Galinovic I, et al. - Authors ascertained the investigator image training as well as results of the quality control done by the central image reading board (CIRB). Prior to being allowed to judge images in the trial, investigators at local centres were given an imaging manual and passed a software-based image training. A high level of homogeneity amongst raters in interpreting the various imaging criteria for patient randomization, including the novel criterion of DWI-FLAIR mismatch was demonstrated in the WAKE-UP study, despite its multicenter design. The confidence of investigators in applying imaging criteria was increased by systemic image training.