CBC with high WBC, low platelets
Urinalysis with urine culture
Creatinine
Blood culture
CT is definitive
Staging:
Class 1 - gas confined to collecting system
Class 2 - gas confined to renal parenchyma alone
Class 3A - perinephric extension of gas or abscess
Class 3B - extension of gas beyond Gerota fascia
Class 4 - bilateral or<unk>  in solitary kidney
Class 1 - gas confined to collecting system
Class 2 - gas confined to renal parenchyma alone
Class 3A - perinephric extension of gas or abscess
Class 3B - extension of gas beyond Gerota fascia
Class 4 - bilateral or<unk>  in solitary kidney
Emphysematous pyelonephritis
Genitourinary infection
Pyelonephritis
Acute cystitis 
Renal abscess
Acute cystitis
Urethritis
Glomerulonephritis