Fig. 2

Relationships between single-count rates and activity concentration obtained from the NEMA count-rate test with the Ingenuity (red) and the Vereos (blue) cameras, with the double-exponential regressions predicting: a Single-count rates based on activity concentration (\( {f}_{A\to S}^{Ing} \) and \( {f}_{A\to S}^{Ver} \) for respectively Ingenuity and Vereos) and b Activity concentration based on single-count rates (\( {f}_{S\to A}^{Ing} \) and \( {f}_{S\to A}^{Ver} \) for respectively Ingenuity and Vereos)