Primary intramedullary tumor is the rarest type of spinal cord tumor growing within the spinal cord tissue which is enclosed by the dura mater. If it is left untreated, the type of tumor can result in significant neurological dysfunction and an increase mortality. Hemangioblastoma, ependymoma and astrocytoma are among the more common types of diagnosed primary intramedullary tumor.

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Confirmed intramedullary tumor is initially treated with gross-total resection (GTR). It is a surgical procedure performed by a neurosurgeon to attempt to remove the whole mass. However, to separate and remove the tumor tissue depends heavily on identifying the interface where spinal cord tissue meets tumor tissue. It is a characteristic that varies widely across different types of tumors.

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There are several ways to visualize the interface to help with the resection of brain tumors, including intraoperative magnetic resonance imaging (MRI), 5-aminolevulkinic acid (5-ALA), fluorescein, and intraoperative ultrasound. Unfortunately, intraoperative MRI is expensive and extends operative time and 5-ALA and fluorescein are only capable of detecting the surface of the tumor tissue and is incapable of getting tumor depth, so these methods are not suitable for spinal tumor resection surgeries. Intraoperative ultrasound, on the other hand, has yet to be used to characterize spinal cord – tumor tissue interface during resection of intramedullary spinal cord tumors.

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The Hofstetter lab is using contrast-enhanced ultrasound (CEUS) imaging as an adjunct to localize and monitor the resection of tumors. The lab is known for using CEUS to detect regions of hypo-perfusion and monitor level of perfusion in spinal cord injuries sustained during a traumatic event. Tumors have higher blood flow in comparison to healthy tissue. When contract is injected for tissue detection, the ultrasound image will show a higher contrast uptake in tumor regions. So, CEUS can delineate the spinal cord-tumor tissue interface. We are currently recruiting participants diagnosed with having intramedullary tumor for the clinical study to consent use of CEUS during their surgeries.