I'd like to compare two maps (A and B, these are 3-dimensional images from an MRI scanner) acquired from a set of 30 subjects. Each map is composed of a number of spatial units ("voxels"). The value of each voxel is one observation (there's about 10,000 per map). I'm running a linear regression analysis of the relationship between the paired voxels in maps A and B (A is the dependent variable Y, B is the independent variable X). I'm doing a regression analysis separately for each of the 30 subjects because pooling them would violate the assumption of independence of Y (I think, please correct me if I'm wrong). When it comes to summarising the results across all subjects, is it appropriate to report the mean + standard deviation of R-squared and the standardised regression coefficients? I'm especially unsure about the latter (the regression coefficients).
Thanks in advance.