Playboy Bunny Sign

The Playboy bunny sign is one of the few classic radiologic signs in use that did not appear originally in the medical literature. Perhaps more appropriately, it was initially described in a letter to the editor of Playboy magazine’. Anatomically, as seen during an ultrasound examination of the liver, it represents the confluence of the hepatic veins with the inferior vena cava: the head of the bunny being the inferior vena cava and the ears the hepatic veins ² (Figure 1). The original patient reportedly had mild congestive heart failure that made the veins more prominent than usual (Joseph Dils, personal communication). This sign is used to recognize the intersection of these important vascular structures. One can then more precisely localize any abnormality detected in the liver. Precise localization of primary and metastatic liver lesions is very important in this age of aggressive treatment with intra-arterial chemotherapy and subtotal surgical resection. Figure 1 ‘Ultrasound study of a human liver.’ Reprinted from Dils<xref ref-type="bibr" rid="ref65_1"> ¹ </xref>. Rabbit test. <italic>Playboy,</italic> 1979, with permission of Playboy Enterprises Inc. (PEI) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003076568/34c29fd5-5662-4e8f-b58c-badd7fa5d724/content/fig65_1_B.jpg"/>