  Random transformations are commonly used for augmentation of the training
data with the goal of reducing the uniformity of the training samples. These
transformations normally aim at variations that can be expected in images from
the same modality. Here, we propose a simple method for transforming the gray
values of an image with the goal of reducing cross modality differences. This
approach enables segmentation of the lumbar vertebral bodies in CT images using
a network trained exclusively with MR images. The source code is made available
at https://github.com/nlessmann/rsgt
