Johannes W. Krug

Contact Information

Johannes Krug

Dr.-Ing. Johannes Krug

Rötgerstraße 9 (Gebäude 53), Room 212
39104 Magdeburg, Germany
Phone: +49 391 6757023

e-mail: johannes.krug at ovgu.de

Research works and affiliations

I am currently working at Prof. Michael Friebe's Chair for Catheter Technologies and Image Guided Therapies where I am part of the INKA project team which is funded by the BMBF.

From 2009 to 2015 I was working at Prof. Georg Rose's Chair for Healthcare Telematic and Medical Engineering. I successfully applied for a AiF/ZIM joint research collaboration project which is funded by the BMWi and was responsible for managing and running the project for almost 2 years (2013-2015). Since 2011 I also have a collaboration with the group of Julien Oster and Dr. Gari Clifford from the University of Oxford.

From 2009 to 2013 I was part of the INKA project group where I was working on technologies for catheter visualisation for interventional MRI as well as on safety issues during MRI.

Topic of my PhD thesis (2011-2015)

ECG signal processing in an MRI environment

The Electrocardiogram (ECG) is an important vital sign which is used for patient monitoring. The ECG is important for cardiac diagnostics, e.g. for the detection of ischemias, ventricular tachycardias or atrial fibrillation.

In the field of MRI, the ECG is mainly used for triggering/gating purposes. MRI based cardiac diagnostics require precise gating to capture images of the heart in well defined states. The magnetohydrodynamic (MHD) effect - which occurs while the patient is inside the MRI scanner - causes severe distortions of the ECG signal (see figure below). These distortions increase with the magnitude of the MR scanner's static magnetic field.

For my PhD thesis, I considered two main aspects of the ECG in MRI - ECG based diagnostics and gating. Considering the diagnostic aspect, the aim was to filter the MHD effect from the ECG signal in order to access the ECG's information, e.g. measurement of the ST-segment or the QT-intervall. Besides its diagnostic application, the ECG is the most important signal for gating in cardiac MRI and is well established for clinical applications (field strengths up to 3T). However, higher magnetic fields (>7T) in research applications lead to an increasing MHD effect. Due to these distortions, the usage of typical ECG/VCG based gating techniques in high field cardiac MRI is prone to errors.

I proposed and evaluated several methods for the supression of the MHD effect in order to obtain an estimate of the underlying ECG signal for gating at 7T and for patient monitoring at magnetic field strengths up to 3T.

Julien Oster and Dr. Gari Clifford from the University of Oxord, UK were supervising me during my PhD thesis time.

My PhD thesis can be downloaded here.

ECG lead I outside the MRI

Johannes Krug Leipzig Thomassschule TU-Dresden MRI ECG MHD INKA OVGU Patient Monitoring