I have on kidney ( congenitally ).  Missing on the right. My ultra sound showed a moderate dilation of the left renal collecting system. A distal obstruction may be present.  I also have left renal cortical thinning which may indicate vascular insufficiency.    My doctor is now ordering a CT scan of my kidney. I am trying to determine what questions i should be asking and the severity of the above findings
HelloThanks for writing to ChatDoctorMost likely left cortical thinning is due to dilated collecting system. Dilatation causes back pressure to kidney thus it causes thinning of cortex. There must be distal obstruction which is causing dilatation. It may be in the form of calculus, stricture etc. Cause of dilatation can be found out by C. T Scan. Functional status is more important in your case as you have one kidney. It can be determined by I.V.U or CT scan. You should ask about functional status and cause of dilatation and its treatment. Get well soon. Take Care Chat Doctor.