16 T diffusion microimaging of fixed prostate tissue: preliminary findings.

Diffusion tensor microimaging was used to investigate the water diffusion properties of formalin-fixed prostate tissue at spatial resolution approaching the cellular scale. Diffusion tensor microimaging was performed at 16.4 T with 40 μm isotropic voxels. Diffusion tensor microimaging clearly demonstrated distinct microscopic diffusion environments and tissue architecture consistent with that seen on light microscopy of the same tissue. The most restricted diffusion environment is the secretory epithelial cell layer (voxel bulk mean diffusivity, D = 0.4 ± 0.1 × 10(-3) mm(2)/sec). Diffusion in the fibromuscular stromal matrix is relatively less restricted (D = 0.7 ± 0.1 × 10(-3) mm(2)/sec). In tumor tissue (Gleason pattern 4+4) distinct glandular and ductal structures are absent in the diffusion-weighted images and diffusivity is low (D = 0.5 ± 0.1 × 10(-3) mm(2)/sec). Distinct stromal and epithelial diffusion compartments are the most likely origin of biexponential diffusion decay observed in vivo.