Fig. 1

Brain magnetic resonance imaging (MRI) in Shih Tzu dogs with lissencephaly. Transverse T1-weighted (a, e), T2-weighted (b, f), fluid-attenuated inversion recovery (FLAIR) (c), dorsal hybrid contrast enhancement (3D HYCE) (g) and mid-sagittal T1-weighted (d, h) imaging of the first and second cases. MRI of the first dog showed broad folds with simplified patterns and shallow grooves (pachygyria) in the frontal and parietal lobe region (arrow). Absence of the marginal gyri, middle ectomarginal gyri and caudal suprasylvian gyri was observed in these regions (arrowhead) (a, b). Ventriculomegaly and enlargement of the sole quadrigeminal cistern (type SFA-QC) was apparent (c, d). MRI of the second dog showed diffuse agyria (arrows) at the level of the interthalamic adhesion (e, f). Rudimentary lateral rhinal sulci were present (arrowhead), and cingulate gyri were not apparent. The internal capsule was abnormally small (e, f). Smooth cortical appearance was observed with a lack of the marginal gyri, middle ectomarginal gyri and middle suprasylvian gyri. Dorsocaudal outpocketing of the third ventricle (type SFA-III) and internal hydrocephalus were visualized (g, h)