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TYPES OF X-RAY

Characteristic, bremsstrahlung

Types of radiation

Ionizing, Non ionizing

Types of ionizing

Particulate, non particulate

Types of particulate

Alpha, Beta, neutron, proton, deutron, electron, di meason

Types of electromagentic radiation

Gamma rays, Xrays

Main sources of radiation

Man made, Natural

82% radiation acquired, 60% externally, 22% internal

Natural Radiation

Annual dose of natural radiation (MSV is the unit of effective dose)

3 millisiever

Four components of natural radiation

Cosmic rays, terrestrial radiation, internally deposited radionuclides, Radon

are particulate and electromagnetic radiation emitted by the Sun and Star, including Carbon 14.

Cosmic Rays

is more intense at higher elevations. For example, living in highaltitude regions or frequently traveling by airplane increases your exposure to

Cosmic Radiation

are deposits from Uranium, Thorium, and other radionuclides in the Earth

Terestrial Radiation

are those we actively take in and ingest natural radioactive elements through our daily diet and the air we breathe.

Internally Deposited

from the organic food the we eat, an environmental radiation that is a natural metabolites and have always been with us.

Pottassium-K40

the largest source of natural environmental radiation. a radioactive gas that is produced by the natural radioactive decay of uranium, which is present in trace quantities in the earth

Radon

16% of radiation acquire diagnostic x-ray costitute the largest man-made source of ionizing radiation , has an approximate annual dose of 3.2 mSv.

Man made radiation

NCRP Meaning

National Council on Radiation Protection and Measurements

What year NCRP made the estimate annual dose of 3.2mSv/year in 2006, from 0.5 mSv/year in

1990

is a measure of the rate at which energy is transferred from ionizing radiation to soft tissue

LET

is expressed in units of kiloelectron volt of energy transferred per micrometer of track length in soft tissue (keV/µm)

LET

effect or response is quantitatively described by the

RBE

the ability of ionizing radiation to produce a ____ increases as the LET of radiation increases.

biologic response

occurs within hours after a whole-body absorbed dose of 1 Gyt or more.

Prodromal stage

It is during this period that either recovery or lethal effects begin

Latent Period

Stages of Acute Radiation lethalit

Hematologic, Gastrointestinal, Cerebrovascular

TYPES OF BIOLOGICAL EFFECT

Occurence, Dose, Syndrome

whoever receives the radiation, will manifest the effect

SOmatic effect

large doses received in short period. - ex. 200Gy in 2 minutes will result to DEATH

Early (Acute)

low dose received repeatedly over a long period of time. - ex. Cataract, Cancer

Late (chronic)

Also called as stochastic effect appear as a late radiation responses years later effect for the dose received will be transferred to the offspring.

Genetic effect

also known as late, low dose, non-deterministic, and probabilistic response follows a linear non-threshold dose response

Stochastic effect

also known as early, high dose, and non-probabilistic response exhibit a dose threshold; there is a dose below which no response occurs. Threshold, Non-linear dose-response relationship

Deterministic effect

What is the most devastating response of high dose radiation?

ARS

are sequences of events that follow high-level radiation exposure leading to death within days or weeks. aka: Radiation “Hangover”

Acute radiation syndrome

LET meaning

Linear Energy Transfer

also known as bone marrow syndrome

Hematopoietic syndrome

Critical organ for hematopoietic syndrome

Bone marrow

Threshold dose for Hematopoietic syndrome

>2-10 GYt

IN rad Hematopoietic syndrome

200-1000

Mean survival time for Hematopoietic syndrome

2-4 weeks or 6 months

Severe nausea, vomiting, and diarrhea persist for as long as 24 hours

Gastrointestinal Syndrome

Gastrointestinal Syndrome Critical organ

Small intenstine

Gastrointestinal Syndrome Threshold dose

>10-50 GYt

Mean sruvival time for Gastrointestinal Syndrome

4-10 days

Cerebrovascular syndrome critical organ

Brain

Cerebrovascular syndrome threshold dose

>50 Gy

Cerebrovascular syndrome Rad

>5000 Rad

Mean survival time for Cerebrovascular syndrome

0-3 Days

Rad for gastrointestinal syndrome

1000-5000 rad

Mean survival time for Cerebrovascular syndrome

0-3 Days

ARS (acute radiation syndrome)results when the central nervous system and cardiovascular system receive doses of

50 Gyt or more

Is defined simply as effective measures employed by radiation workers to safeguard patients, personnel, and the general public from unnecessary exposure to ionizing radiation.

Radiation protection

Getting or acquiring an accurate diagnosis while keeping radiation exposure as low as possible.

Diagnostic Efficacy

produce high-quality, essential images on the first exposure to avoid repeating scans.

The goal

Decides if the procedure is medically necessary.

Physician

Ensure high-quality imaging and keep radiation doses well below maximum limits.

Radiographer and radiologist

Eliminating mistakes or carelessness prevents unnecessary radiation risk to both patients and staff.

Everyone

ALARA MEANING

As low as reasonably achievable

Orp meaning

optimization for radiation protection

What is the cardinal rule of radiation protection

Time, Distance, Shielding

Nausea, Vomiting, Diarrhea, Anemia, Leukopenia, Hemorrhage, Fever, Infection

Hematologic Syndrome

Same as Hematologic plus Electrolyte Imbalance, Lethargy, Fatigue, Shock

GI Syndrome

Same as GI plus Ataxia, System Vasculitis, Meningitis

CNS Syndrome

The RBE of diagnostic x rays is?

1

occurs within hours after a whole-body absorbed dose of 1 Gyt or more.

Prodromal stage

Prodromal is dose related the higher the dose?

The severe the symptoms

nausea, vomiting, diarrhea, and a reduction in the white cells of the peripheral blood (leukopenia)

PRODROMAL SYNDROME

during this time, the subject is free of visible effect. it is during this period that either recovery or lethal effects begin.

Latent period

the period when signs and symptoms involving the hematopoietic, GI, and cerebrovascular syndrome become visible.

Manifest ilness

Types of biological effect

Occurence, Dose , Syndrome

whoever receives the radiation, will manifest the effect

Somatic effect

Minimize the amount of time you are exposed to a radiation source.

Time

Maximize your distance from the radiation source

Distance

which states that doubling your distance from a radiation source drops your radiation exposure to one-quarter (25%) of the original intensity

Inverse square law

Place an appropriate protective barrier between yourself and the radiation source. Materials with high atomic numbers and densities (like lead or concrete) absorb the primary and scatter X-ray photons before they can strike human tissue.

Shielding

ICRU MEANING

International Commission on Radiation Units and Measurement

Exposure unit

Roentgen

EXposure symbol

R

Exposure SL symbol

Gya

Exposure Sl Unit

C/Kg

based on a response produced when radiation interacts with air

Exposure

Absorbed Dose (rad) SI Unit

Gray

Absorbed Dose (rad) SI symbol

Gyt

energy transferred by IR to the interacting medium per unit mass

Absorbed Dose (rad)

Effective Dose (rem) SI unit

Sievert

Effective Dose (rem) Sl symbol

Sv

radiation exposure received by radiation workers

Effective Dose (rem)

was the minimum dose of radiation, that on light of knowledge , would be expected to produce significant radiation effects

MPD ( Maximum Permissible Dose )

current DLs ( Dose limits ) are prescribe for various organs as well as whole body, and for various working conditions so that the lifetime risk from each year’s occupational radiation dose exposure does not exceed 10 years , 1 in 10,000

Whole body effective dose limit

the first dose limit 50,000 mrem / week (500 mSv/week) was recommended in what year?

1902

50 mSv / yr ( 5000 mrem/yr )

Basic annual DL

DL for the lens of the eye

150 mSv / yr ( 15,000 mrem /yr).

DL for other organs

500 mSv/yr (50,000 mrem/yr ).

Commulative whole body DL

10 mSv ( 1000 mrem) / yr.

DL during pregnancy once pregnancy is declared, the monthly exposure should not exceed 0.5 mSv ( 50 mrem )

5 mSv ( 500 mrem) yr.

Dl for the skin and extremeties

500 mSv / yr. (50,000 mrem ) yr

Individuals in the general population are limited to

5 mSv/yr (500 mrem/yr)

if the exposure is frequent, such as hospital workers who may gradually pass by x-ray room.

DL is - 1mSv/yr (100 mrem/yr).

is the DL that physicist use when computing the thickness of protective barriers.

1 mSv /yr (100 mrem/yr)

Student radiographers under the age of 18 may not receive more than

1 mSv/yr (100mrem