3D printable Nuclear Medicine SPECT Cardiac Phantom

Abstract

Purpose: The purpose of this study was to validate a 3D-printed nuclear cardiac phantom to create a low cost, user-friendly phantom for perfusion imaging that is easily implemented with modern cardiac SPECT systems. This new phantom design aims to address common problems with commercial phantoms such as lengthy setup, prohibitive cost, and overly large size, while improving the overall functionality of the phantom. Methods: The phantom was developed using computer aided design software, and fabricated with a 3D printer using optimized watertight printing protocols. The phantom design includes six low perfusion lesions within a stylized myocardium of the left ventricle that are placed in the common quantitation sectors for polar maps. The validation of this phantom was completed with two dedicated cardiac SPECT systems; a dual-head gamma camera and a multi-pinhole CZT system. Multiple SPECT acquisitions were used to demonstrate the functionality of the phantom. Polar maps were reconstructed and used to score the contrast detectability based on the number of visible low contrast objects representing ‘lesions.’ Results: The images reconstructed from the various acquisitions on both SPECT systems closely resemble a clinical examination. Lesion visibility followed the expected relationships between protocol changes affecting contrast and spatial resolution. Lesion visibility improved with iterative reconstruction against filtered back projection. Conclusion: A phantom of a stylized left ventricle with fillable myocardium was developed, 3D printed, and implemented for cardiac nuclear medicine. The phantom simulates the task of perfusion imaging and successfully demonstrates differences in image quality depending on imaging protocol. This study validates the 3D printed design as a low cost and user-friendly phantom that can be easily scanned and scored using various systems, in particular those implementing a non-traditional cardio-centric geometry.