2402
Task Performance or Artifact Reduction? Evaluating the Number of Channels and Dropout based on Signal Detection on a U-Net with SSIM Loss
Rachel E Roca1, Joshua D Herman1, Alexandra G O'Neill1, Sajan G Lingala2, and Angel R Pineda1
1Mathematics Department, Manhattan College, Riverdale, NY, United States, 2Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, United States
Choosing the parameters of a neural network for image reconstruction based on the detection of signals may lead to artifacts which are not acceptable.  Task-based optimization may not align with artifact minimization.
Figure 4. Sample 2AFC trial for network with 64 channels and 0.3 dropout including artifacts which do not affect the detection task. The artifacts may be hyper-enhanced features of the true image.
Table 1. Results for the combinations of initial number of channels and amount of dropout. The choice that did consistently well across all metrics we considered was 64 channels with 0.1 dropout but the network with 64 channels and 0.3 dropout has very similar human observer performance. All networks perform similarly for human detection except for the network with 64 channels and 0 dropout. We also see that the approximation to the ideal observer (LG-CHO) performs similarly except for the networks with 32 channels and 0.3 dropout and 64 channels and 0 dropout.