hrct in diffuse lung diseases - ii (honeycombing, uip pattern, ipf)
DESCRIPTION
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 diagnosesTRANSCRIPT
HRCT in Diffuse Lung Diseases - II
Dr. Bhavin JankhariaJankharia Imaging
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
Honeycombing – layered peripheral cysts, stacked one on top of the other
D/D of Honeycombing
BronchiectasisHoneycombing
Bronchiectasis presents with branching cystic and tubular areas
extending from the hilum to the periphery
EmphysemaHoneycombing
Emphysema presents with centrilobular cystic areas without
walls
Cystic lung disease
Honeycombing
Cystic interstitial lung disease presents with cysts with walls
randomly distributed throughout the lung parenchyma
The presence of honeycombing allows us to confidently make a diagnosis of a usual interstitial
pneumonia pattern (UIP)
Reticular pattern - honeycombingReticular pattern – no honeycombing
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
The Diagnosis of a UIP Pattern
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
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
Upper zone - chronic hypersensitivity pneumonitis
Lower zone – UIP pattern
Long standing sarcoidosis with fibrosis – upper and mid-zone fibrosis
Upper zone predominance of honeycombing usually implies
chronic hypersensitivity pneumonitis or long standng parenchymal sarcoidosis with
fibrosis
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
If all these criteria are met, then we can confidently make the
diagnosis of a UIP pattern
New IPF criteria – ATS/ERS
This is the new algorithm to make a diagnosis of Idiopathic Pulmonary Fibrosis (IPF)
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
IPF
Issues• Complications – neoplasm, infection
IPF with superimposed opacity in the left lower lobe – TB on biopsy
IPF with progressive consolidation over a year – invasive mucinous adenocarcinoma on biopsy
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
IPF
Issues• Complications – neoplasm, infection• Combined emphysema with fibrosis (CPFE)
This patient has both emphysema in the upper lobes and a UIP pattern in the lower lobes
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
The next presentation will be on NSIP and other idiopathic
interstitial pneumonias
Thank You