A prospective study of the use of two novel MRI techniques (oxygen-enhanced and fourier decomposition MRI) in the initial diagnosis and follow-up of patients with Pulmonary Hypertension. The investigators believe these techniques may present a novel set of imaging biomarkers that may be used for risk stratification, prediction of treatment response and longitudinal disease monitoring. The reserach MRI is in addition to standard of care and will not affect treatment decisions.

Inclusion Criteria:

• Confirmed diagnosis of Pulmonary Hypertension.
• Age 18 and over.

Exclusion Criteria:

• Standard contra-indications to MRI (as per NHS MRI safety questionnaire).
• Not medically fit for transfer to MRI.
• Patient judged inappropriate for involvement in study by clinical team e.g. secondary to emotional burden of recent diagnosis.