Fig. 1

Magnetic resonance imaging (MRI) of a heifer with holoprosencephaly and corpus callosum hypoplasia. T1weighted (T1w) images in midsagittal (A, a) and transversal (B, b-G, g) planes on the level of the frontal lobe (B, b), the genu of corpus callosum (C, c), of the pallidal globe rostral (D, d) and caudal (E, e), of interthalamic adhesion (F, f) and on the level of the geniculate bodies (G, g). A-G: MRI of a normal brain of a age matched Holstein Friesian (1.5 months old, male). The animal showed no symptoms of a forebrain lesion and underwent routine in vivo diagnostic imaging due to a disease unrelated to encephalopathy. a-g: MRI of a heifer with holoprosencephaly and corpus callosum hypoplasia. Note the incomplete separation of both cerebral hemispheres at the frontal lobe (b”#”), the generalized abnormal gyrification of the cerebral cortex including the cingulate gyrus (normal: F “cg”; absent in f), absent septum pellucidum and (“*” in D, absent in d) and corpus callosum (“cc”) with decreased thickness and altered shape. The hippocampal tail (G and g “h”) seemed deviated dorsally into the sulcus corporis callosi. Additionally cerebral cortex heterotopia is suspected (“§” in a). Both lateral and the third ventricle were enlarged without any signs of elevated intracranial pressure (a, c-g)