CSCC 1190 Exam 1 Review

X-rays were discovered by

W. C. Roentgen

X-rays were discovered on

November 8th, 1895

X-rays were discovered in

Wurzburg, Germany

The proper term for the image or picture produced using x-ray is a

radiograph

__________ means that credentials issued in one area are recognized in another.

Reciprocity

X-ray images of blood vessels is termed

angiography

GXMO's must be under __________ when performing x-rays

direct supervision

GXMO's cannot perform

mammography, computed tomography, or mobile radiography

MRI

uses a magnetic field and radio waves to generate sectional images of the body

Ultrasonography

uses sound waves to make images of the body

Radiation Therapy

is using radiation to treat cancer tissue

Nuc Med

is utilizing radioactive pharmaceuticals to determine organ function

Mammography

is specialized imaging of the breast

CT

is the use of x-ray to make sectional images or three-dimensional images of the body

Can LXMO's perform routine chest x-rays and assist patients to the radiographic room?

Yes

Can LXMO's perform CT's of the head and administer contrast for angiograms?

No

Scatter Radiation

Comes primarily from the patient, is secondary

Primary Radiation

Comes from the x-ray tube

Remnant Radiation

Radiation resulting after the x-ray beam exits the patient

Collimator

Limits the size of the x-ray field

Grid

Reduces the amount of scatter that reaches the image receptor

Detent

Stops tube movement in a specific location (aligned with Image receptor)

Image Receptor

Device that receives the energy of the x-ray beam and forms an image of the body part

Film Screen

Cassette containing film receives the x-ray beam

CR

Cassette containing phosphor plate receives x-ray beam, plate will be processed and scanned by a laser which will emit light in proportion to x-ray energy received, info is used to form a digital image

DR

Flat panel detector, receives beam and produced electronic signal which is sent directly to the computer for processing

Moving the x-ray tube side to side across the patient

Transverse movement

Moving the x-ray tube from head to toes of the patient

Longitudinal movement

Moving the x-ray tube closer or further from the image receptor

Vertical movement

Tilting the x-ray table so the foot is above the head

Trendelenburg position

ALARA

As Low As Reasonably Achievable

Proton

Positively charged, in nucleus of atom

Neutron

No charge, in nucleus of atom

Electron

Negatively charged, in orbital shell around nucleus of atom

Ion

Charged particle

Ion Pair

Electron and positively charged atom

Ionization

Process of electron leaving its orbit around a neutral atom

Isotropic

Equal in all directions

Energy

Ability to do work

Matter

Anything occupying space with mass

Mass

Quantity of matter

Inverse Square Law

Intensity and distance

Anode

Positive charge, contains target,

Cathode

Negative charge, contains filament, often contains small AND large filament, heated to produce thermionic emission of electrons

99% of energy becomes

heat

Characteristic

Electron striking the target ejects inner shell electrons of target atom, outer shell electron fills vacancy with release of x-ray photon

Bremsstrahlung

Electron striking the target interacts with target atom nucleus, slows down, loses kinetic energy and is converted into an x-ray

Focusing Cup

Propels electrons toward a specific area of target anode

Focal Spot

Area of target which with electrons interact with

Anode

Rotates during exposure to distribute heat

Small Filament

Used to provide greater image detail

The effective focal spot is smaller than the actual focal spot, due to this anode heel effect, radiation intensity is greater at the cathode and less at the anode end of the x-ray beam

True

Autotransformer

Supplies power to kVp selection and other parts of the x-ray circuit

High Voltage Transformer

Changes incoming low voltage to high voltage, i.e. 54V to 54,000V

Rectifiers

Changes alternating current to direct current

APR

Op selects "PA CHEST" x-ray from options, machine sets corresponding exposure factors

AEC

Op selects an x-ray detector area corresponding to anatomy of interest, i.e. center cell may be selected for "AP LUMBAR SPINE" radiograph

Rapid series, high exposure, exposure on cold anode =

Failure due to overheating

kVp

Determines quality of x-ray beam

mAs

Directly related to quantity of x-ray beams

Focal Spot Size

Affects image sharpness

AEC...

requires accurate positioning, requires use of the bucky mechanism, and provides consistent radiographic density

200 mA at 0.25 seconds results in

50 mAs

Radiopaque

absorbs the x-ray

Radiolucent

Easily penetrated by the x-ray

Latent

image in film being processed