<p>Thoracic Imaging at Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review</p>

Abstract

Exacerbations of chronic obstructive pulmonary disease (COPD) are currently diagnosed based on changes in respiratory symptoms. Characterizing the imaging manifestation of exacerbations could be useful for objective diagnosis of exacerbations in the clinic and clinical trials, as well as provide a mechanism for monitoring exacerbation treatment and recovery. In this systematic review, we employed a comprehensive search across three databases (Medline, EMBASE, Web of Science) to identify studies that performed imaging of the thorax at COPD exacerbation. We included 51 from a total of 5,047 articles which met all our inclusion criteria. We used an adapted version of the Modified Newcastle-Ottawa Quality Assessment Scale for cohort studies to assess the quality of the included studies. Conclusions were weighted towards higher-quality articles. We identified a total of 36 thoracic imaging features studied at exacerbation of COPD. Studies were generally heterogeneous in their measurements and focus. Nevertheless, considering studies which performed consecutive imaging at stable state and exacerbation, which scored highest for quality, we identified salient imaging biomarkers of exacerbations. An exacerbation is characterized by airway wall and airway calibre changes, hyperinflation, pulmonary vasoconstriction and imaging features suggestive of pulmonary arterial hypertension. Most information was gained from CT studies. We present the first ever composite imaging signature of COPD exacerbations. While imaging during an exacerbation is comparatively new and not comprehensively studied, it may uncover important insights into the acute pathophysiologic changes in the cardiorespiratory system during exacerbations of COPD, providing objective confirmation of events and a biomarker of recovery and treatment response.

TRPV4 Inhibition Exerts Protective Effects Against Resistive Breathing Induced Lung Injury

“…As previously reported by our group, the magnitude of resistive load and the time frame used in our animal model were chosen to mimic the mechanical consequences observed in exacerbations of obstructive pulmonary diseases. 9,15,19 Indeed, there are human clinical data on the consequences of COPD exacerbations that are consistent with our findings, mainly from imaging studies, 31 since obtaining histological samples or performing lung permeability studies during acute exacerbation of COPD is challenging. In an autopsy study where in 6 patients death was attributed to respiratory failure secondary to COPD exacerbation per se, 3 of these patients were exhibiting bilateral infiltrates and 2 vascular congestion on the chest x-ray on Hospital admission.…”

Diagnostic Imaging of Chronic Obstructive Pulmonary Disease: A Ten Years Systematic Review

“…In an attempt to standardize semi-quantitative clinical assessment of COPD and harmonize it with published data on quantitative computed tomography (QCT) phenotypes, a statement of the Fleischner Society proposed a visual CT based classification system comprised by five different emphysema predominant subtypes and two distinct airway predominant subtypes, and identified this proposal as a work in progress to drive future research, including outcomes of distinct CT phenotypes. 12,13 CT-based investigation has also demonstrated that the lung manifests divergent responses to noxious insults such as chronic tobacco smoke exposure. Smokers may appear resilient to the injurious effects of tobacco smoke or may develop emphysema and even pulmonary fibrosis.…”

Standardisation of Clinical Assessment, Management and Follow-Up of Acute Hospitalised Exacerbation of COPD: A Europe-Wide Consensus

“…Chest X-ray is used frequently 29–31 despite evidence showing that it rarely alters 30 clinical management. Research on the value of a CT of the chest during HECOPD is ongoing; 32 whilst the relative infeasibility of CT scans likely contributed to strongly polarised views on its importance at time of HECOPD.…”