Multi-Parametric Standardization of Fluorescence Imaging Systems Based on a Composite Phantom.

OBJECTIVE

Fluorescence molecular imaging (FMI) has emerged as a promising tool for surgical guidance in oncology, with one of the few remaining challenges being the ability to offer quality control and data referencing. This paper investigates the use of a novel composite phantom to correct and benchmark FMI systems.

METHODS

This paper extends on previous work by describing a phantom design that can provide a more complete assessment of FMI systems through quantification of dynamic range and determination of spatial illumination patterns for both reflectance and fluorescence imaging. Various performance metrics are combined into a robust and descriptive "system benchmarking score," enabling not only the comprehensive comparison of different systems, but also for the first time, correction of the acquired data.

RESULTS

We show that systems developed for targeted fluorescence imaging can achieve benchmarking scores of up to 70%, while clinically available systems optimized for indocyanine green are limited to 50%, mostly due to greater leakage of ambient and excitation illumination and lower resolution. The image uniformity can also be approximated and employed for image flat-fielding, an important milestone toward data referencing. In addition, we demonstrate composite phantom use in assessing the performance of a surgical microscope and of a raster-scan imaging system.

CONCLUSION

Our results suggest that the new phantom has the potential to support high-fidelity FMI through benchmarking and image correction.

SIGNIFICANCE

Standardization of the FMI is a necessary process for establishing good imaging practices in clinical environments and for enabling high-fidelity imaging across patients and multi-center imaging studies.