Image Guidance for Spinal Facet Injections Using Tracked Ultrasound

Abstract

Abstract. Anesthetic nerve blocks are a common therapy performed in hospitals around the world to alleviate acute and chronic pain. Tracking systems have shown considerable promise in other forms of therapy, but little has been done to apply this technology in the field of anesthesia. We are developing a guidance system for combining tracked needles with non-invasive ultrasound (US) and patient-specific geometric models. In experiments with phantoms two augmented reality (AR) guidance systems were compared to the exclusive use of US for lumbar facet injection therapy. Anesthetists and anesthesia residents were able to place needles within 0.57mm of the intended targets using our AR systems compared to 5.77mm using US alone. A preliminary cadaver study demonstrated the system was able to accurately place radio opaque dye on targets. The combination of real time US with tracked tools and AR guidance has the potential to replace CT and fluoroscopic guidance, thus reducing radiation dose to patients and clinicians, as well as reducing health care costs.

Spinal Needle Navigation by Tracked Ultrasound Snapshots

“…In contrast to earlier findings [12], [16], these results suggest that EM-tracked facet joint injections may be routinely performed without ionizing radiation imaging.…”

“…Similar tracked US guidance for facet joint injections was presented earlier [12]. A large, 4.87-mm average targeting error was reported with tracked US needle guidance.…”

“…EM tracking has been used to guide aortic stent-graft deployment [8], the placement of biopsy needles in liver and prostate tumors [9], [10], and in tandem with CT guidance for spinal needle placement [11]. Moore et al used an electromagnetically tracked US probe and developed an augmented reality guidance system for facet joint injections [12]. They found that a prior 3-D model of the spine, typically obtained from CT, was necessary to achieve clinically satisfactory accuracy in needle placement, in phantom models and one cadaver.…”

A multi-vertebrae CT to US registration of the lumbar spine in clinical data

“…Over the past two decades, several research groups have attempted to tackle this challenging problem [6][7][8]11,12,19,22,23]. To the best of our knowledge, these approaches have been validated either on single vertebra registration or on phantom and cadaver experiments.…”

Towards real-time, tracker-less 3D ultrasound guidance for spine anaesthesia

“…Pre-operative computed tomography (CT) data were related to the acquired US volume via volume-to-volume registration and the electromagnetically (EM) tracked needle was guided towards the target using the information from the CT data during the intervention. Moore et al [19] proposed and evaluated three guidance approaches for facet joint injections based on intraoperative US and showed that the integration of a virtual CT-based model improved the accuracy of the injection. EM tracking was again used to relate CT and US information after a landmark-based registration was performed, and to provide the location of the needle accordingly.…”