Brainscape's Knowledge GenomeTM

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


See full index

radiology > intracranial pathology ch27 > Flashcards

intracranial pathology ch27 Flashcards

1
Q

On CT, fourth ventricle appears as

A

an inverted U-shaped structure. It has fluid so it is black.

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

Posterior to the fourth ventricle are the ____;

anteriorly lies the ___ and ___.

A

Posterior to the fourth ventricle are the cerebellar hemispheres;
anteriorly lies the pons and medulla oblongata.

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

The ____ seperates the infratentorial components of the posterior fossa (cerebellum and fourth ventricle) from the supratentorial comnpartment.

A

tentorium cerebelli

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

The interpeduncular cistern lies in ___ and separates the ____.

A

lies in the midbrain and separate the paired cerebral peduncles (which emerge from the superior surface of the pons).

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

The suprasellar cister is ___ to the interpeduncular cistern and usually has a five- or six-point star like ppereane.

A

anterior

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

The ____ are bilaterally symmetric and contain CSF. They seperate the temproal from the frontal and parietal lobes.

A

The sylvian fissures are bilaterally symmetric and contain CSF. They seperate the temproal from the frontal and parietal lobes.

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

The lentiform nucleusis composed of the ____ (laterally) and ___ (medially).

A

The lentiform nucleusis composed of the putamen (laterally) and globus pallidus (medially).

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

The ___ ventricle is slit-like and midline.

A

The third ventricle is slit-like and midline.,

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

At the posterior aspect of the third ventricle is the ___. Farther posterior is the _______.

A

pineal gland.

quadrigeminal plate cistern

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

____ connects the right and left cerebral hemisphers and forms the roof of lateral ventricle. The anterior end is called the ___ and the posterior end is called the ____.

A

corpus callosum connects the right and left cerebral hemisphers and forms the roof of the lateral ventricle. The anterior end is called the genu and the posterior end is called the splenium.

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

The basal ganglia are represented by the ____ and the ___, ____, ____ and ____.

A

The basal ganglia are represented by the subthalamic nucelus and the substantia nigra, globus pallidus, putamen and caudate nucleus.

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

The frontal (also known as anterior horns) of the ____ hug the head of the caudate nucleus.

A

lateral ventricles

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

The two frontal horns of lateral ventricles are separated by the midline ____.

A

septum pellucidum

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

The temporal horns, which are normally very small, are more inferior and contained in the ____ .

A

temporal lobes

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

Posterior horns (occipital horns) of the lateral ventricle lie in the ___.

A

occipital lobes

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

The most superior portion of the ventricular system is _____.

A

the bodies of the lateral ventricles

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

The falx cerebri lies in the ____

A

interhemispheric fissure

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

On an unenhanced CT scan of the brain, anything that appears “white” will generally be either __ density or __, in the absence of a metallic body.

A

bone(calcium)

blood.

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

Calcifications that may be seen on CT of the brain that are nonpathologic are:

A

pineal gland
basal ganglia
choroid plexus
falx and tentorium

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

Normal structures that can enhance after administration of iodinated IV contrast:

A

venous sinuses
choroid plexus
pituitary gland and stalk

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

Hypodense (Dark) AKA Hypointense tissues on CT

A

Fat, Air, Water, Chronic subdural hematomas

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

Isodense tissues on CT

A

Normal brain

Some forms of protein (e.g. subacute subdural hematoma)

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

HYperdense (Bright) AKA Hyperintense tissues on CT

A

MEtal (aneurysm clips, bullet)
Iodine
Calcium
HEmorrhage (high protein)

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

What is the study of choice for detecting and staging intracranial and spinal cord abnormalities

A

MRI

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

What is more sensitive for detecting calcification in lesions or in evealuation cortical bone? CT or MRI

A

CT

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

Initial CT evaluation of the brain in the emergency setting focuses on whether there is
1.
2.

A
  1. mass effect

2. blood

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

How do we determine if there is mass effect

A

We look for displacement or compression of key structures from their normal positions by analyzing the location and appearance of the ventricles, basal cisterns and sulci.

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

Skull fractures can be described as ___, ___ or ___.

A

linear, depressed or basilar.

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

What skull fractures are the most common

A

linear skull fractures

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

What are the most serious fractures of the skull.

A

basilar fractures are the most serious and sonsist of a linear fracture at the base of the skull.

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

What fractures can be associated with tears in the dura?

A

Basilar structures can be associated with tears in the dura mater with subsequent CSF leak, which lan lead to CSFrhinorrhea and otorrhea.

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

The most common orbital fracture is ____, which is produced by ___.

A

blow-out fracture

direct impact on the orbit

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

How to recognize blow-out fracture of the orbit

A
  1. orbital emphysema
  2. fracture (medial wall or floor of orbit)
  3. entrapment of fat and/or extraocular muscle
  4. fluid (blood) in maxiallry sinus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what is tripod fracture

A

result of blunt force to the cheek, another relatively common facial fracture
- involves separation of the zygoma from the remainedr of the facial bones by separation of the frontozygomatic suture, fracture of the floor of the orbit, and fracture of the lateral wall of the ipsilateral maxillary sinus

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

What are 4 types of intracranial hemorrhages that may be associated with head trauma

A
  1. epidural hematoma
  2. subdural hematoma
  3. intracerebral hemorrhage
    4- subarachnoid hemorrhage
36
Q

almost all ___ hematomas have an associated skull fracture, frequently in the temporal lobe

A

epidural

37
Q

How to recognize epidural hematoma

A
  • they appear as a high density, extra-axial, biconvex, lens shaped “mass”, most often found in the temporoparietal region of the brain
  • it is impossible for them to cross suture lines (subdural can)
  • epidural hematomas can cross tentorium but subdural cannot
38
Q

subdural hematomas are most commonly a result of ___

A

deceleration injuries (motorbike) or secondary to fails (elderly)

39
Q

How to recognize an acute subdural hematoma

A

on CT acute subdural hematomas are crescent-shaped, extra-cerebral bands of high attenuatoin that may cross suture lines and enter the interhemispheric fissure. They do not cross the midline.

  • typicall concave inward toward the brain
  • as they become subacute, they become isodense
  • after one week it could demonstrate a fluid-fluid level
40
Q

How to recognize chornic subdural hematoma

A

those that are present more than 3 weeks after injury

- low-density compared with the remainder of the brain

41
Q

Coup injuries are most often due to ___

A

shearing of small intracerebral vessels

42
Q

Contrecoup injuries are due to ___

A

acceleration-decceleratio injuries that occur when the brain is propelled in the opposite direction, striking the inner surface of the skull

43
Q

Hemorrhagic contusions are___

A

hemorrhages with associated edema usually found in the inferior frontal lobes and anterior temporal lobes on or near the surface of the brain

44
Q

How to recognize intracerebrbal hemorrhage on CT

A
  • mutliple small, well-demarcated areas od high attenuation within the brain parenchyma
  • surrounded by hypodense rim from edema
  • intraventricular blood may be present
  • mass effect is common which can produce compression of the ventricles and displacements of the third ventricle and septum pellucidum to the opposite side
45
Q

In subfalcine herniation…

A

the supratentorial brain, along with the lateral ventricle and septum pellucidum, herniates beneath the falx and shifts across the midline toward the opposite side

46
Q

In transtentorial herniation…

A

Usually the cerebral hemisphers are displaced downward through the incisura beneath the tentorium compressing the ispilateral temporal horn and causing dilatation of the contralateral temporal horn

47
Q

in foramen magnum/tonsilar herniation

A

infratentorial brain is displaced downward through foramen magnum

48
Q

in sphenoid herniation

A

supratentorial brain slides over the sphenmoid bone either anteriorly or posteriorly

49
Q

in extracranial herniation

A

displacement of brain through a defect in cranium

50
Q

_____ injury is responsible for the prolonged coma following head trauma

A

diffuse axonal injury

51
Q

How to recognize diffuse axonal injury on MRI

A
  1. small petechial hemorrhages may be bright on T1 weighted images
  2. multiple bright areas on T2 weighted images at the temporal or parietal cervicomedullary junction
  3. gradient susceptibility MRI sequences have the highest sensitivity to detect petechial hemorrhages, which will appear as punctate dark areas
52
Q

What are some of the clinical signs of ICP

A

papilledema, headache, diplopia

53
Q

Cerebral edema is divided into two major types:

A

vasogenic edema

cytotoxic edema

54
Q

what is vasogenic edema

A

extracellular accumulation of fluid and is the type that is associated with malignancy and infection

55
Q

what is cytotoxic edema

A

represents cellular edema and is associated with cerebral ischemia. it is due to cell death

56
Q

Most strokes are ___ in origin.

A

embolic

57
Q

Emoboli in stroke arises from .,…

A

internal carotid artery or the common carotid bifurction; can also arise in the heart and aortic arch

58
Q

Other than embolus, common cause of stroke is …

A

thrombosis, representing in situ occlusion of the carotid, vertebrobasilar or intracerebral circulations from atheromatous lesions. Thrombosis of the middle cerebral artery is particulary common.

59
Q

Strokes are divided into 2 large groups:

A
  1. ischemic (more common)

2. hemorrhagic

60
Q

What are vascular watershed areas

A

Vascular wathershed areas are the distal arterial territories that represent the junctions between areas served by the major intracerebral vessels, such as the region between the anterior cerebral artery distribution and the middle cerebral artery distribution.

Reduction in blood flow, for whatever reason, affects these sensitive and susceptible wathershed areas the most.

61
Q

How to recognize ischemic stroke

A

on CT the findings depend on the amount of time that has elapsed:

  1. 12-24hours: indistinct area of low attenuation in a vascular distribution
  2. > 24 hours: better circumscribed lesion with mass effect that peaks at 3-5 days and usually disappears by 2-4wks
  3. 72 hours: althought contrast is rarely used in the setting of acute stroke, contrast enhancement typically occurs when the mass effect is waning or has disappeared.
  4. > 4 weeks, mass effect disappears, there is now a well-cicrumscribed low attenuation lesion wih no contrast enhancement
62
Q

What stroke is connected with higher morbidity and mortality

A

hemorrhage stroke

63
Q

About 60% of hypertensive hemorrhages (stroke) occur in the ____.

A

basal ganglia

64
Q

How to recognize intracerebral hemorrhage :

A

Freshly extravasated whole blood with a normal hematocrit will be visible as increased density on nonenhanced CT scans of the brain immediately after the event. This is due to the protein in the blood (mostly Hgb)

  • dissection of blood into the ventricular system can occur in hypertensive intracerebral blled
  • as the clot begins to form, the blood becomes denser for a bout 3 days because of dehydration of the clot
  • after the third day, the clot decreases in density and becomes invisible over the next several weeks. The clos loses density from the outside in so that it appears to shrink
  • after about 2 months, only a small hypodensity may remain
65
Q

The most frequent CNS aneurysm is ____,which develops from a ____, usually at the ____.

A

The most frequent CNS aneurysm is berry aneurysm , which develops from a congenital weakening in the arterial wall, usually at the Circle of Willis.

66
Q

What is the critical size for supture of aneurysm

A

10 mm

67
Q

When aneurysm rupture, the blood usually enter …. (where)

A

subarachnoid space

68
Q

What is the most common nontraumatic cause of a subarachnoid hemorrhage

A

rupture of aneurysm

69
Q

most aneurysms are detected by … or …

A

CT angiography or MR angiography

70
Q

How to recognize subarachnoid hemorrhage from a ruptured aneurysm

A

On CT acute blood is hyperdense and may be visualized within the sulci and basal cisterns

  • the region of the falx may become hyperdense, widened, and irregularly marginated
  • generally the greates concetration og blood indicated the most likely location of the tuptured aneurysm
71
Q

HYdrocephalus may be caused by several factors:

A
  1. underabsorption of CSF (communicating hydrocephalus)
  2. restriction of the outflow of CSF from the ventricles (noncommunicating hydrocephalus)
  3. overproduction of cerebrospinal fluid
72
Q

compare cerebral atrophy and hydrocephalus

A

cerebral atrophy: both ventricles and sulci proportionally enlarged
hydrocephalus: ventricles disproportionally enlarged

73
Q

what structure becomes visible in hydrocephalus

A

temporal horns (greater than 2mm in size)

74
Q

Obstructive hydrocephalus is divided into two major categories:

A
  1. communicating (extraventricular obstruction)

2. noncommunicating (intraventricular obstruction)

75
Q

Clasically, the fourth ventricle is ___ in communicating hydrocephalus and ___ in noncommunicating hydrocephalus.

A

Clasically, the fourth ventricle is dilated in communicating hydrocephalus and normal in noncommunicating hydrocephalus.

76
Q

What is normal pressure hydrocephalus

A

normal pressure hydrocephalus is a form of communicating hydrocephalus characterized by a classical triad of clinical symptoms: abnormalities of gait, dementia and urinary incontinence.

77
Q

What are gliomas

A

Gliomas are a common, primary supratentorial intraaxial mass in an adult that accounts for 30% of all brain tumors

78
Q

What glioma has the worst prognosis

A

glioblastoma multiforme

79
Q

how to recognize glioblastoma multiforme

A
  • because of its aggressive growth, glioblastoma multiforme frequently demonstrates necrosis within the tumor
  • the tumor infiltrates the surrounding brain tissue, frequently crossing the white matter tracts of the corpus callosum to the opposite cerebral hemisphere, producing a pattern called butterfly glioma
  • it tends to produce considerable caogenic edema and mass effect and enhances with contrast
80
Q

metastases account for ___ % of all intracranial neoplasms

A

40

81
Q

What are most common primary malignancies to produce brain metastases

A

lung, breast, melanoma

82
Q

How to recognize metastases to the brain?

A

metastases to the brain are frequently well-defined round masses near the gray-white junction

  • they are usually multiple, but can be soitary
  • they are typically hypodense or isodense on non-enhanced CT
  • with IV contrast, they can enhance, sometimes with a pattern of ring-enhancement
  • most evoke some vasogenic edema, frequently disproportionately large to the size of the mass
83
Q

What are the most common priamry brain tumor (benign and malignant)

A

meningioma

84
Q

How to recognize mengiom on CT scan of the brain

A
  • on unenhanced CT over half are hyperdense to normal brain and about 20% contain calcification
  • on contrast-enhanced studies, meningiomas enhance markedly
  • they may induce vasogenic edema in the adjecent brain parenchyma
85
Q

How to recognize MS

A

MRI is the study of choice so that we can visualize plaques

  • the lesions produce discrete globular foci of high-signal intensity (white) on T2-weighted images
  • on T1 weighted nonenhanced images, they are isotense to hypoisotense , but in acute MS, the lesions enhance with gadolinium on T1 weighted images
  • the lesions tend to be oriented with their long axes perpendicular to ventriucla walls

radiology (8 decks)

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