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Into to RAD Test 2
intro to Rad
Question | Answer |
---|---|
How many seconds do you have to remove the patient away from the tube to avoid getting burned by oil if X-ray tube breaks? | 30-40 seconds |
where the catode produce it's source of electrons? | the tungstun filaments |
the anode stops what? | the electrons |
Voltage is? | the energy before it hits the anode |
T or F potenital enery is at rest? | True |
kentic energy is | amount of energy in movement. |
Newton's 1st law of Thermal Dynamics | energy cannot be created or destroyed, but it can be converted. |
Energy is split into two energies what are they? | 1) Thermal energy - is given as heat 2) Radiation energy - X-radiation |
kVp will produce kEv for example | 70kVp = 70 kEv kvp is kilovotage peak kev is kiloelectron volts |
There are ways to get rid of overheating the X-ray tube by. | heat sink-increasing the air surfaces Oil-as the tube get's hot the oil removes some of the heat Fan- 3rd stage a fan will come on to reduce heat |
Low atomic #'s don't absord radiation. T or F | true |
Space charge effect | at a certain point the tube will resist boiling off furter electrons, only boil off so much and then it will boil no more. Also, the X-ray tube will only boil as much ma as you use for example 100ma will equal 100 electrons |
why is the X-ray tube vacumed sealed? | because you want electrons with air. you want it to be in a particle area without movement. |
the rotator on the X-ray tube will | dissipate heat |
Ionizing radiation | carry the risk of biological effect |
Radigrapher responsibility | ALARA; and any other people around that area |
Sources of radiation | Cosmic radiation, Medical radiation- which you will recieve the most dose. Nuclear industry - accidents Radionuclides- smoke detectors, exit signs |
in your body you have low levels of radiation | which is calcium |
Cathode creates | the electron cloud |
the 5 interactions with matter from lowest to highest depending on the level of radiation. | 1) classic coherent scatter/unmodified scatterig 2) photoelectric effect 3) compton scattering 4) pair production 5) photodisintegration 4-5 you will never see in dianostic X-ray only in radiation therapy and nuc med you will see |
Classic coherent | not ionizing,energy went in and goes in a different direction with same energy out, does contribute to fog and added density |
Photoelectric effect | is absorbed in the body,produce high contrast images, the increase energy will pass into the K shell and not an electron out,still low energy but the more kvp the less photoelectric. |
photoelectric effect | the electron the fell out will be filled by other electrons in other shells causing a casade effect which will give out some radition |
compton effect | interacts with outer shell, is ionizing,this is a gray gray film it will produce low contrast, this is where we get occupational dose. |
compton effect | you want a higher dose to go in and out. so more kvp. |
mAS is controls | density |
R=Roentgen | is to measure radiation in air |
QF | is the specific reaction to a biological effectiveness to expsure to radiation. |
Scatter does add Density | increase in density decrease in kVp decrease in density increase in kVp |
QF | is the fundamental difference between RAD and REM |
TJC | The Joint Committee accredits the hospital organizations |
JECERT | acrredits schools |
AEIRS | Association of Educators in Imaging and Radiologic Sciences. in albuquerque |
MPE (Maximum Permissable dose) | says if you get this much radiation we don't think anyting bad is going to happen. this theory is no longer vaild, because non Threshold therum says every dose is dangerous. |
NCRP( National Council on Radiation Protection) | make recommendations about doses to FDA |
FDA(Food and Drug Administration ) | makes the policies for dose |
Effective dose limits new formula says | your allowed one REM a year no matter what old formula was 5(N-18)REM which is dumb |
Target Theory | going to most likely kill DNA or mitocondria which is important in producing in evergy so no energy you will die is a matter of minutes |
certain cells are more resistant than other cells | cells that keep producing like white blood cells are not resistant where as nerve cells dont produce that much and are more resistant G1 is the most sensitive germ cells |
types that are resistant or not | blood cells very sensitive thyroid clee sensitive cells that reproduce sensitive brain cells aer the most resistant |
NVD is | nausea vomiting diarrhea |
Stages of effect | 1st prodromal stage NVD 2nd latent the quite stage 3rd manifest what ever happens is going to happen |
3 cardinal rules | TIME- shortes time possible Distance- longest distance possible Sheilding |
Benefits of collimation | increase visibility, reduce scatter, increase contrast |
Screen/Film | the faster the film speed the lower the patient dose, 400 speed will require 400 times less. film speed dosnt deal with how fast it works but how much it can process |
densitometer | measures amount of dose on density of film |
Radionuclieds | drugs injected into patient that is radioactive |
half life syas | for example if you get 1000bq 10years is the half life so in 10 years you will get 500bq another 10 years you will get 250bq |
added filitration + inherent equals | Total filitration |
3 types of filitrations | added,compensating, inherent |
binding energy | amount it takes to hold and e- in its orbit |
X-rays is on which side | Anode; subatomical particle travel really fast; a photon is little particles that travel in a wave form call quantum |
when the electron hits the anode it will be converted into | heat and energy. |
OSL | PIMA uses this type of badge.; a chip of aluminum oxide and scan it with high frequencies lase will release electrons that where trap when you got exposed and glow to tell you how much you got. it can be read keep them forever. |
increase in scatter | increase in density |
increase in kvp | increase in density |
contrast dose not effect | density kvp increase contrast decrease mas increase density increase |
fractionation says it is better | to break 5 rads at different times then recieve it all at once. |