# Advancing Phantom Fabrication: Exploring 3D-Printed Solutions for Abdominal Imaging Research
## 4 Discussion  
This research presented the development and characterization of a novel anthropomorphic abdominal phantom fabricated using a combination of 3D printing, beeswax, and epoxy resin. This approach offers a promising alternative to traditional phantom fabrication techniques, potentially accelerating advancements in medical imaging research and development. Here, we delve into the key findings, the limitations of the current design, and exciting possibilities for future exploration [19; 20; 21]. The success of the phantom depends on its ability to accurately mimic the human abdominal anatomy and its X-ray attenuation properties [22]. The 3D-printed mold design should be meticulously compared to the reference anatomy used for its creation. High-resolution imaging techniques, such as micro-CT, can provide a detailed comparison of the phantom's geometry to real human abdominal anatomy. This analysis should assess the level of detail captured in the mold, particularly focusing on the accurate representation of organs, blood vessels, and other critical structures [23; 24; 25]. It is important to acknowledge potential limitations in replicating specific anatomical features. For instance, intricate structures like vascular networks or the intricate folds of the small intestine might require further refinement of the 3D printing process or the use of additional casting materials. Future studies could explore techniques like microfluidic channels within the epoxy resin to create more realistic vascular phantoms [26; 27]. The mechanical properties of the phantom, particularly its ability to mimic the elasticity and pliability of real abdominal tissues, are crucial for simulating realistic interaction with X-ray beams. Indentation testing with probes of varying stiffnesses can be employed to evaluate the phantom's response to pressure, comparing the obtained data to established values for human abdominal tissues like fat and muscle. Tensile testing of isolated sections of the phantom can further assess its ability to stretch and deform under stress [28]. Future research could explore incorporating materials with variable mechanical properties within the epoxy resin. For instance, hydrogels with tunable stiffness could be used to mimic the elasticity of different soft tissues. The most crucial aspect of the phantom's performance lies in its ability to mimic the X-ray attenuation properties of real human tissues. The X-ray attenuation characterization process should be thoroughly discussed, including the specific energy spectrum used and the methods employed for calculating Hounsfield units (HUs) [29; 30; 31]. A comprehensive comparison of the HU values obtained for the beeswax, the epoxy resin with and without fillers, and the final phantom to the reference values for human adipose tissue, skeletal muscle, and bone tissue across the relevant X-ray energy range is vital. This comparison should highlight the success of the chosen materials and characterization techniques in achieving tissue-equivalent properties [32]. Potential deviations from the reference HU values should be acknowledged and discussed. Discrepancies for specific tissues or energy ranges could be attributed to the limitations of the beeswax or the chosen filler materials. Future studies could explore alternative fillers within the epoxy resin or investigate surface treatments for the beeswax to achieve a closer match to specific tissue types [33; 34; 35]. Beeswax has a density typically around 0.95 to 0.97 g/cm\({}^{3}\), which is slightly lower than that of soft tissues, making it a suitable material for simulating certain tissue types. Its organic composition, primarily consisting of esters, fatty acids, and hydrocarbons, provides a tissue-equivalent attenuation profile in imaging modalities like CT. The attenuation coefficient is influenced by the wax's composition and can be adjusted by incorporating additives or blending with other materials to match the specific attenuation profiles required for the phantom [36; 37].