Reduced Total Airway Count and Airway Wall Tapering after Three-Years in Ex-Smokers.

Computed tomography (CT) total-airway-count (TAC) and airway wall-thickness differ across chronic obstructive pulmonary disease (COPD) severities, but longitudinal insights are lacking. The aim of this study was to evaluate longitudinal CT airway measurements over three-years in ex-smokers. In this prospective convenience sample study, ex-smokers with ( = 50; 13 female; age = 70 ± 9 years; pack-years = 43 ± 26) and without ( = 40; 17 female; age = 69 ± 10 years; pack-years = 31 ± 17) COPD completed CT, He magnetic resonance imaging (MRI), and pulmonary function tests at baseline and three-year follow-up.

Quantification of pulmonary functional MRI: state-of-the-art and emerging image processing methods and measurements.

Pulmonary functional magnetic resonance imaging (PfMRI) provides a way to non-invasively map and measure the spatial distribution of pulmonary ventilation, perfusion and gas-exchange abnormalities with unprecedented detail of functional processes at the level of airways, alveoli and the alveolar-capillary membrane. Current PfMRI approaches are dominated by hyperpolarized helium-3 (He) and xenon-129 (Xe) gases, which both provide rapid (8-15 s) and well-tolerated imaging examinations in patients with severe pulmonary diseases and pediatric populations, whilst employing no ionizing radiation. While a number of review papers summarize the required image acquisition hardware and software requirements needed to enable PfMRI, here we focus on the image analysis and processing methods required for reproducible measurements using hyperpolarized gas ventilation MRI.

Persistent Xe MRI Pulmonary and CT Vascular Abnormalities in Symptomatic Individuals with Post-acute COVID-19 Syndrome.

Background: In patients with post-acute COVID-19 syndrome (PACS), abnormal gas-transfer and pulmonary vascular density have been reported, but such findings have not been related to each other or to symptoms and exercise limitation. The pathophysiologic drivers of PACS in patients previously infected with COVID-19 who were admitted to in-patient treatment in hospital (or ever-hospitalized patients) and never-hospitalized patients are not well understood.

Purpose: To determine the relationship of persistent symptoms and exercise limitation with xenon 129 (Xe) MRI and CT pulmonary vascular measurements in individuals with PACS.

Pulmonary functional MRI: Detecting the structure-function pathologies that drive asthma symptoms and quality of life.

Pulmonary functional MRI (PfMRI) using inhaled hyperpolarized, radiation-free gases (such as He and Xe) provides a way to directly visualize inhaled gas distribution and ventilation defects (or ventilation heterogeneity) in real time with high spatial (~mm ) resolution. Both gases enable quantitative measurement of terminal airway morphology, while Xe uniquely enables imaging the transfer of inhaled gas across the alveolar-capillary tissue barrier to the red blood cells. In patients with asthma, PfMRI abnormalities have been shown to reflect airway smooth muscle dysfunction, airway inflammation and remodelling, luminal occlusions and airway pruning.