Related Experiment Video
Updated: Aug 8, 2026
Magnetically-Assisted Remote Controlled Microcatheter Tip Deflection under Magnetic Resonance Imaging
Published on: April 4, 2013
Feasibility study of magnetic resonance imaging-guided intranasal flexible microendoscopy
D L Hill1, L A Langsaeter, P N Poynter-Smith
1Division of Radiological Sciences, UMDS, Guy's Hospital, London, United Kingdom. d.hill@umds.ac.uk
Abstract:
Interventional magnetic resonance imaging (MRI) offers potential advantages over conventional interventional modalities such as X-ray fluoroscopy, ultrasonography, and computed tomography (CT). In particular, it does not use ionizing radiation, can provide high-quality images, and allows acquisition of oblique sections. We have carried out a feasibility study on the use of interventional MRI to track a flexible microendoscope in the paranasal sinuses. In this cadaver study, high-speed MRI was used to track a passive marker attached to the end of the endoscope. Automatic image registration algorithms were used to transfer the coordinates of the endoscope tip into the preoperative MRI and CT images, enabling us to display the position of the endoscope in reformatted orthogonal views or in a rendered view of the preoperative images. The endoscope video images were digitized and could be displayed alongside an approximately aligned, rendered preoperative image. Intraoperative display was provided in the scanner room by means of an liquid crystal display (LCD) projector. We estimate the accuracy of the endoscope tracking to be approximately 2 mm.
Insights
Interventional magnetic resonance imaging (MRI) feasibility was studied for tracking a microendoscope in paranasal sinuses. This non-ionizing radiation method achieved approximately 2 mm accuracy for flexible endoscope navigation.
Area of Science:
- Medical Imaging
- Interventional Radiology
- Endoscopy
Background:
- Interventional magnetic resonance imaging (MRI) presents advantages over conventional imaging like X-ray fluoroscopy, ultrasonography, and computed tomography (CT).
- Key benefits include the absence of ionizing radiation, superior image quality, and the ability to acquire oblique sections.
- These features make it a promising alternative for minimally invasive procedures.
Purpose of the Study:
- To assess the feasibility of using interventional MRI for guiding a flexible microendoscope within the paranasal sinuses.
- To evaluate the accuracy and practical application of MRI-based tracking for endoscopic navigation in this anatomical region.
Main Methods:
- A cadaver study was conducted utilizing high-speed MRI to track a passive marker affixed to the microendoscope's tip.
- Automatic image registration algorithms were employed to transfer the endoscope's real-time coordinates to preoperative MRI and CT scans.
- Endoscope video feeds were digitized and displayed alongside rendered preoperative images, with intraoperative visualization via an LCD projector.
Main Results:
- The study successfully demonstrated the capability of interventional MRI to track a flexible microendoscope in paranasal sinuses.
- The system allowed for the display of the endoscope's position in reformatted orthogonal and rendered views of preoperative imaging data.
- The estimated accuracy for the endoscope tracking was determined to be approximately 2 mm.
Conclusions:
- Interventional MRI is a feasible technology for guiding flexible microendoscopes in the paranasal sinuses.
- The non-ionizing nature and high-quality imaging of MRI, combined with accurate tracking, offer significant potential for improving sinonasal interventions.
- Further development could enhance navigation precision and expand applications in minimally invasive sinonasal surgery.
