Design and validation of a technology for 3D printing training phantoms for ultrasound imaging

Due to high cost, training phantoms are often inaccessible and their manufacturing technologies are quite sophisticated. The purpose of this paper is to develop an inexpensive and reproducible technology for creating ultrasound training phantoms. These phantoms are a 3D printed porous medium composed of 156-µm-thick photopolymer resin fibers and include models of cysts ranging from 4 to 8 mm in diameter, effectively simulating a muscle tissue with anechoic lesions. A custom software generates a virtual phantom model, enabling precise control over its properties. We believe that the results of the acoustic characteristics' measurements for the designed phantoms provide an opportunity to mimic muscle (1547 m/s) and breast (1510 m/s) tissues. Following the creation of the phantom, a series of assessments were conducted to evaluate its efficacy for needle insertion (involving 3 observers) and to identify its mimicked tissue type (with 29 observers participating). The findings revealed that the phantom is capable of enduring up to 300 punctures in a single location without exhibiting significant decline in image quality. A subsequent survey of ultrasound specialists, who possessed a range of professional experiences, indicated that the ultrasound images produced by the phantom predominantly corresponded to those of muscle tissues upon visual examination. The 3D printing process for the phantom 60 mm × 60 mm × 30 mm in size was completed in 3 h and 23 min. The proposed technology allows creating low-cost, long-lasting phantoms for training in ultrasound diagnostics and ultrasound-guided procedures. The phantom designed using widely available photopolymer resin, while the custom software and high-resolution 3D printing ensures reproducibility of the shape and positions of the fibers and inclusions. The phantom mimics muscle tissues with multiple cysts and can be used to develop basic coordination and navigation skills required for ultrasound diagnostics.