Image 1: Corpus callosum, agenesis. Sagittal T1-weighted MRI of the brain shows the normal appearance of the corpus callosum.


Image2 :Corpus callosum, agenesis. Sagittal T1-weighted MRI of the brain shows complete absence of the corpus callosum. The cingulate sulcus is absent, and the medial hemispheric sulci reach the third ventricle in a radial fashion.

Corpus callosum, agenesis. Sagittal T1-weighted MRI of the brain shows partial agenesis of the corpus callosum. The genu and anterior body of the corpus callosum are visualized, whereas the posterior body, splenium, and rostrum are absent.

Corpus callosum, agenesis. Axial nonenhanced CT of the brain shows colpocephaly, caused by dilation of the atria, and occipital horns of the lateral ventricle. Note the parallel configuration of the lateral ventricles. Interdigitation of gyri from fenestration of the falx may be noted incidentally. Corpus callosum, agenesis. Axial T1-weighted MRI shows that the lateral ventricles are parallel to each other and do not come into contact with each other as they normally should.

Corpus callosum, agenesis. Coronal T1-weighted MRI of the brain shows absence of the normal corpus callosum. The lateral ventricles form a bull's-horn appearance and are indented medially by the Probst bundle (arrows).


Corpus callosum, agenesis. Sagittal T1-weighted MRI of the brain. Parasagittal section through the lateral ventricle shows dilatation of the atrium and occipital horn (colpocephaly).

Corpus callosum, agenesis. Sagittal T1-weighted MRI of the brain shows apparent atypical callosal dysgenesis in lobar holoprosencephaly. The body and splenium of the corpus callosum are well formed, whereas the genu and rostrum are hypoplastic.

Corpus callosum, agenesis. Axial T2-weighted MRI of the brain shows apparent atypical callosal dysgenesis in lobar holoprosencephaly (same patient as in the previous image). There is fusion across the midline of the inferior basal ganglia (arrow) and the medial cortex of the frontal lobes across the interhemispheric fissure (arrowhead).

http://emedicine.medscape.com/article/407730-overview