Unlike most of the measurements included in the original UK Biobank resource (e.g., alcohol consumption and cognitive test scores), raw imaging data is not a directly useful source of information. In addition to requiring image processing to remove artefacts and align images across modalities and individuals, most useful image phenotypes are derived through complex calculations combining many voxels and/or images. A fully automated processing pipeline was developed, producing both processed images as well as image-derived phenotypes (IDPs) – currently 2501 distinct individual measures of brain structure and function. Example IDPs include: the volume of specific brain structures; the strength of connectivity between pairs of brain regions; the estimated dispersion of fibers in a given white matter tract. IDPs are intended to be useful for non-imaging experts; however, understanding of the confounds and pitfalls of imaging is required to draw appropriate conclusions.
