Test 3 Flashcards
in the 7th week, what does metanephros develop from?
- metanephric diverticulum (uteric bud)
- metanephric mass of the intermediate mesoderm
what is the uteric bud?
outgrowth of the mesonephric bud
what does the uteric bud give rise to?
- ureter
- renal pelvis
- calyces
- collecting tubules
by when dp the kidneys ascend to the adult position?
11 weeks
when do the kindeys start to produce urine?
11 weeks
at the 9th week what does the cloaca divide into?
- rectum posteriorly
- urogenital sinus anteriorly (female and most of male urethra, urinary bladder)
what is the bladder continuous with?
allantois
what does the allantois become?
a fibrous cord, the urachus, which extends from the apex of the bladder to the umbilicus
when is renal architecture finalized?
between 5-15 weeks of intrauterine development
what does the urachus become?
medial umbilical ligament
what does the bladder form from?
devlops from part of the upper part of urogenital sinus
when are female and male genitalia identical?
befpre 11 weeks
in males, when does testicular descent occur?
after 25 weeks gestation
what does evaluation of the AVF provide important info on?
fetal renal and placenta function
when does fetal urine production become a major source of amniotic fluid?
after 16 weeks
what is fetal lung development affected by?
- amniotic fluid adequancy
- available thoracic space
- neuromuscluar functions
what growth factors is lung development regulated by?
fluid volume and hyperoxia to cause cellular proliferation and differentiation
what is an important component of amniotic fluid?
fetal urine
during fetal development what is the kidney a major source of?
proline
what is proline?
aids in the formation of collagen and mesenchyme in the lung
what is one of the most frequent sites of congenital anaomalies?
urinary tract
what does VATER stand for?
- vertebral defect
- anal atresia
- tracheo-esophageal fistula
- radial defects and renal anomlaies
what does VACTERL stand for?
- vertebral defects
- anal atresia
- cardiac defects
- tracheo-esophageal fistula
- radial defects and renal anomlaies
- limb abnormalities
Bilateral renal agenesis is a_____congenital anomaly
lethal
describe bilateral renal agenesis?
- male predomincance
- uteric bud fails to develop
- nephrons do not form
- no urine is produced
- severe olighydraminos
- pulmonary hypoplasia is the major cause of death
what is potter sequence or syndrome?
case that presents with oligohydramnios or anhydramnios regardless of the source of the loss of amniotic fluid. (bilateral renal agenesis)
what is potter syndrome characterized by?
- renal failure
- severe oligohydramnios
- face
- limb deformities
- IUGR
what does the face look like with potter syndrome?
- beaked nose
- low set ears
- prominent epicanthic folds
- hypertelorsim
what are the sonographic findings for bilateral renal agenesis?
- no visualization of fetal kidneys
- no visulization of fetal bladder
- before 16 wks, AVF is not dependant upon fetal renal function and fetal urine may be normal
- after 16 wks, severe olgohydramnios
- lying down adrenal gland
- absent rena; arteries using color doppler
what may be mistaken for kidneys?
bowel or adrenal glans in the renal fossae
what may mimic the bladder?
urachal diverticulum
what excludes bilateral renal agenesis?
visualization of a normal fetal bladder
is unilateral or bilateral renal agenesis more common?
unilaterl (4x)
what is unilateral renal agenesis associtaed with?
- normal AVF
- normal visualization of bladder
what is a pitfall when imaging kidneys?
renal in far field because acoustic shadowing from the spine in TRV
if a kidney is not found in the renal fossa what will the other one look like?
contralateral kidney may be enlarged
what may happen with unilateral renal agenesis?
Vesicoureteral reflux may occur
what are associated abnormalities with unilateral renal agenesis?
- genital
- cardiac
- skeletal
- GI
where may renal ectopia be placed?
- pelvic
- crossed
- crossed fused
- horeshoe
what is the most common renal ectopia?
pelvic kidney
the ectopic kidney may be __________
hypoplastic or dysplastic
what is horse shoe kidney?
bridge of renal tissue connecting the lower poles
what does horseshoe kidney have a higher incidence in?
- vesicoureteral reflux
- renal calculi
- urinary tract infections
- hydronephrosis
what is horsehoe kidney frequently associated with?
- urogenital
- cardiac
- skeletal
- CNS
- chromosomal
what is the most common neoplasm in the fetus and newborn?
congenital mesoblastic nephroma
what is congenital mesoblastic nephroma?
benign hamartoma composed of mesochymal tissue
what is wilms tumor?
Wilms tumour is a malignant lesion that is extremely rare and composed of epithelial tissue
what is the classification of renal cytic disease?
- dysplastic cysts
- hereditary cysts
- non-dysplastic non-hereditary cysts
what results from early severe obstruction?
Multicystic dyspastic kidney and dysplastic kidney
dysplasia
abnormality of development or an epithelial anomaly of growth and differentiation
what is the most common form of cystic disease in childhood?
multi-cystic dysplastic kidney
what is multi-cystic dysplastic kidney associated with?
atretic ureter and pelvoinfundibular atresia
what is atresia?
a condition in which a body orifice or passage in the body is abnormally closed or absent
what does multi-cystic dysplastic kidney look like?
kidney is replaced by multiple cysts of varying size and no normal renal tissue present (kidney not functional)
where are the multiple cysts seen of varying sizes?
right paraspinous location
what does multi-cystic dysplastic kidney look like with other structures?
no normal appearing kidney
-the contralateral kidney, bladder and amniotic fluid are all normal
what is the MCDK main distinguishing feature?
the pattern of renal cysts. randomly distributed, non communicating and of variable size
what is important to assess with MCDK?
contralateral kidney
how often is multicystic renal dysplasia bilateral?
19%-24% of cases
what implies lethal renal disease?
MCDK is present with nonvisualization of the fetal bladder and severe oligohydramnios
what can unilateral obstructive cystic renal disease caused by?
uteropelvic or vesicourethral junction obstructon
what can bilateral obstructive cystic renal disease caused by?
severe bladder outlet obstruction, usually urethral atresia or posterior urethral valves
what is the severity of Obstructive Cystic Renal Dysplasia related to?
the timing and severity of the obstruction to urine flow
what is the sonographic appearance of cystic renal dysplasia?
- variable
- most typical finding, small echogenic kidney with one or several small subcapsualr cortical cysts plus evidence of urinary obstruction
- renal cysts may change in time
what must happen between an autosomal recessive disorder?
two copies of an abnormal gene must be present in order for the disease or trait to develop
what does Infantile Autosomal Recessive Polycystic Kidney Disease involve?
kidneys and liver
what is Perinatal Infantile Autosomal Recessive Polycystic Kidney Disease?
severe renal disease, minimal hepatic fibrosis and early death from pulmonary hypoplasia
what is Juvenile Autosomal Recessive Polycystic Kidney Disease?
minimal renal disease, marked hepatic fibrosis and longer survival
what are the sonographic findings of Autosomal Recessive Polycystic Kidney Disease?
- both kidneys are symmetrically enlarged and show increased echogenicity
- rena function is impaired
- severe oligohydramnios and bladder may not be seen.
do the size of the kidneys and cysts correlate with renal function
no
what is an indication of infantile polycystic kidney disease?
an elevated KC/AC ratio
what can IPKD be associated with?
meckel gruber syndrome
what is autosomial dominant?
A single abnormal gene on one of the first 22 non-sex (autosomal) chromosomes from either parent can cause an autosomal disorder
is adult autosomal dominant polycystic kidney disease unilateral or bilateral?
bilateral
what is the most common finding for adult autosomal dominant polycystic kidney disease?
Nephromegaly with or without an increase in renal echogenicity
-AFV is usually normal
what do simple renal cysts show as?
small solitary, unilocular cyst near the periphery of the kidney
when are simple renal cysts seen?
early as 14-16 weeks
when do simple renal cysts disolve?
20-24 weeks gestation
what does Mild Pyelectasis present as?
mild dilation of the renal pelvis
what is the most common fetal urinary tract abnormality detected with prenatal U/S?
hydronephrosis
what is the most common cause of fetal hydronephrosis?
obstruction
Measurement of the antero-posterior renal pelvic diameter (RPD) on a transverse scan of fetal abdomen is the most common to evaluate and classify
- renal pelvic dilation(mild to moderate marked)
- calyceal dilation
- parenchymal atrophy
what is the RPD at 18-23 weeks?
over 5mm
what is the RPD in the 3rd trimester?
over 7mm
what is grade 0 of hydronephrosis?
no hydronephrosis, intact central renal complex
what is grade 1 of hydronephrosis?
only dilated renal pelvis, there is some fluid in the renal pelvis
what is grade 2 of hydronephrosis?
dilated renal pelvis and a few calices are visbale
what is grade 3 of hydronephrosis?
all the calices are dilated
what is grade 4 of hydronephrosis?
further dilation of renal pelvis and calices with thin renal parenchyma
what is the most common cause of neonatal hydronephrosis?
UPJ obstruction (it is most often unilateral)
what are most UPJ obstructions due to?
musclular abnormality in the uretral wall rather than the result of anatomic lesion such as abberant vessel or kink
what are the sonographic findings of unilateral UPJ obstruction?
- dilation of the renal pelvis with or without dilation of calyces
- the ureter, bladder, and AFV appear normal
- bilateral UPJ is associated with variable degrees of oligohydramnois and a variable prognosis depending on the severity and duration of renal obstruction
what is the second most common cause of fetal and neonatal hydronephrosis?
uretro-vesical junction obstruction
what are the sonographic findings of unilateral UVJ obstruction?
- variable degrees of uretral dilation and hydronephrosis
- AFV and bladder are normal
- with bilateral UVJ obstruction variable severity of oligohydramnios depending on the obstruction
what is a secondary cause of UVJ obstruction?
uterocele
what is a uterocele?
Uterocele is a prolapse of the distal ureteric mucosa into the urinary bladder causing a cystic dilation of the prolapsed segment in the bladder.
what does a simple uterocele look like?
if the ureter is normally located in the bladder wall
what does a ectopic uterocele classified as?
if the ureter inserts into the bladder in an ectopic location
what is ectopic uterocele associated with?
renal duplication. usually associated with focal or segmented hydronephrosis involving the upper pole of the duplex kindey
what does a uterocele look like?
thin walled cystic structure can be seen in bladder in associated wth hydrouterer and /or hydronephrosis
where is the hydrouterer?
located posteriorly and should be seen to communicate with the renal pelvis and/or bladder
what is posterior urethral valve?
obstructive developmental anaomaly in the urethra and genitourinary system of male newborns
what appears with posterior urethra valve?
- extra flaps of tissue in the urethra
- these extra flaps of tissue block the normal flow of urine
what is a common cause of bladder outlet obstruction?
posterior urethral valve
what is the most specific sonographic sign for posterior urethral valves?
key hole sign
what does the key hole sign describe?
dilated urinary bladder with a dilated proximal urethra
what is non visualization of the bladder mostly due to?
specific fetal renal abnormalities and must be bilateral
what causes failure to produce urine?
- bilateral renal ageneisis
- bilateral multicystic kidneys
- bilateral severe renal dysplasia
- bilateral severe UPJ obstruction
- autosomal recessive polycystic disease
- severe intrauterine growth
what cuases the failure to produce urine?
- bladder extrophy
- cloacal extrophy
- bilateral single system ectopic uteres
what is a sign of bladder putlet obstruction?
an abnormal large fetal bladder
what is the most common cause of megacystitis?
posterior urethral valves
what does fetal megacystitis refer to?
the presence of an unusually large bladder in a fetus
what is the bladder diameter in the 1st trimester?
over 7mm
what is the bladder diameter in the 2nd trimester?
over 30mm
what is the bladder diameter in the 3rd trimester?
over 60 mm
what is the main underlying mechanism of bladder megacystitis?
either a diatal stenosis for reflux
what anamalies are associated with bladder megacystits?
- posterior urethral valves
- chromosomal anomalies
- oligohydramnois
- Megacystis microcolon intestinal hypoperistalsis (MMIH) syndrome (Berdon syndrome)
- megacystis megaureter syndrome
- prune belly syndrome
what is a persistant cloaca?
a confluence of the rectum, vagina, and urethra into a single common channel.
who does cloacal malformation occur in?
girls
what defect is the most formidable technical challenges in pediatric surgery
cloacal malformation
what is bladder exstrophy?
anterior abdominal wall and anterior wall of bladder fail to form
what is bladder extrophy associated with?
- seperation of the pubic bones
- low set umbilicus
- abnormal genitalia
what does bladder exstrophy look like sonographically?
- fluid filled bladder not isentified
- mucosa my be seen as irregular mass on the anterior abdominal wall, inferior to umbilicus
what is bladder exstrophy mostly associated with?
OEIS complex
what is the second common cause of urethral level obstruction and causes the most severe form of urinary obstruction?
urethral atresia
what are the sonogrpahic signs of urethral atresia?
megacystis associated with anhydramnois
what is prune belly syndrome also known as?
eagle barrett syndrome
what is prune belly syndrome?
- absent anterior abdominal musculature
- undescended testes
- urinary tract abnormalities
what are te characteristiics for prune belly syndrome?
bladder distention interfaces with the descent of the testes and is responsible for cryptorchisism
what is the classic triad for prune belly syndrome?
- absent abdominal musculature
- undescended testis
- urinary tract abnormalities
what else is associated with prune belly syndrome?
- very large bladder
- dilated prostatic urethra
- ureters tortous and dilated
- kidneys normal, hyponephrotic or displastic
what us hydrocele?
It is the accumulation of fluid in the tunica vaginalis, which surrounds the testes.
when are small hydroceles common and is a normal finding?
in the 3rd trimester
what do large hydroceles suggest?
an open or unclosed processus vaginalis and should be evaluated postnatally for inguinal hernia
majority of fetal ovarian cysts are what?
benign and functional
in the second half of pregnancy the main sources of fluid production are from what?
urine and lung secretions
what are the main sources of fluid clearance?
- fetal swallowing of fluid and passing it back into mothers blood stream
- direct flow across the amnion into placental blood vessels
when is stomach documented?
2nd or 3rd trimester
what is a small or absent fetal stomach associated with?
- aneuploidy
- tracheosophageal fistula
- oligohydramnios
what is esophageal atresia?
a congenital absence of a segment of the esophagus most often associated with tracheoesophageal fistula
what is the most common esophageal atresia?
fistula connecting the distal portion of the esophagus with the trachea (90%)
when should esophageal atresia be suspected?
when an empty or small fetal stomach is seen in the presence of polyhydramnois
what is a direct sign of esophageal atresia? (upper neck puch sign)
visualization of the proximally dilated esophagus
the grouping of anomalies with esophageal atresia is known as what?
VACTERL
what are reasons for an absent stomach?
- normal stomach that recently emptied
- herniated stomach into chest
- displaced stomach into abdominal wall defect
- esophageal atresia
- aneuploidy
- anhydrmnois
- microgastia
abnormal gastric dilation is most commonly seen in association with what?
duodenal atresia
what does diagosing a dilated stomach require?
dilated for 30 min
what is the most common site of intestinal atresia?
duodenal
what is the doubel bubble sign?
2 fluid filled bubbles
- dilated stomach
- silated prox duodenum
when is polyhydramnois frequently presented?
late 2nd trimester
what is the most common etiology hypothesized for jejunoilieal atresia?
isolated vascular compromise
what is diagnosis of Jejunal-ileal obstruction?
dilated loops of bowel
what is the top normal lumen diameter used to diagnose bowel dilation?
7mm
what is the apple peel sign?
subtype of jejunal-ileal obstruction, agenesis of the mesentery and is more often familial
what is a common underlying etiology for ileal obstruction?
cystic fibrosis
of all the large bowel atresias, which is the most common?
anorectal atresia
what have the highest incidence of associated anomalies?
anorectal malformation
what is the sonographic diagnosis of anorectal atresia?
dilated loops of small or colon in the absence of polyhydramnois
what is the management of anorectal atresia?
fetal echocardiogram
genetic counselling
what is echogenic bowel associated with?
- aneuploidy
- cystic fibrosis
- meconium peritonitis
- congenital viral infection
when is echogenic bowel normal?
normal in the 3rd trimester
what is the most common anomaly of abdominal wall?
omphalocele
what is omphalocele identified by?
herniation of abdominal organs (live and bowel) into the base of the umbilical cord
what is omphalocele associated with?
- heart defects
- chromosome anomalies (tri-18 most common)
what is omphalocele mostly associated with?
pentalogy of cantrell and beckwith-wiedemann syndromes
what is the sonographic diagnosis of omphalocele?
- ventral mass seen at the cord insertion site
- may be small or large (bowel and liver) and appear solid
- COVERED BY A MEMBRANE
- ascites may be seen in peritonel membrane
what is pentalogy of cantrell?
- ectopia cordis
- heart defects
- diaphragmatic hernia
- pericardial defect
- omphalocele
what is beckwith-wiedemann syndrome?
- macrosomia
- macroglossia
- omphalocele
- renal neoplasm
- gigantism
what is Gastroschisis?
a cleft defect of the anterior abdominal wall with extrusion of abdominal organs into the amniotic cavity
where is Gastroschisis most commonly located?
right of midline at umbilical level and usually only contains small bowel
what are complications reuslting from bowel malformation and associated with bowel obstruction?
neonatal morbidity and mortality
what is the increase incidence of gastroschisis?
teenage mothers
what are associated GI abnormalities with gastroschisis?
atresias, stenosis, perforations, or volvus
what is located in the fetal abdomen?
- umbilical vein
- liver
- IVC
- descending aorta
- spleen
- fetal stomach
when can hepatomegaly be seen in what?
severe hemolytic disease
splenomegaly
hydrops
do we routinely evaluate the spleen?
no
what is splenomegaly associated with?
severe hemolytic disease due to isoimmunization and infection
what is asplena associated with?
situs inversus
what is heterotaxy sydrome?
a disorder that results in certain organs forming on the opposite side of the body
what are choledochal cysts?
congenital sacculations of the common bile duct
what is the most common type of choledochal cyst?
saccular cystic dilation of the CBD
when are fetal adrenal glands imaged?
after 20 weeks gestation
what is the appearance of adrenal glands?
hypoechoic and the central medulla is moderately echogenic
what is a neuroblastoma?
malignant tumour of the adrenal gland
what is the most common neonatal tumor?
neuroblastoma
what does a neuroblastoma appear as?
complex masses and often areas of calcification
