x-rays

Question 1

Purpose of contrast radiography

Answer 1

To enhance visualisation of structures or organs by altering radio-opacity of structure of interest or surrounding areas.

Question 2

2 positive contrast agents

Answer 2

• Barium Sulphate for gastrointestinal tract

- Water soluble iodine for urogenital system

Question 3

What is double contrast study

Answer 3

Positive agent to line the cavity negative agent to distend it

Question 4

Heavy sedation or GA not recommended during barium swallow due to ?

Answer 4

Risk of regurgitation and aspiration

Question 5

How often to take x-rays for barium study?

Answer 5

every 15-60 mins

Question 6

Contraindications for barium study?

Answer 6

• Risk of regurgitation
• Food withheld for 24hrs prior
• If perforation suspected use water soluble iodine

Question 7

What gas is used for negative media

Answer 7

Room air, oxygen, co2, nitrous oxide.

Question 8

What does emulsion layer of film contain

Answer 8

Silver bromide suspended in gelatine

Question 9

What coats the surface of film

Answer 9

The supercoat

Question 10

What function developer does, temperature, pH

Answer 10

Reduction, 20 for manual or 28 for automatic degrees, Alkaline

Question 11

What function fixer does, pH

Answer 11

Clearing and tanning, acidic

Question 12

What causes yellow staining of developed films

Answer 12

insufficient rinsing of developer

Question 13

What colour is developer splash on film

Answer 13

Black

Question 14

What colour is fixer splash on film

Answer 14

White

Question 15

Too dark x-ray

Answer 15

Overexposure
Overdevelopment
Too high developer temp
Fogging

Question 16

Too pale xray

Answer 16

Underexposure
Underdevelopment
Too low developer temp
Too dilute developer

Question 17

What is soot and whitewash

Answer 17

High contrast - too low kV

Question 18

What is flat film

Answer 18

Low contrast - too high kV, fogging

Question 19

What causes contrast too high (soot and whitewash)

Answer 19

Too low kV - Increase kV

Overdevelopment - reduce developing time/temp

Question 20

What causes contrast too low (flat film)

Answer 20

Scatter radiation - use a grid/collimate beam
Overexposure - reduce kV
Underdevelopment - Increase developing time/temp

Question 21

What causes poor definition

Answer 21

Movement blur
Object film distance too great
Poor screen-film contact

Question 22

What causes too high density

Answer 22

Overdevelopment

Overexposure

Question 23

What causes density too low

Answer 23

Underdevelopment

Underexposure

Question 24

What causes fogging

Answer 24

Scatter radiation

Question 25

2 members of electromagnetic spectrum with highest frequency and shortest wavelenght

Answer 25

x-ray

gamma radiation

Question 26

Properties of x-rays and gamma rays

Answer 26

• Travel through vacuum
• Speed of light
• Can be absorbed or scattered
• Medium is not required for transmission

Question 27

What is atomic number ?

Answer 27

The number of protons possessed by the atom

Question 28

Two types of anodes

Answer 28

Stationary anode

Rotating anode

Question 29

Pros of rotating anode

Answer 29

Less heat in one area as the anode rotates
Allows higher exposure factors
Allows longer exposure times

Question 30

Why is mylobdenum used to rotate the anode

Answer 30

Bad heat conductor

Question 31

What angle is the target area at on a rotating anode

Answer 31

6-20 degrees