CT SCANCT SCAN::

EMPHYSEMATOUS EMPHYSEMATOUS PYELONEPHRITISPYELONEPHRITIS

Dr Jishanth MDr Jishanth M

Prof. Dr E Dhandapani’s unitProf. Dr E Dhandapani’s unit

Left kidney 11*7*6.3 cm with altered densityLeft kidney 11*7*6.3 cm with altered density Right kidney 9*7*4.7 cmRight kidney 9*7*4.7 cm Left perinephric stranding and air pockets notedLeft perinephric stranding and air pockets noted Intrarenal air pockets seenIntrarenal air pockets seen Fat stranding noted adjacent to left psoasFat stranding noted adjacent to left psoas Intra renal fluid collection in left kidneyIntra renal fluid collection in left kidney Features S/o Features S/o

Emphysematous left pyelonephritis, Emphysematous left pyelonephritis, type Itype I

EPN is usually a EPN is usually a rapidly progressive and life-threatening rapidly progressive and life-threatening infection that is seen most commonly in persons with infection that is seen most commonly in persons with diabetes.diabetes.

The infecting organisms usually consist of mixed flora, The infecting organisms usually consist of mixed flora, including including Escherichia coliEscherichia coli (68%), (68%), Klebsiella pneumoniaeKlebsiella pneumoniae (9%), and (9%), and Proteus mirabilis.Proteus mirabilis.

Other organisms Other organisms Pseudomonas; Enterobacter; Candida;Pseudomonas; Enterobacter; Candida; rarely,rarely,ClostridiaClostridia. .

Females are affected twice as often as males, and mortality Females are affected twice as often as males, and mortality rates can be as high as rates can be as high as 80%80%. .

Obstructive uropathy, urinary calculi, calyceal stenosis, Obstructive uropathy, urinary calculi, calyceal stenosis, and neoplasms are significant predisposing factors.and neoplasms are significant predisposing factors.

Often multiple conditions are associated with EPN, such Often multiple conditions are associated with EPN, such as poorly controlled as poorly controlled diabetes, acidosis, dehydration, diabetes, acidosis, dehydration, and electrolyte imbalanceand electrolyte imbalance..

Treatment involves aggressive Treatment involves aggressive antibioticantibiotic therapy, therapy, drainage drainage procedures to relieve obstruction, and prompt procedures to relieve obstruction, and prompt nephrectomy nephrectomy in life-threatening situationsin life-threatening situations

Two subtypes of EPN based on CT appearances have Two subtypes of EPN based on CT appearances have been described. been described.

Type I EPN Type I EPN (33% of patients) is characterized by (33% of patients) is characterized by parenchymal destruction with either absence of fluid parenchymal destruction with either absence of fluid collection or presence of streaky or mottled gas collection or presence of streaky or mottled gas radiating from the medulla to the cortex. A crescent radiating from the medulla to the cortex. A crescent of subcapsular or perinephric gas may be present. of subcapsular or perinephric gas may be present. The absence of fluid collection implies a poor The absence of fluid collection implies a poor immune response. The mortality rate is high, at 66%. immune response. The mortality rate is high, at 66%.

Type II EPN Type II EPN (66% of patients) typically has a confined, (66% of patients) typically has a confined, bubbly, intrarenal gas pattern — probably within bubbly, intrarenal gas pattern — probably within abscesses associated with renal and perinephric fluid abscesses associated with renal and perinephric fluid collection — and gas within the renal pelvis. The collection — and gas within the renal pelvis. The mortality rate in type II is 18%.mortality rate in type II is 18%.

Retroperitoneal perforation of an abdominal viscusRetroperitoneal perforation of an abdominal viscus Psoas abscess secondary to gas-forming Psoas abscess secondary to gas-forming

organismsorganisms Reflux of air from the bladderReflux of air from the bladder Bronchorenal, enterorenal, or cutaneorenal fistulae Bronchorenal, enterorenal, or cutaneorenal fistulae

(as may (as may occur with xanthogranulomatous occur with xanthogranulomatous pyelonephritis)pyelonephritis)

Air in a focal renal abscess (not life threatening)Air in a focal renal abscess (not life threatening)

TT HH AA NN KK

YY OO UU