## 3 Results  
### Study of Optimal Conditions for Awake Acquisition with Point Sources  
The results presented in this section contribute significantly to understanding the relationship between the activity of both the animal and the point sources and the success rate of tracking the point sources. Figure 4 displays the percentage rate of correct tracking of the point sources for frames of 12.5 ms. We have explored how Delayed Window (DW) correction affects detectability, and it is evident that DW correction has a positive impact on the detectability of short frames, expanding the scenarios in which all point sources can be reliably detected. The dash-dotted line serves as a visual representation of the  
Figure 3: Rat with the point sources attached to the head.  
desired activity configuration in an experiment, where there is a 100% rate of correct tracking of the point sources. This figure demonstrates the effectiveness of the tracking system in high-activity scenarios and provides a reference for optimizing future tracking systems. The results presented in this figure are crucial for guiding experimental design and determining the optimal conditions for point source tracking.  
Next, we investigated how the presence of these point sources affects image quality. Figure 5 illustrates the root mean square error (\(RMS_{e}\)) between the image without point sources and the image with point sources at the injected activity of the animal. All simulations encompassed 450 s of acquisition, considering that our acquisitions are of 600 s, and we estimate a loss of counts of approximately 25% due to the methods of subtraction mentioned in Section 2.2. In this case, DW correction is necessary, as it consistently improves the image quality in all cases. The region below the dash line in Figure 5 represents the range of point source activity that has an \(RMS_{e}\) of less than 0.05, which we consider to have a negligible effect on the quantification of activity in different brain regions of the animal.  
By combining the studies on detectability and image quality, we can identify the region of optimal conditions for awake acquisitions with point sources. Figure 6 depicts this region, shown in green. These conditions ensure that the point sources can be tracked every 12.5 ms, and the reconstructed image has a lower degradation than 0.05 \(RMS_{e}\) compared to the image without point sources. The star in the figure represents the conditions of the acquisition analyzed in Sections 3.2 and 3.3.  
The information presented in this section provides valuable insights into the best conditions for awake PET imaging with point sources. These findings will contribute significantly to the advancement of motion detection and correction techniques in this field and serve as a foundation for further optimizing tracking systems in future experiments.  
Figure 4: Point source tracking success as a function of animal and point source activity for frames of 12.5 ms: **(a)** without random correction, **(b)** with random correction using the delayed window method. Since the point source locations are known, the success rate is defined as the percentage of time that all four sources are correctly located. The area above the dashed line represents the ideal activity configuration, where all point sources are tracked with 100% accuracy. This figure is the result of 100 simulations for each configuration.