Busaman
It seems the doc may be concerned about cancer in the Upper Tract - the ureters, renal pelvis and kidneys. In a hospital or outpatient center, the suggested tests would likely be a retro or Reverse Pyelogram (as suggested) -squirting dye up the ureters and taking radiographs, OR a ureteroscopy - like a cystoscopy, but continuing through the bladder, up each ureter to the renal pelvis, looking and taking samples. Google "Ureteroscopy" and also "Upper urinary tract cancer".
Best,
Jack