Annular Lesion

In veterinary imaging and pathology, an annular lesion refers to a ring-shaped abnormality, often characterized by a central area with a surrounding rim of different echogenicity or density. On ultrasound, it may appear as a hypoechoic or anechoic center with a hyperechoic or thickened peripheral border. Annular lesions can be associated with conditions such as abscesses, granulomas, neoplasms, or inflammatory processes.