Ch. 1 Introductio to Imaging Sciences

acute radiodermatitis

Inflammation of the skin caused by exposure to radiation, often resulting in redness, swelling, and pain. It typically appears within days of high-dose radiation exposure.

cathode ray tube

a partial vacuum tube that produces an electron stream

derived quantities

combined from fundamental quantities forming: velocity, acceleration, force, momentum, power

fluroscope

a device that allows dynamic x-ray examination using x-rays and a fluorescent screen

fundamental quantities

mass, length, time

ionizing radiation

radiation that carries enough energy to displace electrons from atoms, creating ions.

mobile equipment

a unit on wheels that can be taken to the patient’s bedside, the emergency department, surgery, or wherever it may be needed

permanently installed equipment

refers to units that are fixed in place in a particular room specifically designed for the purpose and are not intended to be mobile

radialogic quantities

Measurements related to radiation exposure: dose, dose equivalent, exposure, and radioactivity

d

The tube head assembly consists of:
a) x-ray tube
b) tube stand
c) collimator
d) all of the above

c

In the hospital setting, the most widely used tube stand or mount is the:
a) floor mount
b) floor-ceiling mount
c) overhead tube assembly
d) under-table tube assembly

d

The ____________ is the SI unit equivalent to the rem.
a) rad
b) roentgen
c) Becquerel
d) sievert

a

1 rad = ______________.
a) 10-2 Gy
b) 10-1 Gy
c) 10 Gy
d) 102 Gy

b

Permanently installed radiographic equipment can never be replaced because it is permanent.
a) True
b) False

c

Lead shutters are part of the:
a) tube housing
b) tube stand
c) collimator
d) x-ray tube

a

The radiologic unit that quantifies occupational exposure or dose equivalent is the:
a) rem
b) rad
c) roentgen
d) Becquerel

a

1 rem = ______________.
a) 10-2 Sv
b) 10-1 Sv
c) 10 Sv
d) 102 Sv

b

The negative electrode of the x-ray tube is the:
a) diode
b) cathode
c) anode
d) canode

b

The ____________ is the SI unit equivalent to the curie.
a) roentgen
b) Becquerel
c) sievert
d) gray

c

The positive electrode of the x-ray tube is the:
a) diode
b) cathode
c) anode
d) canode

c

The ____________ is the SI unit equivalent to the rad.
a) rem
b) roentgen
c) gray
d) Becquerel

a

A radiographic unit that can be taken to the patient's bedside is considered:
a) mobile equipment
b) permanently installed equipment
c) bedside equipment
d) stationary equipment

a

In a typical radiographic room the anode is located:
a) over the head end of the table
b) over the foot end of the table
c) in the middle of the table
d) away from the table

d

The radiologic unit that quantifies radiation intensity is the:
a) rem
b) Becquerel
c) gray
d) roentgen

d

According to the basic principles of radiation protection , a radiographer should minimize:
a) shielding
b) patient protection
c) distance
d) time

c

5 gray is equal to ___________rad
a) 5 rad
b) 50 rad
c) 500 rad
d) 0.5 rad

b

Lead aprons are considered
a) primary barriers
b) secondary barriers
c) they are not effective means of protection against radiation
d) are 100 % effective of protection against the primary beam

d

A radiographer's dosimetry report is expressed in:
a) mRad
b) mR
c) mCi
d) mRem

d

The curie is an expression of:
a) Quality of radioactive materail
b) intensity of radioactive material
c) absorption of radioactive material
d) Quantity of radioactive material

d

The glass envelope of the x-ray tube is most commonly composed of?
a) Oil
b) lead
c) Tungsten
d) Pyrex

a

Select the charge of the filament during exposure .
a) negative
b) positive
c) neutral
d) no charge

a

The filament(s) are located collimators within the:
a) cathode
b) anode
c) collimators
d) target

c

Radiographic exposure technique selection is performed with what component of an X-ray system?
a) Generator electronics cabinet
b) X-ray tube assembly
c) Operator's console
d) Radiographic table

b

Chest radiographs and upright abdominal studies are conveniently performed using a(n)
a) variable height table
b) upright cassette holder or Bucky.
c) tilting radiographic table.
d) interventional C-arm system with a fixed SID

c

X-ray examination of the lower abdomen and pelvis of the women in reproductive years should be limited to :
a) the time before menstruation
b) the 10 days before the onset of menstruation
c) the 10 days after the onset of menstruation
15 days before and after menstruation

columb/kg (C/kg)

output intensity / radiation intensity in air (SI unit)

roentgen (R)

output intensity / radiation intensity in air (STANDARD UNIT)

gray (Gy)

SI unit of absorbed radiation dose

Rad

Standard unit of absorbed radiation dose

sievert (Sv)

SI unit of effective radiation dose (dose equivalent) used to measure biological effects of radiation on living tissue.

rem

Standard unit of effective radiation dose (dose equivalent) used to measure biological effects of radiation on living tissue.

becquerel (Bq)

SI unit of radioactivity, representing one disintegration per second.

curie (Ci)

Standard unit of radioactivity, representing one disintegration per second.

properties of xray

-highly penetrative
-travels in a straight line
-travels at the speed of light
-can ionize matter
-cant be focused by a lens

momentum

The product of an object's mass and velocity

velocity

Speed in a given direction

work

force applied over a distance

power

rate at which work is done

intertia

tendency of an object to resist a change in motion

energy

ability to do work

ion pair

electron is removed from an atom in a process called ionization

x ray tube, collimator, tube stand

parts in the tube head assemble (3)

x ray tube function

2 electrodes in a tube that converts electrical energy into x rays and produces heat as a byproduct

collimator function

restricts the x ray beam to area of interest of the body and localizes the beam to that area

light source, mirror, crosshairs

What 3 items are in the collimator?

tube stand function

gives mobility to the x ray tube

Bucky assembly

Tray located under the table top positioned between the patient and receptor to reduce scatter radiation

time, distance, shielding

What are the principles for minimizing radiation dose?