 A 2009 MRI study by Luders et al.of 24 MtF transsexuals not yet treated with cross-sex hormones found that regional gray matter concentrations were more similar to those of cisgender men than to those of cisgender women, but there was a significantly larger volume of gray matter in the right putamen compared to cisgender men.Like earlier studies, it concluded that transsexuality was associated with a distinct cerebral pattern.