Instrument Guidance System for MRI-Guided Percutaneous Spinal Interventions

Abstract

In Amyotrophic Lateral Sclerosis (ALS), neurons controlling voluntary muscles die, resulting in muscle weakness. Small animal studies have shown that neurons experience some regeneration when stem cells are injected into the ventral horn of the spinal cord [1]. These results led to large animal and human trials investigating the effects of injecting stem cells into the spinal cord. Direct injection is used for delivering cells as cells do not have to migrate to the therapy site and visual confirmation is possible [2]. This requires a multi-level laminectomy as well as dissection of the dura mater to expose the cell delivery site. In order to adopt this ALS treatment in regular clinical workflow, a minimally invasive alternative for spinal cord cell therapy is desirable. Image-guided needle targeting and positioning systems have been developed by numerous groups which use computed tomography or ultrasound for image guidance. However, MRI must be used for this ALS study because it is the only imaging system capable of visualizing the necessary anatomical locations for delivering cellular therapeutics to the spinal cord; the cell therapy target is the gray matter within the ventral horn of the spinal cord, and only MRI can detect the contrast between gray and white matter. Innomotion and NeuroArm have been used for MRI-guided interventions [3, 4] but they are complex, take a long time to set up, and take up a great deal of space in the MRI bore. An initial solution by our research group provided targeting solutions using an adjustable template on the spine, but was manually adjusted, targeted solely on a grid, and lacked a second rotation axis[5]. The presented device, SpinoBot, percutaneously directs therapeutics under MRI guidance into the spinal cord, allowing accurate and minimally invasive spinal therapies. This study examines the accuracy and workflow of MRI-guided cellular therapeutics injections using SpinoBot, a targeting and injection needle guidance system.