HRCT Interstitial Pneumonia UIP or IPF DIP NSIP EAA or HP RB and RB-ILD BOOP or COP
HRCT Interstitial Pneumonia
UIP or IPF DIP NSIP EAA or HP RB and RB-ILD BOOP or COP
Six diseases
A simplified way to remember the HRCT patterns…
HRCT Features Location Clinical features Specific points about each disease
Secondary Pulmonary Lobule
Line drawing of a secondary pulmonary lobule.
Borders of lobule are interlobular septa.
At center of each lobule is a bronchiole and a pulmonary artery (blue).
Pulmonary vein (red) run in interlobular septa.
Lymphatics (green) are found in interlobular septa and in central or axial interstitium that surrounds bronchovascular bundles.
Secondary Pulmonary Lobule
artery
veinslymphatics
bronchusacini
pleurachest wall
Secondary Pulmonary Lobule
Secondary Pulmonary Lobule
Artery
Bronchus
Vein Lymphatic
HRCT Signs
GGO – see underlying architecture Consolidation – obscures underlying
architecture Reticulation – septal thickening (lacy
appearance Honeycombing – lung destruction Traction bronchiectasis Nodules – centrilobular or random
Secondary Pulmonary Lobule
Secondary Pulmonary Lobule
UIP clinical features
Middle aged to elderly Insidious onset Progressive sob & cough Bad prognosis – mean survival 5-6
years Poor response steroids – incomplete
recovery
UIP HRCT findings
Septal thickening +++ Honeycombing +++ Traction bronchiectasis + Ground glass opacity + Consolidation +
UIP location
Peripheral / sub pleural Basal – lower lobes Posterior
Case 1
Case 1
Case 1
Case 2
Case 2
Case 3
Case 4
Case 4
Case 4
DIP clinical features
Uncommon Insidious onset 90% are smokers Dyspnea and dry cough Good prognosis Good response steroids – complete
recovery possible
DIP can be secondary to...
Drugs Histiocytosis Leukemia Asbestosis Hard metal pneumoconiosis
DIP HRCT findings
Ground glass opacity +++ Reticulation + Traction bronchiectasis + Centrilobular emphysema – association
with smoking
DIP location
Peripheral / sub pleural Basal Posterior
Case 1
Case 1
Case 1
If you see GGO…
Normal expiration Partially filled alveoli Partially collapsed alveoli Alveolar wall thickening Interstitial thickening Increased capillary blood volume
If you see GGO…
Pneumocystis / pneumonia AIP / ARDS Inflammation - CTD / sarcoid / PAP Radiation pneumonitis Pulmonary edema / hemorrhage Fibrosis - UIP / NSIP DIP / RB-ILD / COP BAC
NSIP clinical features
Diagnosis of exclusion – CTD / HP Middle aged to elderly Insidious onset Dyspnea and dry cough Good prognosis Good response steroids – complete
recovery possible
NSIP HRCT findings
Reticulation +++ Traction bronchiectasis +++ Ground glass opacity +++ Consolidation ++
NSIP location
Peripheral / sub pleural May be basal
Case 1
Case 1
Case 2
Case 2
Case 2
Case 2
NSIP
If you see any honeycombing it is probably UIP
Chronic HP is in the differential diagnosis of NSIP (along with everything else!)
NSIP
NSIP
NSIP
EAA (HP) clinical features
Allergic disease inhalation of antigens in organic dusts
Thermophilic actinomycetes – farmers lung
Acute – fever chills dry cough dyspnea Progression to subacute and chronic
with repeated exposure Remove antigen, steroids
EAA (HP) HRCT findings
Patchy Ground glass opacity +++ Centrilobular nodules +++ Mosaic attenuation on inspiration Lobular areas of air trapping on
expiration Chronic EAA - GGO, reticulation,
traction bronchiectasis and honeycombing
EAA (HP) location
Patchy distribution Subacute EAA mid and upper lungs No zonal distribution Chronic EAA often spares the
costophrenic recesses and mimics NSIP
Case 1
Case 1
Case 1
Case 1 - Expiration
RB-ILD clinical features
RB usually has no clinical signs Young adult smokers Insidious onset Progressive dyspnea and chronic
cough Good prognosis Good response steroids - complete
recovery possible
EB / RB-ILD HRCT findings Centrilobular nodules poorly defined Multifocal ground glass opacity Thickened bronchial walls May see reticulation in lower lungs May have centrilobular emphysema
RB /RB-ILD location
Diffusely distributed Upper and mid lungs mainly
Case 1
Case 1
Case 1
Case 1
Case 1
Case 1
If you see centrilobular nodules… EAA or HP (ask about exposure) RB or RB-ILD (ask about smoking) COP (BOOP) CWP, silicosis Histiocytosis, Endobronchial TB Bronchiectasis, BO, CF ABPA, Asthma
If you see centrilobular nodules… Pulmonary edema Pulmonary hemorrhage Vasculitis Asian panbronchiolitis Endobronchial spread of tumor –
bronchoalveolar cell carcinoma
COP (BOOP) clinical features Several month history Non productive cough Low grade fever, malaise, dyspnea Good prognosis Good response steroids – complete
recovery possible
COP (BOOP) HRCT findings Patchy consolidation +++ Patchy ground glass opacity ++ Small ill defined nodules + Large nodules or masses + Bronchial wall thickening +
COP (BOOP) location
Sub pleural Peribronchovascular Sometimes affects the lower lungs
more
COP like reaction….
Drug reactions Pulmonary infections Collagen vascular diseases Wegener`s granulomatosis Toxic fume inhalation
Case 1 Not HRCT
Case 1 Not HRCT
Case 2 Not HRCT
Case 2 Not HRCT
Case 3 Immunosupressed
Case 3
The sequel of AIP
Questions to ask yourself upon seeing HRCT… Age and gender Acute or chronic symptoms Smoking, systemic disease (CTD) Old studies (best friend) What are the HRCT findings? Where are the HRCT findings? Differential diagnosis of above