Functional MR Lung Imaging Using Hyperpolarised 129Xe

General Inclusion criteria * Male or Female aged over 18 years. * Capacity to give informed consent * Normal blood pressure (systolic BP \> 100 mmHg and diastolic BP \> 70 mmHg) * Resting heart rate \> 50 bpm * For women, negative urinary β-hCG at the screening and subsequent visits * Subject able to hold breath for 10 seconds * Subject able to fit into 129Xe chest coil used for MRI * Subject able to understand the requirements of the study and to cooperate with the study procedures Inclusion criteria HEALTHY VOLUNTEERS • No significant respiratory disease within the last year PATIENTS COPD * Evidence of airflow obstruction (FEV/FVC \<0.7) and FEV1 \<80% predicted post bronchodilator * Minimum FVC 1.5L Exclusion criteria HEALTHY VOLUNTEERS * Unsuitable for MRI scanning (e.g. have metal implants or pacemaker or contraindicated following questionnaire) * Acute respiratory illness within 30 days of MRI * Subject has received an IMP (not including hyperpolarized 129Xe) within 30 days of MRI and administration of 129Xe deemed inappropriate in context of other study * Subject deemed unlikely to comply with instructions during imaging * Do not meet the inclusion criteria above * Subject not deemed fit enough to tolerate procedure * Subject deemed unsuitable by clinical investigator for other reasons PATIENTS * Unsuitable for MRI scanning (e.g. have metal implants or pacemaker or contraindicated following questionnaire) * Acute respiratory illness within 30 days of MRI * Subject has received an IMP (not including hyperpolarized 129Xe) within 30 days of MRI and administration of 129Xe deemed inappropriate in context of other study * Subject deemed unlikely to comply with instructions during imaging * Do not meet the inclusion criteria above * Subject not deemed fit enough to tolerate procedure * Subject deemed unsuitable by clinical investigator for other reasons