Second and Third Trimester OB Flashcards
Congenital absence of one or both eyes.
Anophthalmia
Short broad head due to premature suture fusion
Brachycephaly
Congenital anomalies of the head due to teratogens or development disruptions of the nervous system
Cebocephaly
Abnormally formed organs
Dysgenesis
Congenital brain anomaly resulting from a migrational defect of the occipital horns of the lateral ventricles leading to ventricular enlargement
Colpocephaly
Malformation of an organ or structure
Dysmorphic
Long narrow head
Dolichocephaly
Dilatation or distention of a hollow structure
ectasia
Nares means________________
Nostrils
Either the rostral or caudal end of the neural tube
Neuropore
Posterior displacement of the maxilla and mandible
Retrognathia
Rostral is ________________________
Toward the cephalic or head end
Substance that interferes with embryonic development
Teratogen
Central portion of the cerebellum between the hemispheres
Vermis
According to guidelines set by the American College of Radiology, the American Institute of Ultrasound in Medicine, the American College of Obstetricians and Gynecologist and the Society of Radiologist in Ultrasound, what are the minimal elements that must be included in the fetal anatomic examination?
- Lateral cerebral ventricles
- Choroid plexus
- Midline falx
- Cavum septi pellucidi
- Cerebellum
- Cisterna magna
- upper lip
Neural plate development completes at approximately days ___________ to __________
18 to 23
At approximately __________ menstrual weeks, the neural tube differentiates into the primitive brain and spinal cord
Six
What three segments make up the brain?
Prosencephalon(forebrain)
Mesencephalon ( midbrain)
Rhombencephalon ( Hind brain)
The forebrain becomes the_________ and the __________ resulting in the development of the __________, ____________ __________, ____________ ____________, and the ___________ __________.
Telencephalon and diencephalon
thalami, third ventricle, cerebral hemispheres, lateral ventricles
As the brain developes, the choroid plexus takes it’s position in the ____________ area of the ___________ ___________.
posterior
lateral ventricles
The metencephalon and myelencephalon arise from the anechoic _____________
Rhombencephalon
The upper portion of the fourth ventricle, pons and cerebellum originate from the __________
Metencephalon
BPD is measured at the level of the ___________ and ___________
thalami and cavum septi pellucidi or columns of the fornix
Define microcephaly
“Small Head”
Define Macrocephaly
“Large Head”, a HC two or three standard deviations above the mean for gestational age and sex
The image of the cerebellum may be obtained in a plane _________and __________to the BPD level.
parallel and inferior
In an endovaginal approach the lateral ventricles can be clearly seen by _____to _____ weeks of gestation as an ovoid structure filled with ___________ __________.
12 to 13
Choroid plexus
Using the transabdominal approach , the lateral ventricles readily image by ______ weeks gestation as paired anechoic areas within the brain substance
16
A prominent echogenic area is often seen in the lateral ventricle which represents the ___________ ___________.
Choroid plexus
By _______to ________ weeks gestation the corpus callosum is nearly fully developed.
18 - 20
The __________ _________ contains the cerebellum, the fourth ventricle, and the cisterna magna.
Posterior fossa
In the axial plane at the level of the biparietal diameter, what minimal structures that should be seen?
Thalmi, third ventricles, cavum septum pellucidum
In the axial plane when imaging the cerebellum, what are the structures that should be seen?
Cerebellum, cisterna magna, vermis
When imaging the face in the coronal plane, what should be seen?
soft tissues of the nose, lip and chin
When imaging the face in the sagittal plane of the profile, what should be seen?
Confirm correct symmetry of forehead, nose, lips and chin
Hypotelorism is most commonly associated with_______________
Holoprosencephaly
____________is a increased orbital distance, occuring in either isolation , with malformations, or as part of a syndrome.
Hypertelorism
Syndromes associated with hypertelorism include _________, ___________, ____________, ______________-__________ and _____________ _______________.
Apert, Crouzon, Noonan, Pena-Shokeir and Pfeiffer syndromes
Orbital diameter smaller than the fifth percentile for gestational age
Microphthalmia
_______________ in a fetus images as the tongue extending beyond the teeth or alveolar ridge.
Macroglossia
Macroglossia may be seen in images of fetuses with trisomy _________ and ____________-_____________ syndrome
21
Beckwith-Weidmann
Severely hypoplastic mandible
Micrognathia
What type of ectopic pregnancy is surrounded by less than 5 mm of myometrium
Interstitial
What is the failure of pregnancy to develop?
Anembryonic
During a sonographic examination on a first trimester pregnancy, a crescent shaped complex fluid collection is seen between the gestational sac and uterine wall, what is the most likely cause?
Subchorionic hemorrhage
What is the most common location of an ectopic pregnancy
Ampulla of the fallopian tubes
A congenital fissure that remains open past 11 weeks in the wall of the abdomen just to the right of the umbilical cord is
Gastroschisis
Cranial anatomy is routinely visualized after how many gestational weeks
12-14 weeks
A partial absence of the cranium is called
Acrania
Multiple tiny clusters of grape like echoes within the uterine cavity best describes
Gestational trophoblastic disease
Neural plate development completes at days
18-23
What is the sonographic characteristic of cephalocele
Complex paracranial mass
What is a sonographic feature of anencephaly
Frogeyes
During a sonographic examination a wide high third ventricle, teardrop-shaped ventricle, a widened ventricular atria, absent cavum septi pellucid, and a sunburst appearance of the gyri and suli were imaged in the fetal brain, what malformation do these findings support?
Agenesis of the corpus callosum
A large herniation of the posterior fossa contents into the foramen magnum with hydrocephalus and myelomeningocele describes which type of Arnold-Chiari malformation?
IV
Beta hCG levels plateau at __________ weeks
9-11
Define the discriminatory cutoff for beta hCG
The level when an embryo visualizes on ultrasound
What type of pregnancy is indicated by movement of an hourglass-shaped gestational sac with pressure from the endovaginal transducer?
Pending miscarriage
What type of resolution describes the minimum distance between two bright echoes perpendicular to the beam path?
Axial
What is the ratio of the BPD and the OFD called?
Cephalic Index
What is the correct method to measure the BPD
Transverse, lateral outer to inner
What are the anatomic landmarks used to determine the correct level to measure the BPD
Thalamus, Falx, Cavum septum pellucidum
Which measurement is the most important indicator of fetal weight?
Abdominal Circumference (AC)
What portion of the femur does the sonographer measure to obtain the length?
Osseous femoral diaphysis
What weight is considered macrosomia?
> 4000 g
What is the congenital absence of one or both eyes
Anophthalmia
Head end of the neural tube
Rostral
Long narrow head
dolichocephaly
Term describing the ability of embryonic cells to differentiate into any cell type
Pluripotent
What malformation demonstrates cystic dilatation of the fourth ventricle
Dandy - Walker malformation
Absence of the major portion of the brain, skull and scalp
Anencephaly
Type of holoprosencephaly where most of the brain has separated into two hemispheres but the cerebral hemispheres are fused at the frontal cortex
Lobar
Which is the most severe form of holoprosencephaly
Alobar
Neural tube defect resulting from incomplete closure of the bony elements of the spine
Spina Bifida
Abdominal wall defect where the abdominal organs develop outside of the baby’s abdominal cavity and remain attached directly to the placenta
Body stalk anomaly
Birth defect that is a sac like structure with a thin wall that most commonly occurs in the head and neck area
Cystic Hygroma
One or more extra fingers or toes
Polydactyl
Large amount of fluid build up in a baby’s tissue and organs causing extensive swelling
Hydrops
What is the cephalic index formula
BPD/OFDx100
What are the three segments that make up the brain
Prosencephalon (forebrain)
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)
Short broad head due to premature suture fusion
Brachycephalic
Microcephaly/Microencephaly
Small head
Macrocephaly
Large head
__________________carries more than 80% of cerebral blood flow and can be used to assess fetal well being
MCA (middle cerebral artery)
Between 16 and 24 weeks gestation, the cerebellar diameter measured in millimeters correlates _____________with gestational age
1:1
Which phase of pregnancy provides the most accurate dating
early embryonic phase
The normal duration of pregnancy is
40 weeks from the LMP (38 week gestation + or - 2 to 3 weeks
Lateral resolution is
across the path of the beam
The most common and routine measurements to assess the fetal growth and well being are
BPD, HC, AC, FL
To estimate an accurate fetal age, the BPD measurement should be obtained before ________________ weeks
33
Shortening of the ventricle dimension of the skull and widening of both diameters of the transverse plane
platycephaly
Preferred technique for measuring the fetal abdomen and head circumference is
ellipse
Normally conception takes place about ______ weeks after the LMP
two
A structure within the cranium that maintains a relationship to fetal growth throughout pregnancy is the
cerebellum
The femur measurement can reliably used after __________ weeks gestation
14
The choroid plexus invaginates into the
ventricles
The metencephalon and myelencephalon are part of the
rhombencephalon
What is the alternative measurement for the BPD
Head circumference (HC)
The most studied artery in the fetal brain is the
MCA (middle cerebral artery)
The frequent anomaly noted with cleft palate or cleft lip is
club foot
Normal cisterna magna measurement
1 cm
A fetal brain with no recognizable cerebral cortex and defined thalami and cerebellum is
Hydranencephaly
Dandy-Walker malformation consist of
Marked cystic dilation of the fourth ventricle
Smooth cerebral surface after 20 weeks
Lissencephaly
A markedly retroflexed neck is an indication
Iniencephaly
Enlargement of the ventricles and cerebrospinal fluid displacement of the choroid plexus results in a condition called
Dangling choroid plexus
A measurement of the lateral ventricular atrium should not exceed
1 cm
The forebrain is also know as the
Prosencephalon
The great cerebral vein is also called
the vein of galen
The third ventricle is positioned between the ___________ and the frontal horns of the lateral ventricles
thalami
Most frequent craniofacial anomalies
facial clefts
The tongue extending beyond the teeth or alveolar ridge is
macroglossia
