Gray matter volume vs age during development
Finally, to explore the relationship between gray matter volume and age over development as a function of QC threshold, gray matter volume was computed from running the Mindboggle software \cite{klein2017mindboggling} on the entire dataset. Extremely low quality scans did not make it through the entire Mindboggle pipeline, and as a result the dataset size was reduced to 629 for this part of the analysis. The final QC score for the brain volumes was computed by taking the average of the predicted braindr rating from the deep learning model for all five slices. We ran an ordinary least squares (OLS) model on gray matter volume versus age on the data with and without QC thresholding, where the QC threshold was set at 0.7. Figure \ref{182176} shows the result of this analysis, which showed an effect size that nearly doubled and replicated previous findings when QC was performed on the data.
Acknowledgements
This research was supported through a grant from the Gordon and Betty Moore Foundation and the Alfred P. Sloan Foundation to the University of Washington eScience Institute. A.K is also supported through a fellowship from the eScience Institute and the University of Washington Institute for Neuroengineering. We'd like to acknowledge the following people for fruitful discussions and contributions to the project. Dylan Nielson, Satra Ghosh and Dave Kennedy for the inspiration for braindr. Greg Kiar, for contributing badges to the braindr application. Chris Markiewicz, for discussions on application performance, and for application testing in the early stages. Katie Bottenhorn, Dave Kennedy, and Amanda Easson for quality controlling the gold standard dataset. Jamie Hanson, for sharing the MRIQC metrics. Chris Madan, for application testing and for discussions regarding QC standards. Arno Klein and Lei Ai, for providing us the segmented images from the HBN dataset. Tal Yarkoni and Alejandro de la Vega, for organizing a "code rodeo" for neuroimagers in Austin, TX, where the idea for braindr was born. Finally, we'd like to thank all the citizen scientists who swiped on braindr - we are very grateful for your contributions!