Novel Dual-Array Ultrasound Technology for Neuraxial Injections: Evaluation of Thoracic and Lumbar Facet Joint...

Ultrasound-guided neuraxial injections are less accurate than fluoroscopy-guided techniques due to limited needle visualization, particularly in out-of-plane approaches. A novel dual-array ultrasound probe developed by Rivanna Medical Inc., enables in-plane visualization of needle trajectory even when inserted perpendicularly. This study evaluates the accuracy of this novel technology in thoracic and lumbar facet joint injections.

A prevalidation study was conducted using one cadaver. One interventional pain physician independently performed facet joint injections using the dual-array ultrasound system. The system integrates two rotated 64-element curvilinear arrays configured to transmit and receive at 2.5 MHz with multiangle electronic beam steering (three angles per array) and real-time dual-array image blending/compounding, enabling visualization of both anatomy and the full in-plane needle trajectory. Injection accuracy was confirmed via fluoroscopy.

All six injections successfully targeted the intended region. Two injections were classified as Grade 1, three as Grade 2, one as Grade 3, and zero as Grade 4.

The dual-array ultrasound system shows promise in enhancing the accuracy of thoracic and lumbar facet joint injections by enabling in-plane needle visualization even at steep angles. Our findings highlight the potential of this technology to improve procedural precision, while also underscoring the learning curve associated with its use. These feasibility results support further validation for spine interventions requiring steep needle trajectories, and future studies should evaluate true neuraxial applications (e.g., epidural/intrathecal) with quantitative needle-tip localization metrics.