In this study, we found that female participants were involved in 145 studies. Recently, some studies performed on healthy subjects indicated the cerebral functional and structural changes in menstrual period. For example, Veldhuijzen et al. [194] found that the pain-related cerebral activation varied significantly across the menstrual cycle. Hagemann et al. [195] found a significant gray matter volume peak and cerebral spinal fluid loss at the time of ovulation in females. So, for female participants, scanning should be performed during the same physiological period to avoid the possible changes in brain size and activity in menstrual cycles.