Interstitial lung pattern (radiograph)

Last revised by Daniel J Bell on 27 Jan 2020

Citation, DOI, disclosures and article data

Citation:

Jones J, Bell D, Weerakkody Y, et al. Interstitial lung pattern (radiograph). Reference article, Radiopaedia.org (Accessed on 19 Apr 2024) https://doi.org/10.53347/rID-16857

DOI:

https://doi.org/10.53347/rID-16857

Permalink:

https://radiopaedia.org/articles/16857

rID:

16857

Article created:

25 Feb 2012, Jeremy Jones ◉

Disclosures:

At the time the article was created Jeremy Jones had no recorded disclosures.

View Jeremy Jones's current disclosures

Last revised:

27 Jan 2020, Daniel J Bell ◉

Disclosures:

At the time the article was last revised Daniel J Bell had no recorded disclosures.

View Daniel J Bell's current disclosures

Revisions:

5 times, by 5 contributors - see full revision history and disclosures

Systems:

Chest

Sections:

Gamuts

Tags:

cxr, infectiousdisease

Synonyms:

Interstitial lung patterns (radiograph)

An interstitial lung pattern is a regular descriptive term used when reporting a plain chest radiograph. It is the result of the age-old attempt to make the distinction between an interstitial and airspace (alveolar) process to narrow the differential diagnosis.

A re-read of the timeless work of Benjamin Felson in 1979, "A new look at pattern recognition of diffuse pulmonary disease" ¹, explains the difficulty of describing a disease process as purely interstitial. The problem is that despite processes starting in the pulmonary interstitium, by the time they appear on a radiograph, there is almost certainly a degree of airspace involvement.

He cites several examples including:

lymphangitic carcinomatosis: while the process creates a linear pattern, by the time it is recognisable on a radiograph, "at autopsy the spreading neoplasm usually appears to have cut a tornado-like path through all compartments of the pulmonary tissue"
viral pneumonias: while these are widely considered to be interstitial, chickenpox pneumonia is a predominantly alveolar process with airspace opacification on the chest radiograph
pneumocystis pneumonia starts as an interstitial process, but by the time the radiograph is taken, histological examination demonstrates extensive alveolar involvement

The solution from the paper is the use of terms that describe the appearance on the chest radiograph rather than attempting to outline the pathological location of the abnormality.

The list of gamuts he describes are:

bronchial disease, e.g. mucoid impaction, bronchiectasis
discrete miliary nodules
honeycombing
Kerley lines
small irregular shadows - reticular, reticulonodular
vascular abnormality

The importance here is to reduce the confusion that arises when trying to be dogmatic about separating pathology into interstitial or airspace pathology. Take the example of a cavity - it could arise from airspace or interstitial disease:

cavitating pneumonia occurs as a result of airspace pathology but it is unreasonable to say that the interstitium is not involved
cavitation of a tuberculous nodule - the nodule is initially interstitial, but with growth involves the airspaces, and as it enlarges, cavitation occurs