Imaging

Question 1

Primary imaging modalities

Answer 1

x-ray radiography
Computed tomography (CT)
Magnetic resonance imaging (MRI)
Diagnostic ultrasound

Question 2

This type of imaging uses a very small dose of ionizing radiation to produce pictures of the body internal structures

Answer 2

X-ray

Question 3

This type is often used to help diagnose fractured bones, look for injury or infection, and to locate foreign objects in soft tissue

Answer 3

X-ray

Question 4

Gray scale image on x-ray
Air
Fat
Soft tissue
Bone
Metal

Answer 4

Air - black
Fat - dark gray
Soft tissue - gray
Bone - light gray
Metal - white

Question 5

X - ray views

Answer 5

AP
Lateral
Oblique
Flexion
Extension
Special views

Question 6

When would you use an iodine-based contrast material in an xray

Answer 6

to improve visibility of hollow organs, blood vessels, tissues or bone

Question 7

Does cartilage show up on xray

Answer 7

no

Question 8

This is a type of imaging that shows continuous x-ray image on a monitor, similar to an x-ray movie

Answer 8

Fluoroscopy

Question 9

This is based on the absorption of x-rays but it provides a different form of image known as cross-sectional imaging

Answer 9

Computed Tomography (CT)

Question 10

Are CT’s better at spatial or contrast resolution

Answer 10

Spatial (contrast is MRI)
This means that CT are good at showing where edges are things are, or where this structure ends and the other begins.

Question 11

What are CT’s commonly used for

Answer 11

evaluating complex fractures and occult fractures

Question 12

What are the drawbacks to CT

Answer 12

radiation exposure

Question 13

When assessing CT imaging is the image flipped or is it normal

Answer 13

It is flipped, L is R and R is L

Question 14

This uses the magneitc properties of body tissues to create cross sectional images of the body region of interest

Answer 14

Magnetic resonacne imaging (MRI)

Question 15

What are the 2 main types of MRI imaging

Answer 15

T1
T2

Question 16

What shows up as bright on a T1 image

Answer 16

Fat

Question 17

What shoes up as bright on a T2 image

Answer 17

fat and liquid

Question 18

What is it called when the fat is turned dark

Answer 18

Fat saturation

Question 19

What is good for flid assessment

Answer 19

T2 expecially w/ fat saturation

Question 20

When would be a good time to use T2 w/ fat sat

Answer 20

When looking for edema because edema often occurs in conjunction w/ tissue pathology

Question 21

What determines the resolution of an MRI

Answer 21

Strength of magnetic field
(measured in Tesla)

Question 22

This imaging uses sound waves to produce images of structures in the body, the only “live action” form of imaging

Answer 22

Diagnostic ultrasound

Question 23

Does diagnostic ultrasound use ionizing radiation

Answer 23

No

Question 24

How does diagnostic ultrasound work

Answer 24

Sound is reflected from boundaries between anatomic structures with different composition (which yeilds different internal sound speeds)

Question 25

What frequeny does ultrasound use

Answer 25

1-20 MHz

Question 26

What is conducting gel used for in ultrasound

Answer 26

To bridge between the probe and the body tissue

Question 27

What can ultrasound help diagnose

Answer 27

Pathologies in musculoskeletal structrues such as tendons and for real time guidance of musculoskeletal procedures

Question 28

Drawbacks of ultrasound

Answer 28

low image resolution, limited bone prenetration, dependence on operator.