A5067086913- Chronic Obstructive Pulmonary Disease (COPD) Research
- Atomic and Subatomic Physics Research
- Respiratory Support and Mechanisms
- Lung Cancer Diagnosis and Treatment
- Asthma and respiratory diseases
- Advanced NMR Techniques and Applications
- Radiomics and Machine Learning in Medical Imaging
- Pulmonary Hypertension Research and Treatments
- Advanced MRI Techniques and Applications
- Neonatal Respiratory Health Research
- Medical Imaging Techniques and Applications
- Quantum, superfluid, helium dynamics
- Inhalation and Respiratory Drug Delivery
- Interstitial Lung Diseases and Idiopathic Pulmonary Fibrosis
- Respiratory and Cough-Related Research
- Advanced X-ray and CT Imaging
- Congenital Diaphragmatic Hernia Studies
- Phonocardiography and Auscultation Techniques
- Cardiovascular and exercise physiology
- Obstructive Sleep Apnea Research
- Pleural and Pulmonary Diseases
- Optical Coherence Tomography Applications
- Thermal Regulation in Medicine
- Radiation Dose and Imaging
- Cystic Fibrosis Research Advances
Toronto Metropolitan University
2019-2025
University of British Columbia
2015-2025
University of Toronto
2025
Takeda (United States)
2025
St. Paul's Hospital
2014-2024
McGill University Health Centre
2024
Western University
2009-2023
St. Michael's Hospital
2021-2023
Unity Health Toronto
2022
St. Paul's Hospital
2014-2021
There is limited data on the risk factors and phenotypical characteristics associated with spirometrically confirmed COPD in never-smokers general population.To compare by gender severity of airway obstruction ever-smokers.We analysed from 5176 adults aged 40 years older who participated initial cross-sectional phase population-based, prospective, multisite Canadian Cohort Obstructive Lung Disease study. Never-smokers were defined as those a lifetime exposure <1/20 pack year. Logistic...
Rationale: Studies of excised lungs show that significant airway attrition in the “quiet” zone occurs early chronic obstructive pulmonary disease (COPD).Objectives: To determine if total number airways quantified vivo using computed tomography (CT) reflects airway-related changes and is associated with lung function decline independent emphysema COPD.Methods: Participants multicenter, population-based, longitudinal CanCOLD (Canadian Chronic Obstructive Lung Disease) study underwent...
<h3>Importance</h3> Smoking is a major risk factor for chronic obstructive pulmonary disease (COPD), yet much of COPD remains unexplained. <h3>Objective</h3> To determine whether dysanapsis, mismatch airway tree caliber to lung size, assessed by computed tomography (CT), associated with incident among older adults and function decline in COPD. <h3>Design, Setting, Participants</h3> A retrospective cohort study 2 community-based samples: the Multi-Ethnic Study Atherosclerosis (MESA) Lung...
To quantitatively compare hyperpolarized helium 3 (3He) and xenon 129 (129Xe) magnetic resonance (MR) images obtained within 5 minutes in healthy volunteers patients with chronic obstructive pulmonary disease (COPD) to evaluate the correlations between 3He 129Xe MR imaging measurements those from spirometry plethysmography.This study was approved by an ethics board compliant HIPAA. Written informed consent all subjects. Eight 10 COPD underwent imaging, spirometry, plethysmography....
Purpose To compare hyperpolarized helium‐3 ( 3 He) and xenon‐129 129 Xe) MRI in asthmatics before after salbutamol inhalation. Materials Methods Seven provided written informed consent underwent spirometry, plethysmography, He Xe ventilation defect percent (VDP) coefficient of variation (COV) were measured. characterize the airways spatially related to defects, wall area (WA%) lumen (LA) evaluated for two subjects who had thoracic x‐ray computed tomography (CT) acquired 1 year MRI. Results...
After adjustment for the amount of smoking, women have a 50% increased risk chronic obstructive pulmonary disease (COPD) compared with men. The anatomic basis and/or mechanism(s) these sex-related differences in COPD are unknown.To characterize impact female sex hormones on cigarette smoke-induced airway remodeling and emphysema mouse model COPD.Airway were determined morphometrically male, female, ovariectomized mice exposed to 6 months smoke. Antioxidant- transforming growth factor...
<h3>Background</h3> Hyperpolarised <sup>3</sup>He MRI provides a way to visualise regional pulmonary functional abnormalities that in asthma are thought be related airway morphological abnormalities. However, the exact aetiology of ventilation defects is not well understood. <h3>Objective</h3> To better understand determinants asthma, we evaluated well-established clinical as and X-ray CT measurements healthy subjects with asthma. <h3>Methods</h3> Thirty-four (n=26 n=8 volunteers) underwent...
Background Thoracic computed tomography (CT) scans are widely performed in clinical practice, often leading to detection of airway or parenchymal abnormalities asymptomatic minimally symptomatic individuals. However, relevance CT is uncertain the general population. Methods We evaluated data from 1361 participants aged ≥40 years a Canadian prospective cohort comprising 408 healthy never-smokers, 502 ever-smokers, and 451 individuals with spirometric evidence chronic obstructive pulmonary...
The small conducting airways are the major site of obstruction in chronic obstructive pulmonary disease (COPD). This study examined airway pathology using a novel combination multidetector row computed tomography (MDCT), micro-computed (microCT) and histology. Airway branches visible on specimen MDCT were counted dimensions third- to fifth-generation computed, while terminal bronchioles (designated TB), preterminal (TB-1) pre-preterminal (TB-2) with microCT histology eight explanted lungs...
In patients with post-acute COVID-19 syndrome (PACS), abnormal gas-transfer and pulmonary vascular density have been reported, but such findings not related to each other or symptoms exercise limitation. The pathophysiologic drivers of PACS in previously infected who were admitted in-patient treatment hospital (or ever-hospitalized patients) never-hospitalized are well understood.To determine the relationship persistent limitation xenon 129 (129Xe) MRI CT measurements individuals PACS.In...
Rationale: Outdoor air pollution is a potential risk factor for lower lung function and chronic obstructive pulmonary disease (COPD). Little known about how airway abnormalities growth might modify this relationship. Objectives: To evaluate the associations of ambient exposure with COPD examine possible interactions dysanapsis. Methods: We made use cross-sectional postbronchodilator spirometry data from 1,452 individuals enrolled in CanCOLD (Canadian Cohort Obstructive Lung Disease) study...
Rationale: It is increasingly recognized that adults with preserved ratio impaired spirometry (PRISm) are prone to increased morbidity. However, the underlying pathophysiological mechanisms unknown. Objectives: Evaluate of dyspnea and reduced exercise capacity in PRISm. Methods: We completed a cross-sectional analysis CanCOLD population-based study. compared physiological responses 59 participants meeting PRISm spirometric criteria (post-bronchodilator FEV1<80% predicted FEV1/FVC≥0.7), 264...
Several methods quantify gas-trapping on expiration computed tomography (CT) images, but they do not consider the spatial relationship of voxels. The objective this study was to determine if addition CT texture-based radiomics features existing measurements improves model performance for lung function, function decline, COPD classification and visual gas-trapping. CanCOLD participants performed spirometry, plethysmography chest imaging at full-inspiration/expiration with radiologist-assessed...
Individuals at risk for chronic obstructive pulmonary disease (COPD) but without spirometric airflow obstruction can have respiratory symptoms and structural lung on chest computed tomography. Current guidelines recommend COPD diagnostic schemas that do not incorporate imaging abnormalities. To determine whether a multidimensional schema includes tomographic abnormalities identifies additional individuals with disease. This cohort study included 2 longitudinal cohorts: the Genetic...
To quantitatively evaluate a small pilot group of ex-smokers with chronic obstructive pulmonary disease (COPD) and healthy volunteers during approximately 2 years by using hyperpolarized helium 3 ((3)He) magnetic resonance (MR) imaging.All subjects provided written informed consent to the study protocol, which was approved local research ethics board Health Canada compliant Personal Information Protection Electronic Documents Act HIPAA. Hyperpolarized (3)He MR imaging, hydrogen 1 spirometry,...
Purpose To evaluate the predictive value of imaging and clinical physiological measurements chronic obstructive pulmonary disease ( COPD ) in patients monitored for more than 5 years exacerbations that required hospitalization. Materials Methods Exacerbations requiring hospitalization were over 91 subjects who provided written informed consent. Study was local research ethics board Health Canada approved HIPAA compliant. Subjects with underwent spirometry, plethysmography, diffusing capacity...
In subjects with chronic obstructive pulmonary disease (COPD), hyperpolarized xenon-129 ((129)Xe) magnetic resonance imaging (MRI) reveals significantly greater ventilation defects than helium-3 ((3)He) MRI. The physiological and/or morphological determinants of and the differences observed between (3)He (129)Xe MRI are not yet understood. Here we aimed to determine structural basis for in COPD using apparent diffusion coefficients (ADC) computed tomography (CT). Ten ex-smokers provided...
<h3>Background</h3> The functional effects of abnormal diffusing capacity for carbon monoxide (DL<sub>CO</sub>) in ex-smokers without chronic obstructive pulmonary disease (COPD) are not well understood. <h3>Objective</h3> We aimed to evaluate and compare established clinical, physiological emerging imaging measurements with normal spirometry DL<sub>CO</sub> a group Global Initiative Chronic Obstructive Lung Disease (GOLD) stage I COPD. <h3>Methods</h3> enrolled 38 15 subjects COPD who...
Disease accumulates in the small airways without being detected by conventional measurements.To quantify airway disease using a novel computed tomography (CT) inspiratory-to-expiratory approach called probability measure (DPM) and to investigate association with pulmonary function measurements.Participants from population-based CanCOLD study were evaluated full-inspiration/full-expiration CT measurements. Full-inspiration full-expiration images registered, each voxel was classified as...
Rationale: In patients with asthma, X-ray computed tomography (CT) has provided evidence of thickened airway walls and occlusions, but the total number CT-visible airways its relationship disease severity is unknown.Objectives: To measure CT count (TAC) in asthma evaluate relationships severity, morphology, pulmonary function, magnetic resonance imaging (MRI) ventilation.Methods: Participants underwent post-bronchodilator inspiratory CT, prebronchodilator spirometry hyperpolarized 3He MRI....