Zebra spleen, also referred to as psychedelic spleen or more correctly inhomogeneous splenic enhancement refers to the transient heterogeneous parenchymal enhancement of the spleen during the arterial or early portal venous phases of contrast enhancement in CT, MRI, or ultrasound imaging.
It is due to the differing blood flow rates of blood (and contrast) between red pulp (which enhances early) and white pulp (which enhances later). Almost always, a portal venous or delayed phase study will show homogeneous attenuation throughout the spleen (in the absence of pathology).
There are 3 general patterns of enhancement 2:
- archiform: alternating bands of low and high density which may look like rings or zebra stripes
- focal: single area of low density
- diffuse: mottled appearance
Heterogeneity of splenic parenchyma manifested as alternating hypoechoic stripes can also be seen in non-contrast ultrasound examination of spleen with high-frequency linear transducer in children with no underlying splenic abnormalities; this has been assumed to be due to the difference in splenic parenchymal structures 2.
Inhomogeneous splenic enhancement can mimic:
- perisplenic or subcapsular haematoma
- active haemorrhage
- splenic infarct
- normal appearance of the spleen
- pseudolesion of the spleen: inhomogeneous splenic enhancement
splenic lesions and anomalies
- congenital anomalies
- mass lesions
- infiltrative processes
- incidental splenic lesion (approach)
- 1. Kuint RC, Daneman A, Navarro OM et-al. Sonographic Bands of Hypoechogenicity in the Spleen in Children: Zebra Spleen. AJR Am J Roentgenol. 2016; 1-5. doi:10.2214/AJR.16.16401 - Pubmed citation
- 2. Donnelly LF, Foss JN, Frush DP et-al. Heterogeneous splenic enhancement patterns on spiral CT images in children: minimizing misinterpretation. Radiology. 1999;210 (2): 493-7. doi:10.1148/radiology.210.2.r99fe16493 - Pubmed citation
- 3. Cesta MF. Normal structure, function, and histology of the spleen. Toxicologic pathology. 34 (5): 455-65. doi:10.1080/01926230600867743 - Pubmed