Test 1 Flashcards
(158 cards)
1
Q
What is the definition of congenital anomaly?
A
Departure from the normal anatomic architecture of an organ or system
2
Q
What is ultrasound role for congenital anomalies?
A
- Absence of normal anatomic structure
- Disruption of contour, shape, location, texture, or size
- Presence of an abnormal structure
- Abnormal fetal biometry
- Abnormal fetal motion
3
Q
“At Risk” groups for congenital anomalies?
A
- Advanced maternal age
- Positive family history
- Exposure to exogenous teratogenic agents
- Maternal diabetes
- Elevated maternal serum AFP
4
Q
What is the incidence of congenital anomalies?
A
3 in 100 births
10-15% have minor defects
5
Q
True or False?
It is important for the general sonographer, not just the high-risk specialist, to be able to perform a detailed examination and to recognise at least the most common anomalies?
A
True
6
Q
What is the systematic approach?
A
Used for anatomic assessment of the fetus. If it is done without a logical sequence, there is definitive risk that features will be missed.
7
Q
True or False?
Thorax is slightly larger than the abdomen throughout pregnancy?
A
False, smaller
8
Q
Normal appearance of fetal lungs?
A
- Lateral borders of the fetal heart
- Sickle-shaped
- Uniformly echoic
- RT lung profile larger, due to leftward orientation of cardiac apex
9
Q
What do we assess in the lungs?
A
- Fetal breathing movements (after 18 weeks gestation)(abdomen expansion, diaphragmatic bouncing, color nostrils)
- Development (size, texture, location, look for masses)
- Echogenicity (more echogenic as pregnancy progresses)
10
Q
True or False?
Normal fluid- filled fetal lungs are observed as homogenous masses of tissue
A
True
11
Q
Lung echogenicity can be variable depending on fetal age. What is it compared to for relative echo density?
A
Liver
- Earlier Gestation= more hypo echoic than liver
- Later Gestation= more hyper echoic than liver
12
Q
What causes pulmonary hypoplasia?
A
Prolonged oligohydramnios or a reduction in thoracic dimension as a result of structural or chromosomal abnormalities.
13
Q
What does pulmonary hypoplasia lead to?
A
Restriction of lung growth
14
Q
What is thoracic hypoplasia?
A
A cardinal feature in many skeletal dysplasias and is the main cause of death in lethal skeletal dysplasias
15
Q
What may pulmonary hypoplasia occur with?
A
- Kidney Abnormalities (agenesis, MCKD, PUV)
- IUGR (because of oligohydramnios)
16
Q
What is pulmonary sequestration characterized by?
A
- Presence of EXTRA nonfunctioning pulmonary tissue
- Usually no communication w/ bronchial tree
- Receives blood supply from artery other than pulmonary branch
17
Q
What are the two types of pulmonary sequestration?
A
Intralobar and extralobar
18
Q
What is intralobar pulmonary sequestration?
A
Abnormal tissue lies within NL lung, favorable prognosis
19
Q
What is extralobar pulmonary sequestration?
A
Abnormal mass anatomically separate from NL lung
20
Q
Extralobar pulmonary sequestration is most common in?
A
Left Hemithorax, poor prognosis due to associated anomalies
21
Q
Ultrasound characteristics of intralobar pulmonary sequestration?
A
- Spherical, echodense, solid mass
22
Q
Ultrasound characteristics of extralobar pulmonary sequestration?
A
- Highly echogenic, non-pulsatile mass
- May displace heart
- Pyramidal/ triangular shape
- Normal abdominal viscera helps to differentiate from hernia
23
Q
What is cystic adenomatoid malformation (CAM)?
A
Normal lung tissue replaced by cysts, relatively uncommon
24
Q
What are the classifications of “CAM”
A
Types I,II,III
25
What is type I CAM?
- Macrocystic
- Single or multiple large cysts (>2cm)
- Good prognosis after resection
26
What is type II CAM?
- Multiple small cysts (
27
What is type III CAM?
- Microcystic
- Large lesion
- NON-Cystic!!!!
- Produces mediastinal shift (only 1 lobe affected)
- Prognosis is poor
28
Ultrasound characteristics of cystic adenomatoid malformation?
- Usually unilateral (may appear bilateral if affected lung herniates to opposite side)
- May be a cause of polyhydramnios and non-immune hydrops
- Cysts on types I and II
- Solid mass in type III
29
True or False?
| Type classification is imperative due to variance in prognosis
True
30
True or False?
| There should always be fluid collections around the fetal lungs or heart.
False
31
Pleural effusions usually occurs secondary to what?
Malformed thoracic duct (usually rt sided)
32
What is the pleural space?
A double-layered serous membrane surrounding the lungs, fluid in this space may be called pleural effusion or hydrothorax
33
What is pericardial space?
A serous membrane forming a sac around the heart, fluid in this space is called pericardial effusion
34
Ultrasound features of fluid in these spaces?
- Effusions will form an OUTLINING effect of the enclosed organs
- Always considered ABNORMAL
- May be unilateral or bilateral
- May cause ML shift
35
Mortality rate for infants with pleural effusion?
50%, even higher if associated hydrops
| *Some Causes: CHF, RH Disease, Non-Immune Causes, Chromosomal Abnormalities
36
Appearance of fetal diaphragm?
Thin, hypoechoic, curvilinear interface between liver and lungs. Visualization better on the right side.
37
True or False?
| The shape of the diaphragm may be a helpful indicator of disease
True
38
A flattened or inverted diaphragm should raise the index of suspicion for what?
A thoracic mass
39
The stomach should be demonstrated where compared to the diaphragm?
Inferior
40
What is congenital diaphragmatic hernia (CDH)?
Presence of abdominal viscera in the thoracic cavity, due a congenital defect in the diaphragm thru Foramen of Bochdalek
41
CDH is most commonly located where?
On the left side and posterolateral (90%)
42
CDH may involve which organs?
Stomach, intestines, liver
43
What is the prognosis of CDH?
Poor if found before birth or if stomach is found in chest or heart is underdeveloped. 75% mortality rate because of coexisting anomalies and respiratory insufficiency such as complete absence or hemidiaphragm or pulmonary hypoplasia present
44
Ultrasound characteristics of CDH?
- Mediastinal shift by mass
- Inability to demonstrate stomach in NL location
- Small abdominal circumference
- Polyhydramnios or oligohydramnios if stomach or swelling is impaired
- Abdominal organs identified in thoracic cavity
45
What is the only definitive diagnosis for CDH?
Abdominal organs identified in thoracic cavity.
| *Heart is pushed to right due to stomach creating dextroposition
46
When imaging the fetal heart you should evaluate?
- Location
- Orientation
- Chamber proportion
- Excluded masses and large defects
- Function (rate and rhythm)
- Exclude cardiac failure
47
What are the most common forms of heart disease?
1. Ventricular septal defect
2. Atrial septal defect
3. Pulmonary stenosis
48
What is the most anterior chamber?
Right Ventricle, Scan cephalic to stomach and obtain 4-chamber view
49
True or False?
| Size of RT and LT ventricle and thickness of ventricular wall are roughly the same
True (LT ventricular wall thicker in adult)
50
True or False?
| Symmetry of size and wall thickness suspicians cardiac anomaly
False
51
Intraventricular septum should be completely closed otherwise you will have?
Ventricular Septal Defect
52
Intra-atrial septum contains the normal flap of what until birth?
Foramen Ovale
53
Normal heart rate
120-160bpm
| *Signs of cardiac failure: cardiomegaly, effusions, fetal hydrops
54
Associated abnormalities of cardiac anomalies
Ectopia Cordis and Pentalogy of Cantrell
55
What is Ectopia Cordis?
Chest wall fails to close and heart forms outside of the thoracic cavity
56
What is Pentalogy of Cantrell?
RARE, associated with ectopia cordis
57
General OB sonography of the abdomen should include?
```
Stomach
Intestines
Gallbladder
Liver
Spleen
Kidneys and Adrenals
Bladder
Aorta
IVC
Umbilical Art or Vein
Portal Sinus and Ductus Venosus
```
58
Appearance of normal stomach?
- Cystic space in LUQ of fetal abdomen
- Variable size and shape
- Must be identified by 16 weeks gestation
- Filling should occur within 30 min study
59
Appearance of normal bowel?
- Variable dependent upon gestational age
- Echogenic soft tissue "mass" before 24 weeks
- More fluid-filled later
- Meconium products present in the 3rd trimester
- Look for peristalsis
60
Enlarged stomach may suggest?
Polyhydramnios and bowel obstruction
| seen as part of double bubble
61
Absence of stomach may suggest?
- Impedance in fetal swallowing
- Oligohydramnios
- Esophageal atresia
- Congenital diaphragmatic hernia (fetal chest)
62
What is gut atresia?
May occur in any part of GI tract lumen
| *Most result from failure of canalization of primary gut by 11th week*
63
Gut atresia is associated with what other anomalies?
Vacterl Syndrome
- Vertebral
- Anal
- Cardiac
- Tracheoesophageal
- Renal
- Limb
64
Most common sites of intestinal atresia?
Proximal jejunum
| Distal ileum
65
Duodenal atresia most common affected segment is?
2nd portion of duodenum
66
If polyhydramnios is present suspect obstruction where?
Above mid-jejunum
| More distal atresias are NOT associated with amniotic fluid
67
What is the Hallmark Sign?
"Double Bubble" Sign
| - Overdistended stomach and duodenum
68
Small Bowel Obstruction can be due to?
- Atresia
- Stenosis
- Bowel Malrotation (volvulus)
- Abnormally Thick Meconium (cystic fibrosis)
69
What is the danger in small bowel obstruction?
May lead to bowel perforation, thus meconium peritonitis
70
Ultrasound Appearance of Small Bowel Obstruction?
* Grossly Dilated Bowel Loops*
- increased peristalsis
- floating particles in bowel loops
- polyhydramnios (if proximal obstruction)
71
Normal bowel loops are very prominent in 3rd trimester, so only consider obstruction IF inner diameter of bowel loop is?
>7mm, with polyhydramnios
72
What is ileum?
Abnormal bowel distension
73
What is Meconium Ileus caused by?
Abnormally viscid meconium which accumulates and obstructs the distal ileum
74
Most common cause of Meconium Ileus?
Cystic Fibrosis
75
What is Meconium Peritonitis?
Sterile chemical peritonitis occurring in some cases of Intrauterine bowel perforation
76
Most common cause of Meconium Peritonitis?
Meconium Ileus
77
What is Sequelae?
```
Extruded meconium incites inflammatory disease
Results in:
- fibrosis
- calcification
- pseudocyst (sometimes)
```
78
Most reliable ultrasound finding for meconium peritonitis?
Echogenic foci in the fetal abdomen (represents calcifications)
79
Other findings associated?
- Polyhydramnios
- Fetal Ascites
- Large for dates clinically
80
When do we suspect meconium peritonitis?
Evidence of bowel obstruction with ascites
81
What is the only visible part of the normal fetal biliary tract and when is it recognized?
Fetal gallbladder after 20 weeks
82
Normal appearance of gallbladder?
Usually pear-shaped anechoic space in RUQ
83
Gallstones are common or rare?
Very rare but easily detected by ultrasound
| *Resolve spontaneously in utero or childhood*
84
What is Choledochal cyst?
Congenital dilation of CBD
| *Difficult to diagnose antenatally
85
When should you suspect Choledochal cyst?
If cyst is detected in RT half of upper fetal abdomen
| *May compress or displace the gallbladder
86
What is the most significant determinant of abdominal circumference?
Liver
* Very large antenatally (due to Hemopoeitic activity)
* Most significant determinant of abdominal circumference
87
Normal appearance of liver?
- moderately echoic
| - uniform texture
88
Abnormal signals of the liver?
- alterations in echogenicity (neoplasm)
- enlarged AC (Hepatogmegaly)
- decreased AC (abnormal function/IUGR)
- Calcifications (tumor or TORCH infection)
89
What does TORCH stand for?
Toxiplasmosos Rubella Cytomegalovirus Herpes or Human immune deficiency virus
90
Most important reason for identifying portal vein from umbilical vein to liver entrance and ductus venosum
AC circumference level
91
Is the pancreas easily identified?
Difficult to image in utero due to lack of retroperitoneal fat
92
Normal appearance of spleen?
- echoically similar to liver
- MUCH smaller than liver
- lies in posterior part of LUQ
93
Abnormal signals of spleen?
- ascites surrounding spleen
| - splenomegaly (Most commonly related to TORCH and erythroblastosis fetalis)
94
What abdominal vasculature is visualised?
- aorta and ivc anterior to spine
- renal artery branches
- aortic bifurcation
95
When can adrenal glands be sonographically visible?
Around 23-24 weeks
| *Relatively large for the fetus, do not mistake for kidney
96
Location landmarks for adrenal glands?
- anteromedial aspect of kidney's upper pole
| - aorta (lt) and ivc (rt) for anterior margins
97
Appearance of adrenal glands?
- Cortex is hypoechoic (3mm-6mm)
| - Medulla is thin, echogenic central area
98
Fetal kidneys VS adult kidneys?
- more lobulated contour
- larger and more hypo echoic pyramids
- less echogenic sinus
99
Similarities of fetal kidneys and adult kidneys
- collecting system not normally visible (minimal amount of renal pelvic fluid acceptable)
- dilation of renal calyx never normal
- may measure renal dimensions
100
Appearance of urinary bladder?
- spherical/elliptical
- anechoic structure
- in anterior, midline pelvis
- thin walls when distended
101
Abnormal signals of urinary bladder?
- thickened walls (bladder outlet obstruction)
- internal debris (mass or infection)
- abnormal filling/emptying (function or mass)
102
The normal bladder fills in empties every?
30-45 minutes
| if it empties and fills it proves at least one kidney is functioning
103
Appearance of ureters?
Normal ureter are never visible
| *Dilated ureter is ALWAYS pathologic
104
A dilated ureter will be seen as?
- tortuous
- cystic structure
- medial to kidney (in abdomen)
- posterior to bladder (in pelvis)
105
Sonographic findings of obstructive uropathy?
Depend upon level of severity of obstruction and whether its unilateral or bilateral
*Variations will occur in amniotic fluid volume dilation of collecting system "mass" effect
106
Most common causes of obstructive uropathy?
- Ureteropelvic junction (UPJ)
- Posterior Urethral Valves (PUV)
- Ureterocele
107
What is the most common cause of obstructive hydronephrosis in fetus and neonate?
Ureteropelvic Junction (UPJ)
108
Cause of ureteropelvic junction obstruction?
Anatomic developmental anomalies
109
Appearance of ureteropelvic junction obstruction
- asymmetric hydronephrosis
- most frequently on the left side if unilateral
- non-dilaterd ureter
* If both sides are not severely affected there will be normal amniotic fluid volume and normal urinary bladder*
110
What is the second most common cause of obstructive hydronephrosis in fetus and neonate?
Posterior urethral valves
| *Occurs only in male
111
Cause of posterior urethral valves?
Secondary to formation of valve-like soft tissue projecting into proximal part or urethra
112
Appearance of posterior urethral valves?
- bilateral hydronephrosis ALWAYS
(severity may be asymmetrical)
- may see dilated segment of urethra from neck of bladder
- CANNOT demonstrate urethral valves
113
What is the third most common cause of obstructive hydronephrosis in fetus and neonate?
Ureterocele
114
What is the cause of ureterocele?
Prolapse of distal ureteric mucosa into urinary bladder, causing a cystic dilation
115
What are the two types of ureterocele?
Simple- ureter is normally located
| Ectopic- ureter inserts in bladder abnormally (associated with renal duplication)
116
Common appearance for ectopic ureterocele?
- cystic structure with thin, hyper echoic wall in bladder neck region
- dilated ureter
- upper dilated collecting system in duplicated kidney
- possible bladder distension
- possible oligohydramnios
117
What is bladder outlet obstruction and its most common cause?
Condition which impedes the outflow of urine
| *most common cause posterior urethral valves
118
Other causes of bladder outlet obstruction?
- urethral atresia
- stenosis
- urethral diverticulum
- ectopic ureterocele
119
Ultrasound characteristics of bladder outlet obstruction?
- hypertrophied bladder
- bilateral dilated ureters
- bilateral hydronephrosis
- oligohydramnios
120
Cause of prune belly syndrome?
Urethral obstruction leads to massive distension of the bladder and ureters which in turn causes pressure atrophy of the abdominal wall vasculature
(Bladder distention interferes with the descent of testes)
121
Characteristics of prune belly syndrome?
- fetus with protuberant abdomen
- secondary to grossly distended bladder
- a genesis of abdominal wall musculature
122
Associated findings of prune belly syndrome?
- cryptorchidism (undescended testes)
- bilateral hydroureters
- hydronephrosis
123
Prognosis of prune belly syndrome?
Variable depending upon severity of obstruction and severity of oligohydramnios
124
With severe oligohydramnios, what may occur?
Pulmonary hypoplasia
125
Prognosis of potters syndrome?
Lethal condition
126
Primary ultrasound characteristics of potters syndrome?
- absence of visible bladder
| - severe oligohydramnios
127
Other characteristics of potters syndrome?
- absence of kidneys
- oligohydramnios
- pulmonary hypoplasia
- typical facies (low set ears, redundant skin)
- prominent fold at inner can thus of each eye, parrot-beak nose and receding chin
- dolichocephaly
128
What may indicate this condition early?
Failure to visualise kidneys and bladder by 16 weeks
129
Cause of multicystic dysplastic kidney disease (MCKD)?
| AKA Potter Type II
Urinary tract obstruction during nephrogenesis.
(Is NOT genetically transmitted)
*Males 4x more likely
*Kidneys are echogenic
130
Ultrasound characteristics of multicystic dysplastic kidney disease?
- usually unilateral renal involvement
- entire affected kidney replaced by multiple cyst
- no appreciable amount of normal renal tissue seen
- may have hydronephrosis on contralateral side
- normal amniotic fluid if unilaterally affected
131
Cause of infantile polycystic kidney disease (IPKD)?
Genetic defect in nephrogenesis
| *Autosomal RECESSIVE trait (25% risk factors if both parents carry gene)
132
Ultrasound characteristics of infantile polycystic kidney disease?
- bilateral, symmetrically enlarged kidneys (massive)
- renal contour NOT distorted, due to small size of cyst
- usually will not see cyst, only echogenecity of walls
- kidneys are very echogenic
- absent bladder
- oligohydramnios
133
Why is it important to determine fetal gender?
Sex-linked disorders
| *Highly accurate after 20 weeks
134
Error in gender may occur due to?
- umbilical cord between legs
- swollen face genitalia
- undescended testes
135
What is best scanning method in determining genitalia?
Axial-oblique scan between buttocks anteriorly with fetal legs frogged
136
Positive identification for females?
- image the labia major and labia minor with an interface between the two "BIG MAC" sign
(Remember labia may be swollen)
137
Positive identification for males?
- easier if penis is erect
- penis and scrotal sac together "TURTLE" sign
- may observe micturation in color flow
- may see hydrocele around testicles (usually caused by maternal hormone influence)
138
Two most common abdominal wall defects?
Omphalocele and gastroschisis
139
What is omphalocele?
Defect AT the site of umbilical cord insertion
(includes umbilical hernia and other congenital anomalies)
*Prognosis depends of presence/absence of associated anomalies*
140
Characteristics of Omphalocele?
- herniation of abdominal organs into base of umbilical cord
- AFP may increase or normal
- most commonly liver and bowel
- membranous covering
- seen in midline
- variable in size
141
Ultrasound diagnosis of omphalocele cannot be made until after?
12 weeks because normal bowel is located in the umbilical cord until that time
142
What is gastroschisis?
Cleft defect of anterior abdominal wall with extrusion of abdominal organs into abdominal cavity, usually 2-4 cm
* Almost always to the right of the insertion site
* Most often contents ONLY small bowel
143
Prognosis of gastroschisis?
Depends on occurrence of bowel malrotation/obstruction and if identified antenatally (If known about in advance, appropriate delivery and surgical procedures can be planned)
144
Characteristics of Gastroschisis?
- herniation of bowel not associated w/ insertion site
- NO membraneous covering
- Usually to the right
- free floating small bowel
- may see dilated loops of bowel in amnion
145
Similarities between omphalocele and gastroschisis?
Elevated AFPs and polyhydramnios
146
Main differentiation between omphalocele and gastroschisis?
Insertion site- omphalocele
Midline location- omphalocele
Membranous covering- omphalocele
Associated anomalies- omphalocele
147
Three most common bone dysplasias?
1. Achondroplasia
2. Thanatophoric Dysplasia
3. Lethal Osteogenesis Imperfecta
148
Most common dysplasia in our society?
Achondroplasia
| *Autosomal Dominant transmission
149
Survival and reproduction likely?
25% normal offspring
50% heterozygous achondroplasia
25% homozygous achondroplasia
(Most sever manifestations-lethal)
150
Heterozygous achondroplasia growth patterns?
Demonstrates normal growth in early pregnancy, which falls into the abnormal range circa 25 weeks
151
Homozygous achondroplasia growth patterns?
Demonstrates abnormally short femurs prior to 20 weeks
152
Most common spontaneously occurring dysplasia?
Thanatophoric Dysplasia
* Invariably lethal
* One form is inherited as an autosomal RECESSIVE
* This form manifests CLOVERLEAF DEFORMITY of the SKULL
153
Key features to diagnose thantophoric dysplasia in utero?
- very short, bowed femurs
- normal calvarial mineralization
- "cloverleaf" skull shape (in recessive type)
- short ribs
- platyspondyly (flattened spine)
- skin thickening (not always present)
154
True or False?
Because a diagnosis of thanatophoric dysplasia assures "non-viability", a mother may elect pregnancy termination after the 24th week legally
True
155
What is lethal osteogenesis imperfecta?
Abnormal collagen metabolism leads to extremely fragile bones
* Long bones tend to show numerous fractures
* Once though to be an autosomal RECESSIVE disorder, it is more likely a SPONTANEOUS DOMINANT MUTATION
* Recurrence rate currently is stated to be 6%
156
Prognosis of lethal osteogenesis imperfecta?
This dysplasia is UNIFORMLY FATAL, therefore a mother may elect pregnancy termination
157
3 features identified with lethal osteogenesis imperfect?
1. Severe demineralization of the calvarium
- Brain is clearly visible
- Bright calvarial reflection is absent
- Compression of brain may occur
2. Femurs are very short
- Many weeks behind head growth
3. Multiple fractures
- Gives a "wrinkled" appearance to bony cortex
158
Other features include?
```
Angulations of the bone
Rib fractures (Some experts consider this finding to be "pathognomic" (indicative) of Lethal Osteogenesis Imperfecta)
```
