As per your case history, you are diagnosed with 9mm calcification on left kidney.
I would recommend you to undergo CT scan
for same mass. It is just radio-imaging to diagnose certain conditions which can not be make out clearly on X-ray / USG.
Those radiatons will not harm you.
But Some renal mass present on kidney means it can be renal cyst
/ renal tumor-either malignant or benign .
Usually, kidney cancer
is discovered incidentally when some type of radio-graphic evaluation such as a sonogram, CT scan or MRI
has been performed.
Early detection of condition is as good as early treatment.
So go ahead and get CT Scan done.