Gout is a common form of arthritis that causes severe joint pain, disability and joint damage. Aotearoa New Zealand has the highest rates of gout in the world. Gout is caused by high blood urate levels which lead to urate crystals forming in the joints. Once the disease develops, gout is usually treated with allopurinol, a medication that reduces urate levels. We are proposing a clinical trial to determine whether allopurinol treatment can safely prevent the development of gout in people with very high blood urate levels but without arthritis. Prior to embarking on this study, we wish to undertake a feasibility study to ensure that sufficient participants with the required characteristics are available for the main study, that the planned treatment is acceptable to potential participants, and that the scanning procedures we will be testing are accurate in early disease.