Comparing commercial versus low-cost gelatinous phantoms for ultrasound-guided needle tracking: A randomized crossover trial, among emergency medicine residents.

Objectives: The objective of this study was to devise a low-cost indigenous gelatin-based vascular phantom and to compare this newly constructed phantom with a commercially available phantom.

Methods: This was a randomized crossover study conducted at a tertiary care hospital of India. The aim of the study was to develop a prototype low-cost gelatin-based vascular phantom and compare it with a commercially available phantom. Gelatin, psyllium husk, corn starch, antiseptic liquid, food-coloring agent, latex balloons, and metallic containers were used to prepare the gelatin phantom. The newly prepared gelatin model was labeled "Model A" and the commercially available gelatin model was labeled "Model B." Emergency medicine residents (n = 34) who routinely perform ultrasound (USG)-guided invasive procedures were asked to demonstrate USG-guided in-plane and out-of-plane approach of needle-tracking in both the models and fill out a questionnaire on a Likert scale (1-5). An independent supervisor assessed the image quality.

Results: The cost of our phantom was USD 6-8 (vs. USD 1000-1200 for commercial phantom). The participants rated the ease of performance and tissue resemblance as 4 (interquartile range [IQR]: 4-5) for both the models "A" and "B." The supervisor rated the overall performance as 4 (IQR: 3-4) for both the models. In all the parameters assessed, model A was noninferior to model B.

Conclusion: The indigenously developed vascular phantom was noninferior to the commercially available phantom in terms of tissue resemblance and overall performance. The cost involved was a fraction of that incurred with the currently available commercial model. The authors feel that gelatin-based models can be easily prepared in resource-constraint settings which may be used for USG-guided training and medical education in low- and middle-income countries.