Background
Medical imaging instruments are calibrated using standards fabricated in a controlled way, called phantoms, in order to validate performance (e.g., spatial resolution in radiography). With the increasing use of new in vitro and in vivo optical imaging systems by researchers, pharmaceutical companies, and the clinical community, new standards must be developed for the visible/near-infrared portion of the electromagnetic spectrum. Optical phantoms are controlled standards that reproduce the characteristics of light propagation (400–900 nm) in living tissue.
In most cases, phantoms are fabricated in a more or less controlled manner in labs to make specific measurements or test optical instruments. However, at INO, we do things differently. We have implemented rigorous fabrication processes accompanied by ultra-precise characterization that yields phantoms with defined, reproducible optical properties. We also offer the option of adding fluorescent inclusions to solid phantoms. Editor Robert J. Nordstrom
1 cited this initiative noting that this new trend “represents an encouraging move from individually constructed phantoms to commercial product.”
1.
Design and performance validation of phantoms used in conjunction with optical measurement of tissue II edited by Robert J. Nordstrom, Proceedings of SPIE Vol. 7567, 2010.
Solution
Solid phantoms were initially created for ART (Advanced Research Technologies Inc.) for use in laser mammography. INO developed expertise and fabrication processes for solid phantoms consisting of polymers, which ensure a long shelf life and outstanding reproducibility of optical properties. Depending on tissue simulation to performed, these fabrication processes enable us to adjust absorption and scattering properties on a specific wavelength band. It is also possible to prepare a phantom with a number of layers of differing properties. For fluorescence applications, we can embed fluorescent inclusions with different properties at precise positions in the phantom volume. In order to ensure that the phantoms delivered meet the required specifications, we designed measurement and analysis methods as well as innovative and reliable characterization models.