肾盂积水
Hydronephrosis \Hy`dro*ne*phro"sis\, n. [NL., Gr. "y`dwr water + ? a kidney.] (Med.) An accumulation of urine in the pelvis of the kidney, occasioned by obstruction in the urinary passages.
hydronephrosis n : accumulation of urine in the kidney because of an obstruction in the ureter