Sandwich sign (Marchiafava-Bignami disease)
The sandwich sign of Marchiafava-Bignami disease has been described for the appearance of the central layers of the corpus callosum which are preferentially involved by this disease.
T2 and FLAIR hyperintensities are seen in the central region of body and splenium of corpus callosum with sparing of peripheral dorsal and ventral layers of the corpus callosum.