Chapter 24: Sonographic Assessment of the Fetal Neck and Spine Flashcards
Examination of the neck region includes evaluation of the ____ and ____
spinal structures
soft tissues
Examination of the anterior neck region is useful in the detection of different abnormalities that may include:
goiter
hemangioma
teratoma
As early at the ___ week of gestation, the cervical spine structure allows for detailed investigation of the cervical segment of the spine
18th
____ images are considered best for evaluating structures of the fetal neck.
Coronal
abnormally formed organs
dysgenesis
herniation of abdominal contents without a covering into the abdominal fluid
gastrochisis
tumor composed of fat
lipoma
combination of nonimmune fetal hydrops and a cystic hygroma
lymphangiectasia
spinal defect where the meninges protrude
meningocele
protrusion of a sac from a spinal defect containing spinal cord and meninges
Myelomeningocele
Incomplete fusion of the neural tube resulting in a cleft spinal cord
Myeloschisis
either the rostral or caudal end of the neural tube
neuropore
herniation of the abdominal contents with a membranous cover
omphalocele
ability of embryonic cells to differentiate into any type of cell
pluripotent
The fetal spine images as individual verterbrae, with three brightly echogenic ossification centers in the transverse plane by the ____ week of gestation
16th
Two ossification centers lie:
posterior to the spinal canal within the laminae
One ossification center lies:
anterior within the vertebral body
Three types of scanning planes help with the evaluation of spinal integrity:
transverse
coronal
sagittal
Three ossification centers surround the _____
neural canal
At the cervical level, the posterior ossification centers at the cervical vertebrae have a ______ shape.
quadrangular
At the triangular thoracic and lumbar level, the ossification centers image in an :
inverted triangle with the base toward the dorsum of the fetus
At the level of the sacrum, the posterior ossification centers have a _____ placement than the upper vertebrae.
wider
a parallel structure ending in the pointed sacrum
spine
Divergence of the posterior elements suggests abnormality, probably a ______ or ______
meningocele
meningomyelocele
Determination of spinal normalcy is through identification of:
intact neural canal
normal location and shape of spinal ossification centers
intact dorsal skin contour
AFP is a glycoprotein secreted by the ____ and then by the _____.
yolk sac
fetal liver
Maternal serum AFP levels occur through diffusion across the ____ and ____.
placenta
amnion
neural tissue is exposed or covered by only a thin membrane
open neural tube defects
AFP is elevated in ____ neural tube defects
open
Skin-covered or closed neural tube defects result in _____ AFP
normal
Typically, ____ MoM is used as the level for a positive screen
2.5
AFP elevation disorders
omphalocele
gastrochisis
skin disorders
AFP lower disorders
Down Syndrome
Jugular lymph sacs fail to communicate with the venous system, they may enlarge as the fill with lymph and form _____
cystic hygromas
Failure in lymphatic drainage may accompany hydrops fetalis, resulting in a process called ______
lymphangiectasia
Most common located of cystic hygromas
lateral neck region
______ trisomies and trisomy ___ demonstrate an increased incidence of hygromas in the first trimester
autosomal
21
The large veins linked to the development of cystic hygromas are due to:
increased volume of blood flow resulting from lack of lymphatic drainage
Nonimmune hydrops manifests sonographically as:
ascites
pleural effusion
pericardial effusion
skin edema
Differential diagnoses of cystic hygromas
cystic teratomas
cephaloceles
hemangiomas
branchial cleft cysts
nuchal edema
The central nervous system begins as the ____ in the embryo.
neural tube
Infloding of the slipper-shaped ectoderm of the neural plate during the ____ week of embryonic life forms the neural tube.
third
The ______ fuses to form the neural tube beginning midembryo and completing at the cranial and caudal neuropore
neural groove
If the neural tube fails to fuse:
spina bifida with myeloschisis develops
a NTD resulting from incomplete closure of the bony elements of the spine posteriorly
spina bifida
Two types of spina bifida lesions
ventral
dorsal
involves vertebral body splitting and development of a neurogenic-origin cystic structure
ventral defect
Closed spina bifida, or ______, has the split vertebrae covered by skin.
spina bifida occulta
Spina bifida _____ is the simplest form, in which there is a failure of the dorsal portions of the vertebrae to fuse with one another.
occulta
The expected location of spina bifida occulta is:
sacrolumbar level
Open spina bifida, or _______, is a full thickness defect of the skin, underlying soft tissues, and vertebral arches- thus exposing the neural canal.
spina bifida aperta
Spina bifida aperta occurs in ___% of all spina bifida cases
85
The ______ lesion has a thin meningeal membrane that does not contain neural tissue.
Meninogocele
The _____ contains neural tissue inside the protruding sac.
myelomeningocele
Causative mechanics of NTDs
genetic factors
nutritional factors
environmental factors
combo
diabetes mellitus
obesity
folate deficiency
Location and severity of spina bifida defects have the greatest chance of detection on the _____ views.
sagittal
Displacement of cranial structures into the foramen magnum and superior cervical canal is caused by:
cerebrospinal fluid leakage
abnormal lateral curvature of the spine caused by anomalous development of the vertebrae, either failure of formation or segmentation
congenital scoliosis
Congenital scoliosis can be caused by:
cardiac, genitourinary, and skeletal abnormalities
Abnormal anterior angulation of the spine
kyphosis
combination of the abnormal lateral and anterior curvature
kyphoscoliosis
______, caused by aplasia or dysgenesis of one of the who chondrification centers forming the vertebral bodies , identify sonographically by lateral displacement of the anterior ossifications centers or improperly aligned vertebral bodies
Hemivertebrae
a broad term that refers to a heterogeneous group of congenital anomalies affecting the caudal spine and spinal cord, the hindgut, the urogenital system, and the lower limbs
caudal regression syndrome
Disruption of the embryonic process of canalization in the third week of gestation results in varying degrees of:
caudal regression syndrome
In the normal embryo the conus, filum terminale, sacral nerve roots, and lower genitourinary structures originate from:
caudal mesoderm
the main differential for caudal regression syndrome
sirenomelia
The mechanism of sirenomelia is thought to be:
shunting of blood from the aorta through the umbilical artery, resulting in a vascular steel
Main finding for sirenomelia
fusion of the legs
Sirenomelia is also known as:
mermaid syndrome
In the fetus, teratomes develops in the _____, ____, _____ or anywhere on the neural tube with the ______ the most common location.
gonads
umbilical cord
placenta
caudal end (sacrococcygeal_
Tumor that arising from the presacral area of the spine
sacrococcygeal teratomas
most common neoplasm of the newborn
sacrococcygeal teratomas
Germ layers of germ cell tumor
ectoderm
mesoderm
endoderm
The origin of the sacrococcygeal tumor is thought to be a:
remnant of the primitive streak leading to the inclusion of various embryonic tissue types within the tumor.
the pluripotent tissue derived from the area around the Henson node migrates rostrally to lie in the coccyx
sacrococcygeal tumore
images as a protrusion between the anus and the coccyx
sacrococcygeal tumor
Perinatal mortality and morbidity are most strongly related to high-output cardiac failure because of:
arterivenous shunting within the tumor, subsequent fetal hydrops, polyhydramnios, and preterm delivery
The normal fetal spine has three ossification centers:
centrum
right
left neural processes
Sagittal images of the spine include:
vertebral body
lateral ossification centers
caudal end tapering
skin integrity
examination of the spinal curvature
_____ view of the spine is the best plane to identify spinal defects
Transverse (axial)
Elevated MSAFP of ____ MoM raises suspicion for an open neural tube or abdominal wall defect/
2.5
_______ are the result of lymph vessel obstruction, usually occurring in the head or neck region.
Cystic hygromas
an open spinal defect with varying degrees of severity
spina bifida
_____ and _____ are abnormal curvatures of the spine and may be caused by skeletal dysplasias or a hemivertebrae.
scoliosis
kyphosis
germ cell tumors found in the sacral area
sacrococcygeal teratomas
Examination of the anterior neck region is useful in the detection of different abnormalities that may include all except:
a. goiter
b. hemangioma
c. rachischisis
d. teratoma
c
Choose the anatomy that can be detected in the fetal neck.
a. carotid bifurcation
b. anterior communicating artery
c. brachial artery
d. superior vena cava
a
How many ossification centers surround the neural canal?
3
Select the fetal position that offers a true sagittal view of the spine.
a. transverse
b. oblique
c. cephalic
d. prone
d
Determination of spinal normalcy is through identification of all except:
a. an intact neural canal
b. divergence of the posterior ossification elements
c. a normal location and shape of spinal ossification centers
d. an intact doral skin contours
b
Screening for neural tube defects is performed by all except:
a. hCG
b. sonography
c. MSAFP
d. biochemical testing
a
The most common location for a cystic hygroma is:
at the lateral neck region
The form of spina bifida where split vertebrae are covered by the skin is:
spina bifida occulta
Anomalies frequently seen in the fetus relating to spina bifida involve the fetal:
cranium
Fetuses affected by spina bifida aperta commonly demonstrate:
bilateral club feet
Scoliosis is an abnormal:
a. anterior angulation of the spine
b. posterior angulation of the spine
c. lateral curvature of the spine
d. thoracic defect of the spine
c
A term that refers to a heterogeneous group of congenital anomalies affecting the distal spine and cord, the hindgut, the urogenital system, and the lower limbs is:
caudal regression syndrome
A sacrococcygeal teratoma most commonly images as a protrusion:
between the anus and the coccyx
The earliest visible indication of caudal regression syndrome is:
a short crown-rump length and abnormal yolk sac
Cystic hygromas are the result of _____ obstruction, usually occurring in the head or neck region.
lymph vessel
The normal fetal spine has ___ ossification centers: the centrum, right, and left neural processes.
3
The fetal spine images with brightly echogenic ossification centers in the transverse plane by the ____ week of gestation.
16th
Three types of scanning planes help with the evaluation of spinal integrity, ______, ______, and ______.
transverse
coronal
sagittal
AFP is elevated in NTD, other open fetal defects, such as ______ and ______, as well as skin disorders that increase the diffusion of AFP through fetal skin.
omphalocele
gastroschisis
Cystic hygromas appear as either single or ______ fluid-filled cavities and are usually located on the _____ neck.
multiloculated
lateral
The two types of spina bifida lesions are _____ and _____. The most common form of the process is _____ spina bifida.
multiloculated
lateral
The two types of spina bifida lesions are are ____ and _____. The most common form of the process is ____ spina bifida.
ventral
dorsal
closed
The location and severity of spina bifida have the greatest chance of detection on _____ views.
sagittal
Fusion of the fetal legs is known as the _____ syndrome, also known as _____.
mermaid
sirenomelia
The most common location of a neural tube teratoma is the _____ end.
caudal
Sagittal and coronal images of _______ and spinal anatomy assist in detecting spinal normalcy or assist in locating anomalous deviations.
conus medullaris
A break in the skin surface directly over the spine is associated with:
myelomeningocele
A large herniation of the posterior fossa contents into the foramen magnum with hydrocephalus and myelomeninocele describes which type of Arnold-Chiari malformation
3
A markedly retroflexed neck is an indication of
iniencephaly
Neural plate development completes at ____ days
18-23
What central nervous system malformation is identifiable in the first trimester?
spina bifida
What abnormality is most commonly associated with cystic hygroma?
Turner Syndrome
A cystic hygroma is the result of
lymphatic fluid
What would most likely involve the development of a cystic hygroma?
Turners Syndrome
The most common location of a cystic hygroma is within the:
neck
A benign congenital neck cyst found most often near the angle of the mandible
branchial cleft cyst
A large, mostly cystic mass containing a thick, midline septation is noted in the cervical spine region of the fetus. This most likely represents a:
cystic hygroma
Protusion of meninges through a spinal defect
meningoceles
The defect that has a cleft spinal cord
myeloschisis
A group of anomalies associated with the entrapment of fetal parts and fetal amputations is:
amniotic band syndrome
What is the maternal dietary supplement that has been shown to significantly reduce the likelihood of the fetus suffering from a neural tube defect?
folate
Talipes equinovarus is associated with:
clubfoot
The condition associated with the absence of the sacrum and coccyx:
caudal regression syndrome
Spina bifida occulta does not show _____ MSAFP
elevated
Spina bifida cystica has normal MSAFP.
false
An enlarged posterior fossa is associated with spina bifida.
false
The abnormal lateral curvature of the spine is referred to as:
scoliosis
Limb body wall complex shows decreased MSAFP
false
A disorder that results in abnormal bone growth and dwarfism
achondroplasia
______ would increase the likelihood of a fetus developing sirenomelia and caudal regression syndrome.
preexisting diabetes
The most common nonlethal skeletal dysplasia is
achondroplasia
What abnormalities results in limitation of the fetal limbs as a result of joint contractures?
arthropiosis
Shortening of the proximal segments of the limbs
Rhizomelia
An absent sacrum and coccyx is referred to as:
caudal regression syndrome
absent long bones with the hands and feet arising from the shoulders and hips describes:
phocomelia
Upon sonographic interrogation of a 28 week pregnancy, you note that when pressure is applied to the fetal skull, the skull can easily be distorted. This is sonographic evidence of:
osteogenesis imperfecta
A bell shaped chest and multiple fetal fractures are indicative of:
osteogenesis imperfecta
Synechia is not associated with amniotic band syndrome.
true
The exaggerated distance between the first toe and the second toe is:
sandal gap
Sirenomelia is commonly referred to as:
mermaid syndrome
Absence of the radius referred to as:
radial ray defect
