This is the second part of this series on HRCT in diffuse lung diseases, focussing on the diagnosis of honeycombing, UIP pattern and IPF and the associated complications and differential diagnoses

1. HRCT in Diffuse Lung Diseases - II
Dr. Bhavin Jankharia
Jankharia Imaging

2. The key to learning HRCT
interpretation in interstitial lung
diseases is to learn how to identify
honeycombing, which allows us to
recognize the Usual Interstitial
Pneumonia (UIP) pattern

3. Honeycombing – layered peripheral cysts, stacked one on top of the other

4. D/D of Honeycombing

5. Honeycombing Bronchiectasis

6. Bronchiectasis presents with
branching cystic and tubular areas
extending from the hilum to the
periphery

7. Honeycombing Emphysema

8. Emphysema presents with
centrilobular cystic areas without
walls

9. Honeycombing Cystic lung

10. Cystic interstitial lung disease
presents with cysts with walls
randomly distributed throughout
the lung parenchyma

11. The presence of honeycombing
allows us to confidently make a
diagnosis of a usual interstitial
pneumonia pattern (UIP)

12. Reticular pattern – no honeycombing Reticular pattern - honeycombing

13. The absence of honeycombing as
seen on the left image does not
rule out a UIP pattern, but a
diagnosis of UIP cannot be made
with any specificity in that context.
A non-specific interstitial
pneumonia with fibrosis (NSIP)
pattern also then comes into the
differential diagnosis

14. The Diagnosis of a UIP Pattern

15. IPF
UIP Criteria
Reticular abnormality
Honeycombing with or
without traction
bronchiectasis
Subpleural basal
predominance
Absence of other signs like
ground glass, nodules, etc
New IPF criteria – ATS/ERS

16. IPF
UIP Criteria
• Reticular abnormality
• Honeycombing with or without
traction bronchiectasis
• Subpleural basal
predominance
• Absence of features
inconsistent with these
New IPF criteria – ATS/ERS

17. Lower zone – UIP pattern Upper zone - chronic
hypersensitivity pneumonitis

18. Long standing sarcoidosis with fibrosis – upper and mid-zone fibrosis

19. Upper zone predominance of
honeycombing usually implies
chronic hypersensitivity
pneumonitis or long standng
parenchymal sarcoidosis with
fibrosis

20. IPF
UIP Criteria
Reticular abnormality
Honeycombing with or
without traction
bronchiectasis
Subpleural basal
predominance
Absence of other signs like
ground glass, nodules, etc
New IPF criteria – ATS/ERS

21. If all these criteria are met, then
we can confidently make the
diagnosis of a UIP pattern

22. New IPF criteria – ATS/ERS

23. This is the new algorithm to make
a diagnosis of Idiopathic
Pulmonary Fibrosis (IPF)

24. In the presence of a UIP pattern,
in the absence of an identifiable
cause (e.g. rheumatoid arthritis,
familial, etc), the presence of a
UIP pattern implies IPF

25. IPF
Issues
• Complications – neoplasm, infection

26. IPF with superimposed opacity in the left lower lobe – TB on biopsy

27. IPF with progressive consolidation over a year – invasive mucinous adenocarcinoma
on biopsy

28. Patients with IPF have an
increased incidence of
superimposed infection and
neoplasm. The HRCTs of patients
of IPF on follow-up should be
examined for superimposed / new
pathology

29. IPF
Issues
• Complications – neoplasm, infection
• Combined emphysema with fibrosis (CPFE)

30. This patient has both emphysema in the upper lobes and a UIP pattern in the lower
lobes

31. This occurs in smokers, with
emphysema in the upper lobes
and IPF in the lower lobes. It has
a worse prognosis than IPF and
clinically can be a challenge to
diagnose

32. The next presentation will be on
NSIP and other idiopathic
interstitial pneumonias

33. Thank You