Chapter 26

The lemon sign denotes

An abnormal shape of the fetal skull

The group of fetal head and brain abnormalities that often coexists with spina bifida is referred to as:

Arnold-Chiari Il malformation

radial ray defect?

absence or underdevelopment of the radius

polyhydramnios?

an excessive amount of amniotic fluid for the gestational age

meninges?

coverings of the brain and spinal cord

homozygous achondroplasia?

fatal form of achondroplasia

gastroschisis?

herniation of abdominal contents through a right-sided, periumbilical abdominal wall defect

meningocele?

herniation of the cranial or spinal meninges because of an open cranial or spinal defect; contains cerebrospinal fluid but no nerve tissue

appendicular skeleton?

includes the bones of the upper extremities, lower extremities, and pelvic girdle

sacral dimple?

opening in the skin over the distal spine

banana sign?

sonographic sign of the cerebellum being curved in the presence of spina bifida

germ cell tumor?

type of neoplasm derived from germ cells of the gonads; may also be found outside of the reproductive tract

The most common nonlethal skeletal dysplasia is:

Achondroplasia

The artifact seen posterior to solid structures such as fetal bone is referred to as:

Acoustic shadowing

The disorder associated with fetal amputations is:

Amniotic band syndrome

All of the following are associated with amniotic band syndrome

Amputation of fetal parts, Anencephaly, Facial clefting

An absent sacrum and coccyx is referred to as

Caudal regression syndrome

The condition associated with the absence of the sacrum and coccyx:

Caudal regression syndrome

The thalamic tissue located within the third ventricle of the brain that can become enlarged with Arnold-Chiari Il malformation is the:

Massa intermedia

All of the following are characteristic sonographic findings of achondrogenesis

Micromelia, Absent mineralization of the pelvis, Polyhydramnios

A bell-shaped chest and multiple fetal fractures are indicative of:

Osteogenesis imperfecta

Absent long bones with the hands and feet arising from the shoulders and hips describes:

Phocomelia

All of the following are characteristics of spina bifida occulta

Sacral dimple, Hemangioma, Closed defect

Rhizornelia denotes:

Shortening of the proximal segment of a limb

frontal bossing?

angling of the frontal bones that produces an unusually prominent forehead

estriol?

estrogenic hormone produced by the placenta

folate is also referred to as

folic acid

splay?

turned outward

A protein produced by the yolk sac and fetal liver that is found in excess in the maternal circulation in the presence of a neural tube defect is:

AFP

A disorder that results in abnormal bone growth and dwarfism is:

Achondroplasia

What abnormality results in limitation of the fetal limbs as a result of joint contractures?

Arthrogryposis

The form of inheritance in which at least one parent has to be a carrier of an abnormal gene for it to be passed to the fetus is:

Autosomal dominant

All of the following are signs of Arnold-Chiari lll malformation

Banana sign, Lemon sign, Colpocephaly

All of the following are characteristics of spina bifida cystica

Banana sign, Lemon sign, Enlarged massa intermedia

Talipes equinovarus is associated with:

Clubfoot

The abnormal lateral ventricle shape in which there is a small frontal horn and enlarged occipital horn is referred to as:

Colpocephaly

Upon sonographic interrogation of a 28-week pregnancy, you note that when pressure is applied to the fetal skull, the skull can be easily distorted. This is sonographic evidence of:

Osteogenesis imperfecta

Sonographically, you visualize a mass extending from the distal spine of a fetus. This mass could be all of the following

SCT, Meningocele, or Meningomyelocele

The exaggerated distance between the first toe and the second toe is:

Sandal gap

The abnormal lateral curvature of the spine is referred to as:

Scoliosis

What condition is associated with bilateral renal agenesis, oligohydramnios, and fusion of the lower extremities?

Sirenomelia

All of the following are associated with spina bifida

Splaying of the laminae, Lemon sign, Banana sign

What term is defined as fusion of the digits?

Syndactyly

Which of the following is true for the diagnosis of clubfoot?

The metatarsals and toes lie in the same plane as the tibia and fibula.

kyphosis?

abnormal posterior curvature of the spine

cloverleaf skull?

abnormal shape of the cranium caused by premature fusion of the sutures in which there is frontal bossing and a cloverleaf shape to the skull

omphalocele?

anterior abdominal wall defect where there is herniation of the fetal bowel and other abdominal organs into the base of the umbilical cord

acoustic shadowing?

area where sound has been prohibited to propagate resulting in a dark shadow projecting posterior to a structure

lipoma?

benign fatty tumor

hemangioma?

benign tumor composed of blood vessels

maternal serum screening?

blood screening test that evaluates maternal levels of alpha-fetoprotein, estriol, and human chorionic gonadotropin (as well as other labs) during a preg- nancy for neural tube defects and chromosomal abnormalities

dysplasia?

denotes the abnormal development of a structure

hydronephrosis?

dilation of the renal collecting system resulting from the obstruction of the flow of urine from the kidney(s) to the bladder; also referred to as pelvocaliectasis or pelvicaliectasis

neural tube?

embryologic formation that results from fusion of the two folded ends of the neural plate

bilateral renal agenesis?

failure of both kidneys to develop in the fetus

biparietal diameter?

fetal head measurement obtained in the transverse plane at the level of the third ventricle and thalamus; this measurement is obtained from the outer table of the proximal parietal bone to inner table of the distal parietal bone

exencephaly?

form of acrania in which the entire cerebrum is located outside of the skull

osteogenesis imperfecta?

group of disorders that result in multiple fractures in utero; caused by decreased mineralization and poor ossification of the bones

limb-body wall complex?

group of disorders with sonographic findings including a short or absent umbilical cord, ventral vwall defects, limb defects, craniofacial defects, and scoliosis

spinal dysraphism?

group of neural tube defects that describe some manifestation of incomplete closure of the spine

human chorionic gonadotropin?

hormone produced by the trophoblastic cells of the early placenta; may also be used as a tumor marker in nongravid patients and males

axial skeleton?

includes the bones of cranium and spine

oligohydramnios?

lower-than-normal amount of amniotic fluid for the gestational age

clubfoot?

malformation of the bones of the foot in which the foot is most often inverted and rotated medially, and the metatarsals and toes lie in the same plane as the tibia and fibula

myelocele?

mass that results from open spina bifida that contains spinal cord only

meningomyelocele?

mass that results from open spina bifida that contains the spinal cord and the meninges; also referred to as a myelomeningocele

pregestational diabetes?

maternal diabetes that existed before pregnancy; includes both type 1 and 2 diabetes mellitus

spina bifida aperta?

most common form of spina bifida; results in open lesions that are typically not covered by skin and a mass that protrudes from the spine; also referred to as open spina bifida

heterozygous achondroplasia?

most common nonlethal skeletal dysplasia that is characterized by rhizomelia

anencephaly?

neural tube defect that is described as the absence of the cranium and cerebral hemispheres

anhydramnios?

no amniotic fluid

sacral agenesis?

nondevelopment of the sacrum; see key term caudal regression syndrome

alpha-Fetoprotein?

protein produced by the fetal yolk sac, fetal gastrointestinal tract, and the fetal liver; may also be produced by some malignant tumors

encephalocele?

protrusion of brain tissue through a defect in the skull

cephalocele(s)?

protrusions of intracranial contents through a defect in the skull

Achondrogenesis?

rare, lethal condition resulting in abnormal development of the bones and cartilage

caudal regression syndrome is also referred to as

sacral agenesis

maternal serum alpha-fetoprotein?

screening test that detects the amount of alpha-fetoprotein in the maternal blood stream

femur length?

sonographic measurement of the femoral diaphysis that provides an estimated gestational age

lemon sign?

sonographic sign associated with a lemon-shaped cranium; most often found in the fetus with spina bifida

sacral agenesis?

the nondevelopment of the sacrum; see key term caudal regression syndrome

autosomal dominant disorder?

way in which a disorder or trait can be inherited by a fetus; at least one of the parents has to be the carrier of the gene for the disease

SONOGRAPHIC APPEARANCE OF KYPHOSIS

1. Abnormal posterior curvature of the spine

SONOGRAPHIC FINDINGS OF RADIAL RAY DEFECT

1. Absent or hypoplastic radius 2. Various defects in other body systems: cardiac and VACTERL association

SONOGRAPHIC FINDINGS OF CAUDAL REGRESSION SYNDROME

1. Absent sacrum (sacral agenesis) and possibly part of the lumbar vertebra 2. Possible abnormalities in the lower extremities like clubfeet

SONOGRAPHIC FINDINGS OF AMNIOTIC BAND SYNDROME

1. Amputation of fetal parts or severe edema in the affected area 2. Thin, linear bands may be seen 3. Facial clefting

SONOGRAPHIC FINDINGS OF THANATOPHORIC DYSPLASIA

1. Cloverleaf skull 2. Hydrocephalus 3. Depressed nasal bridge 4. Bell-shaped chest (narrow thorax) 5. Polyhydramnios 6. Redundant soft tissue 7. Telephone receiver-shaped long bones

SONOGRAPHIC FINDINGS OF SACROCOCCYGEAL TERATOMA

1. Complex mass extending off the distal fetal spine 2. Mass can be highly vascular 3. Hydronephrosis may be present (when mass invades the pelvis) be present 4. Fetal hydrops may 5. Cardiomegaly

SONOGRAPHIC FINDINGS OF OSTEOGENESIS IMPERFECTA

1. Demineralization of the skull (transducer pressure can alter the shape of the skull) 2. Multiple fractures 3. Bell-shaped chest

CLINICAL FINDINGS OF LIMB-BODY WALL COMPLEX

1. Elevated MSAFP

CLINICAL FINDINGS OF OPEN SPINA BIFIDA APERTA (OPEN)

1. Elevated MSAFP

CLINICAL FINDINGS OF SPINA BIFIDA OCCULTA

1. In utero-normal laboratory values 2. Postnatal-sacral dimple, hemangioma, lipoma, or excessive hair is identified directly over the distal spine

SONOGRAPHIC APPEARANCE OF SCOLIOSIS

1. Lateral curvature of the spine 2. S-shaped spine

SONOGRAPHIC FINDINGS OF ACHONDROPLASIA

1. Macrocrania 2. Frontal bossing 3. Flattened nasal bridge 4. Micromelia (resulting from rhizomelia) 5. Trident hand

SONOGRAPHIC FINDINGS OF ACHONDROGENESIS

1. Severely shortened limbs (micromelia) 2. Absent mineralization of the skull, spine, pelvis, and limbs 3. Large skull 4. Narrow chest and distended abdomen 5. Polyhydramnios

SONOGRAPHIC FINDINGS OF LIMB-BODY WALL COMPLEX

1. Short or absent umbilical cord 2. Marked scoliosis 3. Various other anomalies including craniofacial and limb defects

SONOGRAPHIC FINDINGS OF SPINA BIFIDA APERTA (OPEN)

1. Splaying of the laminae in the area of the defect 2. Cystic mass (meningocele) or complex mass (myelomeningocele) protruding from the spine 3. Lemon sign-lemon-shaped cranium with flattened frontal bones 4. Banana sign-banana-shaped cerebellum 5. Obliterated cisterna magna 6. Colpocephaly 7. Hydrocephalus

CLINICAL FINDINGS OF CAUDAL REGRESSION SYNDROME

1. Uncontrolled maternal pregestational diabetes

AFP exits the fetus through ___ such as with open spina bifida or gastroschisis, thus allowing a greater amount to pass into the maternal circulation.

AFP exits the fetus through an opening in the neural tube if one is present, such as with open spina bifida or gastroschisis, thus allowing a greater amount to pass into the maternal circulation.

Rockerbottom foot?

Abnormal curved shape of the sole of the foot

In VACTERL association, the letter "C" stands for:

Cardiac

Clinodactyly?

Deviation of a finger (e.g., absence of the middle fifth phalanx)

What is the maternal dietary supplement that has heen shown to significantly reduce the likelihood of the fetus suffering from a neural tube defect?

Folate

Achondroplasia is associated with all of the following

Frontal bossing, Flattened nasal bridge, Trident hand

Sirenomelia (mermaid syndrome)

Fusion of the legs

Polydactyly?

Having more than the normal number of digits

What is the anomaly of the spine in which there is absence of all or part of a vertebral body and posterior element?

Hemivertebra

____ is the most common nonlethal skeletal dysplasia.

Heterozygous achondroplasia

Trident hand?

Increases space between the third finger and fourth finger

In VACTERL association, the letter "L" stands for:

Limb

Arthrogryposis?

Limitation of fetal limb motion as a result of joint contractures; most often affecting the hands and feet

Sirenomelia is commonly referred to as:

Mermaid syndrome

Which of the following would increase the likelihood of a fetus developing sirenomelia and caudal regression syndrome?

Preexisting maternal diabetes

Absence of the radius is referred to as:

Radial ray defect

Scoliosis is a deformity of the spine in which there is an abnormal ___ curvature, whereas kyphosis is an abnormal ____ curvature of the spine.

Scoliosis is a deformity of the spine in which there is an abnormal lateral curvature, whereas kyphosis is an abnormal posterior curvature of the spine.

Micromelia?

Shortening of an entire limb

Acromelia?

Shortening of the distal segment of a limb

Mesomelia?

Shortening of the middle segment of a limb

A cloverleaf skull and hydrocephalus is seen with:

Thanatophoric dysplasia

CLINICAL FINDINGS OF SIRENOMELIA

Uncontrolled pregestational maternal diabetes

All of the following are clinical or sonographic findings consistent with LBWC

Ventral wall defects, Marked scoliosis, Shortened umbilical cord

The fetus with thanatophoric dysplasia will have

a cloverleaf skull with frontal bossing and hydrocephalus.

dwarfism?

abnormal short stature

VACTERL association?

acronym for a combination of abnormalities that represent vertebral anomalies, anorectal atresia, cardiac anomalies, tracheoesophageal fistula, renal anomalies, and limb anomalies; may also be referred to as VATER association

synechiae?

adhesions

Osteogenesis imperfecta is commonly also. known as

brittle bone disease

spina bifida occulta?

closed spinal lesions that are completely covered by skin and can be difficult to identify sonographically; also referred to as closed spina bifida

kyphoscoliosis?

combination of both scoliosis and kyphosis in the fetus

amniotic band syndrome?

group of abnormalities associated with the entrapment of fetal parts in the amnion, often resulting in fetal amputations or clefting

triple screen?

maternal blood test that typically includes an analysis of human chorionic gonadotropin, alpha-fetoprotein, and estriol

thanatophoric dysplasia?

most common lethal skeletal dysplasia characterized by a cloverleaf skull with frontal bossing and hydrocephalus

cerebellum?

portion of the brain located in the inferior posterior part of the skull that is responsible for motor output, sensory perception, and equilibrium

posterior fossa?

posterior portion of the cranium located near the cerebellum and containing the cisterna magna

Spina bifida aperta May also be referred to as

spina bifida cystica

The most common location of spina bifida is

the lumbosacral region.

Each fetal vertebra consists of

three echogenic ossification centers: one centrum and two neural processes.

Keep in mind that spina bifida is associated with two ____

two yellow fruits-the banana and the lemon.

A common sonographic finding of LBWC is a short or absent ___

umbilical cord.

trident hand?

wide separation between the middie and ring finger