Student Projects

Myelin is a lipid bilayer surrounding nerve fibers in the brain white matter, which speeds up signal conduction and is critical to proper brain function. Myelin is of great interest to biomedical research, as it undergoes characteristic changes during normal development and is damaged in pathologies such as Multiple Sclerosis and traumatic brain injury. A non-invasive method for tracking myelin status would be a valuable tool to assess disease progression or evaluate the treatment success. While several MR methods to quantify myelin content have been developed, they are indirect and rely on the interaction between myelin and water. Our group at the IBT at ETH has developed powerful hardware which facilitates direct detection of the MR signals from the myelin sheaths that remain invisible in conventional MRI. Tissue samples are widely used in biomedical research, including MRI as they allow for long scan times and thus high data quality. It is important to understand exactly how well observations from such ex vivo scans translate to MR data acquired in vivo. One of the key parameters that differ between ex vivo and in vivo studies is temperature as tissue samples are often scanned at room temperature. The overall goal of this project is the evaluation of the impact of sample temperature on the direct method for myelin imaging recently developed in our group. For this investigation, a sample of porcine brain tissue will be imaged in the scanner at different temperatures. A prototype for temperature control has already been built. The student will contribute to testing and improving the current setup as well as the acquisition and analysis of MRI data at different temperatures.

Characterizing and understanding the temperature dependence of short-lived tissue signals in MRI

Lara Bartels (she/her) bartelsl@ethz.ch

Sampling of MRI data is goverened by the Nyquist criterion, which determines the required amount of sampling and therefore the time needed for data acquisition. However, in certain situations the amount of sampling can be reduced while still fulfilling Nyquist. In this project, this option should be investigated and implemented, thus leading to more efficient MR imaging. The projects includes: - Investigation of the background of the approach - Implementation of the improved acqusition scheme - Implementation of the associated image reconstruction - Experimental demonstration of the approach - Programming in Matlab and C

To demonstrate that by using the suggested approach, faster MRI at uncompromised image quality is possible

weiger@biomed.ee.ethz.ch