIP

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Honeycomb appearance

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Honeycombing Extensive end-stage pulmonary fibrosis

Resulting in lung destruction and obliteration of acinar architecture Cystic spaces present Usually several mm to 1 cm in diameter Characterized by thick, clearly definable fibrous wall Typically lined by bronchiolar epithelium Often have sub-pleural predominance

CXR Honeycombing results in reticular pattern Usually most evident peripherally and in the costo-phrenic angles

HRCT Cystic air-spaces of honeycombing commonly share walls Predominantly sub-pleural Occur in several layers

Most commonly caused by Idiopathic pulmonary fibrosis, collagen vascular diseases, end-stage

hypersensitivity pneumonitis and asbestosis.

Gary Culpan

Gary Culpan

Gary Culpan

Extrinsic Allergic Alveolitis Inflammation of small airways

Immunological reaction to inhaled bioaerosol Biological particles / organic chemicals

Range of effects and severity

Examples conditions related to source of irritant

Named conditions: Farmer's lung, Bird fancier's lung, metalworking-fluid lung,

cheese washer's lung, mushroom worker's lung, doghouse disease, wood pulp worker's lung, rodent handler's lung, woodworker's lung, hot tub lung, humidifier lung, compost lung and peat-moss worker's lung

Gary Culpan

EAA Acute form

CXR usually shows no abnormality until symptoms are moderately severe

Abnormalities - widespread

Ground-glass appearance or alveolar filling pattern

Especially in lower and mid-zones

Sub-acute form Small reticular opacities - same distribution

HRCT shows increased ground-glass density or reticular/nodular infiltration

Hilar lymphadenopathy is rare

Chronic form CXR and HRCT show irreversible fibrotic process

Mainly affecting the upper zones

Gary Culpan

Usual Interstitial Pneumonia Most common type of chronic interstitial pneumonia Early stages characterised by alveolitis and increased cellularity of the

alveolar wall shown histologically Progression leads to pulmonary fibrosis and honeycombing Clinically, UIP is often used synonymously with idiopathic pulmonary

fibrosis, Identical findings of can be seen in patients with other diseases

e.g. collagen vascular diseases (RA) and progressive systemic sclerosis.

5-year mortality for is 45% Only 10% of patients respond to treatment HRCT appearances are characterised by predominance of reticular

opacities Correspond to areas of irregular fibrosis, lung destruction,

honeycombing and traction bronchiectasis Findings visible in virtually all patients and frequently show peripheral,

sub pleural and basal predominance Ground glass opacities seen in less than half of patients

usually related to presence of alveolitis, alveolar wall thickening or early fibrosis.

Gary Culpan

Desquamative Interstitial Pneumonia

Nonspecific reaction of lung to injury Characterised histologically by the presence of numerous macrophages filling

alveoli, mild inflammation of alveolar walls, and minimal fibrosis

Can be seen in patients with a variety of infiltrative lung diseases Including idiopathic pulmonary fibrosis, collagenvascular diseases, histiocytosis

X-pulmonary and drug reactions

Patients have milder symptoms, better prognosis, and respond better to treatment with corticosteroids than patients with UIP

5-year mortality = 5%

Commonest finding on CXR Ground-glass opacities in lower lung zones

In up to 20% of patients with biopsy-proven DIP, CXR is normal On HRCT, predominant abnormality is patchy ground glass opacity

Opacities may have a lower lobe or peripheral predominance Irregular linear opacities and architectural distortion indicates fibrosis Seen in approx. 50% of patients Honeycombing may also be seen but is less common

Gary Culpan

Acute Interstitial Pneumonia

AKA - Hamman Rich syndrome Unknown aetiology

Sudden onset, severe symptoms, short duration Histological findings = diffuse alveolar damage Sometimes referred to as idiopathic adult respiratory distress syndrome Forewarning symptom of viral infection is often present Followed by rapidly increasing dyspnoea and respiratory failure Death may occur despite supportive therapy

Pathological abnormalities Alveolar wall oedema, inflammation and fibroblast proliferation, with

extensive alveolar damage and hyaline membranes.

CXR and HRCT findings Bilateral, symmetrical areas of ground glass opacity Usually involving all lung zones, Bilateral areas of air-space consolidation Subpleural honeycombing in some patients

Gary Culpan

Acute Interstitial Pneumonia

Gary Culpan

Lymphocytic Interstitial Pneumonia Uncommon disease

Mainly in patients with dysproteinaemia, autoimmune disease Particularly Sjogrens syndrome and AIDS

Many cases initially classified as LIP now considered to be lymphomas Often considered "prelymphomatous" condition, except in patients with AIDS Mature lymphocytic and plasma cell infiltrates in relation to lymphatics in association

with the peribronchovascular interstitium, interlobular septa, subpleural interstitium, and centrilobular regions

Fibrosis is uncommon Symptoms are nonspecific

Often those of patient's underlying disease Cough and dyspnoea most frequent respiratory complaints

CXR is nonspecific Shows reticular or nodular opacities, or consolidation Often lower lobe predominance

HRCT Ground glass opacity, ill-defined centrilobular opacities or well-defined nodules in

relation to the fissures and interstitium In Sjogrens syndrome, may be associated with lung cysts

Gary Culpan

Lymphocytic Interstitial Pneumonia

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Cryptogenic Organising Pneumonia

AKA bronchiolitis obliterans organising pneumonia (BOOP)

which is cryptogenic or idiopathic

Emphasizes that physiological abnormality associated with this entity primarily results from an organising pneumonia

Gary Culpan

Bronchiolitis Obliterans Organising Pneumonia

Pathological characterisation Granulation tissue polyps in lumen of bronchioles and alveolar ducts Patchy areas of organizing pneumonia, consisting largely of mononuclear cells and

foamy macrophages

Also known as cryptogenic organizing pneumonia Most cases are idiopathic BOOP may also be seen with pulmonary infection, drug reactions, collagen vascular

diseases and Wegeners granulomatosis chest, and after inhalation of toxic fumes

BOOP typically presents with history of several months of nonproductive cough, low-grade fever, malaise and shortness of breath

Pulmonary function tests usually show restrictive pattern CXR

Patchy, nonsegmental, unilateral or bilateral areas of air space consolidation

HRCT Patchy consolidation Ground glass opacity Subpleural and/or peribronchial distribution Small ill-defined nodules - be peribronchial or peribronchiolar Bronchial wall thickening or dilatation in abnormal lung regions

Patients usually respond to treatment with steroids

Gary Culpan

ARDS Definition

Acute and persistent severe hypoxia bilateral radiographic lung infiltrates, and no evidence of congestive heart failure

Not a disease but a syndrome

May be due to direct parenchymal injury Trauma, pneumonia, aspiration Or capillary leak oedema from systemic inflammation

classical radiographic descriptions 12-24 hours CXR is normal or it shows mild generalised atelectasis 48 hours - here is a rapid increase in density throughout the lungs and

often diffuse ground-glass to alveolar consolidation symmetrically distributed

Then stabilises for several days End of the first week, consolidation becomes less dense, eventually

forming a fibrotic pattern Many have asymmetrical disease, focal areas of dense consolidation, or

dense consolidation alternating with ground-glass opacification Differences may relate, in part, to the underlying aetiology.

Gary Culpan

ARDS extra pulmonary Systemic insult, most often blood borne

Distributes itself diffusely and causes oedema, haemorrhage and atelectasis

Contrast this with ARDS pulmonary - due to bacterial pneumonia, aspiration or direct lung trauma

Only a portion of the lung parenchyma is affected

Early CXR Shows rapidly progressive focal alveolar consolidation mixed with normal areas Eventually, ground-glass opacification in remote areas May be due to atelectasis, lesser effects of initial disease, or systemic effects of

lung disease reaching remaining lung haematogenously.

During the second and third week, fibrosis and repair begin CXR or HRCT show less ground-glass and less consolidation

Replaced with coarser reticular pattern. Lung distorsion appears as fibrosis progresses. Barotrauma may cause

interstitial emphysema leading to pneumomediastinum and pneumothorax and pneumatoceles

Survivors - lung remodelling remarkable CXR returns to normal, or near normal HRCT shows modest areas of interstitial fibrosis

Gary Culpan

Coexisting infection

Nosocomial infection is common in the intubated ARDS patient

Coexisting nosocomial infection is extremely difficult to diagnose both clinically and radiographically

Usual clinical markers of infection such as fever, leukocytosis and malaise have many other possible causes in the Intensive Care Unit (ICU)

Bacteria frequently colonise the tracheobronchial secretions in absence of pneumonia

Classical pattern of symmetrical ground glass infiltrate, pneumonia is uncommon

Gary Culpan

ARDS

Gary Culpan

ARDS - aetilogy Pulmonary

Pneumonia

Pulmonary aspiration

Trauma - direct

Haemorrhage

Toxic inhalation

Extrapulmonary

Sepsis

Hypotension

Trauma indirect

Pancreatitis

Polytransfusion

Gary Culpan

SARS Severe acute respiratory syndrome

Respiratory disease in humans Caused by the SARS coronavirus

CXR appearance Variable

No pathognomonic appearance

Commonly seen to be abnormal

Patchy infiltrates in any part of the lungs

Initial CXR may be clear

Gary Culpan

SARS

Increased

opacity in

both lungs,

indicative of

pneumonia

Influenza

Viral infection, doesnt usually need treatment

Usually affects young, elderly and pre-existing

can lead to severe complications of any underlying conditions, pneumonia and death

Seasonal

H1N1 Bird / avian / swine

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Perspective

SARS mortality 11%

Seasonal influenza mortality 0.5%

H1N1 no more than seasonal

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Huang 2011 Taipei Times

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