MSK Imaging

Question 1

Types of Radiography

Answer 1

X-ray, flouroscopy, digital subtraction angiography, dual energy e-ray absorptiometry, computer tomography

Question 2

Risk of Chest x-ray

Answer 2

low. 0.3% of yearly exposure

Question 3

Risk of CT?

Answer 3

3-5 times the amount of yearly exposure

Question 4

Radiograph color?

Answer 4

White = reflexion and dark is no reflexion (air)

Question 5

Structure closer to projector on x ray appear…

Answer 5

larger

Question 6

Pros to Plain film

Answer 6

Pros= Very Fast/Cheap $/Portable (First line)

Question 7

What is fluoroscopy?

Answer 7

Live action stream of x rays. Iodine dye used to visualize.

Question 8

What is Digital subtraction angiography?

Answer 8

Iodine based contrast is injected Intravenous

temporarily makes vessels visible to X rays. Bone is subtracted from the image

Question 9

Cons of Digital subtraction angiography?

Answer 9

Had on kidneys and radiation.

Question 10

What is Dual energy x-ray absorptiometry? (DEXA)

Answer 10

Two energy levels x ray beams

compare level of bone absorptions

Question 11

What is DEXA used for?

Answer 11

Indication: Bone density scan when

concerned for osteoporosis and osteopenia

Question 12

Cons for DEXA?

Answer 12

radiation

Question 13

What is a CT?

Answer 13

Numerous X rays shots as cross sectional slices
Digital images reassembled by computers
Produces a “3 dimensional” sagittal and transverse
views of the structures

CAN be done with contrast for vasculature/ organ imaging

Question 14

Pros of CT

Answer 14

Pros: affordable ($$), quick (trauma), 3d image

with good resolution

Question 15

Cons of CT

Answer 15

Relatively high risk of radiation
–
If used, contrast can damage kidneys

Question 16

What is a MRI?

Answer 16

Magnetic Resonance Imaging. Uses a powerful magnetic field and radiofrequency waves on
protons abundant in water and fat to generate images

Question 17

Orientation of MRI

Answer 17

Left side of image is right side of patient

(looking at the patient from their

Question 18

Indications of MRI

Answer 18

Indications: Excels in visualizing soft tissue structure

(cartilage, tendons, etc) = Best for joint injury. Can find

Question 19

Pros of MRI

Answer 19

No ionizing radiation
–
Highest resolution , can differentiating soft tissue (i.e.

Question 20

Cons of MRI

Answer 20

Expensive \$\$$ and slow/ t ime consuming
–
Difficult for claustrophobic patients
–
Cannot use in patients with metal implants

Question 21

Ultrasound resolution is based on …

Answer 21

Lower frequency
•
more penetration, lower resolution
–
Higher frequency
•
less penetration, higher resolution

Question 22

Color scale of Ultrasound

Answer 22

Produces grey scale image, similar to X ray

Hyperechoic/White Dense , not able to
penetrate Bone, metal

Anechoic/Black Fully penetrates i.e . Air, fluid (

Hypoechoic/Darkish Organs, soft tissue

Question 23

Pros of Ultrasound

Answer 23

Cheap $, Fast, portable, no ionizing radiation

Question 24

Cons of Ultrasound

Answer 24

Not always available/user dependent
–
Not able to visual structures behind bone (waves blocked) and
bigger anechoic structures (waves scatter)

Question 25

What is nuclear medicine?

Answer 25

Used to measure physiology, not anatomy
•
Radioactive radiotracers injected by IV
•
Radiotracers will bind on targeted
physiologic process
•
Aggregated radiotracer will produce
higher concentration gamma radiation
which is visualized by camera

Question 26

What is Positron Emission Tomography?

Answer 26

Radiotracer is a glucose analog and will
aggregate in areas of most glucose usage
•
Indications: Common way to monitor cancer
as cancerous cells have increase glucose use