Fig. 1

Urothelial (portal) and excretory (delayed) phase scans of CT urography in two patients of urothelial carcinoma. a Axial urothelial phase CT image of a 63-year-old man obtained at 70 s after bolus intravenous contrast material injection shows a small hyper-enhancing polypoid mass (arrow) that enhances more than normal bladder mucosa. b Axial excretory phase CT image shows the enhancing bladder lesion (arrow) but is less pronounced compared to the urothelial phase. c The nodule was also identified using conventional cystoscopy. d Axial urothelial phase CT image of a 74-year-old man shows an intraluminal hyper-enhancing mass (arrow) on the left wall of the bladder. e Axial excretory phase CT reveals the mass as a filling defect (arrow) within the bladder lumen. f The nodule was also detected using conventional cystoscopy