I Had An Ultrasound Of Kidneys And Bladder. The Right

I had an ultrasound of kidneys and bladder. The right kidneys is normal. No evidence of hydronephrosis, masses or cysts. The right kidney show also shows normal cortical thickness and echogeniity with no evidence of hydronephrosis, masses or cysts. There is however, a mild caliectasis in the lower pole of the left Kidney, with moderate amount of postvoid residue. I have had chronic UTI's for years treated with antibiotics. The visualized portions of teh urinary bladder appears normal. My question is: Because the ultrasound showed no evidence of masses or cysts, does that rule out cancer? I have appointments for upcoming C-Scan and cystoscopy next week. Should I be concerned?