SILO2 (Signal Intensity Lung washOut)

Chronic Obstructive Pulmonary Disease (COPD) is a leading and still increasing cause of disease and death worldwide, affecting those in both developed and developing countries. This imparts a massive burden of ill health, in turn imposing huge healthcare costs to society. For effective treatment of COPD (as opposed to providing short term relief) early disease must be targeted. The small airways of the lung (those less than 2mm) are the first affected in COPD, but current methods to assess their function are relatively insensitive. There is therefore a need for new, accurate methods for detection of small airway dysfunction with sensitivity to shortterm change and regional discrimination. In previous studies with hyperpolarised (HP) 3He MRI in smokers with normal pirometry and patients with early stage COPD, we showed sensitivity to early changes in lung ventilation and structure. The hyperpolarised gas MRI technique is safe. In particular, the lack of ionizing radiation permits patients to be imaged on multiple occasions. This and its inherent sensitivity to regional lung ventilation and function make it an ideal imaging tool for the assessment of novel lung therapies for diseases of the small airways. The purpose of this pilot study is to determine short and long term reproducibility of a comprehensive set of functional imaging data? using hyperpolarised gas MRI, conventional MRI and lung physiology measurements in patients with moderate to severe COPD. In addition,how sensitive the imaging techniques are to changes in lung function after treatment with a standard (bronchodilator) inhaler will also be assessed. This pilot study will serve as a platform for future larger scale studies, aimed at better understanding of and intervention in early COPD.