Hi, We are planning to conduct a retrospective study on subjects that have only had 1 MP-RAGE run each. What will be the effect of running recon-all without motion correction? Is there any way of quantifying any possible error/variation? Will this be the same across the whole subject set? For design of a future prospective study, we are limited in scanner time. How essential is it to have 2 or more runs per subject? Thanks, Houman Dr Houman Ebrahimi BSc MBBS(Hons) Radiology Registrar John Hunter Hospital Phone:  +61 2 4921 3434 Fax:     +61 2 4927 0848 Mobile: +61 420 98 93 98 Email: Houman.Ebrahimi@hnehealth.nsw.gov.au