1. A medical test device for use with a magnetic resonance imaging (MRI) scanner using a diffusion tensor imaging (DTI) sequence to generate a baseline model of human or animal tissue, comprising: a plurality of anisotropic arrays stacked in a plurality of rows to form a macro-array, wherein each of the arrays includes a plurality of capillaries and each of the capillaries holds a first fluid; and a housing, holding a second liquid, wherein the arrays are housed within the housing, wherein the test device can be scanned by the MRI scanner using the DTI sequence to generate the tissue baseline model for use in diagnosing disease in the tissue.