System for 3-D Real-Time Tracking of MRI-Compatible Devices by Image Processing

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Real-time processing of MRIs is reported as a method of 3-D tracking of mechanical devices within the field of view using passive microcoil fiducials. The specific implementation described makes use of two scan planes for full 3-D tracking of a 5-DOF manipulator arm used for prostate biopsy under image guidance. Real-time tracking was observed with a maximum update rate of 0.42 frames per second for a maximum probe velocity of 10 mm/s. The localization of fiducials had a mean error of 0.36 (<formula formulatype="inline"><tex>$\pm$</tex> </formula>0.17) mm ( <formula formulatype="inline"><tex>$p ≪ 0.02$</tex> </formula>), leading to a mean error in the needle tip position of 2.6 (<formula formulatype="inline"><tex>$\pm$</tex></formula>0.3) mm (<formula formulatype="inline"> <tex>$p ≪ 0.05$</tex></formula>). </para>