Polo mint sign (venous thrombosis)

The polo mint sign is a description given to a venous thrombosis on contrast-enhanced CT imaging.  When viewed in the axial plane, a thin rim of contrast persists around a central filling defect due to thrombus. This gives an appearance like that of the popular UK mint sweet, the Polo (figure 1), also referred to as the advertising slogan 'The Mint with a Hole'.

It was originally described to refer to the appearances of a pulmonary embolus on CT pulmonary angiography, but the appearances are the same for any venous thrombosis, such as in the portal vein .