Radiology

Question 1

What is radiography?

Answer 1

X-Ray; photons interact with tissue; attenuated photons don’t make it to detector; photons not attenuated will pass through to be recorded by detector

Question 2

Define Radiopaque

Answer 2

No penetration; appears white

Bone, metal

Question 3

Define radiolucent

Answer 3

complete penetration; appears black

Question 4

Define shades of grey in context of radiography

Answer 4

Partial penetration

Question 5

What does degree of penetration in radiography depend on?

Answer 5

Atomic number and thickness; more absorption = higher atomic number/more thick

Question 6

What appears the same on radiography?

Answer 6

water and soft tissue; although all is relative

Question 7

What is used for radiographic contrast? How do they appear on radiograph?

Answer 7

Iodine or barium; highly attenuated

Question 8

What are the two radiographic views?

Answer 8

Frontal (AP or PA) and lateral

Question 9

Put these radio densities in order from highest density to lowest: contrast, acute blood, fat, metal, gas, bone, water/soft tissue

Answer 9

[high] metal/bone, contrast, acute blood, water/soft tissue, fat, gas [low]

Question 10

How does computed tomography (CT) work?

Answer 10

Ionizing radiation creates cross-sectional images of the body

Question 11

What plan is a CT taken?

Answer 11

Images are acquired in axial (transverse) plane then used to create images in any plane (commonly sagittal or coronal) and is composed of voxels

Question 12

What does a CT highlight?

Answer 12

Tissues of interest for CT are soft tissue, lung window, and bones

Question 13

What contrast is used for CT?

Answer 13

Enteric (oral or rectal): barium or iodine

Intravenous: iodine (barium CANNOT be given IV)

Question 14

What is the correct verbiage to describe CT?

Answer 14

Attenuation

Question 15

Describe hypo attenuation

Answer 15

Darker than background organ

Question 16

Describe iso attenuation

Answer 16

equal in attenuation with background organ

Question 17

Describe hyper attenuation

Answer 17

Brighter than background organ

Question 18

Ultrasound is based on the detection and display of what?

Answer 18

It is based on the detection and display of acoustic energy (sound waves) reflected from interfaces in the body

Question 19

What is a pro of using ultrasound imaging?

Answer 19

No ionizing radiation (pediatrics, pregnant women, etc.)

Question 20

Describe amplitude of ultrasound imaging

Answer 20

Amplitude of returned signal indicates strength of reflection; high amplitude appears white and low amplitude appears dark

Question 21

What does timing indicate in ultrasound?

Answer 21

The depth at which the echo originated

Question 22

Describe the ultrasound planes used

Answer 22

Transverse: oriented like axial in CT scan

Longitudinal: imaging an organ along its axis (either sagittal or coronal)

Question 23

What terminology is used to describe ultrasound?

Answer 23

Echogenicity

Question 24

What can be used in CT to better visualize something?

Answer 24

enhancement

Question 25

Describe what hypoechoic looks like

Answer 25

Darker than background organ

Question 26

Describe what anechoic/echolucent appears like

Answer 26

black coloring

Question 27

Describe how hyperechoic appears on an ultrasound

Answer 27

Brighter than background or organ; sound does not pass through bone or gas resulting in hyperechoic appearance on screen

Question 28

Describe how objects in movement appear on an ultrasound

Answer 28

Stationary objects: no change in frequency of sound wave as it bounces off of target (FR=FT) Moving objects: target moving towards transducer (FR>FT) and target moving away from transducer (FR

Question 29

How are magnetic resonance imaging (MRI) images created?

Answer 29

By strong magnetic fields and radio frequency waves: imaging protons (hydrogen atoms in fat and water) Benefit: no ionizing radiation Disadvantage: takes a long time

Question 30

Describe a T2 weighted MRI

Answer 30

Static fluid appears bright (look for CSF); highlights pathology (edema)

Question 31

Describe T1 weighted MRI

Answer 31

static fluid appears dark (look for CSF) and highlights anatomy

Question 32

Describe fat sat for T1 and T2 MRIs

Answer 32

Results in low signal intensity in the appearance of fat

Question 33

How can you tell the difference between MRI and CT?

Answer 33

Look for bones; bones appear more clearly on CT (i.e., look for ribs)

Question 34

What is the correct terminology for MRI scans?

Answer 34

Intensity

Question 35

Describe hypointense

Answer 35

Area appears darker than background organ

Question 36

Describe isointense

Answer 36

area appears equal in color to background of the organ

Question 37

Describe hyper intense

Answer 37

Area appears brighter than background organ

Question 38

What is used for MRI contrast?

Answer 38

Gadolinium based - makes tissue appear brighter on T1 weighted MRI (IV); usually use enhancement after to see even better