Best format for medical imaging dataset • /r/MachineLearning

Hi, I am trying to use machine learning techniques for medical image data. The data comes in a special format (Dicom or Nifti). I want to use 3D patches as my training samples. I would like to know what would be the best option if I want for example read every patch in the data set in advance and store all of them in such a way that I can use easily with TensorFlow for example?