title: [Radio-transparent renal calculi and epithelial tumours. Contribution of ultrasound and CT scan to the diagnosis (author's transl)].
abstract: The aetiological diagnosis of lacunae detected by urography is uncertain in 10 to 20% of cases. Uric acid calculi larger than 2 cm in diameter can be demonstrated by ultrasonography, where they show as echogenic areas with conical shadows. Computerized tomography has wider possibilities: uric acid calculi are extremely dense and clearly visible, clots are not enhanced by contrast media, and the enhancement of epithelial tumours is of the avascular type.
mesh_terms: D002277:Carcinoma / Q000175:diagnosis*; D003937:Diagnosis, Differential; D006801:Humans; D007669:Kidney Calculi / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography; D014527:Uric Acid / Q000378:metabolism; D014571:Urologic Neoplasms / Q000175:diagnosis*
chemical_list: D014527:Uric Acid
vernacular_title: Calculs rénaux radio-transparents et tumeurs urothéliales. Apports diagnostiques de l'échotomographie et de la tomodensitométrie.