Test 1 Flashcards
What is the definition of congenital anomaly?
Departure from the normal anatomic architecture of an organ or system
What is ultrasound role for congenital anomalies?
- Absence of normal anatomic structure
- Disruption of contour, shape, location, texture, or size
- Presence of an abnormal structure
- Abnormal fetal biometry
- Abnormal fetal motion
“At Risk” groups for congenital anomalies?
- Advanced maternal age
- Positive family history
- Exposure to exogenous teratogenic agents
- Maternal diabetes
- Elevated maternal serum AFP
What is the incidence of congenital anomalies?
3 in 100 births
10-15% have minor defects
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?
True
What is the systematic approach?
Used for anatomic assessment of the fetus. If it is done without a logical sequence, there is definitive risk that features will be missed.
True or False?
Thorax is slightly larger than the abdomen throughout pregnancy?
False, smaller
Normal appearance of fetal lungs?
- Lateral borders of the fetal heart
- Sickle-shaped
- Uniformly echoic
- RT lung profile larger, due to leftward orientation of cardiac apex
What do we assess in the lungs?
- 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)
True or False?
Normal fluid- filled fetal lungs are observed as homogenous masses of tissue
True
Lung echogenicity can be variable depending on fetal age. What is it compared to for relative echo density?
Liver
- Earlier Gestation= more hypo echoic than liver
- Later Gestation= more hyper echoic than liver
What causes pulmonary hypoplasia?
Prolonged oligohydramnios or a reduction in thoracic dimension as a result of structural or chromosomal abnormalities.
What does pulmonary hypoplasia lead to?
Restriction of lung growth
What is thoracic hypoplasia?
A cardinal feature in many skeletal dysplasias and is the main cause of death in lethal skeletal dysplasias
What may pulmonary hypoplasia occur with?
- Kidney Abnormalities (agenesis, MCKD, PUV)
- IUGR (because of oligohydramnios)
What is pulmonary sequestration characterized by?
- Presence of EXTRA nonfunctioning pulmonary tissue
- Usually no communication w/ bronchial tree
- Receives blood supply from artery other than pulmonary branch
What are the two types of pulmonary sequestration?
Intralobar and extralobar
What is intralobar pulmonary sequestration?
Abnormal tissue lies within NL lung, favorable prognosis
What is extralobar pulmonary sequestration?
Abnormal mass anatomically separate from NL lung
Extralobar pulmonary sequestration is most common in?
Left Hemithorax, poor prognosis due to associated anomalies
Ultrasound characteristics of intralobar pulmonary sequestration?
- Spherical, echodense, solid mass
Ultrasound characteristics of extralobar pulmonary sequestration?
- Highly echogenic, non-pulsatile mass
- May displace heart
- Pyramidal/ triangular shape
- Normal abdominal viscera helps to differentiate from hernia
What is cystic adenomatoid malformation (CAM)?
Normal lung tissue replaced by cysts, relatively uncommon
What are the classifications of “CAM”
Types I,II,III
What is type I CAM?
- Macrocystic
- Single or multiple large cysts (>2cm)
- Good prognosis after resection
What is type II CAM?
- Multiple small cysts (
What is type III CAM?
- Microcystic
- Large lesion
- NON-Cystic!!!!
- Produces mediastinal shift (only 1 lobe affected)
- Prognosis is poor
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
True or False?
Type classification is imperative due to variance in prognosis
True
True or False?
There should always be fluid collections around the fetal lungs or heart.
False
Pleural effusions usually occurs secondary to what?
Malformed thoracic duct (usually rt sided)
What is the pleural space?
A double-layered serous membrane surrounding the lungs, fluid in this space may be called pleural effusion or hydrothorax
What is pericardial space?
A serous membrane forming a sac around the heart, fluid in this space is called pericardial effusion
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
Mortality rate for infants with pleural effusion?
50%, even higher if associated hydrops
*Some Causes: CHF, RH Disease, Non-Immune Causes, Chromosomal Abnormalities
Appearance of fetal diaphragm?
Thin, hypoechoic, curvilinear interface between liver and lungs. Visualization better on the right side.
True or False?
The shape of the diaphragm may be a helpful indicator of disease
True
A flattened or inverted diaphragm should raise the index of suspicion for what?
A thoracic mass
The stomach should be demonstrated where compared to the diaphragm?
Inferior
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
CDH is most commonly located where?
On the left side and posterolateral (90%)
CDH may involve which organs?
Stomach, intestines, liver
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
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
What is the only definitive diagnosis for CDH?
Abdominal organs identified in thoracic cavity.
*Heart is pushed to right due to stomach creating dextroposition
When imaging the fetal heart you should evaluate?
- Location
- Orientation
- Chamber proportion
- Excluded masses and large defects
- Function (rate and rhythm)
- Exclude cardiac failure
What are the most common forms of heart disease?
- Ventricular septal defect
- Atrial septal defect
- Pulmonary stenosis
What is the most anterior chamber?
Right Ventricle, Scan cephalic to stomach and obtain 4-chamber view
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)
True or False?
Symmetry of size and wall thickness suspicians cardiac anomaly
False
Intraventricular septum should be completely closed otherwise you will have?
Ventricular Septal Defect
Intra-atrial septum contains the normal flap of what until birth?
Foramen Ovale
Normal heart rate
120-160bpm
*Signs of cardiac failure: cardiomegaly, effusions, fetal hydrops
Associated abnormalities of cardiac anomalies
Ectopia Cordis and Pentalogy of Cantrell
What is Ectopia Cordis?
Chest wall fails to close and heart forms outside of the thoracic cavity
What is Pentalogy of Cantrell?
RARE, associated with ectopia cordis
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
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
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
Enlarged stomach may suggest?
Polyhydramnios and bowel obstruction
seen as part of double bubble
Absence of stomach may suggest?
- Impedance in fetal swallowing
- Oligohydramnios
- Esophageal atresia
- Congenital diaphragmatic hernia (fetal chest)
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
Gut atresia is associated with what other anomalies?
Vacterl Syndrome
- Vertebral
- Anal
- Cardiac
- Tracheoesophageal
- Renal
- Limb