Pg 21- Flashcards
What is hematological syndrome
200-1000 rads acute whole body
What is gastrointestinal syndrome
1000-5000 rads, probably die within 2 weeks
Central nervous system syndrome is how many rads
5000+, less than a week to live
Whats LD 50/60
Whoe body exposure that would kill 50% of people within 60 days, traditionally 50/30
LD 50/30 means
“Lethal dose” 350 rads without medical intervietion 50/60. However the 50/30 for us is 300 rads.
Who discovered X-ray for use in chiropractic
Wilhelm conrad roentgen in 1895, professor in germany
What was the first X-ray image that roentgen made
His wife bertha’s hand
X-ray was at first called in german
Roentgen ray, but then was changed to x ray
When was X-ray introduced to palmer
1910 by BJ palmer
All X-rays have
Ionizing capacity which causes biological changes
X-rays ______ mattter and are ______
Penetrate, absorbed by dense material such as lead, cement, compact bone
X-rays make ____ rays from objects they strike
Secondary
Secondary rays have a ___________
Detrimental effect on film and patient
X-rays travel in _______ lines from their source
Diverging
Diverge is a big cause in
Image distortion
X-rays cannot be
Focused
Reflected
Refracted
Film turns _____ when exposed
Dark
Can human senses detect an X-ray
NO
What are the three things needed to give birth to an X-ray
- Source of electrons
- Way to accelerate them at a high speed
- Hard surface to stop them
What contains all three things needed to give birth to an X-ray
The tube
The filter does what
Filters out the weaker photons that would get to the film anyways
Whats a Collimator
Limits the size of the X-ray beam, aka a beaming light device
After the X-rays travel through a patient they hit
The grid which helps absorb the secondary rays and make image clearer
The cassette has
Screens which glow with light and are in contact with the film
Where is an image recorded in an X-ray
Film
What is contained in the tube housing
Lined with lead to prevent leakage,oil surrounds the tube acts as thermal insulator, window or port to allow intended X-rays to exit
What holds the tube housing in position
Tube arm
What holds the tube arm
Tube stand and is perpendicular to the arm, allows arm to. Move the tube vertically
What allows tube to travel horizontally
Tube track
What is a C arm
When tube and receptor oppose each other on a C shaped frame
What part of the glass tube is thinner
The area for the window, easier to penetrate
What is the useful beam
Rays exiting the window or port
What is central ray (CR)
The center most ray, it is perpendicular to the patient, all other rays are diverging
What is the cathode
The negative electrode, the electron producer
What are the two functions of the cathode
Focuses electrons
Produces electrons
What are the two parts of a cathode
The filament and focusing cup
What is a filament in a cathode
Small coil tungsten, withstands the heat created , a current is passed through it to heat it
What passes current through the cathode filament
Milliamperage circuit
What happens when the filament is heated
The electrons are “boiled off”
What is thermionic emission
When electrons are burned off the filament in a cathode
What is a dual focus tube
When a cathode has a large and small filament
Small- clearer images
Large- hands more heat less clear image
What is the indentation that a filament sits in
Focusing cup, helps consolidate the electron cloud
What does a anode do
Creates strong positive charge that pulls electrons across the tube, PRODUCES PHOTONS
What are the 3 functions of the anode
- Stops electrons thus produces X-rays, X-rays only 1% from process
- dissipates heat, heat is 99% of the product
- Conducts electricity
A anode has how many parts
3
Target, stem, rotor, but not all have a rotor
What is the target in the anode
Where the electrons are propelled too, made of tungsten bc of its high melting point
What is the area where X-rays are emitted in the anode
The focal spot
A dual focus anode tube has
A small focal spot and a large focal spot
What are the two types of focal spots for a anode
Actual and effective focal spots
Actual- where electrons are striking
Effective- where photons exit
Large focal spot in anode produces
More penumbra(unclear borders)
Small- more umbra (clear borders)
What does the stem in the anode do
Holds the target and conducts heat away from it
Usually made of copper
What are the two types anodes come in?
Stationary anode and rotating anode, both are beveled. Which is called the anode angle to help dissipate heat
Stationary anodes are used only for
Small exposures ( dont use em)
They have a greater angle than rotating anodes
Whats rotor rotates the rotating anode and increase the surface area this is
The sound you hear before exposure
What is the focal spot called for a rotating anode
Focal trac
Larger angles=
Larger effective focal spots, image is less clear
Smaller angles=
Smaller effective focal spots images are clearer
Larger angle= less clear and
Smaller angle= more clear
This is known as
The line focus principle
What is the anode heel effect
When the bottom bevel decreases beam intensity
Some X-rays exit the heel of the anode from the imbedded target which
Reduces beam intensity,
Anode or cathode should be toward thinner parts of glass tube
Anode thinner parts
Therefore anode up and cathode down for full spine X-ray
