Interstitial Pneumonias/ Diffuse lung diseases

Question 1

LIP 1 ) findings and 2) associations

Answer 1

1) Variable sized thin walled cysts, ground glass opacities, poorly defined centrilobular and subpleural nodules, interlobular septal thickening - can mimic LC
2) Autoimmune diseases (sjrogens - strongest, autoimmune, HIV/AIDS in kids, bone marrow transplant, drug reaction)

**diffuse interstitial lymphoid infiltration - spectrum to lymphoproliferative disorders in the lung

Question 2

List causes of UIP pattern

Answer 2

Idiopathic (most common) = IPF
Collagen vascular disease (rheumatoid, scleroderma, polymyositis/dermatomyositis, mixed CTD)
Drug injury (amiodarone lung)
Chronic HP
Asbestosis

Question 3

Typical features of NSIP

Answer 3

• Basal predominant reticulation & gg
• Sparing of immediate subpleural lung
• May have associated fibrosis (in fibrotic subtype), but this is not the predominant feature

Question 4

Causes of NSIP pattern

Answer 4

Collagen vascular disease (most common*, eg scleroderma)
Drug reaction
Occupational exposure
Dermatomyositis

Question 5

Imaging findings/causes of OP

Answer 5

Patchy, non-segmental consolidation and ground glass in a peribronchovascular and peripheral distribution (can also be perilobular) which change location over matter of weeks, bronchial wall thickening or dilation.
May have atoll (reverse halo) sign

NB: perilobular pattern- poorly defined linear opacities with arcade like or polygonal appearance

DDx: Chronic eosinophilic pneumonia

This is a reaction to a number of different conditions (granulation tissue fills the alveoli)

Causes: drug toxicity, infection, inhalation injury, CTDs, HP, malignancy, radiation therapy, aspiration, etc

Question 6

Imaging findings and demographics RB-ILD

Answer 6

Poorly defined centrilobular nodules and ground glass (slight upper lobe predilection), bronchial wall thickening
Young patients, heavy smokers
Ddx: NSIP (basal), HP (upper)

if not symptomatic, then just RB

Question 7

Imaging findings of DIP

Answer 7

Spectrum with RB –> RB-ILD –> DIP
Extensive, basal predominant peripheral and subpleural gg, centrilobular emphysema
**may have cysts (helpful distinguishing feature)

Question 8

Imaging findings of LIP

Answer 8

Ground glass and scattered thin walled cysts, basal predominant. *prone to pneumothorax

Suspect in patient with Sjorgrens (most common, but can get LIP in other CTDs), can indicate HIV in kids

Question 9

Imaging findings in AIP

Answer 9

AIP = DAD = ARDS (clinical syndrome)
Non-cardiogenic edema
Extensive bilateral ggo’s (geographic, or crazy paving pattern), airspace consolidation which is commonly basilar and dependent
May progress to chronic organizing phase

Question 10

Imaging findings HP

Answer 10

Acute - gg, consolidation, centrilobular nodules
Subacute - centrilobular nodules and mosaic attenuation (head-cheese)
Chronic - findings above +/- upper lobe fibrosis

*Like other inhalation lung diseases, most commonly affects the upper lobes (lower lobes have robust blood supply and lymphatics for clearing particles)

Question 11

Imaging findings in silicosis and CWP

Answer 11

Range of appearances
Classic/simple - multiple, perilymphatic nodules in upper lobes, egg shell nodal calcs (specific for silicosis)
Complicated - confluent nodules/consolidation +/- fibrosis

Question 12

Imaging appearance of simple versus chronic EP

Answer 12

Simple - transient, migratory areas of consolidation with elevated peripheral eosinophils (i.e. Loffler syndrome)

Chronic - patchy, peripheral upper lobe consolidation that is chronic

Question 13

List the vasculitides affecting the lung and imaging features

Answer 13

1) Churg-Strauss - peripheral gg and consolidation
2) Microscopic polyangitis - central gg from hemorrhage (associated with renal failure)
3) GPA - C-ANCA, multiple cavitating lung nodules

*NB: GPA triad = sinusitis, pulmonary disease, renal insufficiency

Question 14

Imaging findings in sarcoid

Answer 14

Upper lobe predominant, variable appearance with perilymphatic nodules, ground glass, galaxy sign when nodules coalesce
Adenopathy (may have stippled or egg shell calcification)

Question 15

Imaging findings/demographics LCH

Answer 15

Almost exclusively smokers
Nodules –> cavitate –> cysts (bizarre)
Upper lobe predominant, spare the costophrenic sulci
Spontaneous pneumothorax

Question 16

Imaging findings/demographics LAM

Answer 16

Middle aged women
Association with TS
Round, regular thin walled cysts, no lobar predilection
Chylous effusion and pneumo

Question 17

List criteria for UIP pattern

Answer 17

Honeycombing
Basal subpleural predominant distribution
+/- reticular opacities and traction bronchiectasis
*absence of features suggesting another diagnosis

Question 18

List criteria for probable UIP

Answer 18

No honey combing
Reticulation +/- ground glass 
Traction bronchiectasis 
Basal subpleural distribution
*absence of features suggesting another diagnosis

Question 19

List criteria for indeterminate UIP

Answer 19

Does not meet criteria for UIP or probable UIP

Subtle reticular abnormalities or subtle ground glass

Question 20

List findings on HRCT that suggest “alternate diagnosis” when assessing for UIP

Answer 20

1) Distribution
- Upper or mid lung predominance
- Peribronchovascular or perilymphatic (i.e. sarcoid , silicosis)

2) Marked mosaic attenuation (air trapping - HP, predominant ground glass - cellular NSIP)
3) Profuse micronodules or centrilobular nodules (HP, sarcoidosis)
4) Pleural changes (thickening, effusion, plaque suggesting asbestosis)

Question 21

Imaging findings PPFE

Answer 21

Upper lobe predominant pleural thickening, subpleural reticulation, volume loss and hilar retraction.

Ddx other upper lobe fibrotic lung processes (sarcoid, silcosis, CWP, ank spond)