Imaging of Head + Neck

Question 1

What imaging modalities are available for neurological imaging?

Answer 1

Radiography (X-Ray)

Fluoroscopy

Ultrasound

Computed Tomography (CT)

Magnetic Resonance (MRI)

Question 2

What is the difference between radiography (X-ray) and fluoroscopy, and when is one preferred over the other?

Answer 2

X-Ray: Used for trauma (fractures)

Fluoroscopy: Continuous X-Ray (barium Swallow, Angiography, Myelography) *uses contrast*

Question 3

What is angiography used for?

Answer 3

Evaluate blood vessels

It is invasive (go up through femoral), but you can intervene by dissolving a clot or imploying a stent right there.

Question 4

What is Myelography?

Answer 4

uses fluoroscopy (contract) w/ cervical or lumbar puncture

cons = could cause CSF leak + invasive

Question 5

What could we use an ultrasound for?

Answer 5

Carotid stenosis

Question 6

What is a CT?

Answer 6

Series of X-Rays scanned axially and then digitally re-sliced in any plane

Question 7

How is a CT measured?

Answer 7

Radiodensity measured in Hounsfield units

Question 8

In CT, Hyperdense =

Answer 8

White/bright (ex. bone)

Question 9

In CT, Hypodense =

Answer 9

Black/dark

Question 10

In Hounsfield units what is a bone window vs soft tissue window?

Answer 10

bone = wide window (+1000)

soft tissue = narrow window (+30-40)

Question 11

What do you typically get first from a patient w/ trauma or stroke?

Answer 11

Non-contrast CT

Question 12

If symptoms last longer than 3 hrs or 1st CT wasen’t in enough detail, then what do you get?

Answer 12

CT w/ contrast (iodine)

Indicated in: neoplasm, Infection, vascular disease, inflammatory disease

Question 13

In contrast, what does enhancement refelct?

Answer 13

Vascularity of the tissue

Wherever it is bright, blood goes

(Ex. enhancement in brain = BBB is absent)

Question 14

What is a CT Angiography?

Answer 14

Non-invasive

Contrast though IV

Used for atherosclerosis, aneurysems

Question 15

What is teh difference between contrast study and angiogram?

Answer 15

Contrast = evaluate breakdown in BBB and other things –> goes where blood goes

Angiograms = evaluate blood vessels

Question 16

On an MRI, what does hyperintense + hypointense mean?

Answer 16

hyperintense = white/bright

hypointense = black/dark

Question 17

When would you use an MRI?

Answer 17

To further evaluate a CT in way higher detail and also for ischema (cause no contrast would go in that area cause there is no blood)

Also, tumors, infections

Question 18

In an MRI what do these mean?

Answer 18

T1 = CSF dark (hypointense)

T2 = CSF bright (hyperintense)

Flair = No CSF (good for edema/stroke)

Question 19

How does an MRI work?

Answer 19

Patient lies in a large magnet, and the magnet aligns all the protons in the body. Radiowaves then pass through the patient and the returning signals are converted to an image.