A Low-Cost Ultrasound Phantom of the Lumbosacral Spine

Background and Objectives: This report describes the production of a low-cost ultrasound phantom of the lumbosacral spine. The phantom should be a very useful tool to teach the basic skills for ultrasound-guided procedures of the lumbosacral spine. Methods: A lumbosacral spine model is secured to the bottom of a microwave-safe container and is immersed in a concentrated gelatin solution. After the gelatin hardens, the model can be used for scanning practice as well as needle placement. The phantom can be recovered after use by melting the gelatin in a microwave to "erase" any needle track marks. Results: A transparent and durable gelatin block is produced. This allows trainees to have direct visual access to the lumbosacral spine model to correlate with the ultrasound images as well as to confirm proper needle placement. Disadvantages of the model include lack of simulated soft tissue structures and an absence of simulated haptic feedback during needle placement. Metamucil can be added to the gelatin to simulate the appearance of soft tissue, although this increases the opacity and thus decreases the visual access of the gelatin. Conclusions: This teaching tool can provide trainees with an opportunity to familiarize themselves with sonoanatomy of the lumbosacral spine in addition to practicing probe handling techniques and needle placement.