Diffusion Tensor Imaging (DTI)
- Fiber Tractography and functional MRI results incorporate into an individual data set for tumor treatment planing.
Diffusion Tensor Imaging (DTI) is an extension to Diffusion Weighted Imaging (DWI), which allows mapping of the diffusion process of molecules in biological tissue in vivo. The technique of DTI became very successful in the beginning of 1996 and was since then extensively applied in numerous studies. In the beginning these studies investigated mainly quantitative parameters provided by DTI like mean diffusivity (MD, ADC) or fractional anisotropy (FA).
Beside calculation of tensor properties like MD or FA, fiber tractography based on DTI data has become very popular. Recently, images of reconstructed white matter fiber bundles even decorated music album covers. In clinics this technique became useful in preoperative surgical planning, since it provides information about the displacement of intact fiber bundles (e.g. due to a tumor). In research sophisticated methods were developed to investigate not only individual tracts in the brain but also complex individual connection patterns. These approaches have lead to the ultimate goal to map the so-called human conncetom, a goal that is currently pursued by European and North American high-ranking research facilities.
In the last years another interesting technique called Track Density Imaging (TDI) has been developed. This technique facilitates high-resolution images of white matter structures by incorporating the complex orientation information from probabilistic fibertracts.
- Track density image of a coronar slice at 0.3 mm isotropic resolution.
- Colored Track density image of a transversal slice at 1 mm isotropic resolution.
DTI can also be applied to biological tissue other than white mater in the brain. Beside diffusion property mapping of different organs in the abdomen (e.g. liver, pancreas, prostate) it was shown that DTI can also be successfully applied to study the tissue structure of muscles.
- Fiber tractography of different muscles (represented by different color) in the shank of a rabbit.
