Brainscape's Knowledge GenomeTM

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


See full index

Neurology 2 > Clin Med - Neuroradio > Flashcards

Clin Med - Neuroradio Flashcards

1
Q

Define Computed tomography (CT)

A

a diagnostic imaging tool that uses X-rays to provides a three dimensional scan.

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

CT is based on…

A

the density of the tissue passed by the X-ray beam.

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

CT is measured in…

A

The Hounsfield unit (HU): a quantity which is commonly used by radiologists to express CT numbers in a standardized and convenient form.

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

Which tissues are hypodense?

A

Air and fat

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

Which tissues are isodense?

A

Pure water and CSF

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

Which tissues are hyperdense?

A

White & gray matter, blood, bone

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

Advantages of CT

A
  • Inexpensive
  • Widely available
  • Allows relatively quick assessment
  • Very sensitive to acute hemorrhage and calcification
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Disadvantages of CT

A

-Craniocerebral trauma (short exam time, well
demonstrated hemorrhage and skull fracture)
-Intracranial hemorrhage
-Infarction (infarct itself not seen well on CT, but looking for cause of infarct: hemorrhage/tumor)
-Seizures (in the ER setting to screen for underlying cause)

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

CT interpretation

-3 aspects

A
  1. orientation
  2. contrast vs. non-contrast
  3. general review
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

CT orientation

  • view
  • slices
A

The CT slice is regarded as being viewed from the patient’s feet, so the left side of the picture as you view it is the right side of the patient.

There are 3 slices:

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

CT with IV contrast

A

Does not cross the normal blood brain barrier and is used if there is a suspicion of tumor, infection (e.g. abscess)

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

When should you use contrast?

A
  • in stroke patients
  • concerned about infection/abscess
  • concerned about a tumor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which feature of the brain should always be visualized on CT?

A

Sulci - if you cannot see it, that’s a sign there’s something in it (blood or inflammation)!

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

CT interpretation mnemonic

A 
Blood
Can (cisterns)
Be (brain)
Very (ventricles)
Bad (bone)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does acute hemorrhage appear on CT?

A

Acute hemorrhage absorbs X-rays and appears hyperdense (white) on CT scans

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

What happens as clot retracts and becomes acute?

A

it becomes isodense (same color) with brain over the following 1-4 weeks and finally hypodense (darker) compared with brain over the subsequent 4-6 weeks.

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

2 normal calcifications of the brain

A
  • choroid plexus

- pineal gland

18
Q

Define dystrophic calcification

A

calcification occurring in degenerated or necrotic tissue

19
Q

What are the 3 intracerebral hemorrhages?

A
  1. intraparenchymal cerebral hemorrhage
  2. intraventricular hemorrhage
  3. extracerebral hemorrhage
20
Q

Intraparenchymal cerebral hemorrhage

  • definition
  • etiologies
A
  • acute accumulation of blood in the parenchyma of the brain

- HTN, trauma, hemorrhagic transformation of an ischemic stroke, or venous infarct

21
Q

What is the first imaging modality for hemorrhage?

A

CT without contrast - always!!

22
Q

When would you order CT angiography?

A

concern for a vascular underlying cause

23
Q

When would you order MRI?

A

if an underlying tumor/abscess is suspected

24
Q

Intraventricular hemorrhage

  • definition
  • etiology
A
  • The present of blood within the brain ventricular systems
  • Primary etiologies include HTN, vascular malformations, anticoagulation, tumors

-Secondary etiologies include trauma or extension from
other intracerebral hemorrhages

25
Q

Extracerebral hemorrhage

-definition

A

occurring within the skull, but outside the brain

26
Q

Subdural hematoma

-5 features

A
  • between the dura and arachnoid
  • venous blood (bridging veins MC)
  • +/- fracture
  • concave shape
  • does cross suture lines
27
Q

Epidural hematoma

-5 features

A
  • between the inner surface of the skull and outer layer of the dura
  • arterial blood (middle meningeal A is MC)
  • ALWAYS associated with fracture
  • convex shape
  • does NOT cross suture lines
28
Q

Subarachnoid hemorrhage

-3 features

A
  • hemorrhage into CSF and cisterns (blood on spinal tap)

- etiologies: aneurysms, trauma, AVMs

29
Q

Cisterns

A
  • collections of CSF, which surround and protect the brain

- look for evidence of effacement, asymmetry, presence of blood

30
Q

Steps to CT interpretation of brain matter

A
  1. compare the sulci pattern for effacement (squishing closed) and volume asymmetry
  2. look for midline shift secondary to mass effect
  3. look for inconsistencies in the gray-white
    differentiation (evolving stroke?)
  4. identify hyperdense (white/bright) regions: blood, IV contrast, calcification
  5. identify hypodense (dark) regions: air, fat ischemia, tumor
31
Q

CT interpretation of ventricles

A

Ventricles

-Examine lateral, 3rd, and 4th ventricles: asymmetry, dilation, effacement, and hemorrhage

32
Q

CT interpretation of bone

A

Cortical bone has the highest density on the CT scan and is best viewed on separate bony windows when looking for evidence of fractures or tumors.

33
Q

MRI advantages

A
  • No ionizing radiation
  • Various thickness in any plan
  • Excellent discrimination between gray and white matter
  • Excellent soft-tissue contrast
34
Q

MRI indications

A
  • Congenital anomalies
  • Vascular Malformations
  • Infarct (infarct itself seen better on MRI, but usually CT is done first to look for secondary cause)
  • Brain tumors (contrast-enhanced)
  • Infection (contrast-enhanced)
  • Neurodegenerative diseases
  • Anything spinal cord related
35
Q

MRI interpretation

A
  • 3 planes: axial, sagittal, coronal
  • T1 and T2 weighted (most brain MRIs use both, hint to tell which one: T1= fluid is dark/T2=fluid is very bright)
  • bone and air are dark
  • you can use contrast
36
Q

Cerebral angiography (CTA/MRA) advantages

A

***gold standard for assessing vascular abnormalities (vasculitis, aneurysm, malformations)

37
Q

CTA disadvantages

A
  • Expensive
  • Invasive procedure (main issue)
  • Risk of stroke
38
Q

CTA indications

A
  • Aneurysm (CTA)
  • Infarct (reveal the extent/location of vessel occlusion, volume/severity, predict final infarct size)
  • Cerebral vascular malformations
39
Q

CTA procedure

A

Contrast material is injected into the desired vessel via a small catheter, which has been introduced into the body through the femoral or brachial artery

40
Q

What information does CTA record?

A

Information about the arterial, capillary, or venous circulation of the brain is recorded on serial plain films or digitized (MC)

41
Q

Indication for CTA

A
  • aneurysms
  • acute ischemic stroke
  • vascular abnormalities (arteriovenous malformation, arteriovenous fistula or caroticocavernous fistula)

Neurology 2 (21 decks)

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