Evaluation of Homemade Ballistic Gelatin Phantoms as a Low-Cost Alternative to Commercial-Grade Phantoms in Medical Education

Background: Cost limitations of commercial-grade ultrasound phantoms often prevent ultrasound education from being incorporated into medical curricula (Bahner et al., Acad Med. 89:1681–6, 2014). While production of homemade agar gelatin phantoms to offset costs has been well documented, use of ballistic gelatin has only recently been described (Domenico et al., J Ultrasound. 11 (4):135-42, 2008; Zerth et al., J Emerg Med. 43:1066-9, 2012; Chao et al., J Emerg Med. 45:240-3, 2013; Shobeiri et al., J Ultrasound Med. 32:1393-6, 2013; Woywodt et al., Clin Nephrol. 79:241-5, 2013; Zeiler et al., Can J Neurol Sci. 40:225-9, 2013; Hunt et al., Eur J Radiol. 82:594-600, 2013; Lo et al., Emerg Med J. 29:738-41, 2012; Li et al., J Ultrasound Med. 30:263-72, 2011; Morrow and Broder, J Emerg Med. 49 (3):313-7, 2015). There exists a critical need for learner evaluation of homemade ballistic gelatin phantoms (BGPs) and their comparison to commercial-grade phantoms to better inform BGP introduction into medical education. The primary aim of this study is to describe survey-based evaluation of homemade BGPs and commercial-grade Blue Phantoms TM by medical students. The secondary aim is to compare image quality of BGPs and Blue Phantoms TM . Materials and Methods: Described are construction of BGPs and introduction in voluntary ultrasound training sessions offered to 61 first through fourth-year medical students. The evaluation and success of this model are reported. Results: Students reported that versatility of homemade BGPs surpassed that of commercially available phantoms (4.52 ± 0.71) and that they felt more confident in their ultrasound skills after the session (4.82 ± 0.37). Side-by-side evaluation of images generated using BGPs and Blue Phantoms TM had comparable simulated vessel shape and echogenicity, adding objective assessment to subjective survey-based results. Discussion: Training sessions were enabled by low-cost homemade BGPs at $4 vs $400+ cost of commercial-grade phantoms, a 100-fold reduction in cost. Conclusion: As students found BGPs and Blue Phantoms TM comparable, the results of this study can equip other institutions struggling with costs of incorporating ultrasound into their medical curricula with not only a cost-effective solution but also a learner-validated one. © 2016, International Association of Medical Science Educators.