Figure 2.

Showing initial gate placement. (A) Anterior SEED gate placement: the most superior point of the anterior commissure is found on a First eigenvector fractional anisotropy (FEFA) axial DWI slice. The anterior boundary of the SEED gate is placed just anterior to the commissure and the gate is extended broadly posteriorly past the columns of the fornix. The anterior commissure is labeled. (B) Posterior SEED gate placement: In an axial T1 image, the slice above the most superior visible part of the pineal gland is chosen. The anterior boundary of the SEED gate is placed approximately at the mid thalamus and extended to where the mid pineal is found on the slice below. The gate should extend laterally to cover the approximate stalks of the pineal gland. Note that the pineal is visible in this image, as this is taken to show the pineal for localization purposes. The pineal is labeled. (C) Mid AND gate placement: the mid-point of the thalamus (using the inter-thalamic adhesion if present) is found on a coronal T1 image slice. The superior boundary of the AND gate is placed above the thalamus at the lower level of the fornix and extended to the lower thalamus, making sure to encompass the inter-thalamic adhesion if present. The gate should be wide enough to cover most of the “curve” of the thalamus. The inter-thalamic adhesion is labeled. (D) Sagittal and (E) axial-sagittal views of the initial SEED and AND gates. The anatomical fixed points for gate placement: anterior commissure, inter-thalamic adhesion and pineal gland are labeled.