UK Biobank pilot imaging enhancement

In UK Biobank, questionnaire data, physical measurements and biological samples have been collected from 500,000 men and women aged 40-69, and their health is now being followed long-term. A prospective cohort like UK Biobank allows reliable assessment of the relevance of many different exposures to the development of many different diseases. However, such studies need to be big because only a relatively small proportion of participants will develop any particular disease. It is now planned to conduct specialised imaging of the brain, heart, large blood vessels, abdomen, bone and joints in 100,000 UK Biobank participants. Although imaging has been done in some other studies, these have involved only small numbers of people (typically less than 5,000) and have focussed on imaging particular parts of the body. By contrast, combination of imaging data from different parts of the body in 100,000 UK Biobank participants with the detailed non-imaging data already collected will provide a unique resource for researchers from around the world to investigate the causes of different diseases. (For example, dementia may be related to imaging measures not only from the brain but also from other parts of the body, as well as to genetic, biochemical or environmental information.)

Prospective cohorts, such as UK Biobank, have advantages for the comprehensive and reliable quantification of the combined effects of different types of risk factor on disease. However, they need to involve large numbers of participants because only a relatively small proportion will develop any particular condition. UK Biobank has collected extensive baseline questionnaire data, physical measures and biological samples from 500,000 men and women aged 40-69 at baseline and their health is being followed by linkage to health records. Central adjudication of health outcomes will ensure that consistent definitions are used and facilitate access to the resource. It is now planned to enhance further the phenotyping of 100,000 participants with information from multiple imaging modalities involving Magnetic Resonance imaging of brain, heart, large blood vessels and abdomen, Ultrasound of carotid arteries, and Dual-Energy X-ray Absorptiometry (DXA) of bone and joints. The availability of imaging measures that quantitatively define phenotypes that are closely related to disease will provide substantial power for detecting associations with incident health outcomes occurring during follow-up (as well as allowing cross-sectional analyses with prevalent disease and other measures recorded at baseline). Although imaging measures have been included in other population-based studies, the small numbers of people involved (typically less than 5,000), and the focus of those studies on imaging particular organ systems, has limited their ability to assess associations with incident disease. Integration of complementary imaging data that inform on a range of organ systems from 100,000 UK Biobank participants, along with the detailed non-imaging data collected at baseline (including genotyping and biomarker data), will provide a unique resource for investigating the biological mechanisms of disease. (For example, the risk of developing dementia may be related to imaging measures derived not just from the brain but also from other parts of the body, as well as to genetic, biochemical or environmental information from baseline.) Subject to successful piloting during 2013-14, the main phase of imaging assessments will be conducted in dedicated imaging centres during 2014-2019. After completing imaging in 100,000 participants, these imaging centres could then be used to conduct repeat imaging in a subset of participants to allow investigation of the relevance of changes in imaging measures to particular outcomes (e.g. dementia). As is the case for the rest of the UK Biobank resource, the imaging data will be made available to all bona fide researchers for health-related research that is in the public interest.