Renal Infections

acute pyelonephritis is an

inflammation of the kidney or kidneys

bacteria can spread to the kidney through the

bloodstream or, more commonly, from the lower urinary tract

bacteria spreading through the bloodstream or the lower urinary tract is referred to as an

ascending infection

with an ascending infection, the infection begins in the

bladder and refluxes up through the ureters and into the kidney

acute pyelonephritits is most commonly encountered in —and is treated with antibiotics

women

complications of acute pyelonephritis include the development of

a renal abscess, pyonephrosis, xanthogranulomatous pyelonephritis, emphysematous pyelonephritis, and chronic pyelonephritis

Acute pyelonephritis. Acute renal infection with interstitial hemorrhage produces hyperechoic focal swelling in the upper pole of this kidney (arrows).

clinical findings of Acute pyelonephritis

1. flank pain

2. bacteriuria

3. pyuria

4. leukocytosis

5. dysuria

6. urinary frequency

sonographic findings of Acute pyelonephritis

1. may appear normal

2. renal enlargement

3. focal areas of altered echotexture

4. compression of the renal sinus

yonephrosis describes the condition of —, also referred to as purulent material, within the collecting system of the kidney

having pus

the accumulation of pus is most likely caused by some —, as seen in many cases of pyelonephritis

obstructive process or infection that leads to urinary stasis

clinical findings of pyonephrosis

1. pyuria

2. bacteriuria

3. fever

4. flank pain

5. leukocytosis

Pyonephrosis. Pus (arrows) is noted within the dilated calices (c) and renal pelvis (P) in this kidney (between calipers).

sonographic findings of pyonephrosis

1. hydronephrosis

2. pus and debris appear as internal layering and low-level echoes within teh dilated collecting system

chronic pyelonephritis is the

recurrent kidney infections or chronic obstruction may lead to scarring of the calices and renal pelvis

chronic pyelonephritis can lead to

xanthogranulomatous pyelonephritis and end-stage renal disease

children with a history of — are at increased risk for developing chronic pyelonephritis

vesicoureteral reflux (VUR)

A scar will appear as an

echogenic area that extends from the renal sinus through the renal parenchyma

Chronic pyelonephritis. Longitudinal image of a 10-year-old boy showing a small echogenic left kidney with a dilated calyx (C) and overlying parenchymal atrophy (arrows).

clinical findingd of chronic pyelonephritis

1. flank pain

2. bacteriuria

3. pyuria

4. leukocytosis

5. dysuria

6. urinary frequency

7. history of VUR

sonographic findings of chronic pyelonephritis

1. small echogenic kidneys that have lobulated borders

2. renal scar appears as an echogenic area within the kidney that extends from the renal sinus through the renal parenchyma

a renal abscess can occur in regions of the kidney

affected by pyelonephritis or be located adjacent to the kidney

a perinephric abscess is a collection of

purulent material that has leaked through the capsule into the tissue surrounding the kidney

gas development within the abscess produces

dirty shadowing or reverberation artifact

clinical findings of a renal or parinephric abscess

1. flank pain

2. high fever

3. symptoms of pyelonephritis (pyuria, hematuria, and flank pain)

4. leukocytosis

sonographic findingd of a renal or perinephric abscess

1. can appear anechoic, hypoechoic, or complex

2. gas shadows or dirty shadowing may be present within the mass

emphysematous pyelonephritis is a

rare, and yet life-threatening, complication of pyelonephritis

although emphysematous pyelonephritis may be the result of a long-standing urinary tract obstruction, it is found more often in patients who have

diabetes mellitus or who are immunocompromised

the term emphysematous denotes the

formation of air within an organ

with emphysematous pyelonephritis, bacterial formation allows gas to accumulate within the

renal parenchyma

— is the most common culprit of emphysematous pyelonephritis

escherichia coli infection

clinical findingd of emphysematous pyelonephritis

1. flank pain

2. diabetes mellitus

3. immunocompromised patient

4. fever

5. leukocytosis

sonographic findings of emphysematous pyelonephritis

1. gas or air within the renal parenchyma

2. dirty shadowing or reverberation artifact coming from the renal parenchyma

xanthogranulomatous pyelonephritis is uncommon and is typically caused by a

chronic urinary tract obstruction and subsequent infection

the word part “xantho” means

yellow

with xanthogranulomatous pyelonephritis, — are often present

a staghorn calculus, hydronephrosis, and perinephric fluid

clinical findings of Xanthogranulomatous pyelonephritis

1. dull or persistent flank pain

2. pyuria

3. hematuria

4. fever

5. leukocytosis

sonographic findings of Xanthogranulomatous pyelonephritis

1. hydronephrosis

2. staghorn calculus

3. perinepheric fluid collection

the most common cause of fungal urinary tract infections is

Candida albicans

— are at increased risk for developing a fungal infection within their kidney

immunocompromised patients

patients with a history of — are more likely to suffer from renal fungal disease

diabetes mellitus, intravenous drug abuse, and infants who have longstanding, indwelling catheters

when — are noted within the collecting system, the diagnosis of a renal fungal disease can be made

fungal balls

clinical findingd of renal fungal disease

1. immunocompromised person

2. diabetes mellitus, IV drug abuse or long-standing indwelling catheter

3. infant with an indwelling catheter

4. flank pain

5. fever

6. chills

Fungus ball. Transverse image of the kidney in a 2-month-old infant with Candida albicans showing a dilated renal pelvis (p) and calices (c) that contain echogenic urine and a mobile fungal ball (arrow).

sonographic findingd of renal fungal disease

1. fungal balls appear as hyperechoic, nonshadowing, mobile structures within the renal collecting system

glomerulonephritis can be caused by a

distant infection, such as strep throat, or an autoimmune reaction

some conditions, such as —, have glomerulonephritis as a characteristic feature

lupus

glomerulonephritis can lead to

significant glomerular damage, and the kidneys can slowly shut down secondary to diminished filtration capabilities

glomerulonephritis can be

acute or chronic

in the acute stage of glomerulonephritis, the kidney may appear

normal, enlarged, and have an overall increase in echogenicity

the renal pyramids may appear more prominent with

acute glomerulonephritis

chronic glomerulonephritis, the result of a long-standing infection, can lead to

end-stage renal disease

clinical findings of glomerulonephritis

1. recent throat infection (acute)

2. smoky urine

3. hematuria

4. proteinuria

5. fever

6. hypertension

7. azotemia

sonographic findings of acute glomerulonephritis

1. enlarged kidney(s) with increased echogenicity

2. prominent renal pyramids

sonographic findingd of chronic glomerulonephritis

1. small, echogenic kidneys

glomerulonephritis can be caused by a

distant throat infection like strep throat

the most common renal parasitic infection is from

schistosomiasis

schistosomiasis

is a worm that enters humans by penetrating the skin

schistosomiasis is most often seen in the

bladder, causing thickening of the bladder wall

the kidney can also succumb to —, with the development of a hydatid cyst

Echinococcus granulosus

Hydatid disease is most often found in

sheep- and cattle-raising countries such as the Middle East, Australia, and the Mediterranean

clinical findingd of parasitic urinary tract infectiion

1. hematuria

2. flank pain

3. pyuria

4. dysuria

5. possible recent travel out of the country (hydatid cyst: middle east, austrailia, and mediterranean)

sonographic findings of parasitic urinary tract infection

1. schistosomiasis: bladder wall thickening

2. hydatid cyst: depends on the stage of its maturation, as it may appear completely anechoic, contain a daughter cyst with internal debris, or as a complex mass with calcifications