Alexandria Urology Hospital

1. Pediatric urinary tract infection
role of imaging
Dr/Ahmed bahnassy
Consultant Radiologist
Alexandria Urology Hospital
Alexandria Urology Hospital AUH

2. Importance
Urinary tract infection (UTI) is a common
pediatric malady, and a frequent source
of morbidity in the pediatric population.
several studies have noted an association
between children with renal scarring
caused by APN with hypertension and end
stage renal disease.

3. Goals of imaging
(1) to discover a possible cause for the infection to prevent
recurrence and lessen morbidity.
(2) to determine whether the kidneys are normal, involved,
or at risk for scarring.
(3) to determine whether vesicoureteral reflux
(VUR) exists, which facilitates the ascent of infection
from the bladder.
(4) to identify urinary tract calculi, which may perpetuate or
result from repeated UTI.
(5) to identify urine outflow obstruction.

4. Technique
US evaluation of the urinary tract in the pediatric
patient with UTI should include evaluation of the
kidneys; ureters (if visible); and urinary bladder.
The highest frequency transducer that penetrates
the area should be used.
For infants and toddlers a curved 8- to 13-MHz
transducer, for young children a curved array 4-
to 9-MHz transducer, and for adolescents, a 2-
to 5-MHz curved array transducer

5. Hints for infants
For infants and young children, one should first
examine the bladder ,the bladder wall; and distal ureters (their caliber
and insertion sites).
The bladder should be reasonably well-distended, and examined in
transverse and sagittal planes.
In the transverse plane,images should be obtained from the bladder
dome to the bladder outlet.
In the sagittal plane,images should include the bladder outlet, the
bilateral distal ureters, and ureteral insertion sites.
Color Doppler US can be useful in identifying the latter when ureteral
jets are seen.

6. Bladder wall
The bladder wall thickness is usually
regarded as normal up to 0.3 cm
with a full bladder and 0.5 cm with an
empty bladder .

7. Dysfunctional elimination syndrome
US of the urinary bladder (transverse) prevoid (A) and postvoid (B) in
a 6-year-old girl with frequency, dribbling, and recurrent UTIs shows bladder wall
thickening and moderate post voiding residue.

8. Urinary bladder diverticulum

9. Bacterial cystitis

10. Viral cystitis mimicking bladder
mass

11. Pyoureteronephrosis due to
ureterocele

12. Acute pyelonephritis
Renal enlargement may not be apparent on US 1 to 2
weeks after presentation once the infection has
cleared.
In addition to unilateral or bilateral renal
enlargement, other findings that can be seen,
particularly in severe infections, include loss of
corticomedullary differentiation, and localized
areas of hypoechogenic or hyperechogenic renal
parenchyma .
Thickening of the uroepithelium of the renal pelvicalyceal
system or ureters may be seen in pyelitis and VUR .

13. Acute pyelonephritis
The left kidney is globally enlarged and increased in its overall echogenicity.
There is loss of normal corticomedullary differentiation and thickening of the
uroepithelium of the renal pelvis

14. Focal acute pyelonephritis
Doppler image demonstrates marked decreased flow within the affected
echogenic upper pole

15. APN-use of high frequency probe
Linear high-resolution image shows multifocal regions (arrows) of striated
cortical hypoechogenicity

16. THI
Harmonic imaging accentuates
posterior shadowing, acoustic
enhancement, or comet tail artifacts, and
can also provide improved image quality
and resolution of small renal lesions

17. multifocal APN-use of power
doppler
Power Doppler US demonstrates diminished perfusion in
the upper and lower poles (arrows) of the left kidney compatible with multifocal
APN.

18. Renal candidiasis
cast of echogenic material within the mildly dilated
intrarenal pelvicalyceal system.

19. complications detection
US may detect complications related to
APN, such as renal abscess, perinephric
abscess, xanthogranulomatous
pyelonephritis, and renal stones

20. Xanthogranulomatous
pyelonephritis
renal enlargement with large hypoechoic regions
secondary to moderately severe caliectasis. A small
calculus (arrow) is seen within the left renal pelvis.

21. APN with renal abscess
US of the right kidney shows right renal enlargement,with loss of normal upper
pole architecture and multiple focal hypoechoic areas . Color Doppler US shows
marked decreased perfusion of the upper pole

22. Chronic pyelonephritis
focal scarring

23. to summarize
Due to advantages gained by ultrasound
examination including its use for depicting
structural urinary tract abnormalities, it is
still wize to include US as an integral part
of the routine evaluation of firsttime
UTI in pediatric patients.