Anatomical Imaging

Question 1

Xray:

Answer 1

Electrons hitting anode = image
Different tissues absorb electrons differently
Usually used in trauma ,degenerative diseases or post operative procedures

Question 2

Fluoroscopy

Answer 2

Continuous XR radiation passes through body onto fluorescent screen creating moving image = moving XR
Could be used in swallow studies, IR, arthrography or cardiac cath

Question 3

Angiography

Answer 3

Form of fluoroscopy used to evaluate vasculature

Used for aneurysms etc.

Question 4

Pros of Angiography:

Answer 4

Fast

Diagnostic and therapeutic

Question 5

Cons of angiography:

Answer 5

Invasive
Need contrast
Uses radiation

Question 6

Angiography requires …

Answer 6

Injection of contrast into vasculature (barium or iodine)

Question 7

Myelography:

Answer 7

Uses fluoroscopy and needs intrathecal (spinal) injection of contrast, invasive

Question 8

Pros of Myelography:

Answer 8

Defines subarachnoid space

Identifies spinal block

Question 9

Cons of Myelography:

Answer 9

Invasive
Could worsen CSF leak, headache
Radiation
Contrast

Question 10

CT:

Answer 10

Series of XRs scanned axially and resliced in any plane

Read caudal up

Question 11

Hounsfield units (HU:)

Answer 11

Measure of radiodensity for CT

All densities compared to water which is 0 HU

Question 12

Hyperdense (high HU) appears…

Hypodense (low HU) appears …

Answer 12

White

black

Question 13

CT used for (head and neck relevant) :

Answer 13

Skull and vertebrae path
Ventricle studies 
Masses 
Hemorrhage, ischemia 
Calcification

Question 14

Pros of CT:

Answer 14

Fast
Inexpensive
Good at detecting large pathology

Question 15

Cons of CT:

Answer 15

Less detail than MRI
Radiation exposure
Low sensitivity in posterior fossa

Question 16

Use CT contrast for …

Answer 16

Neoplasm
Infection
Vascular disease
Inflammatory disease 
More than 3 hours after symptoms onset

Question 17

Do not use CT contrast if …

Answer 17

Trauma 
Hemorrhage
Hydrocephalus
Dementia
Epilepsy
Within 3 hours of symptoms

Question 18

CT contrast:

Answer 18

Indicates whether BBB is intact. Enhancement/whiter of contrast = not intact BBB

Question 19

Structures that enhance IV contrast:

Answer 19

Cerebral blood vessels 
Meninges
Pineal gland
Pituitary gland
Choroid plexus

Question 20

CT angiography:

Answer 20

Uses IV contrast bolus. Arteries digitally reconstructed into 2d and 3d images

Question 21

Pros of CT angiography:

Answer 21

Non invasive

Examine vessels from origin

Question 22

Cons of CT Angiography:

Answer 22

Contrast
Radiation
Lower resolution

Question 23

MRI:

Answer 23

Uses magnet alignment of atoms in tissue to form an image

Question 24

Hyperintense structure appears … in MRIHypointense structure appears .… in MRI

Answer 24

White

Black

Question 25

Uses of MRI:

Answer 25

Further eval CT findings, tumors, infection, joint imaging (TMJ)

Question 26

Pros of MRI:

Answer 26

High level of detail
Safe to use in pregnancy
Vessel imaging can be obtained without use of contrast

Question 27

Cons of MRI:

Answer 27

Time consuming
Contraindications (metal devices in body)
Expensive
Not good for claustrophobic patients

Question 28

T1 weighted MRI

CSF appears
White matter appears
Good for?

Answer 28

Dark = hypointense
White = hyperintense
Imaging normal anatomy

Question 29

T2 weighted MRI

CSF appears …
White matter appears …
Good for ….

Answer 29

Bright = hyperintense (white looking brain)
Dark = hypointense
Visualizing pathology

Question 30

T2 FLAIR MRI

Answer 30

Removes CSF from T2

Enhances high protein fluid (edema/abscesses)

Question 31

Ultrasound:

Answer 31

Noninvasive

Transducer emits US waves into body and it turns into an image

Question 32

US used for?

Answer 32

Evaluation of carotid arteries and placement of central lines

Question 33

Pros of US:

Answer 33

Non invasive
Cheap
No radiation

Question 34

Cons: of US:

Answer 34

Learning curve