Physics 2 test 1

Question 1

Thicker patient Increases or decreases scatter production?

Answer 1

Increases

Question 2

What can you do to reduce scatter and get a shorter scale of contrast?

Answer 2

Decrease kVp

Question 3

Base support

• Dimensional Stability
• Lucent
• Often polyester

Adhesive Layer

Emulsion-usually double, is the active layer

Protective coating

Answer 3

Screen/Film Radiography

Question 4

Backing

Base

Reflective Layer

Photostimulable Phosphor

-barium flurohalide crystals coated with europium

Protective Layer

Answer 4

CR or DR Image Receptors

Question 5

How often should you erase unused CR or DR plates?

Answer 5

48 hrs

Question 6

You should process an exposed CR or DR cassete by when?

Answer 6

1 hr after exposure

Question 7

Film Emulsion consists of:

Answer 7

Gelatin and Silver Halides

-Silver Bromide & Silver Iodide

Sensitivty Speck (Silver Sulfide)

-Attracts photoelectrons and silver ions during exposure

Question 8

Low kV and compression reduce scatter in what modality?

Answer 8

Mammo

Question 9

Absorption is…

Answer 9

Photoelectric

Compton is the “other intereaction” in the Patient

Question 10

Reciprocity law

Answer 10

Image density should be the same as long as you use the same mAs, regardless of combination of mA and time

Question 11

Image Intensifier Parts:

Answer 11

Input Phosphor: takes xrays to light, then light to electrons

Electrons cross from each side to light by focusing lenses, electrons cross at the anode neck inverting the image

Electrons go from there to the the output phosphors to the windows

Question 12

How do you figure Magnification factor?

Answer 12

SID/SOD

SOD= SID-OID

SID/SOD=image/object

object is always smaller than image

Question 13

Liklihood of Compton as kVp goes up

Answer 13

Both Compton and Photoelectric go down, because more photons are going through

But compton is more liiely than photoelectric in higher kVp’s