MRI plays a key role in clinical disease diagnosis and life science research. Diffusion weighted imaging (DWI) is one of the most important imaging techniques in MRI. It has been widely used in clinics for diagnosis and in neuroimaging for fiber tracking and microstructure mapping. To detect micro-scale random motion of water molecules in DWI, single-shot EPI is widely used for signal acquisition due to its high acquisition speed and motion insensitivity. However, it suffers from the problems of low-resolution, geometric distortion and image blurring due to its low bandwidth along the phase-encoding direction and significant T2* decay during the EPI readout.

Dr. Guo and his team have been systematically developing a series of DWI methods to suppress or remove image distortion, increase in-plane and through-plane resolution, boost sampling efficiency and improve the new methods’ practicability. In particular, when reconstructing multi-shot diffusion images, phase variations are not treated as a source of imaging artifacts, but as a kind of image encoding. Similarly, field inhomogeneity induced phase can also be used for signal encoding. With these new reconstruction theories, signals can be significantly saved while image quality can be well maintained. By taking advantage of improved image quality, Dr. Guo is working on advanced fiber tracking algorithms and micro-structural information quantification now.

Dr. Guo is also interested in translational studies. Part of his techniques have been adopted by domestic MRI companies. At present, he and his team are working with companies clsoely to develop new interventional MRI scanners.