Thursday, March 10, 2011

Banana sign


On ultrasound scan performed prior to birth, the fetal cerebellum may appear compressed and curved like a banana. This banana sign may indicate the presence of spina bifida where the neural tube, the precursor of the central nervous system (brain & spinal cord), has failed to close, usually in the lower back region.
In the common form of spina bifida – myelomeningocele – patients may have bladder and bowel dysfunction, loss of sensation below the level of the lesion as well as an excess of cerebrospinal fluid in the brain’s ventricles (hydrocephalus).
Reference:
Benacerraf BR, Stryker J, Frigoletto FD: Abnormal US Appearance of the Cerebellum (Banana Sign): Indirect Sign of Spina Bifida. Radiology 1989, 171(1):151-3. Go to reference

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