Mimics in chest disease: interstitial opacities

Our plain-English summary of Mimics in chest disease: interstitial opacities, by A. Oikonomou, P. Prassopoulos (Insights Into Imaging, 2013).

The study

• Authors: A. Oikonomou, P. Prassopoulos
• Journal: Insights Into Imaging
• Published: 2013;4(1):9-27
• Cited by: 39 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Septal, reticular, nodular, reticulonodular, ground-glass, crazy paving, cystic, ground-glass with reticular, cystic with ground-glass, decreased and mosaic attenuation pattern characterise interstitial lung diseases on high-resolution computed tomography (HRCT). Occasionally different entities mimic each other, either because they share identical HRCT findings or because of superimposition of patterns. Idiopathic pulmonary fibrosis (IPF), fibrosis associated with connective tissue disease, asbestosis, end-stage sarcoidosis or chronic hypersensitivity pneumonitis (HP) may present with lower zone, subpleural reticular pattern associated with honeycombing. Lymphangiomyomatosis may be indistinguishable from histiocytosis or extensive emphysema. Both pulmonary oedema and lymphangitic carcinomatosis may be characterised by septal pattern resulting from thickened interlobular septa. Ill-defined centrilobular nodular pattern may be identically present in HP and respiratory bronchiolitis-associated with interstitial lung disease (RBILD). Sarcoidosis may mimic miliary tuberculosis or haematogenous metastases presenting with miliary pattern, while endobronchial spread of tuberculosis may be indistinguishable from panbronchiolitis, both presenting with tree-in-bud pattern. Atypical infection presenting with ground-glass mimics haemorrhage. Ground-glass pattern with minimal reticulation is seen in desquamative interstitial pneumonia (DIP), RBILD and non-specific interstitial pneumonia (NSIP). Obliterative bronchiolitis and panlobular emphysema may present with decreased attenuation pattern, while obliterative bronchiolitis, chronic pulmonary embolism and HP may manifest with mosaic attenuation pattern. Various mimics in interstitial lung diseases exist. Differential diagnosis is narrowed based on integration of predominant HRCT pattern and clinical history. Teaching Points • To learn about the different HRCT patterns, which are related to interstitial lung diseases. • To be familiar with the more "classical" entities presenting with each HRCT pattern. • To discuss possible overlap of different HRCT patterns and the more common mimics in each case. • To learn about some clues that help differentiate the various diagnostic mimics on HRCT.

In plain English

This article was a pictorial review by two authors from a radiology department in Alexandroupolis, Greece. It described the patterns that interstitial lung diseases show on high-resolution computed tomography (HRCT) scans and which diseases can look alike. It did not study a group of patients; it was illustrated with example scans. For each pattern, the authors described a classic disease, which they said was chosen arbitrarily, and its look-alikes. Asbestosis was presented as a look-alike of idiopathic pulmonary fibrosis, because both show a reticular (mesh-like) pattern. The review described early asbestosis as reticulation beneath the lung lining with small dot-like opacities, mostly in the back and lower parts of the lungs, with honeycombing common at later stages. It listed pleural plaques, diffuse pleural thickening, subpleural lines or parenchymal bands as possible clues that separate asbestosis from idiopathic pulmonary fibrosis. No asbestos fiber types or exposure levels were discussed. The authors concluded that no HRCT pattern gives a specific cause, and that diagnosis should be narrowed by combining scan findings with clinical and laboratory findings.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: pictorial review of HRCT patterns of interstitial lung disease and their diagnostic mimics
• Who was studied: No study population. The review was illustrated with HRCT images of individual example cases, and no patient numbers were given. Authors from the Department of Radiology, University Hospital of Alexandroupolis, Greece.
• Exposure: No exposure was studied. Asbestosis was discussed as one of several diseases that can mimic idiopathic pulmonary fibrosis on HRCT. No asbestos fiber types, products, jobs or doses were described.
• Main results:
  • The review stated that idiopathic pulmonary fibrosis, fibrosis associated with connective tissue disease, asbestosis, end-stage sarcoidosis and chronic hypersensitivity pneumonitis may all show a lower-zone, subpleural reticular pattern.
  • Asbestosis was described as showing subpleural reticulation with subpleural dot-like opacities at early stages. Findings were mainly in the posterior and basal segments, and honeycombing was common at later stages.
  • Pleural plaques were listed as a possible clue for telling asbestosis apart from idiopathic pulmonary fibrosis.
  • The same list of clues for asbestosis continued with diffuse pleural thickening, subpleural lines or parenchymal bands. In the text this sentence is interrupted by figure captions.
  • In the asbestosis example image, calcified subpleural and diaphragmatic pleural plaques were described as giving a definitive clue to the diagnosis of asbestosis.
  • The authors stated that no HRCT pattern provides a specific cause (etiological diagnosis).
• The authors' conclusion: The authors concluded that the differential diagnosis should be narrowed by identifying distinctive imaging clues and integrating HRCT findings with clinical and laboratory findings.
• Limitations the authors state:
  • The authors stated that the classic disease chosen for each HRCT pattern was selected in an arbitrary way.

Topics

Medical terms in this study, explained in our Lexicon: Interstitial, Interstitial Lung Disease, High-Resolution CT (HRCT), Idiopathic, Pulmonary Fibrosis, Fibrosis, Pneumonitis, Honeycombing.

Related studies

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• Agreement between chest radiography and high-resolution computed tomography in diagnosing dust-related interstitial lung fibrosis — R.R. Tiwari (2015)
• The effect of cigarette smoking on the detection of small radiographic opacities in inorganic dust diseases — P.D. Blanc, G. Gamsu (1988)
• Yellow Nail Syndrome with Bilateral Pleural Plaques and Diffuse Pleural Thickening: A Mimic of Asbestos Related Disease — A. Dallmann, R.L. Attanoos (2018)
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