Signal recovery algorithm for accelerated data acquisition in water activation studies

In this study a method is proposed to separate the signals from different water bolus injections which overlap in time. This technique is of great interest for [¹⁵O]H₂O activation studies that consider repeated injections during a single scan session. Conventionally, the time between injections is chosen so that the activity from the previous injection has almost completely vanished by the time of the next injection. The proposed technique allows injections to be administered at significantly higher frequencies, thus significantly reducing (potentially up to a factor of 2) the total time of a complete study, typically consisting of 12 injections. Simulation experiments with the proposed algorithm indicate great promise for the method. It is shown that the levels of bias and the increase in variance introduced by the novel method are well below the expected errors encountered in routine PET imaging.