Development of Radiomics Phantom for Multi-Scanner Evaluation

To facilitate the study of the inter-scanner variability of quantitative image features, we developed the CCR phantom, Figure 1(a). The phantom comprises 10 cartridges, each 10.1×10.1×3.2 cm³, with an acrylic case. The cartridge materials were chosen to produce a wide range of radiomics feature values when scanned, ideally spanning the range of feature values found in human tissue, particularly NSCLC tumors. The first four cartridges composed of acrylonitrile butadiene styrene (ABS) plastic and were fabricated using a MakerBot® Replicator 2 3D (MakerBot Industries, LLC Brooklyn, NY) printer. These four cartridges are filed with honeycomb patterns of ABS plastic with air-filled holes of sizes of approximately 6.0, 1.4, 1.0, and 0.9 mm, making the materials 20%, 30%, 40%, and 50% filled, respectively. A block of sycamore wood provided a natural, directional texture. Two cartridges were composed of cork, one standard and one high density. The eighth cartridge, composed of rubber from shredded tires with a proprietary bonding agent (Ecoborder, Tampa, FL), had a density of 0.93 g/cm³ and a speckled texture. The ninth cartridge, a solid block of zp® 150 power bonded with Colorbond™ (3D Systems, Inc. Rock Hill, SC) bonding agent, had the highest average density, 1.5 g/cm³, and a barely visible texture corresponding to the pattern the 3D printer used when it sprayed the bonding resin on the powder. The last cartridge was solid polymethyl methacrylate (acrylic) with a density of 1.1 g/cm³ and very little texture. The textures of the CCR phantom cartridges are shown in Figure 2.