MSK Imaging

Question 1

What are the imaging modalities?

Answer 1

Radiography, Magnetic Resonance Imaging, Ultrasound, Nuclear medicine

Question 2

How many types of X-rays are there?

Answer 2

5

Question 3

What are the types of X-rays?

Answer 3

Radiograph(plain film), Fluoroscopy, Digital subtraction angiography, DEXA, CT/CAT (computer tomography)

Question 4

What absorbs X-rays?

Answer 4

High density structures – bone/metal

Question 5

Structures closer to X-ray projector appear how?

Answer 5

Larger than their actual size

Question 6

-Single still image for a high density structure
pros = fast, cheap, portable
cons = only 1 perspective obtained

Answer 6

Plain film/radiograph

Question 7

-constant stream of x-rays to produce a live image
pros = live image, high penetration
cons = increased cancer risk due to many x rays

Answer 7

Fluoroscopy

Question 8

-Iodine based contrast injected to make vessels visible to x-rays and then the computer subtracts bone from image
pros = allows imaging of blood vessels
cons = contrast is BAD for kidneys

Answer 8

Digital Subtraction Angiography

Question 9

-Bone density scan when concerned for osteoporosis
pros = bone density measurement
cons = ionizing radiation

Answer 9

DEXA - dual energy x-ray absorbiometry

Question 10

-Numerous x-rays shot as cross sectional slices assembled via computers to create a high resolution 3D image
pros = 3D, affordable, QUICK
cons = contrast sometimes used, high risk of radiation

Answer 10

CT/CAT scan - computer tomography

Question 11

What does MRI stand for?

Answer 11

Magnetic Resonance Imaging

Question 12

Describe the process of an MRI

Answer 12

1. Magnetic field aligns protons in body
2. Radiofrequency pulse disrupts them and changes alignment
3. Radiofrequency stops and the protons realign and release energy as they do so that is captured by the MRI machine for an image

Question 13

Which 2 modalities take image slices to create a 3D image?

Answer 13

CT scan and MRI

Question 14

If you are looking at the left side of an MRI image, what side of the patient are you looking at?

Answer 14

Right side

Question 15

What is MRI great for imaging?

Answer 15

Soft tissue, joints and small fractures

Question 16

Pros of MRI?

Answer 16

Highest resolution, no ionizing radiation

Question 17

Cons of MRI?

Answer 17

Expensive and slow, not good for claustrophobic patients and cannot be used with patients who have metal implants

Question 18

How does ultrasound work?

Answer 18

Uses echolocation; waves travel into body and reflect back to make a single, live, 2D image

Question 19

If a lower frequency wave is used for ultrasound, what results?

Answer 19

More penetration, lower resolution

Question 20

If a higher frequency wave is used for ultrasound, what results?

Answer 20

Less penetration, higher resolution

Question 21

Pros of ultrasound?

Answer 21

Cheap, fast, portable, no ionizing radiation

Question 22

Cons of ultrasound?

Answer 22

Not able to visualize structures behind bone or bigger anechoic structures because waves are blocked or scatter

Question 23

Not able to penetrate bone structures, image looks white for ultrasound

Answer 23

Hyperechoic

Question 24

Fully penetrates structures such as air and fluid to create a black image for ultrasound

Answer 24

Anechoic

Question 25

Organs and soft tissue create a darkish image for ultrasound

Answer 25

Hypoechoic

Question 26

What is nuclear medicine used for?

Answer 26

Physiology, not anatomy

Question 27

What is the process of nuclear medicine?

Answer 27

Radiotracers are injected into the body, they then bind target organs, and emit gamma radiation that is visualized

Question 28

A common way to monitor cancer, radiotracer is glucose analog

Answer 28

Positron Emission Tomography (PET)

Question 29

Pros of nuclear medicine?

Answer 29

Targets absorption structures

Question 30

Cons of nuclear medicine?

Answer 30

Radiotracers produce ionizing radiation