Development Of A Novel 3d Dynamic Cardiac Phantom Simulated Human Anatomy

1808 Objectives: We developed a dynamic cardiac phantom equipped with double pump can move both epi- and endocardium in previous study. However, that cardiac phantom was not simulated the form of the body contour such as oblique of the cardiac axis, and was not equipped with the liver and gallbladder simulated scatter and attenuation from human body as the structure of human anatomy. The aim of this study was to demonstrate the utility of development of the novel 3D dynamic cardiac phantom simulated the structure of human anatomy.Methods We improved previous phantom as follows: tilting approximately 30 degrees to body axis, changing the shape of body from circle to ellipse, attaching liver and gallbladder in phantom as other organs. In addition, the LV volume of cardiac created three-types which simulated small size as a small heart, size as normal heart and large size as a dilated cardiomyopathy. The cardiac true volumes of small, regular and large types were 20.8, 40.0 and 202.0 mL for ESV, 20.8-221.9, 40.0-241.1 and 202.0-403.1 mL for EDV, 0-90.6%, 0-83.4% and 0-49.9% for LVEF, respectively. The LV chamber and myocardial parts of the phantom filled with non-radioactive and 99mTc solution, respectively. A dual detector SPECT-CT (Symbia T6; Siemens) system with the low-energy high-resolution (LEHR) collimator used to acquire the phantom. Acquisition parameters were set on 16 flames per cardiac cycle, energy window 140 keV ±10%, 64×64 matrix, a rotation angle of 360, 60 projections. Acquisition time was determined from the average myocardial counts obtained by region of interest (ROI) on the lateral myocardial wall in left anterior oblique (LAO) 45 degree’s view, and the average myocardial counts set on approximately 140 counts per pixel. Image reconstruction was performed with filtered back projection (FBP) and ordered subset expectation maximization (OSEM) methods. The pre- and reconstruction filters for FBP method used the Butterworth with the cut-off frequency 0.39 cycles/cm and 16 and Ramp. Furthermore, the subset and iteration for OSEM method set 12 and 10, and Gaussian filter as post-filter was used with the full width at half maximum (FWHM) 13.2 mm. The full width at half maximum (FWHM) for Gaussian filter was set 13.2 mm. The attenuation, scatter and resolution corrections were not performed. The ESV, EDV and LVEF were analyzed using a quantitative gated SPECT (QGS).Results The correlation between true and measured value in each LV function such as the EDV, ESV and LVEF for the three types was very good.Conclusion We developed a novel dynamic cardiac phantom simulated human anatomy that is able to change the myocardial wall and LV volume. It was suggested that the phantom may be possible to the standardization.