Fig. 3
A 64-year-old female patient presenting with gross hematuria and neoplastic cells at urine cytology. a, g T2WI (axial and sagittal plane) shows an endophytic lesion (13 × 20 mm) of the right pyelo-ureteral junction (white arrow), which determines stenosis of the lumen, third-grade hydronephrosis on the same side and adjacent “fat stranding” appearance. b, c DWI (b = 1,000 s/mm2) and ADC map show a lesion with a significant restriction of diffusion (white arrowhead). d, e, f Dynamic sequences after gadolinium-based contrast injection (corticomedullary, nephrographic, and excretory phase) show an early lesion enhancement, extending through the muscularis layer (white arrowhead). All these MRI findings are suspicious of muscle invasion. At final pathology, the lesion proved to be muscle-invasive. ADC, Apparent diffusion coefficient; DWI, Diffusion-weighted imaging; T2WI, T2-weighted imaging