Superior Parietal Gyrus Protocol

  1. The superior parietal gyrus is the most superior structure of the parietal lobe. The anterior boundary is the postcentral sulcus and the posterior boundary is the parieto-occipital fissure. Laterally, the boundary of the superior parietal gyrus is the intraparietal sulcus. Medially, the inferior boundary is the calcarine sulcus and the cingulate sulcus. (Fig. 1)
  2. Masking of the superior parietal gyrus is done in the coronal view. Begin masking anteriorly where the intraparietal sulcus first comes into view. Follow the intraparietal sulcus to its inferior end and angle a line to the top of the cingulate sulcus. Follow the cingulate sulcus to its medial endpoint and mask up the interhemispheric fissure, excluding all cortex from the other hemisphere. (The interhemispheric fissure is the division between the left and right hemispheres.) Mask everything within these boundaries. (Fig. 2)
  3. Once the cingulate sulcus is no longer visible, mask from the intraparietal sulcus down to the calcarine sulcus and up the interhemispheric fissure. Mask everything within these boundaries. (Fig. 3)
  4. Moving posteriorly, the parietal occipital fissure will appear. At this point, mask the intraparietal sulcus to its inferior end and draw a straight line to the parieto-occipital fissure. The parieto-occipital fissure can be found easily in the saggital view (Fig. 5). Follow the interhemispheric fissure up to its superior end point and mask everything within these boundaries. End masking when the parieto-occipital fissure is no longer visible. (Fig. 4, Fig. 5, Fig. 6)