banana sign

banana sign

the abnormal curvature of the cerebellum noted on ultrasound imaging in a fetus with Arnold-Chiari malformation.
An ultrasonographic finding seen when a major neural tube defect accompanies Arnold-Chiari malformation, spina bifida and other neural tube defects
Appearance Cerebellar tonsils and midbrain structures herniate into the foramen magnum, causing ventriculomegaly 2º to compression of the outflow from the 3rd and 4th ventricles; the ‘banana’ corresponds to the compressed cerebral hemisphere

banana sign

Imaging An ultrasonographic finding seen when a major neural tube defect accompanies Arnold-Chiari malformation Appearance Cerebellar tonsils and midbrain structures herniate into the foramen magnum, causing ventriculomegaly 2º to compression of the outflow from the 3rd and 4th ventricles; the 'banana' corresponds to the compressed cerebral hemisphere.

ba·na·na sign

(bă-nan'ă sīn) The abnormal curvature of the cerebellum noted on ultrasound imaging in a fetus with Arnold-Chiari malformation