Neuroimaging

Question 1

Combines continuous gantry rotation with table motion

Answer 1

Helical CT

Question 2

The density in a CT is expressed in

Answer 2

Hounsfield units

Question 3

Intermediate density similar to the brain

Answer 3

Isodense

Question 4

Better than CT for a subtle area of tumor, infarct, or demyelination

Answer 4

MRI

Question 5

Which is better for a fresh hemorrhage, CT or MRI?

Answer 5

CT

Question 6

Which is better for an old hemorrhage, CT or MRI?

Answer 6

MRI

Question 7

Fast, can scan large areas of the body quickly, and is less costly than an MRI

-Very sensitive to hemorrhage

Answer 7

CT

Question 8

Most effectively used for intracranial hemorrhage, acute trauma, stroke, fractures, and sinusitus

Answer 8

CT

Question 9

CT contrast contains

Answer 9

Iodine

Question 10

Do not use contrast when the concern is an

Answer 10

Intracranial hemorrhage (especially subarachnoid)

Question 11

On CT, hyperdense in sulci, cisterns, and fissures

-ill defined and “whispy”

Answer 11

Subarachnoid Hemorrhage

Question 12

Aneurysmal subarachnoid hemorrhage leads to

Answer 12

Hydrocephalus

Question 13

Collection of blood in potential space b/w skull inner table and dura mater

-Lense shaped

Answer 13

Epidural Hematoma

Question 14

Epidural hematomas do not cross

Answer 14

Sutures

Question 15

Common when an epidural hematoma is present (85-95%)

Answer 15

Skull fractures

Question 16

What fraction of patients with an epidural hematoma have neurological deterioration after the lucid interval?

Answer 16

1/3

Question 17

Thromboembolic events are principal causes of ischemic stroke leading to vascular insufficiency

Answer 17

Acute cerebellar infarct

Question 18

Leads to low density on CT

-Low density takes approximately 4-6 hours to develop

Answer 18

Acute cerebellar infarct

Question 19

In an acute cerebellar infarct, edema peaks at

Answer 19

3-7 days

Question 20

All current MRI techniques based on receiving and processing signals from

Answer 20

Protons

Question 21

At the core of all MRIs is a homogenous

Answer 21

Magnetic Field

Question 22

The magnetic field strength in an MRI is referred to in units of

Answer 22

Tesla

Question 23

1 Tesla = 10,000 Gauss units. The Earth’s magnetic field =

Answer 23

0.5 Gauss

Question 24

A sequence is a particular set of parameters used to generate a specific type of

Answer 24

Image

Question 25

Dependent on characteristics and strength of energy released by hydrogen ions

Answer 25

T1 and T2 weighting

Question 26

Depends mainly on differences in hydrogen ions in fat and water

Answer 26

MRI contrast

Question 27

For T1W images, what is the intensity of 1. ) Water (CSF) 2. ) Edema 3. ) White matter (fat) 4. ) Gray matter

Answer 27

1. ) Hypointense 2. ) Hypointense 3. ) Hyperintense 4. ) Isointense

Question 28

For T2W images, what is the intensity of 1. ) Water (CSF) 2. ) Edema 3. ) White matter (fat) 4. ) Gray matter

Answer 28

1. ) Hyperintense 2. ) Hyperintense 3. ) Hypointense 4. ) Isointense

Question 29

Are similar to T2W, but CSF is HYPOintense

Answer 29

Fluid Attenuation Inversion Recovery (FLAIR)

Question 30

Allows for exquisite evaluation of white matter adjacent to ventricles -I.e. as in multiple sclerosis

Answer 30

FLAIR

Question 31

Primary sequence for detection of ischemic (not hemorrhagic) infarct

Answer 31

Diffusion Weighted Image (DWI)

Question 32

Hyperintensity on DWI with acute or subacute

Answer 32

Infarcts (up to 14 days old)

Question 33

Used as contrast for MRI -Produces hyperintensity in vessels and areas of blood brain barrier breakdown

Answer 33

Gadolinium

Question 34

Gives an exquisite delineation of anatomy and is excellent for the detection of small lesions

Answer 34

MRI

Question 35

Excellent for evaluation of posterior fossa structures such as brainstem and cerebellum (CT fraught with artifact)

Answer 35

MRI

Question 36

MRIs are contraindicated for patients with a

Answer 36

Pacemaker

Question 37

Can be primary or metastatic to the brain

Answer 37

Intracranial Lymphoma

Question 38

Caused by HSV-1 infection -Bilateral and asymmetric

Answer 38

Herpes Encephalitis

Question 39

Benign tumor that shows as an extra-axial mass - Dural based - Arise from the meninges

Answer 39

Meningioma

Question 40

More prominent in female than males

Answer 40

Meningioma

Question 41

Cytotoxic edema that conforms to vascular territories

Answer 41

Acute infarct

Question 42

Autoimmune mediated demyelination

Answer 42

MS

Question 43

Loss of myelin with preservation of neurons early, but loss of neurons late

Answer 43

MS

Question 44

What are the location of foci for MS?

Answer 44

Periventricular, corpus callosum, and brainstem

Question 45

Inferior descent of cerebellar tonsil through foramen magnum > 5mm

Answer 45

Chiari I Malformation

Question 46

Associated with cervical cord syrinx, skeletal anomalies (fusion anomalies, skull base flattening, congenital elevation of scapula), syndromes

Answer 46

Chiari I malformation

Question 47

apitalizes on creating intensity differences between flowing blood in vessels and stationary tissues

Answer 47

MRI angiography

Question 48

Flowing blood or even CSF --> produce signal depending on velocity and imaging parameters

Answer 48

MRI angiography

Question 49

Used to image intracranial vessels (COW + venous sinuses), carotid vasculature, vertebral arteries, venous anatomy of neck

Answer 49

MRI angiography

Question 50

Vascular malformation with arteriovenous shunting (no intervening capillary bed)

Answer 50

Parieto-Occipital AVM

Question 51

Round or lobulated outpouching from COW -Rupture results in "worst headache of life"

Answer 51

Basilar Tip Aneurysm

Question 52

Measures brain neurotransmitters and biochemicals -Interrogates chemical environment of brain noninvasively

Answer 52

Magnetic Resonance Spectroscopy (MRS)

Question 53

Used to measure: Amino acids, Lipid, lactate, NAA, Choline, Creatine, and Myoinositol

Answer 53

MRS

Question 54

Aids in evaluation of brain tumors, radiation necrosis, infections, metabolic disease

Answer 54

MRS

Question 55

Allows assessment of white matter tracts based on water diffusion characteristics along these tracts of axons

Answer 55

Diffusion Tensor Imaging (DTI)

Question 56

Used for evaluation of neurodegenerative disease, epilepsy, traumatic brain injury, multiple sclerosis

Answer 56

DTI

Question 57

Assess brain metabolic activity (indirect measure of neuronal discharge) and therefore specific areas of function

Answer 57

Functional MRI

Question 58

Uses BOLD (blood oxygen level dependent) imaging -When brain is activated by a task, increase of blood flow we get a signal

Answer 58

Functional MRI

Question 59

Catheter inserted via femoral artery and directed into Aorta under fluoroscopy -Iodinated contrast material injected to visualized vasculature

Answer 59

Catheter Angiography

Question 60

Minimally invasive treatment treatment options for conditions involving brain, H + N, and spine

Answer 60

Interventional Neuroradiology

Question 61

Used for endovascular treatment and embolization of IC aneurysms, AVMs, dAVFs

Answer 61

Interventional Neuroradiology