RADT 150 Radiation Protection RAD UNIT KONN UNIT 2

who discoverd x ray and what year

Wilhelm Conrad Roentgen discovered X-rays on November 8,1895

what did Wilhelm Conrad Roentgen discover on his experiment

wonder ray -unkown sources of radiaiton or energy

over the years what was detected to be dangerous

potential biological or somatic damage from exposure to radition

first person to die from radiation exposure in 1904

clarence dally

clarence dally was what

an assistance to Thomas Edison

when was the first occupational exposures documented

1910

what did radiologist started to show

started to show sign radiodermatitis

what is radiodermatitis

inflammation of the skin as a result of radiation exposure

in addition in 1910 what has occurred during that time

alot of death as a result of radiation exposure - there were potential of biological effects

what was the unit or measurement for radiation exposure 1900-1913

SED-skin erythema dose

x ray can not be detected by

any human senses-can not see,feel, touch or taste it

what is the only way to know when the person was receiving radiation exposure

was seeing changes in the biology -skin turning red, inflammation

what radiation number was required to cause SED

650 rem

in today tech know that 650 rem of radiation exposure TO THE WHOLE BODY of human

the human would die in 30 days

in 1921 the British X-Ray and Radium Protection Committee was formed to do

provide Guidelines for manufacturing to eliminate occupational exposures

the x ray tube was not house in lead housing but would be positioned on a

stand or a wood box

when was in ICRU(ICRP) created

1925

in 1928 what did ICRU formulate

formulated a new unit to measure radiation exposure ( called the Roentgen)

occupational limits was created, and early on 1934 what was created

tolerance dose

what is tolerence dose

Amount of dose a person can be continually exposed without harmful effect (which was replaced by MPD)

what was MPD replaced to

1 rem X h

what was the tolerance dose in 1934

.2 roentgen/day

in 1936 the tolerance was reduced to

.1 roentgen/day

what is threshold dose

dose of radiation below which an indvidual has negligible change of biological damage

when was MPD(maximum permissible dose) created and what did it represent

1950-1980; represented the maximum amount of radiaiotn that a personal can receive with minimal to no damage to human tissue

what was the calculation of MPD

5 Rem (n-18) = MPD; n represented the age ; number 18 meant the legal age to enter the profession

when was dose equivalency created

in the 1970

What did does equivalency allowed to do

allowed to compare the effect of radiation exposure from different type of radiation of tissue

why is dose equivalency used today

used today to measure rad (radiation absorb dose ) x a qualifying factor- represent the penetrability of the different types of radiation

alpha radiation does not

penetrate human tissue as much as x ray- therefore alpha would deposit more energy into human tissue as a pass through

x ray deposit 20 times less than alpha at the same amount of exposure

what is the qualifying factor for alpha and x ray

alpha factor of 20

x ray factor of 1

Rem represent

effective exposure

what was the type of tissue that was considered in 1977 thst was being radiated

Effective Dose Equivalency

Purpose of Effective Dose Equivalency

to figure out the average absorbed dose X weighting factor (Wr) for tissue

bones absorbes

more radiation then air in our lung and soft tissue- bone would have higher weighting factor and the effect of radiation would be greater; soft tissue eould allow greater penetration; deposting less energy

The ICRP in 1991 came up with

effective dose- takes into account the sensitivity of tissue

what does roentgen measure

the amount of ionization produced in air- related to the amount of radiation reaching or subjected to the person

RAD represent

the radiation absorbed dose.- the amount of energy that is absorbed in the tissue as it passes through

REM is what

a calculation of the potential effect of that absorb dose

SED, Roentgen, RAD, REM are

american units

the rest of the world us

system international ( metric system)

Roentgen is equivalent to

C/kg(air kerma)

what is coulamb

measurement of electrical charge

RAD is equivalent to

Gray

REM is equal too

Seivert

what is the Units of measure for exposure

Roentgen

Roentgen is the measure of

Roentgen measures

Ionization of air

x ray and gamma radiation

Exposure is what

the amount of radiaiton a person is SUBJECTED or EXPOSED to; it is what reaches the person not what enters or absorbed

1 Roentgen is equivalent to

n2.58 x 10^-4 C/kg of dry air

if you take away x 10^-4 what would the number be

.000258 C/kg ( very small amount of electrical charge)

what is the only way to detect exposure

using ionization chamber

What is Air Kerma?

A new SI unit that is used to express the amount

of radiation transferred to the patient’s skin

(ionization in air)

What is the SI unit for Air Kerma?

Gray (Gy), which is equal to joules per kilogram (J/kg).

What older unit is Air Kerma replacing?

Coulombs per kilogram (C/kg), a unit of radiation exposure.

What does Air Kerma measure?

The amount of kinetic energy released by radiation in air.

What is Air Kerma used to express in radiography?

X-ray tube output and radiation levels at the image receptor (IR).

What does DAP stand for?

Dose Area Product.

What is the purpose of DAP?

To measure radiation output across the exposed area, helping monitor patient radiation exposure.

What equipment can have sensors that measure DAP?

Radiographic and fluoroscopic equipment.

What does J/kg stand for?

Joules per kilogram.

Why is Air Kerma important in radiography?

It helps measure radiation output and assess patient radiation exposure.

what is absorbed dose measured

by RAD radiation absorbed dose

Radiation absorbed dose measured

The amount of energy deposited in irradiated deposited in irradiated object per unit mass(ionizing raditon)

the exposure will reach the pt but what will the x ray do

penetrate the person but not 100%

the denser an object is

the greater the absorption of radiation will be

What are the units used to measure dose equivalent?

Sievert (Sv) and REM.

What does REM stand for?

Radiation Equivalent Man.

What is dose equivalent (DE)?

A measurement used to calculate the biological effect of absorbed doses from different types of ionizing radiation.

What is the formula for dose equivalent?

DE = Absorbed Dose × Quality Factor.

What is the formula for dose equivalent using RAD?

DE (REM) = RAD × Quality Factor.

ex: DE = 5 RAD x 1 (x-ray)   =  5 REM

What is the formula for dose equivalent using Gray?

DE (Sv) = Gray × Quality Factor.

ex:DE = 5 Gray x 20 (alpha) = 100 Sv

What is the quality factor for X-rays?

1.

What is the quality factor for alpha radiation?

20.

Which type of radiation causes more biological damage to the same tissue for the same absorbed dose: X-rays or alpha particles

Alpha particles because they have a higher quality factor (20).

Why is the quality factor important?

accounts for differences in the biological effects of different types of radiation.

What is the difference between RAD and REM?

RAD measures absorbed radiation dose, while REM measures dose equivalent, accounting for biological effectiveness.

What is the difference between Gray and Sievert?

Gray measures absorbed dose, while Sievert measures dose equivalent

what are the qualifying factors

1   = x-ray, beta, gamma,

           high energy external protons

2   = low energy internal protons

5   = thermal neutrons (slow)

20 = alpha particles, fast neutrons,

          unknown energies

X ray is created by

electron displacement within the x ray tube

Gamma

short wavelength, high energy electromagnetic waves emitted by nuclei of radioactive substances - comes from displacement of neutron

Beta are

high speed electrons or positrons- created in a artificial reaction

alpha are

a positively charged particle ejected by certain radioactive elements consists of 2 protons and 2 neutrons

Protons and neutrons are ejected by

Nucleus - done in nuclear reaction

100 Rad=

200RAD=

1 Gray

2 Gray

100 rem=

300 rem=

1 Sievert

3 Sievert

what are in radiation Quantities

Exposure

Absorbed Dose

Dose Equivalency

Equivalent Dose

Effective Dose

Collective Effective Dose

what is exposure and what does it do and what does it messure

is Ionization in air and it is adding or removing electrons from atoms and are measured in Roentgen

what is absorbed dose, where does it transfer and what is it measured

the amount of energy deposited in irradiated object per unit mass (ionizing radiation)’ transfer of energy to tissue and it is measured in RAD

what is dose Equivalency, what is the formula and what is it measured in

• method to calculate the effect of absorbed dose for all types of ionizing radiation-takes into consider the different absorption characteristic of each type of radiation

• formula :DE = RAD x Qualifying factor

• measured in REM

what is Equivalent Dose (Ht)

the product of the average absorbed dose in a tissue or organ in the human body

in the Equivalent Dose (Ht) what is being consider

Weighting Factor (W_R)-for the type of tissue

Equivalent Dose (Ht) formula

ED = RAD x WF     same as    H_T = D x W_R

ED = Gray x WF     same as    H_T = D x W_R

what id the Equivalent Dose Calculation

pH_T = D x W_R

  SV = Gray x WF

Effective Dose (E) provides

the measure of the overall risk of exposure to different tissue

Effective Dose (E) is consider and what is the formula

Tissue weighting factors (W_T)

E   = D X W_R X W_T  

_ex:ei.)  E = 5 gray (xray) x 1 x .20 (gonads) = 1 sv

Tissue Weighting Factor for gonads

.20

Tissue Weighting Factor for Red bone marrow,colon,lungs,and stomach

.12

Tissue Weighting Factor for bladder,breast,liver,esophagus,thyroid and other

.05

Tissue Weighting Factor for skin and bone surface

.01