Development of Hardware and Software for Pulmonary Magnetic Resonance Imaging Using Inhaled Tracer Gases
Development of Hardware and Software for Pulmonary Magnetic Resonance Imaging Using Inhaled Tracer Gases
This is a single centre study. The overarching hypothesis of this study is that MRI with inhaled tracer gases can provide high quality images of lung function to complement conventional 1H MRI. The study interventions do not affect the standard of care.
Respiratory diseases are a significant healthcare burden worldwide. In Canada, this is expected to increase. Non-invasive medical imaging tests are able to provide regional functional and structural information of the lung and may aid in the diagnosis and treatment of respiratory diseases. Current examples include chest x-ray, x-ray computed tomography (CT), and nuclear medicine techniques. However, these techniques suffer from various associated limitations. X-ray based methods offer high resolution and rapid acquisitions, but only reflect lung structure and anatomy by measuring tissue density. Nuclear medicine techniques may be used to measure lung function but suffer from poor resolution and long acquisition times. Furthermore, both x-ray based and nuclear medicine imaging techniques make use of ionizing radiation, which may not be suitable for longitudinal imaging, or imaging in vulnerable populations such as children.
Conventional Magnetic Resonance Imaging (MRI) images the 1H nucleus (proton) attached to water molecules in biological tissues. MRI can provide high-resolution anatomical and functional information of the lung with multiparametric contrast without the use of ionizing radiation. However, major drawbacks associated with conventional 1H MRI of the lung are the low tissue density, large magnetic susceptibility differences between numerous air/tissue interfaces, and image corruption by cardiorespiratory motion during the necessarily long image acquisition time frame. Wo;;
One strategy which may be employed to overcome the limitations associated with conventional 1H MRI is the application of safe MR-sensitive inhaled tracer gases. This allows for the direct visualization of the spatial distribution of these gases, revealing regional ventilation directly. In this study we aim to develop, implement, and test these technologies for improved in-vivo imaging of lung structure and function in adults and children with no history of respiratory disease.
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