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In biophotonic imaging, turbid phantoms that are low-cost, biologically-relevant, and durable are desired for
standardized performance assessment. Such phantoms often contain inclusions of varying depths and sizes in order to
quantify key image quality characteristics such as penetration depth, sensitivity and contrast detectability. The emerging
technique of rapid prototyping with three-dimensional (3D) printers provides a potentially revolutionary way to fabricate
these structures. Towards this goal, we have characterized the optical properties and morphology of phantoms fabricated
by two 3D printing approaches: thermosoftening and photopolymerization. Material optical properties were measured by
spectrophotometry while the morphology of phantoms incorporating 0.2-1.0 mm diameter channels was studied by μCT,
optical coherence tomography (OCT) and optical microscopy. A near-infrared absorbing dye and nanorods at several
concentrations were injected into channels to evaluate detectability with a near-infrared hyperspectral reflectance
imaging (HRI) system (650-1100 nm). Phantoms exhibited biologically-relevant scattering and low absorption across
visible and near-infrared wavelengths. Although limitations in resolution were noted, channels with diameters of 0.4
mm or more could be reliably fabricated. The most significant problem noted was the porosity of phantoms generated
with the thermosoftening-based printer. The aforementioned three imaging methods provided a valuable mix of insights
into phantom morphology and may also be useful for detailed structural inspection of medical devices fabricated by
rapid prototyping, such as customized implants. Overall, our findings indicate that 3D printing has significant potential
as a method for fabricating well-characterized, standard phantoms for medical imaging modalities such as HRI.
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