Longitudinal multi-centre brain imaging studies: guidelines and practical tips for accurate and reproducible imaging endpoints and data sharing. Link to paper on Trials Journal. Authors Stewart J. Wiseman, Rozanna Meijboom, Maria del C. Valdés Hernández, Cyril Pernet, Eleni Sakka, Dominic Job, Adam D. Waldman and Joanna M. Wardlaw Abstract Background: Research involving brain imaging is important for understanding common brain diseases. Study endpoints can include features and measures derived from imaging modalities, providing a benchmark against which other phenotypical data can be assessed. In trials, imaging data provide objective evidence of beneficial and adverse outcomes. Multi-centre studies increase generalisability and statistical power. However, there is a lack of practical guidelines for the set-up and conduct of large neuroimaging studies. Methods: We address this deficit by describing aspects of study design and other essential practical considerations that will help researchers avoid common pitfalls and data loss. Results: The recommendations are grouped into seven categories: (1) planning, (2) defining the imaging endpoints, developing an imaging manual and managing the workflow, (3) performing a dummy run and testing the analysis methods, (4) acquiring the scans, (5) anonymising and transferring the data, (6) monitoring quality, and (7) using structured data and sharing data. Conclusions: Implementing these steps will lead to valuable and usable data and help to avoid imaging data wastage. Keywords Longitudinal Multi-centre Magnetic resonance imaging Study design Data sharing Guidelines Big data Related links Link to paper on Trials Journal Publication date 09 Jan, 2019