Magnetic Detection

Magnetic detection has become a common technology in our daily life. For reliable sensing the magnetic route proves to be superior to the electrical alternative in many applications. In cars magnetic sensors are used to sense motor functions and to the check status of the driver and the passengers. Also all mobile communication in our daily life (GSM, RFID, NFC and WLAN) detects subtitle variations in the magnetic field. As a result a huge number of magnetic sensors is produced and applied worldwide (>109 per year).

Magnetic techniques such as MEG and MCG have been developed for measurements on the electrophysiology, but these are still mainly used in research and only a limited number of pre-clinical applications. In clinical practice the electrical route (EEG/ECG) is still the preferred route, despite the complex hassle with the electrical contacts. This is because the requirement of a cost-intensive and patient unfriendly Magnetically Shielded Room for an MEG or an MCG exam is a formidable hurdle.

The magnetic detection group tries to overcome this hurdle by implementing a handheld magnetic sensor that can work outside such a shielded room. The Diffmag sensor is the first attempt at such a sensor which proved to be clinically useful for detecting iron oxide particles in sentinel lymph nodes.

For the technology development the MD&I group collaborates with its low temperature colleagues in the recently founded EMS and ICE groups.

Principal Investigator:
Dr. ir. Bennie ten Haken

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Magnetic Imaging

In healthcare magnetic imaging with MRI has become a leading imaging modality, able to image virtually all pathologies that show up in a clinical setting. Current developments in MRI are leading to high-field scanner systems with dedicated local detection systems to maximize the signal coming from the patient. However, these systems have also become very costly and require much expertise which makes the clinical introduction go slowly. Therefore a more cost-effective but also clinically interesting low-field MRI scanner was purchased by the University of Twente.

A unique point of this low-field MRI scanner is its ability to rotate the subject which opens up worlds that are yet to be discovered with MR. The most obvious application of this feature is in child orthopedics, in order to remove the radiation dose that is associated with CT which is the current modality of choice. But other less obvious subjects might also benefit from the upright positioning, such as the quantification of pelvic organ prolapse in women after child birth. Next to that, the open design of the scanner theoretically allows for interventional procedures to be performed under MR guidance. This is a topic which is being researched together with the MST. Together with their vascular surgery group we evaluate the use of low-field MRI guidance during minimally invasive procedures. A final use of the scanner lies in the fact that artifacts generated by metallic implants are much smaller on this machine than on regular clinical scanners due to its low magnetic field. This opens up the possibility to more accurately and more safely measure metallic implants such as bone prostheses.

Principal Investigator:
Dr. ir. Frank F.J. Simonis