MR image quality in ophthalmological MRI can be substantially reduced by motion artifacts, which may hinder the reliable diagnosis as well as accurate radiotherapy treatment planning of uveal melanoma. There is still no known general method to prevent motion artifacts caused by movement of the eyes and blinking. Previous studies describe several approaches, including different fixation schemes and special MR sequences with blinking pauses, to minimize motion artifacts caused by eye movements and blinking with non-invasive methods. All these methods only achieved limited success. This work presents a new approach to prevent motion artifacts resulting from movements of the eye. The detectability of eye motion with an eye tracker (medEyeTrack) was used to trigger a 3D TurboFLASH sequence using the external trigger signal interface of an MR scanner. This new approach showed significant improvement in anatomical recognizability and reduction of the artifact level present in the resulting MR images. The achieved enhancement in image quality dramatically improves the accuracy of radiation therapy treatment planning. Results of this thesis will serve as an important basis for further work aiming to prevent motion artifacts in ophthalmological MRI imaging.
|Qualification||Master of Science|
|Publication status||Published - 2014|
- magnetic resonance imaging