Differences in imaging protocols (IP) and post-processing methods (PM) may influence relative cerebral blood volume (rCBV). Our goal was to leverage a dynamic susceptibility contrast (DSC) DRO to characterize rCBV consistency across 12 sites, focusing on differences due to site-specific IPs and/or PMs. Our results indicate high agreement when one center processes rCBV despite slight variations in the IP. However, substantial disagreement was observed when site-specific software was applied for rCBV measurements. These results have important implications for comparing DSC-MRI data across sites/trials, where PM variability could confound the use of rCBV as a biomarker of therapy response.