A Systematic Review of Chest Imaging Findings in Long COVID Patients

Abstract

Long COVID is the persistence of one or more COVID-19 symptoms after the initial viral infection, and there is evidence supporting its association with lung damage. In this systematic review, we provide an overview of lung imaging and its findings in long COVID patients. A PubMed search was performed on 29 September 2021, for English language studies in which lung imaging was performed in adults suffering from long COVID. Two independent researchers extracted the data. Our search identified 3130 articles, of which 31, representing the imaging findings of 342 long COVID patients, were retained. The most common imaging modality used was computed tomography (CT) (N = 249). A total of 29 different imaging findings were reported, which were broadly categorized into interstitial (fibrotic), pleural, airway, and other parenchymal abnormalities. A direct comparison between cases, in terms of residual lesions, was available for 148 patients, of whom 66 (44.6%) had normal CT findings. Although respiratory symptoms belong to the most common symptoms in long COVID patients, this is not necessarily linked to radiologically detectable lung damage. Therefore, more research is needed on the role of the various types of lung (and other organ) damage which may or may not occur in long COVID.

Residual Lung Abnormalities in Survivors of Severe or Critical COVID-19 at One-Year Follow-Up Computed Tomography: A Narrative Review Comparing the European and East Asian Experiences

“…The differences between our findings and those reported previously [26,31,[47][48][49] are probably due to a different method of analyses.…”

“…Unlike previous systematic reviews [26,31,[47][48][49], our study included only chest CT abnormalities in survivors of COVID-19 after severe or critical SARS-CoV-2 infection, and the CT findings were grouped based on the region of origin (Europe vs. China).…”

“…Based on the literature, residual lung abnormalities on chest CT are relatively common in survivors of COVID-19 . At one-year follow-up chest CT, survivors with the lowest frequency of lung parenchymal abnormalities were those with previous mild to moderate disease [14,20,21,[24][25][26]29,32,33,35,[43][44][45][46][47][48][49]. These patients have mild to moderate symptoms with a blood oxygen saturation ≥ 90% and without signs of severe pneumonia [50].…”

Towards Building a Trustworthy Deep Learning Framework for Medical Image Analysis

“…The proposed framework is by no means perfect, but we hope the TRUDLMIA can contribute to the fight against pandemics, including post-acute COVID syndrome (long COVID) [49,50], and establish a viable path for future ones. In our future work, we are interested in investigating the use of Vision Transformers [51] to replace the CNNs used in the TRUDLMIA framework.…”

Long COVID as a functional somatic symptom disorder caused by abnormally precise prior expectations during Bayesian perceptual processing: A new hypothesis and implications for pandemic response

“…This returned 52 citations, and on review of the abstract and full text to detect data on structural organ pathology, 3 were included. [87][88][89] Second, we searched "Long COVID" OR "Post COVID condition," AND "pathology," AND "systematic review" with the same date restriction. This returned nine citations, and on review of abstract and full text to detect data on structural organ pathology, two more publications were included.…”