We classified urographic filling defects into four patterns: ovoid, polypoid, infiltrating, and plaque-like.
Yi-Lun Lee 2003, 'Correlation Between Filling Defect Patterns on Urography and Pathologic Staging ofUreteral Transitional Cell Carcinomas', Kaohsiung Journal of Medical Scienceshttp://www.sciencedirect.com/science/article/pii/S1607551X09704899. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)