Comparison of tissue-mimicking materials to create a realistic and durable fascia iliaca block phantom

Ultrasound phantoms, designed to mimic human tissue and anatomy, are important tools for training physicians. Commercial phantoms are expensive leading to the creation of do-it-yourself (DIY) phantoms. This study evaluates DIY fascia iliaca (FI) block phantoms made from different mediums compared to a commercial grade trainer to determine the best phantom material in terms of image quality, anatomical accuracy, and durability.

FI block phantoms were created using latex tubing to mimic vessels, bungee cord for nerve, and ballistics gel for muscle and fascia layers. Five mediums (agar, gelatin, konnyaku jelly, Dragon Skin™ silicone rubber, and ballistics gel) were poured over and between block components to create five different phantoms. Participants scanned each phantom and a commercial femoral trainer rating each on a five-point Likert scale.

Two medical students and 17 emergency medicine residents participated. The gelatin phantom ranked the highest (median = 5) in all categories except durability (median = 4, IQR 3-5) and outperformed the commercial trainer in image quality, anatomic accuracy and overall impression. The agar model performed similarly to the commercial trainer (median = 4, p < 0.01) in all categories except durability (median = 3, IQR 3-4). The other mediums underperformed compared to the commercial trainer. The gelatin phantom was the top choice, favored by 79% of participants.

DIY FI block phantoms are easily made and outperform commercial trainers in image quality and anatomic accuracy. DIY phantoms have the advantage of including more block specific landmarks and costing a fraction of the price of commercial trainers.