Fig. 1
Left panel: Exemplar high-resolution (0.42 mm isotropic) imaging conducted at 3 T on 5 bottles (15E031; 15E033; 15E034 shown here; 30E017; 30E018 shown here) sampled out of the original batch in August 2017 (this is 2 years post manufacture) confirmed their structural integrity. The whole length of the phantom was imaged (three exemplar slices only shown here, represented by the green dashed lines). The internal tubes are labeled. Surrounding the tubes is a speckled pattern due to high density polyethylene (HDPE) macrobeads in an agarose/NiCl2 mixture . Confluent bright patches between tubes represent patches of agarose/NiCl2 mixture due to displacement of macrobeads. There were no signs of structural deterioration of the phantoms 2 years after manufacture. Middle panel: The nine tubes are supported on a translucent resin base composed of unsaturated polyester/styrene. The matrix fill is packed with compact HDPE pellets and agarose/NiCl2 mixture. Right panel: The outer physical appearance (front and back surfaces) of a phantom (30E018) at 2 years post manufacture (the plastic packaging wrap around the bottle cap dates back to the time of manufacture). HDPE, high-density polyethylene; NiCl2, nickel chloride; PE, polyethylene; PVC, polyvinyl chloride