Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Penny ob/gyn > Ch. 24 The Fetal Head and Brain > Flashcards

Ch. 24 The Fetal Head and Brain Flashcards

1
Q

The abnormal enlargement of the ventricles within the brain is referred to as ___________.

A

ventriculomegaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

__________ refers to dilatation (dilation) of the ventricular system caused by an increased volume of CSF, resulting in increased intraventricular pressure. Hydrocephalus may be reserved for cases of ventriculomegaly that are more severe and are caused by some type of obstruction to the flow of CSF, resulting in a backup of the fluid in the cerebral ventricles.

A

Hydrocephalus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The sonographic finding of the “_________” sign describes the echogenic choroid plexus, hanging limp, and surrounded by CSF, within the dilated lateral ventricle. (this finding is exceedingly specific for ventriculomegaly)

A

dangling choroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Ventriculomegaly has been cited as the most common cranial abnormality. Suspicion of ventricular dilatation occurs when the atrial diameter measures more than _______. The lateral ventricle that will be readily seen on sonography is most often the ventricle ________ from the transducer.

A

10 mm; farthest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the two main type of hydrocephalus?

A

communicating and noncommunicating hydrocephalus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

he obstruction of cerebrospinal fluid from a source outside the ventricular system

A

Communicating hydrocephalus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

the obstruction of cerebrospinal fluid from a source within the ventricular system

A

noncommunicating hydrocephalus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

the duct that connects the third ventricle of the brain to the fourth ventricle; also referred to as the aqueduct of Sylvius

A

aqueductal stenosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Sonographic Findings of _________

1.Atrium of the lateral ventricle measures greater than 10 mm
2.Atrial measurement greater than 15 mm is considered moderate to marked ventriculomegaly
3.Dangling choroid sign
4.Dilatation of any part of the ventricular system

A

Ventriculomegaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

______________is the most common cause of hydrocephalus in utero

A

Aqueductal stenosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The ___________, located between the third and fourth ventricles of the brain, may be narrowed, thus preventing the flow of CSF from the third to the fourth ventricle. This obstruction level will cause the ________and both the _________ to expand, whereas the fourth ventricle remains normal.

A

cerebral aqueduct(adqueduct of Sylvius); third ventricle; lateral ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Sonographic Findings of __________

1.Atrium of the lateral ventricle measures greater than 10 mm
2.Atrial measurement greater than 15 mm is considered moderate to marked ventriculomegaly
Dangling choroid sign
Dilatation of the lateral ventricles and the third ventricle; the fourth ventricle remains normal

A

Aqueductal Stenosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Sonographic Findings of _________

1.Fluid-filled cranium
2.Absent or partial absence of the falx cerebri
3.Maintained brainstem, basal ganglia, and, perhaps, the thalamus
4.No identifiable cerebral cortex

*fatal condition, with death occuring in the first year of life

A

Hydranencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

___________is a fatal condition in which the entire cerebrum is replaced by a large sac containing CSF

A

Hydranencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

the lower part of the brain composed of the pons, midbrain, and medulla oblongata

A

brainstem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

a group of nuclei within the brain that function in several ways, including information processing and emotional response

A

basal ganglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

There have been several postulations regarding the cause of _____________, including bilateral occlusion of the internal carotid arteries with subsequent destruction of the cerebral hemispheres. Another hypothesis is that intrauterine infections such as cytomegalovirus and toxoplasmosis lead to the destruction of the cerebral hemispheres.

A

hydranencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

the most severe form of holoprosencephaly

A

alobar holoprosencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

a group of brain abnormalities consisting of varying degrees of fusion of the lateral ventricles, absence of the midline structures, and associated facial anomalies

A

holoprosencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Hydranencephaly can be difficult to differentiate with the sonographic findings of severe ventriculomegaly and _______ holoprosencephaly. It is important to note that with both severe ventriculomegaly and holoprosencephaly, there will typically be a rim of cerebral tissue maintained, whereas with hydranencephaly, there is ____cerebral mantle present.

A

alobar; no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

one large ventricle within the brain associated with holoprosencephaly

A

monoventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

____________is a midline brain anomaly that is associated with not only brain aberrations but also atypical facial structures. It may be detected with endovaginal imaging as early as the first trimester.

A

Holoprosencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the 3 types of holoprosencephaly?

A

alobar, semilobar, and lobar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the severe form of holoprosencephaly? What shapes does it take on?

A

alobar, “pancake” “cup” “ball”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Although the ______ form can be consistent with life, alobar holoprosencephaly is the most severe form, often resulting in neonatal death.

A

lobar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

With ____________, there will be evidence of a horseshoe-shaped monoventricle, and the lobes of the thalamus may be fused and echogenic in appearance.

A

holoprosencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

the least severe form of the holoprosencephaly

A

lobar holoprosencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

a subdivision within the middle of the lip

A

median cleft lip

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

close-set eyes (hypotelorism) and a nose with a single nostril

A

cebocephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

the absence of the eye(s)

A

anophthalmia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Infants with lobar holoprosencephaly may experience severe _______ retardation. _________, or Patau syndrome, is present in 50% to 70% of fetuses diagnosed with holoprosencephaly

A

mental; Trisomy 13

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Facial anomalies associated with _______

Cyclopia

Hypotelorism

Proboscis(false nose above the orbits)

(Median) cleft lip

Anophthalmia

Cebocephaly

A

alobar holoprosencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Sonographic Findings of __________

1.Horseshoe-shaped monoventricle
2.Fused echogenic thalami
3.Absence of the CSP, interhemispheric fissure, falx cerebri, corpus callosum, and third ventricle
4.Normal cerebellum and brainstem
5.Facial anomalies (e.g., cyclopia, proboscis, cebocephaly, facial clefts, hypotelorism)

A

Alobar Holoprosencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

___________ is actually a classification within a larger group of anomalies referred to as the Dandy–Walker complex. Dandy–Walker complex is a spectrum of posterior fossa abnormalities that involve the cystic dilatation of the _________and __________.

A

Dandy–Walker malformation (DWM); cisterna magna and fourth ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

_________ is thought to be caused by a developmental abnormality in the roof of the fourth ventricle.

A

DWM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Sonographic Findings of ____________

1.Enlargement of the cisterna magna greater than 10 mm in the anteroposterior dimension
2.Communication of the enlarged cisterna magna with a dilated fourth ventricle
3.Agenesis or hypoplasia of the cerebellar vermis (As a result, the tentorium, the structure that separates the cerebrum from the cerebellum, is elevated)
4.Varying degrees of ventriculomegaly

*There are often other midline brain abnormalities present as well. For instance, agenesis of the corpus callosum, ventriculomegaly, holoprosencephaly, and cephaloceles are all associated anomalies of DWM.

A

Dandy–Walker Malformation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

The sonographic findings of DWM include an enlarged cisterna magna that communicates with a distended _________ through a defect in the cerebellum

A

fourth ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Sonographic Findings of ________

1.Enlargement of the cisterna magna greater than 10 mm in the anteroposterior dimension
2.Normal cerebellum and fourth ventricle

A

Mega Cisterna Magna

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

The __________ is a bridge of tissue located within the midline of the brain that connects the two cerebral hemispheres. It functionally provides a pathway for communication between the hemispheres and is completely formed by ____ weeks.

A

corpus callosum; 18

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

The CSP, located inferior to the corpus callosum, and the corpus callosum develop at the _________. The congenital lack of these structures is termed ________, as in _________ of the corpus callosum, and CSP.Most often, if the corpus callosum is absent, the _______ will be absent as well.

A

same time; agenesis; CSP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q
A

Apert syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q
A

trisomy 8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q
A

Colpocephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Sonographic Findings of ___________ and __________

1.Partial or complete absence of the corpus callosum and absence of the CSP (after 18 weeks)
2.“Sunburst” sign—radial arrangement of the sulci that produces a “spoke-wheel” pattern
3.Colpocephaly—small frontal horns and enlarged occipital horns (teardrop-shaped lateral ventricles)
4.Elevated and dilated third ventricle

*Their nonexistence has been linked to as many as 50 to 200 different syndromes and anomalies such as Apert syndrome, holoprosencephaly, DWM, aqueductal stenosis, trisomy 18, trisomy 8, and trisomy 13.

A

Agenesis of the Corpus Callosum and Cavum Septum Pellucidum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

With agenesis of the _________, the sulci tend to have a more perpendicular or radial arrangement and often appear to have a “spoke-wheel” pattern.

A

corpus callosum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

_____________ is associated with the development of fluid-filled clefts within the cerebrum.

A

Schizencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

The etiology of schizencephaly is unknown, although there may be an association with intrauterine exposure to some illicit drugs. It may be described as _____ lip or _____lip, with ______ lip being more readily identified in utero. The sonographic appearance of open lip schizencephaly is that of a cerebrum containing gray matter–lined _____ filled containing anechoic CSF

A

open; closed; open; cleft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Sonographic Findings of _________

1.Fluid-filled clefts within the cerebrum
2.Agenesis of the CSP and corpus callosum (50% of the time)
3.Ventriculomegaly

A

Schizencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

_________is a rare condition in which a cyst communicates with the ventricular system. ________ can occur after the fetus has experienced __________ within one or both of the cerebral hemispheres. As the hemorrhage changes states, it will form into a cystic cavity and will eventually communicate with the _________of the affected side. This condition may be caused by ischemic events or vascular occlusion within the brain

A

Porencephaly; hemorrhage; lateral ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

benign cysts within the brain that do not communicate with the ventricular system

A

Arachnoid cysts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Arachnoid cysts can be confused with porencephaly. It is important to note that arachnoid cysts will ______communicate with the ventricular system.

A

not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Sonographic Findings of _______

1.Cystic mass that communicates with the lateral ventricle
2.Most often unilateral

A

Porencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

____________literally means “smooth brain.”

A

Lissencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Agyria, and the absence of sulci within the brain, is not typically diagnosed until the_______trimester or postnatally and almost always carries a poor prognosis.

A

third

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

“smooth brain”; condition where there is little to no gyri or sulci within the cerebral cortex

A

Lissencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Sonographic Findings of __________

Lack of sulci and gyri within the cerebrum

A

Lissencephaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

_________ are cysts located within the choroid plexus of the lateral ventricles. These small cysts are frequently encountered during a routine sonographic examination and typically regress by the end of the ______ trimester.

A

Choroid plexus cysts; third

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Sonographic Appearance of a __________

Anechoic, round, smooth-walled cyst located within the choroid plexus of the lateral ventricle (measures more than 2mm)

A

Choroid Plexus Cyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Choroid plexus cysts often regress, although there is a slight association with trisomy _____.

A

18

60
Q

__________occur when the embryonic neural tube fails to close. Among the list of neural tube defects are cephaloceles, various spinal dysraphisms, anencephaly, and spina bifida.

A

Neural tube defects

61
Q

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

A

spinal dysraphisms

62
Q

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

A

anencephaly

63
Q

________ and _______ are the most common neural defects, occurring in 1 per 1,000 pregnancies. Although several causes have been implicated, such as maternal diabetes and the use of valproic acid (seizure medication), chromosomal anomalies, including Edwards syndrome (trisomy 18), Patau syndrome (trisomy 13), and triploidy, have all been linked with neural tube defects.

A

Anencephaly and spina bifida

64
Q

studies have shown that a supplement of 0.4 mg of __________ in a woman’s diet significantly reduces the likelihood of her fetus developing a neural tube defect.

A

folate (folic acid)

65
Q

However, increased levels of _____ may not always indicate that a neural tube defect is present. Elevated levels of ______ are also found with omphalocele, gastroschisis, multiple gestations, fetal demise, and incorrect gestational dating.

A

AFP

66
Q

________ remains one of the most common neural tube defects. _______ is defined as the absence of the cranial vault above the bony orbits. It can be further divided into two main subtypes depending on the amount of cerebral tissue present, ______ and _______

A

Acrania; acrania; anencephaly and exencephaly

67
Q

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

A

exencephaly

68
Q

__________ is considered when there are no cerebral hemispheres present, whereas _________ denotes a normal amount of cerebral tissue. Nonetheless, the cranium is absent, making this condition fatal.

A

Anencephaly; exencephaly

69
Q

Clinical Findings of Acrania/Anencephaly

Elevated _______

A

MSAFP

70
Q

Sonographic Findings of ________

Absent cranial vault
Some cerebral tissue may be present
“Froglike” facies or bulging eyes
Possible fetal movement and active fetal heart tones

A

Acrania/Anencephaly

71
Q

___________ or Chiari II malformation is a group of cranial abnormalities associated with the neural tube defect spina bifida.

A

Arnold–Chiari II

72
Q

The most common location of spina bifida is within the __________

A

distal lumbosacral region

73
Q

The cerebellum will become displaced inferiorly and posteriorly and appear curved in the presence of spina bifida, which is referred to as the “_______” sign, whereas the head shape will be shaped like a _______ (“________sign”). Remember, when open spina bifida is present, both yellow fruit signs (_________)are demonstrated in the skull.

A

banana; lemon; lemon sign and banana sign

74
Q

Clinical Findings of Arnold–Chiari II Malformation

Elevated _________

A

MSAFP

75
Q

Sonographic Findings of _________

1.Lemon sign—lemon-shaped cranium with flattened or scalloped frontal bones
2.Banana sign—banana-shaped cerebellum
3.Obliterated cisterna magna
4.Colpocephaly
5.Enlarged massa intermedia
6.Hydrocephalus
7.Open spinal defect

A

Arnold–Chiari II Malformation

76
Q

__________ are protrusions of intracranial contents through a defect in the skull

A

Cephaloceles

77
Q

Cephaloceles can also be distinguished by their location. The most common location for a cephalocele is in the _______region. However, cephaloceles may also have frontal and parietal positions. _______ cephaloceles often lead to hypertelorism. Encephaloceles, which include brain tissue, are common findings in __________syndrome and have varying sonographic appearances based on their content.

A

occipital; Anterior; Meckel–Gruber

78
Q

Clinical Findings of Cephaloceles

Possible elevation of ________

A

MSAFP

79
Q

Sonographic Findings of ________

1.Open cranial defect (typically posterior in location)
2.Small or obliterated cisterna magna
3.Complex- or simple-appearing mass protruding from the cranium

A

Cephaloceles

80
Q

Type of Cephalocele:
Meningocele

Content of the Mass: _____

A

Meninges only

81
Q

Type of Cephalocele:
Encephalocele

Content of the Mass: _____

A

Brain tissue only

82
Q

Type of Cephalocele:
Encephalomeningocele

Content of the Mass: _____

A

Both meninges and brain tissue

83
Q

Type of Cephalocele:
Encephalomeningocystocele

Content of the Mass: _____

A

Meninges, brain tissue, and lateral ventricle

84
Q

Maternal serum screening for intrauterine infections resulting from _______, _________, ________, _________, and __________ (TORCH) can be performed. This is referred to as a TORCH panel

A

toxoplasmosis, other agents, rubella, cytomegalovirus, and herpes simplex virus

85
Q

The sonographic intracranial findings consistent with intrauterine infections are the ___________and __________.

A

calcifications around the ventricles and ventriculomegaly

86
Q

The most common intracranial tumor found in utero is the _________.

A

teratoma

87
Q

_________ contain tissues such as hair, sebum, and fat and most often appear as complex masses that distort the normal architecture of the brain.

A

Teratomas

88
Q

Choroid plexus papillomas are found within the ________ and produce an increase in the production of CSF, which, in turn, leads to _________. Other sonographic findings associated with brain tumors are macrocephaly and intracranial calcifications. Corpus callosum lipomas may also be present with _______ of the corpus callosum. A lipoma will appear as a solid echogenic mass.

A

choroid plexus; ventriculomegaly; agenesis

89
Q

________ is worrisome for premature infants weighing less than 1,500 g and those born before 32 weeks’ gestation, it occurs less often in utero. Maternal use of cocaine, trauma, and a history of amniocentesis are all listed as predisposing condition of fetal intracranial hemorrhage; however, the most common risk factor for fetal intrauterine intracranial hemorrhage has been listed as _____________

A

intracranial hemorrhage; maternal platelet disorders

90
Q

Most often, the origin of ________, also referred to as intraventricular hemorrhage, is within the _________.

A

intracranial hemorrhage; germinal matrix.

91
Q

a group of thin-walled blood vessels and cells within the subependymal layer of the fetal brain responsible for brain cell migration during fetal development

A

germinal matrix

92
Q

The ________ is a group of thin-walled, pressure-sensitive vessels located in the _________ of the ventricles. These vessels are prone to rupture secondary to their thin walls. The hemorrhage can spread into the lateral ventricle, often leading to noncommunicating hydrocephalus, because the clot obstructs the flow of CSF within the narrowed regions of the ventricular system.

A

germinal matrix; subependymal layer

93
Q

the area just beneath the ependymal lining the lateral ventricles

A

subependymal layer

94
Q

the functional part of an organ

A

parenchyma

95
Q

a shortage of oxygen or decreased oxygen in the blood

A

hypoxia

96
Q

an arteriovenous malformation that occurs within the fetal brain and is associated with congestive heart failure

A

vein of Galen aneurysm

97
Q

an abnormal accumulation of fluid in at least two fetal body cavities

A

hydrops (fetal)

98
Q

Hemorrhage can also occur within the ______ of the brain. Localized areas of hemorrhage within the cerebral hemispheres will eventually lead to the formation of cystic cavities that communicate with the ventricular system, a condition known as __________

A

parenchyma; porencephaly

99
Q

The normal cerebral circulation typically yields a _________Doppler pattern, with continuous forward flow throughout the cardiac cycle. Doppler assessment of the middle cerebral artery (MCA) has been shown effective at evaluating for potential _______ in fetuses that are small for dates

A

high-impedance; hypoxia

100
Q

When the fetus is starved for oxygen, redistribution of the blood to the vital organs—such as the brain—occurs in order to spare it from damage. This is referred to as the ___________.

A

brain-sparing effect

101
Q

The resistance pattern of the MCA should be ________ than that of the umbilical artery and thus should be compared when ________ is suspected.

A

greater; fetal shunting

102
Q

The MCA/umbilical artery resistive index is normally above _____, whereas an index lower than _____ is considered abnormal.

A

1.0; 1.0

103
Q

The ________ is an arteriovenous malformation that occurs within the fetal brain.

A

vein of Galen aneurysm

104
Q

Sonographic Findings of _________

1.Anechoic mass within the midline of the brain that contains turbulent arterial and venous flow when interrogated with pulsed and color Doppler
2.Fetal hydrops
3.Cardiomegaly (caused by cardiac overload)

A

Vein of Galen Aneurysm

105
Q

The vein of Galen aneurysm is associated with ________in the newborn.

A

congestive heart failure

106
Q

Clinical Findings of _____________(Neonatal)

Congestive heart failure

A

Vein of Galen Aneurysm

107
Q

The depth of the cisterna magna should not measure more than _______or less than ______ in the transcerebellar plane. Measurement more than 10 mm is consistent with _______ and ________, whereas a measurement of less than 2 mm is worrisome for________.

A

10 mm; 2 mm; mega cisterna magna and Dandy–Walker complex; Arnold–Chiari II malformation

108
Q

The cerebellum grows at a rate of _______per week between 14 and 21 weeks and thus correlates agreeably with the gestational age of the fetus. That means, the cerebellum of a 16-week fetus will measure approximately _______.

A

1mm; 16mm

109
Q

The cerebellum is measured in the transverse plane at the same level as the ________and _______. The CSP will also be in the image. This measurement, referred to as the ________, will likely lose its accuracy in the presence of chromosomal abnormalities, typically measuring _______than normal. TCD proven to be useful in several studies as an indicator of growth restriction or large for gestational age when other measurements are lacking.

A

cisterna magna; thalamus; transcerebellar diameter (TCD); smaller

110
Q

The lateral ventricle is measured in the transaxial plane at the level of the ______. The _____ of the lateral ventricle is the optimal site for measuring the lateral ventricle, because it is the first region where ventricular enlargement occurs. The calipers are placed at the level of the ______ of the choroid plexus.

A

atrium; atrium; glomus

111
Q

The normal lateral ventricle does not typically measure more than _______at the level of the atrium. Enlargement beyond 10 mm is referred to as ________.

A

10mm; ventriculomegaly

112
Q

the largest part of the choroid plexus

A

glomus

113
Q

the ratio used for assessing fetal head shape

A

cephalic index

114
Q

round or short and wide skull

A

brachycephalic (brachycephaly)

115
Q

an elongated, narrow head shape; may also be referred to as scaphocephaly

A

dolichocephaly

116
Q

normal head shape

A

mesocephalic

117
Q

The formula used to calculate the cephalic index considers the BPD and the OFD as follows: cephalic index = _________________

A

cephalic index = BPD/OFD × 100

118
Q

A cephalic index of _______________dolichocephalic shape, whereas an index of ____________denotes a brachiocephalic shape.

A

less than 75; more than 85 denotes

119
Q

The corrected-BPD is “shape corrected” and is equivalent to the _____, independent of the shape of the skull.

A

HC

120
Q

represents the biparietal diameter of a standard-shaped fetal head with the same cross-sectional area

A

corrected-BPD

121
Q

The OFD is obtained at the same level of the ______and ______. For the OFD, one caliper is placed in the anterior midline in the middle of the _______bone, whereas the other is placed in the middle of the echogenic line of the _______bone

A

BPD and HC; frontal; occipital

122
Q

OFD can also be added to the BPD and multiplied by ______ to obtain an _____.

A

1.62; HC

123
Q

_______is obtained in the axial plane at the level of the CSP, thalamus, falx cerebri, and a measurement around the entire cranium is obtained. This is the same level as the third ventricle, which may be seen between the two lobes of the thalamus.Cranial bones must be symmetric on both sides of the head.

A

HC

124
Q

HC can also be obtained by measuring the occipitofrontal diameter (OFD) and taking an _________ diameter measurement at the level of the BPD

A

outer-to-outer diameter

125
Q

Some authors suggest that the ______ measurement is typically more accurate than BPD because this measurement is independent of the __________, consequently providing a more consistent parameter for estimating gestational age.

A

HC; fetal head shape

126
Q

The _______ is obtained in the axial plane at the level of the CSP, thalamus, and falx cerebri. This is the same level as the third ventricle, which may be seen between the two lobes of the thalamus. The cranial bones must be symmetric on both sides of the head, and the measurement is obtained from the ______ table of the proximal parietal bone to the ________ table of the distal parietal bone. That means, the measurement is obtained from leading edge to leading edge (can be taken after the first trimester has ended, typically starting between 13 and 14 weeks)

A

BPD; outer; inner

127
Q

The normal cerebellum is a dumbbell-shaped or figure _____–shaped structure noted in the _________ cranium of the fetus. The two hemispheres(right and left) of the cerebellum should be symmetric, although ______ of one cerebellar hemisphere can occur, resulting in the hypoplastic hemisphere appearing smaller than normal.

A

eight; posterior; hypoplasia

128
Q

The cerebellum consists of two hemispheres—right and left—that are coupled at the midline by the _______. The _________, named for their shape, are located on the undersurface of the cerebellum and become distorted with spina bifida and Arnold–Chiari malformations.

A

cerebellar vermis; cerebellar tonsils

129
Q

The ______, located in the posterior fossa of the cranium, is the largest cistern in the head.

A

cisterna magna

130
Q

a prominent space within the skull that contains cerebrospinal fluid; a cistern is created by the separation of the arachnoid membrane and pia mater

A

cistern

131
Q

the portion of the cerebellum, located within the midline of the brain, that connects its two hemispheres

A

cerebellar vermis

132
Q

On sonography, the _________ appears as an anechoic, fluid-filled space, posterior to the cerebellum, between the cerebellar vermis and the interior surface of the occipital bone. It is considered common to find some small septations within the __________.

A

cisterna magna

133
Q

The greater part of CSF is produced by the cells of the ________that are located within the trigone of the lateral ventricles.

A

choroid plexus

134
Q

CSF moves from the lateral ventricles into the third ventricle through the ________. From the third ventricle, CSF travels to the fourth ventricle through the _________. Once in the fourth ventricle, the fluid can exit either through the _____ aperture or through the ________apertures. CSF also flows inferiorly and around the spinal cord.

A

foramina of Monro; cerebral aqueduct; median; lateral

135
Q

________, also referred to as arachnoid villi, are responsible for the reabsorption of CSF into the venous system. This process occurs at the _________sinus, located along the superior surface of the cerebrum within its midline.

A

Arachnoid granulations; superior sagittal

136
Q

nodular structures located along the falx cerebri that reabsorb cerebrospinal fluid into the venous system; also referred to as arachnoid villi

A

Arachnoid granulations

137
Q

The ________system is composed of _______ ventricles, whose primary function is to provide cushioning for the brain

A

ventricular; four

138
Q

Head Shape:
__________

Associated Anomalies:
Chiari II malformation

A

Lemon

139
Q

Head Shape:
__________

Associated Anomalies:
Trisomy 18

A

Strawberry

140
Q

Head Shape:
__________

Associated Anomalies:
Thanatophoric dysplasia

A

Cloverleaf

141
Q

Head Shape:
__________

Associated Anomalies:
TORCH infections

Trisomy 13 and trisomy 18

Meckel–Gruber syndrome

Fetal alcohol syndrome

A

Microcephaly

142
Q

Head Shape:
__________

Associated Anomalies:
Hydrocephalus

Hydranencephaly

Intracranial tumors

Familial inheritance

Beckwith–Wiedemann syndrome

A

Macrocephaly

143
Q

Head Shape:
__________

Associated Anomalies:
Craniosynostosis

Trisomy 21

Trisomy 18

A

Brachycephaly

144
Q

Head Shape:
__________

Associated Anomalies:
Craniosynostosis

A

Dolichocephaly

145
Q

an enlarged head circumference

A

macrocephaly

146
Q

small head

A

microcephaly

Penny ob/gyn (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions