The MRIcroGL preferences allow you to choose between radiological or neurological convention
  https://www.nitrc.org/plugins/mwiki/index.php/mricrogl:MainPage#Neurological_versus_radiological_convention
which reverses whehterh the patinets left is on the left or right side of the screen. All conventions have anterior toward the top of the screen and posterior toward the bottom for the axial slices.