Lecture 23

Question 1

Computerized Tomography (CT) uses and time

Answer 1

Acute hemorrhage, bone abnormalities, fractures, calcified lesions, sinus disease. Used in emergency situations. 5 minutes

Question 2

Computerized Tomography (CT) radiation

Answer 2

radiation is present

Question 3

Magnetic Resonance Imaging (MRI) uses and time

Answer 3

Stroke, soft tissue disease, including tumors, multiple sclerosis, or inflammation. 30-120 minutes

Question 4

Magnetic Resonance Imaging (MRI) radiation

Answer 4

no radiation

Question 5

Diffusion Tensor Imaging (DTI) MRI uses and time

Answer 5

White matter tracts, surgical planning. 30 minutes

Question 6

Diffusion Tensor Imaging (DTI) MRI radiation

Answer 6

no radiation

Question 7

Positron Emission Tomography (PET) uses and time

Answer 7

Measure blood flow, glucose metabolism, and oxygen consumption. 30 minutes

Question 8

Positron Emission Tomography (PET) radiation

Answer 8

radiation is present

Question 9

Functional Magnetic Resonance Imaging (fMRI) uses and time

Answer 9

Detect neural activity by evaluating changes in blood flow. 60 minutes

Question 10

Functional Magnetic Resonance Imaging (fMRI) radiation

Answer 10

no radiation

Question 11

Contrast-enhanced CT

Answer 11

Used when trying to detect increased angiogenesis or breakdown of blood-brain barrier

Question 12

Keys to CT

Answer 12

The #1 best study to evaluate a neurological patient in the emergency room (fast and available)
The study of choice for suspected bleed or trauma.
Best diagnostic tool for evaluating a patient with headache and/or neurologic deficit of unknown origin.
Best radiological tool for evaluation of hydrocephalus and shunt malfunction.

Question 13

MRI T1

Answer 13

T1 images have increased contrast between gray and white matter compared to T2 images

Question 14

MRI T2

Answer 14

Pathology is generally more evident on T2 scans compared to T1 scans

Question 15

T2 images. what structures appear bright?

Answer 15

CSF, fat and edema

Question 16

T1 images what structures appear bright?

Answer 16

Just fat, everything else is dark

Question 17

Fluid-attenuated Inversion Recovery (FLAIR)

Answer 17

able to detect lesions in the lateral ventricles better with FLAIR

Question 18

Contrast Magnetic Resonance Imaging

Answer 18

Use of a contrast agent with MRI highlights areas of breakdown of the blood-brain barrier or increased angiogenesis.
avoid during pregnancy
Able to detect tumors with contrast

Question 19

T2 FLAIR with contrast

Answer 19

Gold standard for demyelination, infections, and axonal degeneration

Question 20

DWI (diffusion weighted imaging)

Answer 20

Particularly useful when evaluating for ischemia

Also helpful in differentiating various lesions

Question 21

DTI (diffusion tensor imaging)

Answer 21

Indicates shifts in water

Used to image pathways in the brain or fiber bundles in white matter

Question 22

CTA (Computed tomography angiography)

Answer 22

is helpful in screening for carotid stenosis, aneurysm, and abnormal connections between arteries and veins

Question 23

MRA (Magnetic resonance angiography)

Answer 23

very similar to CTA but can be performed with or without injection of contrast material.

Question 24

Ventricles will be enlarged under certain conditions:

Answer 24

Hydrocephalus and brain atrophywill result in ventricular enlargement Hydrocephalus ex vacuo

Question 25

Decrease in ventricles indicates mass effects

Answer 25

tumor and edema

Question 26

Functional Magnetic Resonance Imaging

Answer 26

Measures neuronal activity by detecting changes in oxygenated blood flow
Measures gray matter activity

Main advantage over PET scan is no radiation

Question 27

Positron Emission Tomography (PET)

Answer 27

The value of PET is the ability to measure the gamma rays as they travel through cerebral vasculature.
Tumor detection