Development of a material database for human tissue properties
The material database containing electrical and mechanical properties of
human tissue of individuals is mainly achieved by the application of
magnetic resonance strain imaging (MRSI) and diffusion tensor imaging (DTI).
Both methods basically rely on
magnetic resonance imaging (MRI) and have
been developed very recently.
Development of an individual conductivity
tensor map using DTI
Multimodal MR-imaging strategies in combination with high
level registration and segmentation algorithms and the
application of the mathematical homogenisation theory to the voxel-wise
measured, anisotropic water diffusion leads to an individual conductivity
tensor map of the considered BOI. This map accounts for an exact
representation of various tissue types with regard to their specific
anisotropic resistance, a prerequisite for modelling in e.g.
EEG and MEG
(see also Introduction to
Pathological conditions such as e.g. skull holes and brain lesions like
tumours or cerebral ischemia, strongly changing the resistance of the
involved head tissues, can now be modelled individually and appropriately.
This material modelling is highly innovative compared with today's
volume conductor models (e.g based on the
boundary element method),
where e.g. the head layers brain, skull and skulp can only be assigned
constant and isotropic resistance values. This will improve the diagnostic
performance of EEG and MEG and will have a large impact not only on basic
and clinical research but also on patient outcome in a variety of diseases.
Development of an individual mechanical
tissue behaviour map using MRSI
Until now strain imaging techniques have been applied for some
isolated 'in vitro' organs (kidneys) only. So we will set-up this
technique for the "in-vivo brain", which will provide detailed knowledge
of material properties of 'in place' substructures in the brain in general.
Furthermore the projected 'advanced in vivo strain imaging' of patients brain
will provide most important insights in individual mechanical brain
properties and processes for diagnostics and therapy. Development and
installation of this method will be a demanding part of the project
and at the moment it is unforeseeable which state of realisation will
be reachable during the runtime of the project.