Urinary tract imaging diagnostic in children

1. Urinary tract imaging diagnostic in children The most common disorders

2. Urinary tract in children - methods of diagnostic imaging • Ultrasonography (US)‏ • Plain abdominal rentgenogram • Conventional intravenous urography (IVU)‏ • Scintigraphy (renal cortical scintigraphy, diuresis renography)‏ • Voiding cystourethrography (conventional and sonocystourethrography)‏ • Computed tomography • Magnetic resonanse tomography / MR urography (MR hydrography)‏

3. Urinary tract in children - methods of diagnostic imaging Voiding cystourethrography (VCU)‏ • remains thegold-standard examination for imaging the bladder and the urethra and for detecting vesicoureteral reflux • detecting VUR in children with a history of urinary tract infection or prenatal diagnosis of abnormal dilatation • examination should not be performed during acute infection or • immediately after treatment • patient should be maintained on antibiotics until the examination is performed

4. Urinary tract in children - methods of diagnostic imaging Voidingcystourethrography (VCU)‏- technique • placing of catheter - retrogradeaccess (mainriskispost-proceduralinfection - sterilityextremelyimportant!) suprapubicapproach(in neonateswithposteriorurethralvalves, incase of urethral trauma, hypospadias, cloacalmalformation) • thebladderisfilledwith a dilutedc.m. (120mgI/ml) bladdercapacity (ml) = [age (years) + 2] x 30 *(2 or 3 cycles of bladderfilling) - cycling VCU hasbeenshown to be more efficientindetecting VUR • voidingpictures – centered AP viewin girls, obliqueinboys to analyzeurethra • if VUR isdetectedduringmicturition – obliquebladderviews to visualizethe refluxinguretherwithitsretrovesicalportion • a post voiding film – to assessresidualurine

5. Urinary tract in children - methods of diagnostic imaging Voidingcystourethrography (VCU)‏

6. The most common urinary tract disorders in childhood • Urinary tract infections • Abnormalities of micturation • Abdominalgia • Haematuria Asymptomatic children but: • Abnormalities found prenataly in US • Incidentally found abnormalities in US

7. Urinary tract infections UTI – one of the most common bacterial diseases in children the prevalence varies with age and sex much more common in infant boys, in school-age group occur mainly in girls SYMPTOMATIC UTI • HIGHER-TRACT INFECTIONS - acute pyelonephritis and pyelitis high fever, generalized symptoms (newborns, younger children)‏ • LOWER TRACT INFECTIONS - acute cystitis voiding symptoms (older children)‏

8. Urinary tract infections ACUTE PYELONEPHRITIS VESICO-URETERIC REFLUX FORMATION OF SCARS REFLUX NEPHROPATHY = CHRONIC PYELONEPHRITIS RENAL HYPERTENSION RENAL FAILURE

9. Urinary tract infections IMAGING GOAL : identification of individualswithcomplicated UTI, thosewithabnormalities of thekidneys, VUR orbladderdysfunction Infection - may be themainsign of majority of congenitalurinarytractanomalies! • Vesico-ureteric reflux • Vesico-uretericjunctionobstruction • Ectopic ureter • Ureterocele • US • Voiding cystourethrography • IVU, MR urography

10. Urinary tract infections Acute pyelonephritis • US • Increased renal volume • Areas of increased or heterogeneous echogenicity (high echogenicity of the parenchyma, especially the renal cortex, hypo- or non-echogenic foci representing microabscesses, larger defect in necrosis, demarcation of abscess formation)‏ • Loss of corticomedullary differentiation • Thickening of pelvic wall (> 0.8 mm)‏ • Renal sinusal hyperechogenicity • Increased perirenal fat echogenicity • Ureteritis with ureter wall thickening • Sedimentation in the bladder or renal pelvis • Perirenal fluid collection in perinephritis

11. Urinary tract infections Acute pyelonephritis • US (Colour Doppler and power Dopplersonography)‏ • Segmental perfusion defects • Areas of devascularization • Non-perfusion in abscess formations • Adjacent hyperperfusion Chronic pyelonephritis • Diffuse or local scarring (the echogenicity increases, a lost of cortical-medullary differentiation is observed)‏ • Volume measurements (to detect a stagnation of growth in the renal parenchyma)‏

12. Urinary tract infections Acute pyelonephritis (US, transverse prone scan of bothkidneys)‏ L kidney - more echogenic with pelvic wall thickening US (sag scan) sinusal hyperechogenicity

13. Urinary tract infections Acute pyelonephritis (US) tumefactive hyperechogenicity of the upper pole of the R kidney (US-PD) lack of vascularization of this area

14. Urinary tract infections Chronic pyelonephritis (US, sag)- scarred kidney small R kidney with thinning of the renal parenchymaand calyceal dilatation at the upper pole Cystitis US (sag scan)‏ thickening of the bladder wall > 3.5mm (irregular and/or pseudo-tumoral), urine within the bladder may be echogenic

15. Urinary tract infections Acutepyelonephritis • CT • theionizinghazards and the need of contrast injection prevent a routine use in the acute phase • should be used if theclinical progression under appropriate therapy is not favorable or if an abscess is suspected • may be helpful in cases ofa poorly functioning kidney and in case of underlyinglithiasis • lesions are best demonstrated on the late post-injection phase and appear as hypodensestriated triangular-shaped areas within the renal parenchyma

16. Urinary tract infections Acute pyelonephritis (CE-CT) triangular-shaped areas of decreased enhancement corresponding to the diseased parenchyma Evolution towards an abscess formation at the right middle and upperpole renal parenchyma appears necrotic and does not enhance

17. Urinary tract infections Acute pyelonephritis • MR • can detect renal scarring and acute edema (hypointense on T1 CE)‏ • DWI - to ascertain abscess formation and to differentiate between acute and more chronic inflammatory lesions • MR-urography - visualization of the urinary tract or renal function analysis • Voiding cystourethrography • because of a significant association between pyelonephritisand VUR, children should be studied to assess refluxup to several weeks after the acute infection • gives the possibility to grade VUR, to visualize intrarenalVUR, to evaluate the bladder function and to display urethral anomalies

18. Urinary tract infections Acute pyelonephritis (CE-MR, cor) early phase, heterogeneous enhancement of the left upper pole late phase, no enhancement of the upper pole parenchyma is visible

19. Abnormalities of micturation • Posterior urethral valve in boys • Urethral meatal stricture in girls • Ectopic – urethral – orifice of ureter • Neurogenic urinary bladder • US • Voiding cystourethrography • Cystometric and uroflowmetric examinations

20. Haematuria • Kidney parenchyma diseases (eg. glomerulonephritis)‏ • Urolithiasis • US • Plain abdominal rentgenogram • IVU, MR urography

21. Abdominalgia • Urinary tract infections (pyelonephritis, cystitis)‏ • Hydronephrosis of any cause • Urolithiasis • US • Plain abdominal rentgenogram • Voiding cystouethrography • IVU, MR urography

22. Some of the congenital anomalies of urinary tract in children • Vesico-urinary reflux – incompetent ureteral sphincter • Double kidney and pelvicocaliceal system • ureter duplex (with ectopic ostium)‏ • ureter fissus • Ureteral strictures (pelvico-ureteral and vesico- ureteral)‏ • Posterior urethral valve in boys • Urethral stricture in girls • Ureterocele (simple or ectopic) • Ectopic kidneys, Horseshoe kidney, one kidney • Polycystic kidneys (ARPKD and ADPKD)‏ • Multicystic dysplastic kidney

23. Vesico-ureteric reflux +  VUR results from the lack of a normal valve-like mechanism of the vesicoureteric orifice 0 intramural segment submucosal segment the competence of the vesicoureteric junction is influenced by thelength of the intravesical segment of the ureter: ashorter distance is likely to result in VUR

24. Vesico-ureteric reflux Ureterovesicaljunction Ureteral orifices divericula

25. Vesico-ureteric reflux • primary VUR - mainly in neonates and in infants, ♂, congenital anomalies of the kidneys and urinary tract • secondary VUR - results from/is associated with various uronephropathies, school-age ♀ with bladder dysfunction • Frequent familial occurrence (40-65% siblings will be affected)‏ • Prevalence of VUR in healthy children is ~ 1-2% ♂

26. Vesico-urinary reflux VUR grading Grade I VUR limited to the ureter Grade II VUR up the renal cavities without dilatation Grade III VUR into the renal cavities inducing dilatationand eversion of the calyces Grade IV moderate to marked dilatation of the ureterand pyelocalyceal system Grade V marked tortuosity and dilatation of the ureterand pyelocalyceal system

27. Vesico-urinary reflux Dilatated ureter andpelvocaliceal system in the left kidney VUR IV

28. Vesico-urinary reflux Cystography – vesico-ureteric reflux IV/V grade

29. Vesico-urinary reflux Combined static-dynamic MRU

30. Vesico-urinary reflux Combined static-dynamic MRU high-resolution anatomic images of the entire urinary tract + functionalinformation about the concentration and excretion of the individual kidneys dynamic scanning after iv Gd-DTPA bolus injection combination of T2-w and dynamic 3D T1-w sequences

31. Hydronephrosis • Ureteral strictures!!!- pelvico-uretericjunction - vesico-uretericjunction • Double kidney with ectopic ureter and ureterocele • Posterior urethral valve • Nephro/ureterolithiasis • Other urinary tract anomalies (retrocavalureter, ectopickidneys, VUR)‏ • Causes outside the urinary system PruneBellysyndrome

32. Hydronephrosis • Differential diagnosis of hydronephrosis • RPD with obstruction • RPD with no obstruction • Megaureter (with or without reflux) • Multicystic dysplastic kidney • VUR with upper-tract dilatation • Bladder outlet obstruction (commonly posterior urethral valve) • Complicated duplex kidney • Upper moiety dilatation, due to either a ureterocele or ectopic drainage of the ureter • Lower moiety dilatation, due to either VUR or less commonly RPD • RPD - renal pelvic dilatation

33. hydronephrosis Left vesico-ureteral stricture Double left kidney with dilatated lower pelvicocaliceal system – possible ectopicleft lower ureter

34. hydronephrosis PUJ stricture

35. hydronephrosis PUJ obstuction VUJ obstruction

36. hydronephrosis Horseshoe kidney Pelvic kidney IVU– VUR V

37. PruneBellysyndrome IVU VCUG

38. ureterocele • Simple – in single kidney, ostium in vesical triangle, balloon-like deformation of intramural fragment of ureter, usually small, without hydronephrosis, contrast-filled mass in bladder (urography) • Ectopic – in double kidney, ectopic, anomalous ostium of (usually) upper ureter, dilatation (may be huge) of whole ureter and pelvicocaliceal system, often kidney dysfunction, defect in contrast-filled bladder (urography)

39. ureterocele Left renal obstructiondue to ureterocele Cobra-head ureterocele

40. ureterocele

41. ureterocele Bilateral hydronephrosis, left double kidney,invisible upper P-C system,ectopic left ureterocele

42. Urethra – normal appearance

43. Urethralobstruction boys Male urethraposterior part dilatationposterior urethral valve Normal urethra – impression ofurogenital diaphragm

44. girls Urethralobstruction Female urethraMeatal stenosis

45. Cystic diseases of kidneys • ARPKD – autosomal recessive polycystic kidneys disease • ADPKD – autosomal dominant polycystic kidneys disease • Multicystic dysplastic kidney – nonheritable kidney disorder

46. Multicystic dysplastic kidney • ONE KIDNEY! affected • Obstruction of urinary drainage of affected kidney (ureter atresia, distal ureter obstruction, ectopic ureteral insertion)‏ • Large cysts easily seen in USG, no normal renal parenchyma • No function in the kidney • Possible VUR to functioning kidney (25%) – voiding cystography is recommended • Dysplastic kidney has a tendency to involution with time

47. Multicystic dysplastic kidney No renal function on the right (IVU)‏ Multiple cystic formations in US and CT

48. ARPKD – autosomal recessive polycystic kidneys disease • Both kidneys and liver (ectasia of collecting tubules in kidneys and biliary ducts in liver, fibrosis)‏ • Very large kidneys (up to 10 cm in a neonate)‏ • Death in infancy or first decade of life due to renal failure, systemic and portal hypertension

49. ARPKD – autosomal recessive polycystic kidneys disease US IVU CT

50. ADPKD – autosomal dominant polycystic kidneys disease • Both kidneys, may be asymmetrically involved • Also liver and pancreas • Large and more numerous cysts with increasing age • Renal failure or hypertension in the fourth-fifth decade of life • Clinical symptoms – rare in childhood (kidney enlargement, haematuria, flank pain if bleeding into the cyst • US screening of parents and siblings of affected child should be routine