1. The superior occipital gyrus is the superior part of the occipital lobe. Its anterior boundary is the parieto-occipital fissure. Its lateral boundary is the intraparietal sulcus. Its medial boundary is defined by the lateral boundary of the cuneus. (Fig. 1, Fig. 2)
  2. Begin masking in the coronal view where the intraparietal sulcus begins posteriorly. Sometimes this will only be when there is cortex lateral to the intraparietal sulcus, and other times the sulcus will still be clearly defined after this point. Follow the intraparietal sulcus down to its end point and connect it to the highest medial sulcus. (Fig. 3)
  3. Follow step 2 until the parieto-occipital fissure comes into view. This sulcus can be found clearly in the sagittal view. At this point masking of the superior occipital gyrus ends. (Fig. 4, Fig. 5)