Emphysematous pyelonephritis: Six case reports and review of literature

Table 2 Emphysematous pyelonephritis classification systems

Classification	Radiological basis	Class
Wan et al[25]	CT	I: Renal necrosis with presence of gas but no fluid; II: Parenchymal gas associated with fluid in renal parenchyma, perinephric space or collecting system
Huang and Tseng[24]	CT	1: Gas in collecting system only; 2: Gas in the renal parenchyma without extension to extrarenal space; 3A: Extension of gas or abscess to perinephric space; 3B: Extension of gas or abscess to pararenal space; 4: Bilateral EPN or solitary kidney with EPN

CT: Computed tomography; EPN: Emphysematous pyelonephritis.