The MVIWAS R package and corresponding resources on GitHub include 1) a function for implementing the Multivariate Imaging Wide Association Study for testing causal brain imaging endophenotypes using GWAS summary statistics and a reference panel and 2) a detailed analysis pipeline from the corresponding paper (https://doi.org/10.1016/j.neuroimage.202...), which can be followed to test for causal brain imaging phenotypes in brain-related diseases using MV-IWAS.