Chapter 62 Fetal Abdomen PPT

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1

2nd

arteries; vein

Introduction:

Fetal abdominal organs well formed by ____ trimester

Differences between fetal and adult abdomen:

1. Umbilical ____ and ___ provide important anatomic landmarks for fetal abdominal anatomy and measurements.

2

Ductus

larger

larger

Introduction:

_____ venous is patent; serves as conduit between portal veins and systemic veins

3. Proportions of fetal body differ from adult:

  • Fetal abdomen _____ relative to body length
  • Liver occupies ____ volume of fetal abdomen
3

small

unfused

ascites

Introduction:

Fetal pelvic cavity ____

  • Urinary bladder, ovaries, uterus lie in abdominal cavity

4. Apron of greater omentum small

  • Contains little fat
  • Remains ____ in fetus
  • Therefore, fetal ____ may separate omental leaves
4

4th

Embryology of the Digestive System:

  • Primitive gut forms during __ week of gestation as dorsal part of yolk sac incorporated into embryo during folding
  • Primitive gut divided into three sections:
    • Foregut
    • Midgut
    • Hindgut
5

duodenum

Foregut:

  • Derivatives of foregut
  • Pharynx
  • Lower respiratory system
  • Esophagus
  • Stomach
  • Part of the ____
  • Liver and biliary apparatus
  • Pancreas
6

beginning

7th

Tracheoesophageal

Esophagus:

  • Short in ____
  • Rapidly lengthens as body grows
  • Reaches its final length by ___ week
  • _____ septum partitions trachea from esophagus
7

atresia; tracheoesophageal

posterior

hydramnios

Esophagus:

  • Esophageal ____ usually associated with ______ fistula
  • Results from abnormal deviation of tracheoesophageal septum in ____ direction
  • Amniotic fluid cannot pass to intestines for absorption; ____ results
8

stenosis

8th

Esophagus:

  • Esophageal ____ is narrowing of esophagus
  • Usually in distal third portion
  • Occurs from incomplete recanalization of esophagus during ___ week of development
9

caudal

5th; 6th

Stomach:

  • Appears as fusiform dilation of ____ part of foregut
  • During ___ and ___ weeks, dorsal border (greater curvature) grows faster than ventral border (lesser curvature)
10

left

epiploic foramen

Stomach:

  • Suspended from dorsal wall of abdominal cavity by dorsal mesentery or dorsal mesogastrium
  • Dorsal mesogastrium carried to ____ during rotation of stomach and formation of cavity known as omental bursa, or lesser sac of peritoneum
  • Lesser sac communicates with main peritoneal cavity or greater peritoneal sac through small opening, called ____ _____
11

Two

Duodenum:

  • Develops from caudal part of foregut and cranial part of midgut
  • ___ parts grow rapidly and form C-shaped loop that rotates to right
  • Comes to lie primarily in retroperitoneum
12

CBD

celiac; SMA

Duodenum:

  • Junction of two embryonic parts of duodenum in adult just distal to entrance of ___
  • Supplied by branches of ___ trunk and ____
13

5th; 6th

8th

Duodenum:

  • During ___ and ___ weeks, lumen of duodenum becomes partly or totally occluded (depending on proliferation of its lining of epithelial cells)
  • Normally duodenum recanalized by end of __ week
14

3rd; 4th

Duodenum:

  • Partial or complete failure of process results in either:
    • Duodenal stenosis (narrowing) or
    • Duodenal atresia (blockage)
  • Usually __ or ___ parts of duodenal affected
15

4th

Liver and Biliary System:

  • Liver, gallbladder, biliary ducts arise as bud from most caudal part of foregut in ___ week
  • Hepatic diverticulum grows between layers of ventral mesentery
  • Rapidly enlarges and divides into two parts
16

primordium

gallbladder; cystic duct

Liver and Biliary System:

  • Liver grows rapidly
  • Intermingles with vitelline and umbilical veins; divides into two parts
  • Fills most of abdominal cavity
  • Large cranial part is _____ of parenchyma of liver
  • Small caudal part gives rise to ____ and ____ ____
17

Hemopoietic

transversum

Liver and Biliary System:

  • _____ cells, Kupffer cells, connective tissue cells derived from mesenchyme in septum transversum
  • Septum _____ is mass of mesoderm between pericardial cavity and yolk stalk
  • Forms major part of diaphragm and ventral mesentery
18

6th

7th; 9th

Liver and Biliary System:

  • Hemopoiesis (blood formation) begins during ___ week
  • Accounts for large size of liver between ___ and ___ weeks of development
  • By 12th week, bile formation by hepatic cells has begun
19

infection

Liver and Biliary System:

  • Extrahepatic biliary atresia
    • Blockage of bile ducts results from failure to recanalize following solid stage of development
  • Malformation may result from interference with blood supply of ducts resulting from _____ during fetal period
20

foregut

right

Pancreas:

  • Develops from dorsal and ventral pancreatic buds of endodermal cells that arise from caudal part of _____
  • When duodenum grows and rotates to ____, ventral bud carried dorsally and fuses with dorsal bud
21

accessory

Pancreas:

  • Ducts of two pancreatic buds join
  • Combined duct becomes main pancreatic duct that opens with bile duct into duodenum
  • Proximal part of duct may persist as ____ pancreatic duct
22

mesogastrium

Spleen:

  • Lymphatic organ derived from mass of mesenchymal cells located between layers of dorsal ____
  • Lobulated in fetal period
23

SMA

The Midgut:

  • Derivatives of midgut:
    • Small intestines
    • Cecum and cloaca exstrophy
    • Ascending colon
    • Most of transverse colon
  • All structures supplied by ____
24

mesentery

yolk sac

The Midgut:

  • Suspended from abdominal wall by elongated dorsal ____
  • Communicates with ___ ____ via yolk stalk
  • While midgut lengthens and forms midgut loop, it herniates outside abdomen into proximal part of umbilical cord
25

10th; 11th

The Midgut:

  • Usually by ___ or ____ week, midgut herniation returns to abdomen
  • Undergoes further rotation resulting from decrease in size of liver and kidneys and growth of abdominal cavity
26

retroperitoneal

The Midgut:

  • After intestines return to abdominal cavity, they enlarge, lengthen, and assume final positions.
  • Mesenteries pressed against posterior abdominal wall
  • Ascending colon and descending colon become _____
27

ileocecal

The Midgut:

  • Duodenum and most of pancreas also become retroperitoneal structures
  • Small intestines form new line of attachment that extends from where duodenum becomes retroperitoneal to _____ junction
28

omental bursa

The Midgut:

  • Mesentery of transverse colon fuses with dorsal mesogastrium to form posterior wall of inferior part of ____ ____
  • Sigmoid colon retains its mesentery
    • Shorter than in early fetus
29

10th

OMPHALOCELE AND GASTROSCHISIS:

  • Defects that occur when midgut fails to return to abdominal cavity from umbilical cord during ___ week
30

Omphalocele

Umbilical cord

OMPHALOCELE AND GASTROSCHISIS:

_____: Coils of intestine protrude from umbilicus and are covered by transparent sac of amnion

____ ____ pierces central part of omphalocele

31

Gastroschisis

right

OMPHALOCELE AND GASTROSCHISIS:

_____: Condition in which bowel and/or organs free floating from midline defect

Is usually located to ____ of umbilical cord

32

protruding mass

Umbilical Hernia:

  • Forms when:
    • Intestines return abnormally to abdominal cavity
    • Herniate either prenatally or postnatally through inadequately closed umbilicus
  • Hernia differs from omphalocele in that ____ ____ (omentum or loop of bowel) covered by subcutaneous tissue and skin
33

most common

5

Meckel’s Diverticulum:

  • Is the ____ ____ malformation of midgut
  • Remnant of proximal part of yolk stalk that fails to degenerate and disappear during early fetal period
  • Usually small fingerlike sac, about __ cm long, projects from border of ileum
34

Superior

IMA

The Hindgut:

  • Derivatives of hindgut:
    • Left part of transverse colon
    • Descending colon
    • Sigmoid colon
    • Rectum
    • _____ portion of anal canal
    • Epithelium of urinary bladder
    • Most of urethra
  • All of structures supplied by ____
35

14; 16

STOMACH:

  • Identified as fluid-filled structure in left upper quadrant inferior to diaphragm
  • Most fetuses older than __ to __ weeks should have fluid in their stomach.
36

...

STOMACH:

  • If no fluid apparent, stomach should be reevaluated in 20 to 30 minutes to rule out possibility of:
    • Central nervous system problem (swallowing disorders)
    • Obstruction
    • Oligohydramnios
    • Atresia
37

day; week

least

STOMACH:

  • If fluid still not noted during sonographic evaluation, fetus may be reexamined following ___ or ____ to see if there is a change in stomach size
  • Esophageal anomalies are ___ common problem for nonvisualization of stomach
38

Echogenic

STOMACH:

  • Fluid within stomach should be anechoic with linear rugae.
  • ____ debris may sometimes be seen along dependent wall of stomach. May represent:
    • Vernix
    • Protein
    • Intra-amniotic hemorrhage
39

hematoma

STOMACH:

  • Presence of echogenic mass in fetal stomach in patient who demonstrates clinical or sonographic evidence of placental abruption should raise possibility of _____ formation associated with intra-amniotic hemorrhage
40

left

situs inversus

STOMACH:

  • Is usually located on ____ of abdomen
  • If stomach seen in right upper quadrant, condition is called ___ ____
  • Fetal position must be identified, followed by identification of right and left sides of fetus
  • If fetus is in vertex presentation with spine up, both aorta and stomach should be seen to left of spine
41

2nd; 3rd; echogenic

Esophagus:

  • Normal esophagus can be visualized in thorax during ___ and ___ trimesters as two or more parallel ____ lines (“multilayered” pattern)
  • Sometimes possible to see fluid in esophagus as fetus swallows amniotic fluid
42

round; oval

Abdominal Circumference:

  • Measured at level of portal sinus and umbilical portion of left portal vein (“hockey stick” appearance on sonogram)
  • Abdominal circumference should be ____, not ____.
  • Pressure of transducer should not compress abdominal cavity
43

cephalically

left

Umbilical Cord Insertion:

  • In fetus, umbilical vein courses _____ in free, inferior margin of falciform ligament
  • Joins umbilical portion of ___ portal vein at caudal margin of left intersegmental fissure of liver
44

4th; 5th

11

Bowel:

  • Movement of gastric musculature begins in approximately ___ to ____ month of gestation
  • Sonographic appearance of bowel varies with menstrual age
  • Fetus capable of swallowing sufficient amounts of amniotic fluid to permit visualization of stomach by __ menstrual weeks
45

15th; 16th

Desquamated

Bowel:

  • After ___ to ____ week, meconium begins to accumulate in distal part of small intestine
  • Is a combination of:
    • _____ cells
    • Bile pigments
    • Mucoproteins
46

20

Bowel:

  • Until mid-second trimester, small bowel lumen quite difficult to demonstrate
  • Appears as ill-defined area of increased echogenicity in mid to lower abdomen
  • Distinction of large bowel from small bowel possible after __ menstrual weeks
47

hyperechoic

Hyperechoic

Hyperechoic

Bowel:

  • Region of small bowel is slightly _____, compared with liver
  • May appear “masslike” in central abdomen and pelvis
  • _____ appearance could be secondary to reflections from walls of collapsed loops of small bowel or from mesenteric fat between loops
  • _____ appearance of small bowel persists throughout pregnancy
48

less

27

5; 15

Bowel:

  • As pregnancy progresses:
    • Hyperechoic area becomes ____ prominent
    • Small bowel located more centrally in abdomen than colon
    • After ___ weeks, peristalsis of normal small bowel increasingly observed
    • Normal diameter of small bowel lumen ≤_ mm, with length of __ mm near term
49

hypoechoic

Haustral folds

thin

Bowel:

  • Colon seen near end of second trimester as long tubular _____ structure with well-defined walls
  • ____ ____ of colon help to differentiate it from small bowel
  • In early gestation, haustral folds appear as ___ linear echoes within lumen of colon
  • Later, colon diameter increases and folds become longer and thicker
50

3-5; 23

not

Bowel:

  • Normal measurements of colon diameter range from __-__ mm at 20 weeks to ___ mm or larger at term
  • Colon more peripheral than small bowel
  • Hypoechoic echoes from meconium may be seen within lumen
  • Colon does ___ have peristalsis like small bowel
51

14

hypoechoic

Bowel:

  • After __ weeks of gestation, lipid absorbed from fetal colon and remaining contents collect in colon as meconium
  • Meconium within lumen of colon appears _____ relative to fetal liver and in comparison with bowel wall
  • This is the point where normal colon can be mistaken for abnormally dilated small bowel or other pathologic processes, including renal cysts and pelvic masses.
52

10; 11; 5

LIVER:

  • Relatively large compared with other intraabdominal organs
  • Occupies most of upper abdomen in fetus
  • Accounts for __% of total weight of fetus at __ weeks and __% of total weight at term
53

1st

Left; right

Reverses

Liver:

  • Hepatic veins and fissures formed by end of ___ trimester
  • ___ lobe of liver larger than ___ in utero secondary to greater supply of oxygenated blood
  • ____ after birth
54

20

Gallbladder:

  • May be seen sonographically after __ weeks of gestation
  • Both gallbladder and portal-umbilical vein appear as oblong, fluid-filled structures on transverse view of fetal abdomen through liver
55

utero

Pancreas:

  • Normal fetal pancreas has been seen in ____ but is more difficult to routinely visualize because of the lack of fatty tissue within the gland
  • Lies in the retroperitoneal cavity anterior to the superior mesenteric vessels, aorta, and inferior vena cava (IVC)
56

kidney

less

Spleen:

  • Homogeneous in texture
  • Similar in echogenicity to ____
  • Slightly ___ echogenic than liver
  • Increases in size during gestation
  • Imaged on transverse plane posterior and to left of fetal stomach
57

hematopoiesis

Abnormalities of the Hepatobiliary System - Liver:

  • Is involved in several congenital anomalies but rarely affected by isolated hepatic lesions
  • Liver parenchymal cysts and hemangiomas of liver have been reported
  • Enlarges in fetuses with Rh-immune disease in response to increased ______
58

Hemangioendothelioma

Liver:

  • Liver tumors, hamartoma, hepatoblastoma uncommon but may be seen
  • Other tumors seen with sonography include hepatic teratoma, adenoma, or metastases from neuroblastoma.
  • ______
    • Most common symptomatic, vascular hepatic tumor of infancy (although rare)
    • May cause nonimmune hydrops in fetus
59

hypoechoic

5

Liver: Sonographic Findings

  • Most liver tumors appear as ____ solid masses; cystic components have also been reported as mixed with solid masses
  • About __% of benign and malignant liver tumors are calcified.
60

calcification

benign

Liver:

  • Liver ____ may be observed as isolated echogenic focus
  • Is usually a _____ finding
  • If multiple calcifications seen within liver, other organs such as brain and spleen may be affected
61

more severe

Situs Inversus:

  • May present as total reversal of thoracic and abdominal organs or as partial reversal (mirror image)
  • Partial situs inversus
    • Is ___ ____ disorder
    • May develop in two different combinations of organ reversals
    • Thoracic viscera usually reversed
    • Abdominal viscera may or may not be reversed
62

asplenia; polysplenia

Asplenia

Situs Inversus:

  • Partial situs divided into ____ and _____
  • ____ (absence of spleen):
    • Abnormally positioned stomach and gallbladder
    • More centrally positioned liver
    • Abnormal positioning of aorta and IVC on same side
63

Polysplenia

two

Heart block

Situs Inversus:

  • _____ represented as transposition of liver, spleen, stomach, and absence of gallbladder
  • Interruption of IVC and azygos vein directly posterior to heart and in front of spine
  • At least ___ spleens present along greater curvature of stomach
  • ____ _____ common in polysplenia syndrome
64

99; 90

Situs Inversus:

  • Cardiac malformations common (__%) in asplenia syndrome; are seen with less frequency in polysplenia syndrome (__%)
  • Cardiac defects:
    • Endocardial cushion defects
    • Hypoplastic left heart
    • Transposition of great vessels
65

normal

20

90; 95; 80

Situs Inversus:

  • Infant with total situs inversus usually has ____ outcome
  • About ___% may have Kartagener’s syndrome (immotile cilia, bronchiectasis)
  • Mortality rate for partial situs inversus extremely high; death occurs in ___% to __% with asplenia syndrome and __% with polysplenia syndrome
66

Total

Partial

Situs Inversus: Sonographic Findings

  • ____ situs inversus (right-sided heart axis and aorta; transposition of liver, stomach, spleen; left-sided gallbladder)
  • ____ situs inversus (right-sided stomach, left-sided liver); dextrocardia with normal stomach position (see previous section)
  • Other anomalies to check for include gastrointestinal, genitourinary, and neural tube defects
67

...

Causes of Ascites:

  • Genitourinary
  • Gastrointestinal
  • Liver
  • Cardiac
  • Infections
  • Metabolic storage disorders
  • Idiopathic
68

meconium peritonitis; ascites

Pseudoascites: Many causes of pseudoascites in fetus

  • Gastrointestinal obstruction with bowel perforation may present as ____ _____ and _____
  • Nongastronintestinal causes include:
    • Immune and nonimmune hydrops
    • Urinary tract obstruction
    • Congenital infection
    • Some abdominal tumors
69

18

small

Pseudoascites: Sonolucent band near fetal anterior abdominal wall commonly identified during routine obstetric examinations in fetus over __ weeks of gestation

  • Band results from normal musculature surrounding abdominal wall
  • True ascites identified within peritoneal recesses; is interspaced between loops of ____ bowel
  • Pseudoascites always confined to anterior fetal abdomen and centrally located
  • Pseudoascites never outlines falciform ligament like true ascites
70

Cholelithiasis

Gallbladder:

  • Anomalies of the gallbladder may be detected using prenatal sonographic techniques.
  • _____ may be identified in fetus when calcifications are found within gallbladder.
  • Gallstones resolve spontaneously in utero or childhood period.
71

Choledochal

Choledochal

Gallbladder:

  • _____ cyst (dilation of CBD) may be diagnosed when cystic mass identified adjacent to fetal stomach and gallbladder
  • _____ cysts may be confused with malformations of stomach or bowel or duodenal atresia
  • Gallbladder more anterior than duodenum, and cystic mass attached to bile duct near gallbladder would make mass more likely to be a choledochal cyst
72

neck

SONOGRAPHIC CRITERIA FOR CHOLEDOCHAL CYST

  • Close proximity of cyst to ____ of gallbladder
  • Ovoid right upper quadrant cyst with entering bile duct
  • Cyst and gallbladder that enlarge as gestation progresses
  • Absence of peristaltic activity in cyst
73

Agenesis; 20

Gallbladder:

  • ____ of gallbladder occurs in approximately __% of patients with biliary atresia
  • Absence of gallbladder can occur in association with polysplenia and rare multiple anomaly syndromes
  • The ability to visualize fetal gallbladder increases with gestational age.
74

asplenia

Spleen:

  • Fetal spleen can be evaluated to exclude splenic anomalies
  • Asplenia (absence of spleen) may be amenable to antenatal identification
  • When ____ associated with congenital heart disease, polysplenia-asplenia syndrome should be considered
75

rare

Enlargement

Rh-immune disease

Spleen:

  • Congenital splenic cysts ___
  • ____ of spleen (splenomegaly)
  • Spleen, like liver, may enlarge in fetuses with ___ ____
76

infarcts

Polyhydramnios

Abnormalities of the Gastrointestinal Tract: Atresia

  • Develop when portion of bowel grows and ____
  • Occurs anywhere in gastrointestinal tract
  • ____ evident on ultrasound
77

Membrane

narrowed

hydramnios

Abnormalities of the Gastrointestinal Tract:

  • Obstruction of normal swallowing sequence may occur because of atretic or obstructive process
  • _____ covering lumen and intestinal loops enlarges above obstruction
  • Bowel loops below atresia ____ (stenotic)
  • Blockage results in back-up of amniotic fluid and _____
78

respiratory; digestive

Most common

Esophageal Atresia:

  • Is a congenital blockage of the esophagus resulting from faulty separation of foregut into its ____ and ____ components
  • ____ _____ form occurs in conjunction with a fistula, communicating between trachea and esophagus (tracheoesophageal fistula). allows passage of amniotic fluid into stomach
79

not; not

not

Esophageal Atresia:

  • Gastric secretions may contribute to stomach fluid
  • Fistula may not be present and fluid will ___ reach stomach; stomach will ___ be visualized by ultrasound
  • Combination of polyhydramnios and absent stomach over repeated studies may be suggestive of esophageal atresia
  • Will ___ be diagnosed in majority of cases because of tracheoesophageal fistula
80

50

Upper neck

Esophageal Atresia:

  • May observe absent stomach and hydramnios
  • In >___% of cases, stomach present because fistula usually present that leads to fluid filling stomach
  • Hydramnios may exist from impaired reabsorption of swallowed fluid and be associated with esophageal atresia; usually does not develop until third trimester
  • ___ ____ sign has been observed as additional finding
81

50; 70

40

Esophageal Atresia:

  • Coexisting anomalies common in __% to __% of fetuses with esophageal atresia
  • Most commonly observed anomaly is anorectal atresia and VACTERL
  • Growth restriction present in __% of cases
  • Chromosomal trisomies (18 and 21) reported
82

membrane

below

Duodenal Atresia:

  • Blockage of duodenal lumen by _____ that prohibits passage of swallowed amniotic fluid
  • Atresia or narrowing of bowel segment ____ obstruction occurs
  • Amniotic fluid fails to move beyond obstruction, and, consequently, amniotic fluid backs up in duodenum and stomach.
83

stomach; duodenum

double bubble

always

annular pancreas

Duodenal Atresia: Sonographic Findings

  • Two echo-free communicating structures (_____ and _____) found in upper fetal abdomen
  • Sonographic appearance termed “____ ____ sign”
  • Hydramnios almost ____ seen with duodenal atresias later in pregnancy
  • Most cases found distal to ampulla and often coexist with ____ _____
84

stenosis

Annular

Duodenal Atresia: CAUSES OF DOUBLE BUBBLE

  • Duodenal atresia
  • Duodenal ____
  • ____ pancreas
  • Ladd’s bands
  • Proximal jejunal atresia
  • Malrotation
  • Diaphragmatic hernia
85

30

50

Duodenal Atresia:

  • About ___% of fetuses with duodenal atresia have trisomy 21 (Down syndrome)
  • Cardiovascular anomalies frequent; fetal echocardiography invaluable in excluding cardiac lesions
  • Anomalies occur in approximately ___% of infants with duodenal atresia.
86

more

drug

Bowel Intestinal Obstructions:

  • Atresia or stenosis of jejunum or ileum, or both, and small bowel atresia slightly ____ common than duodenal atresia
  • Occurs in 1 in 3000 to 5000 live births; thought to be secondary to vascular accident, volvulus or gastroschisis or be sporadic
  • Various fetal malformations may occur with maternal ___ use.
87

hydramnios

Bowel Intestinal Obstructions:

  • Entire length of bowel subject to obstruction
  • Blockage of jejunum and ileal bowel segments (jejunoileal atresia or stenosis) appears as multiple cystic structures (more than two) proximal to site of atresia within fetal abdomen
  • Structures high in abdomen, so ____ may be present
88

distal; less

Bowel Intestinal Obstructions: General rule: The more ___ the obstruction, the ___ severe the hydramnios, and the later it will develop.

  • Causes of fetal small-bowel obstruction include:
    • Malrotation
    • Atresias
    • Volvulus
    • Peritoneal bands
    • Cystic fibrosis
  • Dilated bowel loops isolated or associated with other anomalies, ascites, or meconium peritonitis
89

gastroschisis

Bowel Intestinal Obstructions: Sonographic Findings

  • Intestinal obstructions appear as cystic bowel loops discontinuous with stomach
  • Fetal intestinal obstruction should be suspected when clear cystic structures found in pelvis
  • Vascular restriction may lead to obstruction secondary to _____
90

meconium

10; 15

cystic fibrosis

Meconium Ileus:

  • Is a small-bowel disorder marked by presence of thick ____ in distal ileum
  • Earliest manifestation of cystic fibrosis occurring in __% to __% of patients; is third most common form of neonatal bowel obstruction after atresia and malrotation
  • Most cases of meconium ileus occur in newborns with ____ ____
91

2nd

Meconium Ileus:

  • Meconium begins to accumulate in the fetal bowel in the ___ trimester, at which time it can be seen sonographically as tiny echogenic reflections within the peristaltic small bowel.
  • Because the colon does not exhibit peristalsis in utero, the meconium remains suspended at the rectum.
  • The anal sphincter prevents the passage of meconium (meconium plug) into the amniotic fluid, unless the fetus is stressed or traumatized.
92

echogenic

cystic fibrosis

Meconium Ileus: Sonographic Findings

  • Ileum dilates because of impacted meconium (which appears _____)
  • Increased production of mucus by GI organs and electrolyte imbalance explains overproduction of meconium (characteristic of ____ ____)
93

echogenic

echogenic

Pseudocyst

Meconium Ileus:

  • Normal small bowel may appear _____ during second trimester of pregnancy.
  • Other fetal conditions associated with ____ small bowel (cytomegalovirus and trisomy 21)
  • Meconium peritonitis may occur secondary to perforation of obstructed bowel.
  • Inflammatory response occurs because of leakage of bowel contents, which may cause fibrosis of tissue and calcifications.
  • ____ may develop because of chronic meconium peritonitis.
94

microcolon

Pitfalls in the Diagnosis of Meconium Ileus:

  • Significant dilation of meconium-filled ileum in meconium ileus can simulate colon in morphology and location, especially in presence of expected _____
  • More proximal small bowel can retain expected features of active peristalsis and fluid-filled contents
    • Discrepancy in caliber between proximal and distal small bowel should not distract sonologist from diagnosis of small-bowel obstruction or meconium ileus
95

complex

VACTERL

poor

Anorectal Atresia:

  • Presents as ____ disorder of bowel and genitourinary tract
  • Imperforate anus is disorder that occurs when membrane covers anus, prohibiting expulsion of meconium
  • May present as part of _____ association or in caudal regression
  • Prognosis ____ with anorectal atresia because of associated anomalies
96

normal

Anorectal Atresia:

  • May be diagnosed sonographically by observing dilated colon and calcified meconium
  • Amniotic fluid typically ____ or may be decreased with associated renal problems
97

Megacolon

Hirschsprung’s Disease:

  • _____ is congenital disorder in which there is abnormal innervation of large intestine
  • Sonographic Findings
    • Is difficult to diagnose prenatally but may be suspected when dilated bowel loops observed
98

Hydramnios

Meconium Peritonitis:

  • Condition that may arise when fetus has sterile chemical peritonitis secondary to in utero bowel perforation
  • ____ present in 65% of fetuses
  • Complication may result in formation of meconium pseudocyst, as inflammatory reaction seals perforation
99

Calcifications

echogenic

Meconium Peritonitis: Sonographic Findings

  • ____ seen on peritoneal surfaces or in scrotum via processus vaginalis
  • Ascitic fluid may be ____.
  • Is unusual to see calcification in meconium ileus in fetus with cystic fibrosis
100

Mildly; diffuse

Moderately; focal

Very

Hyperechoic Bowel:

Grade 1: _____ echogenic and typically ____

Grade 2: ____ echogenic and typically ____

Grade 3: ____ echogenic; similar to that of bone structures

101

always

poor

Ascites:

  • True ascites in fetal abdomen ____ abnormal
  • In fetus, ascitic fluid collects between two leaves of unfused omentum, resulting in cystlike appearance in abdomen
  • Prognosis ____ in nonimmune hydrops
  • Other conditions that may cause ascites to develop include bowel perforation or urinary ascites secondary to bladder rupture.