Case study: Sven Jaeshke

2015 CDT student Sven Jaeschke is working on contact-free motion correction and cardiac gating

As a Biomedical Engineering undergraduate and postgraduate Sven had undertaken imaging related, industry-sponsored projects, before working for a while in the medical devices industry, so it is perhaps not surprising that he chose an industry project for his DPhil.


His research project aims to develop new methods for cardiac gating and motion correction using only power reflections of the MR-coils. The current gold standard, the electrocardiogram (ECG), could be affected by the high magnetic field strength in 7T MRI and result in missed or false trigger results that can increase scan time or significantly degrade image quality in cardiovascular MRI. Sven’s novel approach is to use parallel transmit imaging systems and only parts of the commercial MR-Scanner that are already available. This eliminates the need for additional hardware or any expert setup and enables simultaneous measurements of the scattering of the coil.

The basic principle behind the scattering of the coils is that any returned voltage will arise from a combination of different sources, including mismatching of the antennas. Displacement of tissue or blood will change the complex conductivity and permittivity distribution which influences the imaging pulse as it travels from one antenna to another or back to its source. The changes in scattering over time can then be used to assess cardiac and respiratory motion. This approach has the potential to improve cardiac imaging at ultra-high field by providing robust triggering in periods of breath-hold and free-breathing, additional gating information and an optimized workflow with no additional set-up.