Intro to Diagnostic Imaging

Question 1

In an x-ray, dense objects appear _______. Non-dense objects appear_____.

Answer 1

white (radio-opaque)
black (radio-lucent)

Question 2

why diagnostic imaging?(4)

Answer 2

1. to localize the anatomic problem
2. identify tissue involved
3. identify the nature of the tissue damage
4. direct treatment

Question 3

why would you need an x-ray?

Answer 3

to identify bony defects

Question 4

what are the advantages and disadvantages of xray?

Answer 4

Advantage:
-quick, inexpensive, ideal for bony changes
Disadvantage:
-does not show soft tissue changes, radiation exposure

Question 5

what is a CT? What are the advantages and disadvantages?

Answer 5

a CT is a moving x ray that provides detailed planar images
Advantage:
-quick
-cross sectional images that can be enhanced with contrast
- more sensitive that x-ray
Disadvantage:
- high radiation exposure and less sensitive than MRI

Question 6

What is an MRI? What are the advantages and disadvantages?

Answer 6

An MRI is ideal for soft tissue contrast that produces slice images in any plane
Advantage:
-any structure can be highlighted and no radiation exposure
-can image through bone
Disadvantage:
- price, not good for bone tissue, length of time, tube size, not specific, cant use metal

Question 7

what is ultrasound? What are advantages and disadvantages?

Answer 7

Ultrasound produces a 2-D image in real time which can be moving
Advantages:
- biologically harmless, portable, distinguishes solid from fluid, records and displays motion
Disadvantages:
- does not penetrate bone well, does not go through air/gas, skill dependent

Question 8

What is a bone scan? How does it work?

Answer 8

A bone scan is used to help diagnose problems with bones. A small amount of radioactive drug is injected into the blood stream so that it will travel to areas of bone damage. Dark spots on the image are the area of damage.

Question 9

why would we use a bone scan?

Answer 9

to identify if someone has a metastatic disease, arthritis, stress fractures, osteomyelitis, loose implants, or trauma.

Question 10

What does nuclear imaging image well?

Answer 10

-thyroid masses
-bone metastases from cancer with a PET scan
-lung circulation and ventilation
-cancer
-GI disease
-Endocrine disease