Polka dot appearance on CT scan is seen in which of the following?
Ewing's sarcoma
Osteosarcoma
Vertebral hemangioma
Eosinophilic granuloma
Ans. is 'c' i.e., Vertebral hemangioma Characteristic radiological features of few bone tumorso Celery-stick appearanceEnchondromaso Coat-hanger appearanceOsteochondromao Codman tumor and chicken-wire calcificationChondroblastomao Double density sign on radionuclide scanOsteoid osteomao Nidus and sclerotic rimOstoid osteomao "Driven snow" appearancePindborg tumoro Fallen fragment/'Hinged fragment signSimple (unicameral) bone cysto "Eggshell" covering of expansile cortex over surface of lesionABCo ' Soap bubble' appearanceABCo Soap bubble appearance (& goes into comers)GCT (Osteoclastoma)o 'Floating tooth' signEosinophilic granuloma, adamantinomao Onion skin (onion peel) appearanceEwing sarcomao Skip lesionsOsteosarcoma, Ewings sarcomao 'Sunrav/Sunburst' appearanceOsteosarcomao String sign (to differentiate from myositis ossificans)Parosteal osteosarcomao Popcom/mottled calcificationChondrosarcomao Shepherd's crook deformityFibrous dysplasiao Codman's triangleOsteosarcoma, Ewing sarcomao Winking owl signMetastasis to pedicles of vertebrao Corduroy/accordian vertebra'vertical striationsVertebra] hemangiomao Polka dot sign on CTVertebral hemangiomao Geographical skullEosinophilic granulomao Hole-within-a-hole lesionEosinophilic granuloma
Imaging of Musculoskeletal Tumors