MRI-guided percutaneous needle-based surgery has become part of routine clinical practice. There are millions of these procedures performed in Canada. The conventional MRI-guided needle intervention is usually performed with the primary goal of navigating a needle to a target while sparing healthy and/or critical structures. Potential limitations of conventional unassisted free-hand needle placement include the physician's ability to align and maintain the correct trajectory and angle toward a target, especially in case of deep targets. In contemporary practice, images are displayed on the operator's 2D console only outside the treatment room, where the physician plans the intervention. Then the physician enters the room, mentally registers the images with the anatomy of the actual patient, and uses hand-eye coordination to execute the planned intervention. Previous concept has been shown and preliminary results discussed from demonstrated MRI-guided needle intervention using an augmented reality 2D image overlay system in a closed configuration 1.5T MRI scanner. However, the limited availability of interventional MR imaging systems and the length of time of MR-guided interventions have been limiting factors in the past. This dissertation addresses topics related to evaluating and developing the 2D augmented reality system, the assistance device for MRI-guided needle interventions. This research effort has primarily focused on developing a new adjustable 2D MR image overlay system and validating the previous 2D image overlay system in the clinical environment. The adjustable system requirement is to overcome the oblique insertions, difficulties inherent to MR-guided procedures, and to promise safe and reliable needle placement inside closed high-field MRI scanners. This thesis describes development of the image overlay system including requirements, mechanism design and evaluation of MR compatibility. Additionally, a standalone realization of an MR image overlay system, named “The Perk Station” was developed, implemented and evaluated. The system was deployed in the laboratory as a training/teaching tool with non-bio-hazardous specimens. This laboratory version of the system allows for evaluation of trial interventions. The system also supports recording of the complete intervention trajectory for operator performance, technical efficacy, and accuracy studies of insertion techniques. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2013-09-30 22:21:51.469

Numerous studies have demonstrated the potential efficacy of percutaneous image-guided interventions over open surgical interventions. The conventional image-guided procedures are limited by the freehand technique, requiring mental 3D registration and hand-eye coordination for needle placement. The outcomes of these procedures are associated with longer duration and increased patient discomfort with high radiation exposure. Previously, a static image overlay system was proposed for aiding needle interventions. Certain drawbacks associated with the static system limited the clinical translation. To overcome the ergonomic issues and longer calibration duration associated with static system, an adjustable image overlay system was proposed. The system consisted of monitor and semi-transparent mirror, attached together to an articulated mobile arm. The 90-degree mirror-monitor configuration was proposed to improve the physician access around the patient. MicronTracker was integrated for dynamic tracking of the patient and device. A novel method for auto-direct calibration of the virtual image overlay plane was proposed. Due to large mechanical structure, the precise movement was limited and consumed useful space in the procedure room. A mobile image overlay system with reduced system weight and smaller dimensions was proposed to eliminate the need for mechanical structure. A tablet computer and beamsplitter were used as the display device and mirror respectively. An image overlay visualization module of the 3D Slicer was developed to project the correct image slice upon the tablet device. The system weight was reduced to 1 kg and the image overlay plane tracking precision (0.11mm STD=0.05) was similar to the printed physical markers. The auto-calibration of the image overlay plane can be done in two simple steps, away from the patient table and without additional phantom. Based on the successful pre-clinical testing of the previous static system, the mobile image overlay system with reduced weight, increased tracking precision and easier maneuverability, can be possibly hand-held by the physician to explore the image volume over the patient and be used for a wide range of procedures. The mobile image overlay system shall be classified as Class II device as per FDA regulations, do not require extensive verification and validation efforts and further improves the commercialization opportunities. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2014-06-26 18:51:03.958