Peculiar high resolution computed tomography patterns in post-covid fibrosis

Abstract

Background: With the advent of the covid era, a new entity has been added to the bulk of interstitial lung diseases i.e. post covid fibrosis. The radiological findings on high resolution computed tomography (HRCT) of thorax range from mild ground glass opacity to widespread fibrosis. We noticed certain odd patterns of fibrosis and are reporting the same.

Method: The study was done over a period of six months (from August 2020 to January 2021) in the departments of Respiratory Medicine and Radiodiagnosis, King George’s Medical University, India. The HRCT patterns of consecutive patients who suffered from Covid-19 (serologically confirmed) without prior history of respiratory disease were studied.

Result: Out of the total 56 subjects, ground glass opacities were present in 89%, reticulations in 86% with a unique pattern of fibrosis parallel to pleural surface seen in 54%,patchy consolidation in 49% and cysts in 43%. Majority had lower lobe predominance (57%) (Figure 1: Axial section of HRCT thorax of post-covid patients showing prominent subpleural fibrotic bands with red arrows and cysts with black arrows)

Conclusion: Reticulations, ground glass opacities and consolidation are common in those with respiratory sequelae of Covid-19. It has an odd predilection for subpleural involvement with fibrosis occurring in cupola shaped bands along with cystic changes.