2. THE URINARY TRACT AND EVALUATION
• The urinary tract consist of kidneys, ureters, bladder and urethra.
• Most common sites of congenital abnormalities.
• Systematic approach begins with evaluating the amniotic fluid volume
• ldentifying the kidneys and bladder.
• Find if ureters are dilated
• Localise and characterising abnormalities.
• Searching for associated abnormalities in other fetal organs.
4. CONGENITAL MALFORMATIONS
RENAL AGENESIS
• Is the failure to develop of one or both kidneys,can be unilateral or bilateral.
• In Unilateral renal dysplasia bladder and AFV may be normal
• In bilateral dysplasia results in non visualised bladder and severe oligohydramnios
or anyhydramnios.
• Other sonographic fetures include non visualisation ok kidney in renal fossa,
Horizontal orientation of ipsilateral adrenal gland (lying down adrenal sign) , no
renal artery on CD and compensatory enlargement of contralateral kidney.
• Bilateral renal agenesis is congenital absence of both kidneys and is called porter
syndrome.
• Key sonographic features are no kidneys, bladder not visualised, severe
oligohydramnios, neonatal mortality because of severe pulmonary hypoplasia
due to severe oligohydramnios.
8. Renal malposition
• # One or both kidneys
• # Ectopic kidney
• # Crossed renal ectopia (one kidney has crossed to the contralateral
side)
• # Associated with fusion of kidneys
• Horseshoe kidney
• Fusion of upper pole
• # Abnormalities of rotation are often associated with ectopic kidneys
10. RENAL ECTOPIA
• A condition whereby the kidney is not located in its normal position.
• It maybe in the lower abdomen/pelvis due to failure to ascend from
its origin in the true pelvis or it may be in the chest when its superioly
escended.
• Key sonographic features are an empty renal fossa, a lying down
adrenal sign, and a reniform structure seen elsewhere in the body
most common ectopia seen in pelvis adjacent to the bladder.
12. CONGENITAL MALFORMATIONS
multicystic dysplastic kidneys (MCDK)
• Is a condition whereby normal renal parenchyma is replaced by
multiple cysts of varying sizes. Also called porter 2 syndrome.
• Not genetically transmited or associated with other organs anomalies.
• Sonographic features include plycystic kidney wti cysts of varying
sizes, non communicating cystic structures, no renal tissue between
cysts.
• Is different from severe hydronephrosis in that hydrophrosis, renal
cysts are equal in size, they are communicating cysts, they are
systemically distributed
14. OBSTRUCTIVE CYSTIC RENAL DISPLASIA
• Is porter 4 renal cystic disease.
• Results from urinary tract obstructions in the first half of gestation.
• Unilateral condition caused by UPJ and UVJ whereas bilateral OCRD is
caused by BOO commonly urethral valves PUR
• Sonographic features include cysts in subcapsular cortical region indicative
of irreversible renal damage. Increased renal parenchymal echogenicity,
hydronephrosis.
• OCRD is different from MCDK in that in OCRD there maybe some
hydronephrosis and recognisable parenchyma is seen surrounding the
relatively small cysts, In MCDK there is no hydronephrosis, and no normal
ranal parenchyma seen.
16. Infantile polycystic kidney disease(IPKD)
• Porter 1 renal cystic disease, an autosomal recessive disorder.
• Sonographic features are bilateral symmetrical nephromegally
• Increased echogenicity
• Individual cysts too small to be seen
• Loss of corticomedullary differentiation
• Renal function severely impaired
• Severe oligohydramnios
• Small bladder difficult to see.
• May involve bith kidneys and liver (hepatic fibrosis)
• May not be seen earlier in preg, usualy visible in 3rd trimester.
18. Adult polycystic kidney disease(APKD)
• Autosomal dominant porter 3 renal cystic disease.
• Similar features with IPKD except that;
• small parenchymal cysts maybe seen.
• There is normal renal function i.e. normal AFV and bladder is seen.
• In adults it appears as enlarged kidneys with multiple cysts of
variable sizes.
• Usualy indicated if there is family history or one parent has the
condition, its easy to diagnose it in utero in such cases.
19.
20. URINARY TRACT OBSTRUCTIONS
Important finding of urinary tract obstruction is hydronephrosis
or hydroureter. Common sonographic features include;
• Pyelectasis is the dilatation of the renal pelvis only
• Caliectasis refers to the dilatation of the renal calyces
• Hydronephrosis is measured as the maximum anteroposterior
dimension of the dilated renal pelvis (renal pelvic diameter) on
transverse section.
21. URETERIC JUNCTION OBSTRUCTIONS
UTEROPELVIC JUNCTION OBSTRUCTION(UPJ)
• Generalized calyceal distention is seen with a large renal pelvis having
a rounded shape. It may appear to be a cyst in the midabdomen
• Usually caused by muscle abnormality in ureteral wall. Most common
cause of hydronephrosis in utero. Common in males.
• On USS pyelectasis with or without caliectasis is seen.
• dilated renal pelvis with a collapsed proximal ureter.
• If the hydronephrosis is bilateral and severe, there may be
oligohydramnios.
• Severe unilateral or bilateral renal pelvic enlargement, results in
polyhydramnios caused by gut compression by the dilated renal pelvis
22.
23. dilated renal pelvis with a collapsed proximal
ureter. Cortical and renal pelvis
measurement. PUJ
24. URETEROVESICAL JUNCTION
OBSTRUCTION(UVJ)
• Is mostly caused by an aperistaltic distal ureter segment (primary
megaureter).
• Common in males and usually unilateral.
• Causes pyelectasis and hydroureter
• Normal AFV and bladder unless there is bilateral UVJ.
• Bilateral UVJ results in oligohydramnios.
25.
26. Congenital Megaureter
• Obstructed primary megaureter
• Refluxing primary megaureter (caused by VUR due to paraaureteric
diverticulum,
• ureterocoele , duplicated collecting system)
• Non-refluxing unobstructed primary megaureter
• Association : renal dysplasia, megacalyces
• the ureter is enlarged ( >7 mm ).
• In obstructed form the distal ureter is most dilated++ (fig12 and 13)
• In refluxing primary megaureter, VUR is demonstrated with other
abnormalities.
28. Vesicoureteric reflux (VUR)
• The most frequent congenital anomalies of urinary tract.
• • Urinary tract infections++
• • VUR may be an isolated or associated with other congenital anomalies:
• posterior urethral valves, duplex collecting system, neurogenic bladder…
• • Voiding cystourethrogram (VCUG) : primary diagnostic procedure +++
• • Presence and grade of VUR
• • Micturition or during bladder filling VUR
• • Associated anatomical anomalies
• • Ultrasound : Renal parenchyma,
• • Contrast ultrasound : Viewing VUR using micro-bubbles
29. URETEROCELE
• Is the prolapse of distal ureter into the urinary bladder causing a
cystic dilatation of the prolapsed segment.
• Simple ureteocele is when the ureter inserts at a normal location and
ectopic ureterocele when the ureter inserts at an obnormal site.
• Ectopic ureretorocele is associated with duplex kidney/utreters and
segmental hydronephrosis of one pole of the duplex kidney
• Sonographically ureterocoele is seen as a thin walled cystic structure
in the bladder at the site if ureter insertion in association with
hydroureter or hydronephrosis.
31. MEGACYSTITIS
• Is abnormal distention of the fetal urinary bladder.
• It is a sign of bladder outlet obstruction.
• Usually seen in association with oligohydramnios.
• Commonly caused by posterior urethral valves.
• Sonographically bladder appears abnormally enlarged, variable
thickening of the bladder wall
32.
33. POSTERIOR URETHRAL VALVES
• Valve like tissue flaps in the proximal or prastatic portion of male
urethra
• They cause total, intermittent or partial urinary tract obstruction.
• Sonographic features are the keyhole sign with megacystitis and
dilated proximal urethra
• Thick bladder wall.
• Bilateral hydroureter and hydronephrosis.
• Mild to severe oligohydramnios depending on degree of obstruction.
34.
35. URETHRAL ATRESIA
• Is a severe urinary tract obstruction since no urine enters the
amniotic fluid.
• Sonographic fetures are megacystis and anyhydramnios
• No detectable amniotic fluid seen.
36. Adrenal Hemorrhage
• Bleeding occur spontaneously or as a result of maternal loss of blood
pressure.
• A mass in both adrenals is seen, evenly echogenic or partly or
completely cystic.
• The mass will be superior to the kidney and posterior to the liver.
• Hemorrhage evolves and rapid changes in acoustic texture over some
days will be seen.
37. Neuroblastoma
• common at birth and usually so small it cannot be seen. It generally
regresses spontaneously.
• densely echogenic, but may be evenly echogenic or fluid- filled if its
associated with adrenal hemorrhage.
• Tumor is usually seen in the third trimester but has been reported at
20 weeks.
• Metastases to the liver may be seen.
38. Renal Tumor
• Renal masses are rare, occur in the third trimester and usually
mesoblastic nephroma. Wilms tumor or (nephroblastoma) rare in
utero common in early childhood
• Are large and evenly echogenic, but there may be cystic components.
• Always associated with severe polyhydramnios, ascites, macrosomia
etc
39. Second Collecting System
• Occurs when there is duplication of upper half of the kidney which is
obstructed, an echogenic mass containing cysts is seen due to
multicystic dysplastic changes in the kidney.
• OR a cystic lesion may be seen representing all that remains of the
duplicated kidney.
