Development and Characterization of Synthetic Tissue- Equivalent Material for CT Imaging Applications

Introduction: The use of a simple tissue analog material in the fabrication of medical computed tomography (CT) imaging phantoms has great potential to help researchers. The purpose of the present study is to develop new gel tissue-equivalent materials and determine whether their CT numbers and relative electron densities vary in CT images obtained by scans at different energies. Materials and Methods: First, we designed a phantom using six cuvettes. We then made 36 gels using nickel-doped agarose, sucrose, urea, and sodium chloride, and six solutions using K2HPO4. Finally, we measured the CT numbers and relative electron density of each gel and solution using a Siemens SOMATOM Emotion 16 scanner. Results: The CT numbers and relative electron density of the gels closely resembled those of real tissue. The CT number of each gel was higher than that of water. In addition, the CT numbers for all materials decreased as the X-ray energy increased from 80 to 130 kVp. Conclusion: Our study found that the CT numbers and relative electron density of gels that include nickel- doped agarose, sucrose, urea, and sodium chloride (as soft tissue) and K2HPO4 (as bone) indicate that the gels have the potential to be used as tissue substitutes. It is feasible to create an anthropomorphic phantom using the gels developed in this study.