Postrenal Acute Kidney Injury After Forced Diuresis During 68Ga-PSMA PET/CT

For active surveillance assessment, 68 Ga-PSMA PET/CT was performed in a 73-year-old man with Gleason 3+3 prostate adenocarcinoma. PET/CT showed a markedly enlarged prostate indenting the bladder base, with focal midline activity suggestive of prostatic urethral urinary retention. Intravenous furosemide was administered before 120-minute delayed imaging, which showed complete resolution of the activity and excluded pathologic uptake. After discharge, he developed urinary urgency and incomplete emptying, progressing to lower abdominal and pelvic pain with elevated creatinine. Postrenal acute kidney injury from acute urinary retention was diagnosed. Catheterization and inpatient monitoring normalized renal function, highlighting an underrecognized risk of forced diuresis.