The wheel within a wheel sign describes one of several possible ultrasound findings of hepatic candidiasis. The finding consists of a round lesion with three layers corresponding to the following histopathological changes 2:
- peripheral hypoechoic area (fibrosis)
- middle hyperechoic area (inflammatory cells)
- central hypoechoic area (necrosis)
The histopathologic correlates were shown via an animal model.
This appearance is in contrast to the more common bull’s-eye sign ultrasound finding, which consists of a central echogenic nidus surrounded by a hypoechoic rim.
- 1. Lawrence PH, Holt SC, Levi CS, Gough JC. Ultrasound case of the day. Hepatosplenic candidiasis. (1994) Radiographics : a review publication of the Radiological Society of North America, Inc. 14 (5): 1147-9. doi:10.1148/radiographics.14.5.7991822 - Pubmed
- 2. Pastakia B, Shawker TH, Thaler M, O'leary T, Pizzo PA. Hepatosplenic candidiasis: wheels within wheels. (1988) Radiology. 166 (2): 417-21. doi:10.1148/radiology.166.2.3275982 - Pubmed