Dialated fluid filled separated within the bilateral kidneys--hydronephrosis?

I am a 45 yo female.  I had a renal artery scan to rule out kidney problems to be the cause of high bp.  Test came out fine:

Normal renal artery scan-bilaterally
No evidence of renal artery stenosis
Normal resistive index-bilaterally
Normal kidney dimensions-bilaterally
Normal abdominal aorta dimensions--no evidence of aneurysm

The note on the bottom indicated that there were dilated fluid filled separated areas within the bilateral kidneys.  Characteristics resemble hydronephrosis.  Correlative study is recommended if further evaluation is required.  

Dr. is sending me to urologist.  What does all this mean?  Could there be fluid filled areas in both kidneys and not have hydronephrosis?  Truth is, I have no symptoms of hydronephrosis (fever, chills,etc.)  and had I not had the ultrasound, I would not have this information.  How concerned should I be?

[Paderla Anitha, DNB]

Hello and hope you are doing well.

It could be Hydronephrotic changes, which is consequent to an obstruction in the ureter. The obstruction can be a stone, tumor or scar tissue. With this you may sometimes experience pain which is spasmodic in nature as the ureter is trying to push through the obstruction. The cause needs to be treated for the hydrnephrosis to resolve. The causes for the fluid filled spaces could be cysts in the kidney. For further correlation you may need blood tests, urine analysis, an x ray and an ultra sonogram of the abdomen. Sometimes he may ask for an Intravenous pyelogram and a CT scan. Please discuss this with your doctor am sure he will provide further assistance.

Hope this helped and do keep us posted.