Download Pediatric GUT I

Urinary tract imaging
diagnostic in children
The most common disorders
Urinary tract in children - methods
of diagnostic imaging
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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)
Urinary tract in children - methods
of diagnostic imaging
Voiding cystourethrography (VCU)
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remains the gold-standard examination for imaging the bladder and the
urethra and for detecting vesicoureteral reflux
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detecting VUR in children with a history of urinary tract infection
or prenatal diagnosis of abnormal dilatation
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examination should not be performed during acute infection or
immediately after treatment
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patient should be maintained on antibiotics until the examination is
performed
Urinary tract in children - methods
of diagnostic imaging
Voiding cystourethrography (VCU) - technique
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placing of catheter - retrograde access (main risk is post-procedural infection sterility extremely important!)
suprapubic approach (in neonates with posterior urethral valves, in case of
urethral trauma, hypospadias, cloacal malformation)
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the bladder is filled with a diluted c.m. (120mgI/ml)
bladder capacity (ml) = [age (years) + 2] x 30
*(2 or 3 cycles of bladder filling) - cycling VCU has been shown to be more
efficient in detecting VUR
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voiding pictures – centered AP view in girls, oblique in boys to analyze urethra
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if VUR is detected during micturition – oblique bladder views to visualize the
refluxing urether with its retrovesical portion
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a post voiding film – to assess residual urine
Urinary tract in children - methods
of diagnostic imaging
Voiding cystourethrography (VCU)
The most common urinary tract
disorders in childhood
Urinary tract infections
 Abnormalities of micturation
 Abdominalgia
 Haematuria
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Asymptomatic children but:
 Abnormalities found prenataly in US
 Incidentally found abnormalities in US
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
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HIGHER-TRACT INFECTIONS - acute pyelonephritis and pyelitis
high fever, generalized symptoms
(newborns, younger children)
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LOWER TRACT INFECTIONS - acute cystitis
voiding symptoms (older children)
Urinary tract infections
ACUTE PYELONEPHRITIS
VESICO-URETERIC REFLUX
FORMATION OF SCARS
REFLUX NEPHROPATHY = CHRONIC PYELONEPHRITIS
RENAL HYPERTENSION
RENAL FAILURE
Urinary tract infections
IMAGING GOAL : identification of individuals with complicated UTI,
those with abnormalities of the kidneys,
VUR or bladder dysfunction
Infection - may be the main sign of majority of congenital urinary tract anomalies!
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Vesico-ureteric reflux
Vesico-ureteric junction obstruction
Ectopic ureter
Ureterocele
• US
• Voiding cystourethrography
• IVU, MR urography
Urinary tract infections
Acute pyelonephritis
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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
Urinary tract infections
Acute pyelonephritis
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US (Colour Doppler and power Doppler sonography)
Segmental perfusion defects
Areas of devascularization
Non-perfusion in abscess formations
Adjacent hyperperfusion
Chronic pyelonephritis
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Diffuse or local scarring (the echogenicity increases, a lost of corticalmedullary differentiation is observed)
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Volume measurements (to detect a stagnation of growth in the renal
parenchyma)
Urinary tract infections
Acute pyelonephritis
(US, transverse prone scan of both kidneys)
L kidney - more echogenic with pelvic wall
thickening
US (sag scan) sinusal hyperechogenicity
Urinary tract infections
Acute pyelonephritis
(US) tumefactive hyperechogenicity of the upper pole of the R kidney
(US-PD) lack of vascularization of this area
Urinary tract infections
Chronic pyelonephritis
(US, sag) - scarred kidney
small R kidney with thinning of the renal
parenchyma and 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
Urinary tract infections
Acute pyelonephritis
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CT
the ionizing hazards and the need of contrast injection prevent
a routine use in the acute phase
should be used if the clinical progression under appropriate therapy is
not favorable or if an abscess is suspected
may be helpful in cases of a poorly functioning kidney and in case of
underlying lithiasis
lesions are best demonstrated on the late post-injection phase and appear as
hypodense striated triangular-shaped areas within the renal parenchyma
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 upper pole
renal parenchyma appears necrotic and
does not enhance
Urinary tract infections
Acute pyelonephritis
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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 pyelonephritis and VUR, children
should be studied to assess reflux up to several weeks after the acute
infection
gives the possibility to grade VUR, to visualize intrarenal VUR, to evaluate the
bladder function and to display urethral anomalies
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
Abnormalities of micturation
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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
Haematuria
Kidney parenchyma diseases (eg.
glomerulonephritis)
 Urolithiasis
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• US
• Plain abdominal rentgenogram
• IVU, MR urography
Abdominalgia
Urinary tract infections (pyelonephritis,
cystitis)
 Hydronephrosis of any cause
 Urolithiasis
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US
Plain abdominal rentgenogram
Voiding cystouethrography
IVU, MR urography
Some of the congenital anomalies
of urinary tract in children
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Vesico-urinary reflux – incompetent ureteral sphincter
Double kidney and pelvicocaliceal system
ureter duplex (with ectopic ostium)
ureter fissus
Ureteral strictures (pelvico-ureteral and vesicoureteral)
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
Vesico-ureteric reflux
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VUR results from the lack of
a normal valve-like mechanism
of the vesicoureteric orifice
intramural
segment
submucosal
segment
the competence of the vesicoureteric junction is influenced by
the length of the intravesical segment of the ureter:
a shorter distance is likely to result in VUR
Vesico-ureteric reflux
Ureterovesical
junction
Ureteral orifices
divericula
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
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Frequent familial occurrence (40-65% siblings will be affected)
Prevalence of VUR in healthy children is ~ 1-2%
Vesico-urinary reflux
VUR grading
Grade
Grade
Grade
Grade
Grade
I VUR limited to the ureter
II VUR up the renal cavities without dilatation
III VUR into the renal cavities inducing dilatation and eversion of the calyces
IV moderate to marked dilatation of the ureter and pyelocalyceal system
V marked tortuosity and dilatation of the ureter and pyelocalyceal system
Vesico-urinary reflux
Dilatated ureter and
pelvocaliceal system
in the left kidney
VUR IV
Vesico-urinary reflux
Cystography – vesico-ureteric reflux IV/V grade
Vesico-urinary reflux
Combined static-dynamic MRU
Vesico-urinary reflux
Combined static-dynamic MRU
high-resolution anatomic
images of the entire urinary tract +
functional information 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
Hydronephrosis
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Ureteral strictures!!!
- pelvico-ureteric junction
- vesico-ureteric junction
Double kidney with ectopic ureter and ureterocele
Posterior urethral valve
Nephro/ureterolithiasis
Other urinary tract anomalies (retrocaval ureter, ectopic
kidneys, VUR)
Causes outside the urinary system
Prune Belly syndrome
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
hydronephrosis
Left vesico-ureteral stricture
Double left kidney with dilatated lower
pelvicocaliceal system – possible ectopic
left lower ureter
hydronephrosis
PUJ stricture
hydronephrosis
PUJ obstuction
VUJ obstruction
hydronephrosis
Horseshoe kidney
Pelvic kidney
IVU– VUR V
Prune Belly syndrome
IVU
VCUG
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)
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ureterocele
Left renal obstruction
due to ureterocele
Cobra-head ureterocele
ureterocele
ureterocele
Bilateral hydronephrosis,
left double kidney,
invisible upper P-C system,
ectopic left ureterocele
Urethra – normal appearance
Urethral obstruction
Male urethra
posterior part dilatation
posterior urethral valve
boys
Normal urethra – impression of
urogenital diaphragm
Urethral obstruction
girls
Female urethra
Meatal stenosis
Cystic diseases of kidneys
ARPKD – autosomal recessive polycystic
kidneys disease
 ADPKD – autosomal dominant polycystic
kidneys disease
 Multicystic dysplastic kidney –
nonheritable kidney disorder
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Multicystic dysplastic kidney
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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
Multicystic dysplastic kidney
No renal function on the right (IVU)
Multiple cystic formations in US and CT
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
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ARPKD – autosomal recessive
polycystic kidneys disease
US
IVU
CT
ADPKD – autosomal dominant
polycystic kidneys disease
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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
ADPKD – autosomal dominant
polycystic kidneys disease
Urolithiais and nephrocalcinosis
Urolithiasis – calculi in renal pelvis and
calices, ureters and urinary bladder, due to
kidneys obstruction, anomalies or
metabolic disorders
 Nephrocalcinosis – calcifications in renal
parenchyma, in dilated tubules in sponge
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kidney
Urolithiais and nephrocalcinosis
Nephrocalcinosis – calcifications
in renal parenchyma
Urolithiasis – stones
in distended calices
Urolithiais and nephrocalcinosis
IVU
Nephrocalcinosis CT
Plain film
Renal calculi in pelvocaliceal
sysem and in VUJ