Evidence map›Paper›PMID 41872922›Full record

ArticleRespiratory research2026

Imaging biomarkers of post-COVID dyspnea: insights from machine learning CT patterns and parametric response mapping.

Julien G Cohen, Vicente Estopier-Castillo, Cécile Olivier, Marie Destors, Gilbert R Ferretti, Jean-Louis Pépin, Renaud Tamisier, Sam Bayat

Registry-linked trialAbstract read
In one paragraph

Article in Respiratory research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04406324 (COVID-19), which is not on this map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT04406324 unknown statusnot on this map

COVID-19: Prospective Follow-up of Pulmonary Function, Sleep Disorders, Quality of Life and Post-traumatic Stress

TypeobservationalSponsorUniversity Hospital, GrenobleRan2020 to 2026Enrolled395ConditionsCOVID-19ArmsNo intervention
3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Julien G CohenUniversity Hospitals of Geneva, Geneva, Switzerland.
Vicente Estopier-CastilloSTROBE Laboratory, INSERM UA7, Pôle Thorax et Vaisseaux CHU Grenoble Alpes, University Grenoble Alpes, Grenoble, France.
Cécile OlivierSTROBE Laboratory, INSERM UA7, Pôle Thorax et Vaisseaux CHU Grenoble Alpes, University Grenoble Alpes, Grenoble, France.
Marie DestorsDepartment of Pulmonology & Physiology, Grenoble University Hospital, Grenoble, France.
Gilbert R FerrettiDepartment of Radiology, Grenoble University Hospital, Grenoble, France.
Jean-Louis PépinDepartment of Pulmonology & Physiology, Grenoble University Hospital, Grenoble, France.
Renaud TamisierDepartment of Pulmonology & Physiology, Grenoble University Hospital, Grenoble, France.
Sam BayatSTROBE Laboratory, INSERM UA7, Pôle Thorax et Vaisseaux CHU Grenoble Alpes, University Grenoble Alpes, Grenoble, France. SBayat@chu-grenoble.fr.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundDyspnea is one of the most common symptoms in the post-acute phase of COVID-19 pneumonia. Conventional pulmonary function tests and computed tomography (CT) scores often fail to show correlation with symptom severity, highlighting the need for more sensitive imaging biomarkers. Machine-learning–based quantitative CT analysis and parametric response mapping (PRM) can capture subtle structural and functional abnormalities that may be associated with persistent dyspnea.

methodsWe analyzed inspiratory and paired inspiratory–expiratory CT scans of early (3–6 months) post-COVID-19 pneumonia patients. Inspiratory CT images were segmented using a random forest algorithm to quantify lung parenchymal patterns. Paired inspiratory/expiratory scans were co-registered to derive ventilation metrics and PRM-defined functional small airway disease (fSAD), emphysema, emptying emphysema, and normal lung. Associations between imaging metrics and patient-reported dyspnea assessed by a visual analogue scale (VAS) were evaluated using univariable and multivariable linear regression, with adjustment for age, sex, BMI, and smoking history.

resultsOne hundred twenty-three patients had usable inspiratory CT scans, and 116 patients had paired inspiratory/expiratory scans of sufficient quality for analysis. In the adjusted multivariable models, greater PRM-defined functional small airway disease (fSAD) was positively associated with dyspnea (standardized β = 1.21, p = 0.002). Moreover, a lower standard deviation of dense ground-glass attenuation in the left lung (standardized β = −0.82, p = 0.033) and greater total volume of dense ground-glass opacities (standardized β = 0.71, p = 0.033) were independently associated with dyspnea.

conclusionsIn early post-COVID-19 pneumonia, machine-learning–based CT pattern recognition and PRM revealed that functional small airway disease, and the total volume and heterogeneity of lung dense ground-glass opacities are significantly associated with persistent dyspnea. These findings highlight the potential of quantitative CT to identify pulmonary imaging biomarkers relevant to long COVID symptom burden.

trial registrationClinicalTrials.gov (NCT04406324).

Indexed as

COVID-19DyspneaLungMachine LearningTomography, X-Ray ComputedAgedBiomarkersFemaleHumansMaleMiddle AgedPost-Acute COVID-19 SyndromeBiomarkersCOVID-19CT parametric response mappingdyspneamachine learningquantitative CT analysissmall airway disease

Identifiers

PMID41872922
PMCPMC13130808

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.