Three-Dimensional Realistic Brain Phantoms Containing Detailed Grey Matter And Bone Structures For Nuclear Medicine Imaging

470 Objectives The aim of this study is to develop and evaluate a physical 3-dimensional phantom that simulates a realistic head model. Methods The phantom was made of transparent photo-curable polymer (density 1.09 g/mL) constructed with a laser-modeling technique . The grey matter structure was designed by tracing a high-resolution MRI on a healthy volunteer, consisting of cortical grey matter, striatum, thalamus, and the cerebellum. Additional component was for bone structure, in which bone-equivalent solution of K2HPO4 was inserted. Careful attention was made to avoid air-bubble contamination. X-ray CT and MRI images were acquired to confirm the design structure. SPECT images were also acquired for I-123 and Tc-99m using different reconstruction-programs. Results The grey-matter compartment was 550mL, and the bone 180 mL. The apparent attenuation coefficient for the whole brain was 0.173 cm-1 for Tc-99m, slightly higher than typical values for normal volunteers (0.168 cm-1. Air bubbles can be avoided relatively easily from each of compartments, and X-ray CT images did not show any existence of bubbles in either of compartments. The X-ray CT and MRI images showed a good agreement with the design of the phantom geometry. SPECT images obtained with the QSPECT package also showed a good agreement with the design, suggesting the validity of this reconstruction. SPECT images were also consistent between T-123 and Tc-99m. Conclusions The realistic 3D-brain phantom constructed using the laser-modeling technique appeared to be accurately constructed as designed, and may be of use for evaluating various reconstruction programs.