Subjects aged 18-85 with lung disease will undergo hyperpolarized Xenon 129 (129-Xe) MRI and Pulmonary Function testing for the development of tools to evaluate the Apparent Diffusion Coefficient (ADC), ventilation defect percent (VDP) and pulmonary gas exchange measurements obtained by analysis of hyperpolarized 129-Xe MRI.
Briefly, during a one to two hour visit, subjects will provide written informed consent and then undergo: 1. brief medical history and vital signs, 2. full pulmonary function tests, 3. proton MRI, 4. spin-density, diffusion weighted, and/or dissolved phase 129-Xe MRI, 5. Low-dose thoracic CT Full pulmonary function tests including spirometry, plethysmography and diffusing capacity of carbon monoxide (DLCO), Multiple Breath Nitrogen Washout (MBNW) to measure Lung Clearance Index (LCI), and Forced Oscillation Technique (FOT) will be performed according to American Thoracic Society (ATS) guidelines. MedGraphics Elite Series, MedGraphics Corporation. St. Paul, Minnesota USA and/or nDD EasyOne Spirometer, nDD Medical Technologies Inc. Andover, Massachusetts USA will be used. All measurements will be performed in the Pulmonary Function Laboratory at Robarts Research Institute. Subjects will be placed in the 3T Magnetic Resonance (MR) scanner with one of three 129-Xe chest coils fitted over their torso and chest. Hearing protection will be provided to each subject to muffle the noise produced by the gradient radiofrequency (RF) coils. A pulse oximeter lead will be attached to all of the subjects to monitor their heart rate and oxygen saturation. MRI will be performed for up to a period of 30 minutes. All subjects will have supplemental oxygen available via nasal cannula at a flow-rate of 2 liters per minute as a precaution in the event of oxygen desaturation. Thoracic low dose CT will be performed with the same inhalation breath-hold volume and maneuver (nitrogen gas only) used for MRI to obtain participant-specific high resolution images of lung anatomy (tissue structure and airway morphology).
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
100
Hyperpolarized noble gas imaging using Xenon-129 has been used to explore structural and functional relationships in the lung in patients with lung disease and healthy controls. In contrast to proton-based MRI imaging, 129Xe gas is used as a contrast agent to directly visualize the airways, and thus ventilation. Whereas the normal density of gas is too low to produce an easily detectable signal, this is overcome by artificially increasing the amount of polarization per unit volume using optical pumping.
Robarts Research Institute; The University of Western Ontario; London Health Sciences Centre
London, Ontario, Canada
RECRUITINGVentilation Defect Percent (VDP) of the lung
VDP is a widely used noble gas MRI biomarkers that is calculated by normalizing ventilation defect volume to the thoracic cavity.
Time frame: 5 years
Apparent Diffusion Coefficients (ADC) of the lung
Diffusion weighted noble gas MRI provides a way to quantify pulmonary microstructure by sensing the movements of inhaled gas atoms. The "apparent" dif fusion coefficient (ADC) during the diffusion time interval can be used to reflect the extent of alveolar restriction of gas atom movements, providing a surrogate measurement of airspace dimensions.
Time frame: 5 years
Dissolved phase spectroscopy measurements
129-Xe dissolved phase MRI data will be reconstructed using a re-gridding method. The following ratios will be determined by the area-under-the curve obtained from spectroscopy: red-blood-cell to alveolar membrane ratio (RBC:membrane); RBC to gas ratio (RBC:gas); and the membrane to gas ratio (membrane:gas). Spectroscopic signals will be used to reconstruct perfusion and alveolar membrane maps.
Time frame: 5 years
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.