Traceable working standards with SI units of radiance for characterizing the measurement performance of investigational clinical NIRF imaging devices

摘要

All medical devices for Food and Drug market approval require specifications of performance based upon Internationa] System of Units (SI) or units derived from SI for reasons of traceability. Recently, near-infrared fluorescence (NIRF) imaging devices of a variety of designs have emerged on the market and in investigational clinical studies. Yet the design of devices used in the clinical studies vary widely, suggesting variable device performance. Device performance depends upon optimal excitation of NIRF imaging agents, rejection of backscattered excitation and ambient light, and selective collection of fluorescence emanating from the fluorophore. There remains no traceable working standards with SI units of radiance to enable prediction that a given molecular imaging agent can be detected in humans by a given NIRF imaging device. Furthermore, as technologies evolve and as NIRF imaging device components change, there remains no standardized means to track device improvements over time and establish clinical performance without involving clinical trials, often costly. In this study, we deployed a methodology to calibrate luminescent radiance of a stable, solid phantom in SI units of mW/cm~2/sr for characterizing the measurement performance of ICCD and IsCMOS camera based NIRF imaging devices, such as signal-to-noise ratio (SNR) and contrast. The methodology allowed determination of superior SNR of the ICCD over the IsCMOS system; comparable contrast of ICCD and IsCMOS depending upon binning strategies.