腎盂 is read as じんう (jinu) and means renal pelvis.
じんう
jinu
じんうえん
pyelitis
じんうじんえん
pyelonephritis
きゅうせいじんうじんえん
acute pyelonephritis
じんぞう
kidney
じんふぜん
kidney failure
じんえん
nephritis