Radiology 2

Question 1

What is fluoroscopy?

Answer 1

real-time moving radiographic images

Question 2

What is a c-arm?

Answer 2

portable fluoroscopy

Question 3

What does a ct scan create?

Answer 3

Cross sectional imaging, using computer data can create 3-d images

Question 4

CT Scan problem

Answer 4

• increased radiation exposure
• more expensive than radiographs
• poor soft tissue contrast

Question 5

CT pros

Answer 5

detailed view of anatomy without superimposition
faster and less expensive than MRI
best for bone, lung, abdomen

Question 6

Types of CT scans

Answer 6

single splice (slow old)
Spiral (fast, new)
Multi-detector (fast, new, better)

Question 7

pixel vs voxel

Answer 7

radiograph creates pixel (2-D)
Ct creates voxel (3-D, has slice thickness)
- thinner slices are better (isotopic =cube= great)

Question 8

hounsfield U

Answer 8

there are more than 4,000 HU
(human eye can see 20 shades of gray)
Use WINDOWS and LEVEL to see image better

Question 9

What is window and level?

Answer 9

Window= selected range of HU (can see tissues better at a certain range)
Level = central value of HU displayed

Question 10

Word used to describe CT scans color?

Answer 10

attenuation

Question 11

Word to describe radiograph color?

Answer 11

opacity

Question 12

Hyperattenuating color

Answer 12

Highest HU value (bone, metal)

WHITE COLOR

Question 13

Hypoattenuating color

Answer 13

lowest HU value (air)

BLACK

Question 14

MRI principles

Answer 14

Needed: Magnet, computer, hydrogen protons

odd number of protons( like abundant hydrogen)
act like a tiny magnet - as tissues relax at different rates an image is formed (simplified)

Question 15

what is weighting?

Answer 15

using parameters to optimize the differences in relaxation rates of different tissues in order to provide contrast in the image

Question 16

Most important weights

Answer 16

T1, T2

Question 17

Qualities of T1 weighted images

Answer 17

Fluid is black
Fat is white

(bone is also black, and muscle/tissue is gray)

Question 18

word to describe MRI

Answer 18

intense

Question 19

hypointense

Answer 19

MRI- less bright (black)

Question 20

hyperintense

Answer 20

MRI- brighter than (white)

Question 21

isointense

Answer 21

MRI- same brightness

Question 22

Pros of MRI

Answer 22

better soft tissue contrast and detail
noninvasive
no radiation!

Question 23

cons of MRI

Answer 23

long scan times (anesthesia)
cost! (most expensive)
projectiles (magnet is ALWAYS on)

Question 24

Ultrasound principles

Answer 24

• high sound wave frequency

- transmits sound waves, and MEASURES the intensity/time of returning waves

Question 25

low US frequency transducers

Answer 25

penetrate farther, but have lower resolution

Question 26

high US frequency transducers

Answer 26

do not penetrate far, but have high resolution

Question 27

word to describe US

Answer 27

echoic

Question 28

Anechoic color?

Answer 28

Black

urine/bile

Question 29

Hypoechoic color?

Answer 29

Dark gray (darker than…)

Question 30

Isoechoic color?

Answer 30

same echogenicity (color)

Question 31

Hyperechoic color

Answer 31

White (brighter than…)

bone, gas, organ boundaries

Question 32

Doppler Effect in US (what it needs, colors, etc.)

Answer 32

Allows for determination of velocity and direction of blood flow (needs constant motion and direction like blood flow)

Blue= away
Red= towards
(car physics example)