This article describes apparatus to aid histological validation of magnetic resonance
imaging studies of the human prostate. The apparatus includes a 3D-printed patientspecific
mold that facilitates aligned in vivo and ex vivo imaging, in situ tissue fixation, and
tissue sectioning with minimal organ deformation. The mold and a dedicated container
include MRI-visible landmarks to enable consistent tissue positioning and minimize
image registration complexity. The inclusion of high spatial resolution ex vivo imaging
aids in registration of in vivo MRI and histopathology data