Sonographic Bands of Hypoechogenicity in the Spleen in Children: Zebra Spleen.
OBJECTIVE
Zebra spleen is the normal pattern of splenic enhancement during the arterial phase of CT and MRI and is attributed to different flow rates. The purpose of this study was to describe the appearance and occurrence of bands of hypoechogenicity in the spleen on unenhanced sonograms of children with no splenic abnormalities.


METHODS
We reviewed 100 abdominal ultrasound studies to evaluate the ultrasound characteristics of the spleen. Demographic data were collected for all patients.


RESULTS
Homogeneous echogenicity of the spleen was found in 92 children. Heterogeneous echogenicity was present in eight. Three of the eight had discrete macronodules due to known splenic disease. The other five had bands of hypoechogenicity. These five had no known splenic disease, but one had mild splenomegaly of unknown cause.


CONCLUSIONS
The pattern of hypoechoic bands occurred in 5% of our series. This pattern cannot be explained simply by different flow rates and probably reflects different structural components of the parenchyma. At ultrasound this pattern should be considered a normal finding that may simulate a splenic mass.
1 Department of Medical Imaging, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada.|2 Present address: Shaare Zedek Medical Center, 12 Shmuel Bait St, Jerusalem, Israel 9103102.
Ruth Cytter
RC
Kuint
1 Department of Medical Imaging, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada.
Alan
A
Daneman
1 Department of Medical Imaging, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada.
Oscar M
OM
Navarro
1 Department of Medical Imaging, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada.|3 Present address: Department of Radiology, Birmingham Children's Hospital, Birmingham, United Kingdom.
Adam
A
Oates
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012189:Retrospective Studies; D013154:Spleen / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*
D003287:Contrast Media
echogenicity; normal anatomy; pediatrics; sonography; spleen