Figure 2.

Cranial magnetic resonance imaging (MRI) of the olfactory bulb region in a control man (a and b) and a man affected by Kallmann syndrome (c and d). (a and b) MRI T2-weighted sequence in coronal plane shows normal olfactory bulbs in the control individual (a, white arrows), and posterior to the olfactory bulbs, good differentiation of the rhinal sulci (b, white arrows) and olfactory tracts (b, white arrowheads). (c) MRI T2-weighted sequence in coronal plane shows very small olfactory bulbs in the KS patient (white arrows). On the right side, the rhinal sulcus (white arrowhead) is visible, with good differentiation between the right gyrus and orbital gyrus. On the left side, there is no rhinal sulcus (black arrowhead), and no differentiation between the right and orbital gyri. (d) MRI T1-weighted sequence in coronal plane, posterior to olfactory bulbs, confirms the presence of the rhinal sulcus on the right side (white arrow), with a relatively good differentiation between the right (white arrowhead) and orbital (black arrowhead) gyri, and the absence of the rhinal sulcus on the left side (black arrow).