Project Description

The magnetic resonance (MR) technique is best-known as a valuable diagnostic tool for clinical use. Indeed, its noninvasive character, along with the feasibility of spatially localizing the signal as in MR imaging (MRI), make it quite a powerful method in medical practice. Because of the low-frequency electromagnetic radiation employed, MR methods can be used to examine regions deep underneath the surface of the specimen, thus making the method relevant for tissues such as brain and for other optically turbid or opaque media. MRI has been shown to be sensitive to the changes associated with numerous diseases as well as to processes such as development and aging. 

Despite these advantages, MRI has a serious limitation. Due to its poor sensitivity, it is impossible to use conventional MRI methods to resolve microscopic structures; the number of spins residing within a micron-scale pore is insufficient to produce a detectable level of MR signal. This limitation can be overcome by sensitizing the MR signal to the random motion or diffusion of spin bearing molecules. Within the timeframe of the MR signal acquisition, the water molecules traverse distances in the micrometer range. Thus, by quantifying the effect of diffusion on the detected MR signal, it is possible to infer information regarding the micron-scale structure of the medium.

Numerous studies in materials science and biotechnology have shown that the microstructural features of porous materials substantially influence their physical characteristics including those related to the transport of heat and mass—a phenomenon with huge implications for applications such as catalysis, tissue engineering, and water purification. It is no surprise that there is also a close link between the microscopic architecture of a biological tissue with its function. Consequently, characterizing the geometric features of porous structures and tissues is paramount to many areas of science. 

The ability of magnetic resonance (MR) to measure the transport properties of spin bearing molecules makes it an ideal experimental tool to examine the microstructural and morphological features of biological tissue and other heterogeneous specimens. For this reason, MR techniques are widely employed across the world by several industries. For example, food manufacturers routinely employ such MR techniques to assess and control the quality of their products. MR measurements of transport properties are also used by oil exploration companies for obtaining information regarding the microstructure of rocks, which helps in determining the feasibility of oil or water extraction from them. Consequently, many companies have invested in developing MR technology over the years. 

The goal of our project titled “Unraveling intravoxel tissue composition via diffusion MRI” is to overcome the resolution limitation of MR by introducing a comprehensive framework with which the local (microscopic) directionality of diffusion processes can be reliably quantified. In cooperation with scientists at Schlumberger-Doll Research Center (Cambridge, MA, USA) and CR Development (Lund, Sweden), we plan to develop a software package that transforms the MR data into a valuable descriptor of the microstructural constituents making up the specimen (in spectroscopic applications) or voxel (in imaging studies). We acknowledge funding provided by Center for Industrial Information Technology (CENIIT), Linköping University.

Subpages (2): People Publications