Helium-3 MRI Imaging Study in COPD

Chronic Obstructive Pulmonary Disease (COPD) is an important cause of morbidity, mortality, and healthcare costs worldwide. COPD is characterized by progressive airflow limitation that is not fully reversible and is associated with an abnormal inflammatory response of the lungs to noxious particles or gases. It has become clear that simple measures of airflow obstruction are inadequate to relate lung function to exercise capacity or symptoms, and that complex expressions such as dynamic hyper-inflation need to be invoked in seeking to understand overall physiology. In addition to abnormalities of air flow, gas exchange is also deranged. Therefore in considering new treatment approaches, both abnormalities need to be addressed. Techniques to study ventilation variation and perfusion matching across the lung exist but are invasive and exacting, and do not give an indication of the anatomical distribution of changes. There is a clear need for techniques which can provide sensitive, useful and safe repeated measures reflecting regional changes in ventilation and gas exchange in COPD. This study investigates use of hyperpolarised helium magnetic resonance imaging (MRI) in reflecting the regional differences in lung function of moderate to severe COPD patients. A Beta2 bronchodilator - Salbutamol - and a anticholinergic - Ipratropium - will be used in this study.