This dataset includes human brain stimulated-echo (STE) diffusion MRI (dMRI) images acquired at the long diffusion time of 1 second from 10 healthy volunteers and an ex vivo brain hemisphere, as described by Aganj et al (MRM 2026). Also included are MPRAGE T1 images for all scans and standard dMRI images for the 10 in vivo scans. All images have been anonymized, and the T1 images have been de-faced.