pyelorenal backflow

例句：

1. 1.The patient's urine output was significantly reduced due to the renal backflow.
   由于肾盂反流，患者的尿量显著减少。
2. 2.The diagnosis of pyelonephritis often requires a renal biopsy.
   肾盂肾炎的诊断通常需要肾活检。
3. 3.The treatment for pyelonephritis involves antibiotics and possibly surgery.
   治疗肾盂肾炎包括抗生素和可能的手术。