Gating of MR Data Acquisition Using Sensors Without the Need for Fixation to Patient’s Body

Abstract

The thesis focuses on synchronisation of magnetic resonance imaging (MRI) data acquisition based on monitoring of patient’s cardiac and respiratory activity. In clinical practice the synchronization (gating) techniques are a standard for motion artifact compensation. This thesis includes a detailed description of MRI gating techniques and extensive overview of clinically used methods for monitoring of cardiac and respiratory cycle in MR environment. Furthermore a summary, together with list of advantages and disadvantages of clinically used and other alternative systems for MR in-bore patient monitoring, is provided. To solve the common pitfalls of clinically used methods, author presents a virtual instrumentation based system utilizing a pneumatic method for MR in-bore patient monitoring. First, system solely for patient’s cardiac activity monitoring, is introduced, together with adaptive cancellation system for suppression of acoustic and mechanical interference. The system is evaluated in two studies where it is compared with clinically used ECG based monitoring system and a different alternative systems. In final part of the thesis, a novel multi-channel system allowing monitoring of both cardiac and respiratory activity is introduced and evaluated.