Middle Temporal Gryus Protocol

  1. For the MTG, it is necessary to have a 3D object model in order to reference the upper and lower boundaries. The upper boundary of the MTG is the superior temporal sulcus and the lower boundary is the inferior temporal sulcus. In order to easily identify the inferior temporal sulcus, keep in mind that the inferior temporal sulcus is somewhat parallel to the superior temporal sulcus. Sometimes the inferior temporal sulcus is interrupted by gyri, but because the middle temporal gyrus has a consistent width. If this is the case cut across the gyri in order to maintain a consistent width of the MTG. It is also helpful to note that the MTG in the right hemisphere is slightly more at an inclined slope, making the MTG in both hemispheres is slightly asymmetrical. (Fig. 1)
  2. The middle temporal gyrus is masked in the coronal view. Start anteriorly where the superior temporal sulcus and the inferior temporal sulcus are clear. Trace the superior temporal sulcus to its internal endpoint and draw a straight line to the internal endpoint of the inferior temporal sulcus. Fill in everything within these sulci. (Fig. 2)
  3. Moving anteriorly the temporal stem disappears. Continue to follow the previous step until then upper and lower boundaries of the MTG are no longer distinguishable, using the 3D object as a reference. Keep in mind that the anterior end of the temporal lobe ends with the superior temporal gyrus, middle temporal gyrus and inferior temporal gyrus merging together. (Fig. 3, Fig. 4, Fig. 5)
  4. To identify the posterior end of the MTG, go to the first slice masked. Continue the previous step until the superior temporal sulcus and the inferior temporal sulcus are no longer distinguishable. The posterior end of the MTG should coincide with the anterior end of the occipital lobe. (Fig. 6, Fig. 7, Fig. 8)