@article {Kadrmas1737, author = {Dan Kadrmas and Phil Triolo}, title = {A tool for rapid prototyping and validation of multi-tracer PET protocols}, volume = {59}, number = {supplement 1}, pages = {1737--1737}, year = {2018}, publisher = {Society of Nuclear Medicine}, abstract = {1737Objectives: Rapid multi-tracer PET imaging can measure functional processes for 2-3 PET tracers in a single scan, providing a wealth of information for a variety of personalized medicine applications. The technique uses dynamic scanning with sequential tracer administrations spaced several minutes apart. Signal-separation algorithms are then applied, which use kinetic constraints to recover individual-tracer signals from the multi-tracer imagesets. While some information about each individual tracer is lost by the rapid scanning approach, several clinically relevant imaging measures can be accurately recovered for each tracer. A major challenge of the approach is that the performance of the technique depends strongly on the tracers used, injection order and timing, and desired imaging endpoints. This work reports on a new tool for rapidly designing multi-tracer PET scanning protocols and assessing their robustness for recovering a number of output imaging measures for each tracer. Methods: Multi-tracer PET signal-separation depends upon in vivo tracer kinetics, and it is important to accurately account for the kinetics in the target image volume(s) when designing multi-tracer protocols. A widely used technique for evaluating rapid multi-tracer PET performance is the use of {\textquotedblleft}emulated{\textquotedblright} multi-tracer data, which combines separately-acquired single-tracer datasets to emulate a multi-tracer measurement. The original single-tracer data provide {\textquotedblleft}gold standard{\textquotedblright} imaging measures, and the performance of signal-separation algorithms can be evaluated by comparing imaging measures recovered from the emulated multi-tracer data to these standards. Under an NIH-funded partnership, a software tool has been developed and integrated with the MFI research software (MultiFunctional Imaging LLC) that enables users to rapidly emulate multi-tracer imagesets from separate single-tracer input images, process them, and evaluate performance of prototype scanning protocols. Results: The software tool provides a graphical user interface for selecting the input images, varying the tracer injection order and timing, and varying the temporal sampling schedule. Populations of multiple noise realizations can also be simulated. Several signal-separation algorithms are provided, and output options include dynamic and static images for each tracer, SUVs, and kinetic micro- and macro-parameters. Graphical features are also provided for comparing the recovered images, time-activity curves, and imaging measures to the single-tracer standards. Application of the new software to previously published research studies produced results in full agreement with those studies. Conclusions: This software tool enables researchers to rapidly prototype scanning protocols based on example single-tracer dynamic images of each tracer. The interface allows users can vary the tracer injection order and timing, and predict the accuracy and robustness of the output image measures as compared to single-tracer standards. Research Support: R01 CA135556}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/59/supplement_1/1737}, eprint = {https://jnm.snmjournals.org/content}, journal = {Journal of Nuclear Medicine} }