RADT 101 EXAM #1

What are the FOUR components found in a typical radiographic room?

1. x-ray tube

2. operating console

3. high voltage generator

4. x-ray table

What are parts on the X-RAY TUBE?

cathode, anode, vacuum, protective housing

overhead = ceiling suspension (sets of rails)

floor = tube-support column mounted on floor

What is the purpose of a HIGH VOLTAGE GENERATOR?

convers voltage into kilovoltage

Describe the X-RAY TABLE

• it can move around

• contains a bucky tray with grid

• it is radiolucent (means x-rays can go through it)

• made of carbon fiber (which is radiolucent)

• most have a weight limit

• can act as a fomite

Describe the PROTECTIVE HOUSING on an x-ray tube (why is it there, what does it protect from, etc)

• x-rays go out isotrophically (goes in all directions, not one controlled way)

• x-rays don’t just go out the window, so they need protection to prevent leakage

What is the appropriate level of leakage?

1 milligray (mGya) : per 1 hour : per 1 meter (1:1:1)

What is the typical kilovoltage (kvp) range?

25 to 150

What is the typical millamperage (mA) range?

100 to 1200 mA

mA controls ______, kVp controls ______

quantity, quality

What does a LINE VOLTAGE COMPENSATOR do?

• keeps technique consistent

• what comes out of the wall and converted into kVp needs to stay constant, so it keeps the voltage constant

Describe what an R/F room is

• can take regular x-rays and dynamic x-rays

• contains a fluoroscopic unit (usually contained under radiographic table) and is used in studies where necessary to watch a procedure on a monitor

What is mAs? (word description)

the quantity/intensity of x-rays and is identified as effecting receptor exposure

too much/too little of it would be overexposure/underexposure

Why should I be changing kVp?

it depends on what you need to get through (a finger would require less than an abdomen)

too much/too little would be overpenetrated/underpendetrated

HIGH CONTRAST is less shades of (color) and is described as (scale)

black/white … short scale

LOW CONTRAST is more shades of (color) and is described as (scale)

grays … long scale

What things are considered HIGHER CONTRAST (would appear white/black)

bone, fat, air

What things are considered LOWER CONTRAST (would appear gray)

muscle, water, fat

What are the FOUR radiographic qualities?

receptor exposure, grayscale (contrast), spacial resolution/recorded detail, size/shape distortion

Describe RECEPTOR EXPOSURE (aka density)

overall blackness of x-ray (the x-rays that got through and hit the image receptor rather than getting absorbed or partially absorbed)

Describe GRAYSCALE (contrast)

caused by a difference between adjacent densities (some things appear more black/white while others appear gray)

Describe SPATIAL RESOLUTION/RECORDED DETAIL

smallest object detected … sharpness of the lines of an image

Describe SIZE/SHAPE DISTORTION

a misrepresentation of the true size or shape of image (e.g. size = less SID = more magnification)

Describe SHAPE DISTORTION

elongation / foreshortening (angle towards where bone is growing)

bad tube angling is what causes this

If you decrease the SID, that would result in _____, which is an example of _______. This would in turn decrease ________ as it created a ______.

magnification … size distortion … spacial resolution ... blur

Give examples of POOR diagnostic images

• over exposed - too much exposure on patients, can be fixed by computer

• over penetrated - too much exposure to patients, can be fixed by computer

• poor spatial resolution size distortion - cannot be fixed by computer

• poor spatial resolution shape distortion - cannot be fixed by computer

RAD UNITS - what is Gya ?

gray air, exposure that is going out into the air

aka Air Kerma or Roentgen

RAD UNITS - what is Gyt ?

gray tissue, absorbed dose in tissue

aka rad

RAD UNITS - what is Sv?

sievert, tissue absorbed this much, exposed to x rays, occupational assessment, what were you exposed to

aka rem

RAD UNITS - what is Bq?

bequerel, measurement of radioactivity itself

aka curie

Matter occupies ______

space

Describe MATTER

• has space

• is a material substance

• has shape

Building blocks of MATTER are _____ and ______

atoms … molecules

The primary characteristic of MATTER is _____

mass

______ is the quantity of an object

Mass

Mass does not change when matter changes (T/F)

TRUE

Weight is the mass of matter in an object in ______

gravity

POTENTIAL ENERGY - how does it relate to x-ray?

when the electrons are being boiled off

KINETIC ENERGY - how does it relate to x-ray?

when electrons slam into anode, the pressure of them moving across

ELECTRIC ENERGY - how does it relate to x-ray?

needed for it all to happen, for the machine to work it needs to be powered by this

THERMAL ENERGY - how does it relate to x-ray?

the heat of boiling off electrons, 99% heat produced

NUCLEAR ENERGY - how does it relate to x-ray?

particulate radiation (THESE HAVE MASS, X-RAY IS JUST ENERGY)

At the bottom of the electromagnetic spectrum, the wavelengths are ______, and as you go up, the wavelengths _____ /get ______.

longer … decrease / shorter

When wavelengths get really _____, they are now _____ radiation

short … ionizing

Define IONIZING RADIATION

has the ability to knock out electron within body … the loss or gain of an electron

What radiation is NOT ionizing?

radio waves, microwaves, infrared radiation, visible light, ultraviolet

What radiation IS ionizing?

x-rays and gamma rays

What is the sequence of the ELECTROMAGNETIC SPECTRUM? (longest wavelength / low frequency → shortest wavelength / high frequency)

• radiowaves

• microwaves

• infrared

• visible light

• ultraviolet

• x-rays

• gamma rays

What are the FOUR examples of background radiation (found in natural environment)

• cosmic

  • particulate and electromagnetic radiation emitted by SUN AND STARS

• terrestrial

  • from deposits of URANIUM, THORIUM, and other RADIONUCLIDES on the earth

• internally deposited radionuclides

  • POTASSIUM and NATURAL METABOLITES

• radon

  • RADIOACTIVE GAS that is produced by the natural RADIOACTIVE DECAY OF URANIUM

What type of background radiation is MOST COMMON? (we receive the most of this naturally)

Radon 222 (68%)

What is the difference between PARTICULATE RADIATION and ELECTROMAGNETIC RADIATION

• particulate is little particles that emit ionizing radiation and HAS MASS

• photons/x-rays are just bundles of energy

• both can produce ionizing radiation

What two forms of particulate radiation ionize matter?

alpha, beta

What are gamma rays?

it is an electromagnetic ray, but spits out particulate radiation

WHEN and by WHO were x-rays discovered?

Wilhelm Roentgen discovered them through the CROOKES TUBE on accident on NOVEMBER 8, 1895

RECOGNIZE Roentgen’s original properties of x-rays (pretty much same as they are now)

• highly penetrating INVISIBLE rays that are a form of electromagnetic radiation

• electrically neutral, not affected by electric/magnetic fields

• can be produced over wide variety of energies and wavelengths

• release very small amounts of heat when passing through matter

• travel in straight lines

• travel at the speed of light

• can ionize matter

• cause fluorescence of certain crystals

• cannot be focused by a lens

• affect photographic film

• produce chemical/biological changes in matter through ionization/excitation

• produce secondary and scattering radiation

Describe the earlier RADIATION INJURIES

• anemia, erythema, and loss of hair were common

• first fatality = clarence dally in 1904

What does ALARA stand for?

As Low As Reasonably Achievable

Why was protective apparel developed?

developed when it was noted that radiologists were developing a high rate of leukemia and aplastic anemia

List the DEVICES used to minimize radiation to pt/worker

• filtration

• collimation

• protective barriers

• protective apparel

  • gonadal shielding/thyroid shielding

• technical factors (highest optimal kVp, shortest time)

Describe VELOCITY

• aka speed

• measure of how fast something is moving or the rate of change of its position with time

• velocity of an object changes as its position changes

Describe ACCELERATION

• the rate of change of velocity with time is this

• how quickly or slowly velocity is changing

• if velocity is constant, this is zero

Describe WEIGHT

• force on a body caused by the pull of gravity on it

• this is equal to the product of its mass and the acceleration of gravity

Describe MOMENTUM

• the product of the mass of an object and its velocity is called is

• the greater the velocity of an object, the more ____ the object possesses

• the total ____ before any interaction is equal to the total ____ after the interaction

Describe BASE QUANTITIES

• three measurable quantities

• length, mass, and time

• building blocks of all other quantities

Describe DERIVED QUANTITIES

• secondary quantities

• combination of one or two or more of the base qualities

• e.g. velocity (length / time), mass density (mass / volume), volume (length cubed)

Describe SPECIAL QUANTITIES

• additional quantities designed to support measurement in specialized areas of science and technology 

• e.g. exposure, dose, effective dose, and radioactivity

Describe MAGNITUDE

• part of a measurement, the number part

• not meaningful unless a unit is also designated

Describe UNIT

• part of a measurement, the word/abbreviation part

• makes magnitude meaningful

• e.g. cm, inches

Describe MKS

• stands for meters, kilograms, and seconds

• represents the current state of units

• SI includes the three base units of this system plus an additional four

Describe NEWTONS FIRST LAW

• aka inertia

• a body will remain at rest or will continue to move with constant velocity in a straight line unless acted on by an external force

• if no force acts on an object, there will be no acceleration

• the property of matter that acts to resist a change in its state of motion is called inertia

Describe NEWTONS SECOND LAW

• aka force

• the force that acts on an object is equal to the mass of the object multiplied by the acceleration produced

• can be thought of as a push or pull on an object

Describe NEWTONS THIRD LAW

• for every action, there is an equal and opposite reaction

• if you push on a heavy block, the block will push back on you with the same force that you apply

Describe WORK

• the work done on an object is the force applied to that object times the distance over which it is applied

• e.g. when you lift an IR, you are doing work

Describe POWER

• the rate of doing work

• gives us a way to include the time required to perform the work

Describe ENERGY (potential and kinetic)

• kinetic = associated with the MOTION of an object

• potential = STORED energy of position or configuration

Describe HEAT

• kinetic energy of the random motion of molecules

• the more rapid and disordered the motion of molecules, the more heat an object contains

• heat is transferred from one location to another by conduction, convection, and radiation

Describe CONDUCTION

• the transfer of heat through a material or by touching

• molecular motion from a high-temp object that touches a low-temp object equalizes the temp of both

Describe CONVECTION

• the mechanical transfer of hot molecules in a gas or liquid from one place to another

• e.g. a steam radiator or forced-air furnace warms a room by this

  • the air around the radiator is heated, causing it to rise, while cooler air circulates in and takes its place

Describe THERMAL/INFRARED RADIATION

• the transfer of heat by the emission of infrared radiation

• the reddish glow emitted by hot objects is evidence of heat transfer by radiation

• an x-ray tube cools primarily by radiation

The FUJI SYSTEM in the energized lab uses _____ for technique ranges

EI / exposure index

The FUJI SYSTEM PORTABLE uses _____ for technique ranges

DI / deviation index

Describe the EXPOSURE INDEX (EI)

• exposure range for mAs

• be within 200-800, you’ve given appropriate amount of quantity to the patient

• below 200 is TOO MUCH mAs, above 800 is TOO LITTLE mAs

• INDIRECT SYSTEM

Describe the DEVIATION INDEX (DI)

• be as close to 0

• above 0 is TOO MUCH, below 0 is TOO LITTLE

• direct system

Define ATOM

smallest part of an element that has all of the properties of that element (protons, neutrons, electrons)

HISTORY - greeks and matter

earth, wind, water, air and fire

HISTORY - John Dalton’s atom

• matter classified by atomic mass

• hook and eye

• elements composed of identical atoms reacted in the same way

Who created the first periodic table?

Dmitri Mendeleev

What do particle accelerators do?

tears the atom apart in order to study it

HISTORY - Neils Bohr

states that atom is a mini solar system

AMU stands for

atomic mass unit

Gamma rays come from the ______, x-rays come from _____

nucleus, electrons

Smallest part of a compound is an _____

element

Fundamental parts of the atom are _____, _______, _______

proton, neutron, electron

Atomic mass number for an electron is _____

0

Out of the two types of NUCLEONS, which one is heavier?

neutron

Which particle determines the chemical behavior of an atom?

proton

A _____ atom has the same number of electrons in orbit as protons in the nucleus

neutral

What are the names of the electron shells?

ALWAYS START WITH K … l m n o p q

The outermost shell is identified by the _____ and the number of electrons in the outermost shell is identified by the _____ on a periodict table

period, group

Describe CENTRIFUGAL FORCE

• centriFugal → Flying out into space

Describe CENTRIPETAL FORCE

• centriPetal force = Pulling into the center