Imaging Modalities- Chapter 6 Washington Leaver

Question 1

What are the (3) ionizing radiation image procedures we use

Answer 1

Conventional radiography
Computed tomography (CT)
Nuclear Medicine (bone scans)
Positron Emmision Tomography (PET)

Question 2

Non ionizing image procedures/techniques

Answer 2

Magnetic Resonance Imaging (MRI)

Ultrasonography

Question 3

Filling defects, channels that are not completely visible or that appear frothy can demonstrate the presence of pathological changes

Answer 3

Lymphangiograpy
(provides useful information for treatment field design)
Uses specific dyes or contrast injected into lymphatic

Question 4

Provides two-dimensional image of the interior body (images produced because of differences in body density)

Answer 4

Conventional and Digital Radiography

Question 5

What imaging modalities look like slices of the body?

Answer 5

CT- computed tomography (virtual or 3D)
each slice seconds
multiple slice machine takes 64-128 slices at time
images have 10 to 20 times the detail of conventional

Question 6

Detects more metastatic disease than primary tumor

Answer 6

Nuclear Medicine- Isotope

Question 7

What allows tracking of a “moving tumor”

Answer 7

Four dimensional CT

Ex; Lung tumor hidden while breathing

Question 8

PET- Positron Emission Tomography

Answer 8

Gamma Rays

Question 9

What image modality can demonstrate function rather than structure?

Answer 9

PET- Positron Emission Tomography

Ex; cancer cells absorb sugar isotopes more quickly than normal cells

Question 10

Radioisotopes used for diagnosis and treatment

Provides information physiology and anatomic structure

Answer 10

Nuclear Medicine

Question 11

Short lived isotopes injected into the body

Answer 11

Nuclear Medicine

Question 12

This image can be static or moving

Answer 12

Ultrasound

Question 13

Ultrasound advantages

Answer 13

• No exposure to ionizing radiation
• Noninvasive and painless
• Requires no contrast media

Question 14

Disadvantages of Ultrasound

Answer 14

Does not penetrate bone or air-filled spaces effectively

Question 15

Magnetic Resonance Imaging (MRI)

Answer 15

• resulting image looks like a CT image
• provides information about chemicals
• uses no ionizing radiation

Question 16

What are the advantages of using PET and CT together

Answer 16

allows visualization of small lesions

retains spatial accuracy of CT

Question 17

What types of fields does MRI use for imaging

Answer 17

magnetic files and radio waves

Question 18

What type of fields does Ultrasongraphy use

Answer 18

echoed sound waves

Question 19

Disadvantages of an MRI

Answer 19

• Expensive shielding required
• More expensive than CT
• Low patient throughout

Question 20

Ultrasound

Answer 20

• Uses high frequency sound waves
• transducer generates high frequency sound waves
• transducer is moved over the body part being examined
• transducer picks up returning sound waves

Question 21

MRI properties

Answer 21

• hydrogen nuclei
• magnetic field applied; nuclei and patient pulsed with radio waves
• nuclei sends out a weak radio wave and an image is formed