My brother is suffering from severe abdominal pain. The CT scan reports says below: A calculas of size 6.1×5.6×5.6mm is noted in right proximal ureter (approx 30 mm distal to PU junction ) .mild hydronephrosis and proximal hydroureter upstream to calculas is noted.(AP diameter of renal pelvis is 13mm) Please suggest if operation is necessary and what is the size of stone. I did not understand what the report says. Thanks in advance for help