RAD 300: Intro to Radiology

energy

capacity or ability to do work

what are the major forms of energy? (5)

1. mechanical

2. electrical

3. heat

4. nuclear

5. electromagnetic

radiation

energy transmitted from one location

types of radiation (4)

1. electromagnetic radiation

2. acoustic radiation (sound)

3. partical radiation (alpha radiation)

4. gravitation radiation

electromagnetic radiation

type of energy that travels through space as waves of electric and magnetic fields.

frequency

number of times something occurs

wavelength

distance from one point to the next point

ionizing radiation

any radiation that has the ability to knock an electron out of order, creates anions and cations, lead to harmful effects causing biological changes, AKA radiation dose

electromagnetic spectrum

gamma, high energy ultraviolet, xray

non-ionizing radiation

any radiation that does not knock electron out of order

particulate radiation

alpha (severe damage but can’t pass through paper) and beta particles- come from nucleus, gamma radiation (gamma rays)- travels longest bust also the weakest, neutrons strongest do not travel far

where are protons located in an atom?

nucleus: positive charge

where are neutrons located in an atom?

nucleus

where are electrons found in an atom?

orbiting the nucleus (in motion)

what are the sources of radiation?

natural (background) and man-made (artificial)

sources for natural radiation (3)

terrestrial, cosmic, internal source of radionuclides

terrestrial radiation

long lived radioactive elements. EX: uranium 238, radium 226, thorium 232

8% common exposure except radium

radon

colorless, odorless, and heavy radioactive gas in air.

enters buildings through cracks in foundation or framework

second leading cause of lung cancer in smokers and leading cause of lung cancer in on smokers

55% of common exposure

cosmic and galactive radiation

result from nuclear inter actions in the sun and other stars (natural)

cosmic rays vary with altitude relative to earth’s surface, occurring at higher attitudes and lowest at sea level.

our atmosphere and magnetic field shield it from cosmic rays,

8% of common exposure

internal source of radiation

radioactive atoms that make up sm percentage of body’s tissue; tissues of human body contain many naturally radionuclides that have been ingested from food or inhaled as particles in the air, 11% of common exposure

radionuclides

unstable nucleus that emits one or more forms of ionizing radiation to achieve greater stability

types of man-made radiation (6)

1. consumer products containing radioactive material

2. medical radiation

3. air travel (plane)

4. nuclear fuel (generating power)

5. atmospheric fall out

6. nuclear power plant accidents

consumer products that contain radioactive materials

close and timepieces, gemstones, smoke detectors, exit signs, TSA

air travel

man-made radiation: plane encapsulates radiation energy to power plane

medical radiation

nuclear fuel

nuclear power plants use uranium-235 as fuel, atoms of isotope split apart in controlled chain reaction within the reacctor core

atmospheric fall out from nuclear weapons and nuclear power

like Oppenheimer (catastrophe)

measuring radiation in the air

what: ionization in air

measurement: Rotengen (R)

systems international: coulombs per kilogram (C/kg)

type of radiation that use this unit: xray and gamma ONLY

measure radiation in tissue

what: absorption fo radiation in matter (any object)

measurement: Radiation absorbed dose (RAD)

systems international: GRAY (Gy)

type of radiation that use this unit: any ionizing radiation

measure radiation biological effect

what: biological effects on body tissue

measurement: Radiation equivalent man (REM)

systems international: sievert (Sv); PER YR ONLY 50 miliSv

type of radiation that use this unit: any ionizing radiation

measure radioactivity

what: radioactivity and how fast a radionuclide disintegrates in seconds (cath lab); any object

measurement: Curie (Cu)

systems international: becquerel (Bq)

type of radiation that use this unit: radioactive particles/radioactivity

biological effects at 0.25 Sv=25 REM

blood changes; leukemia low WBC=decreased immune system

biological effects at 1.5 Sv= 150 REM

nausea & diarrhea

biological effects at 2.0 Sv= 200 REM

erythema= reddening of the skin

biological effects at 2.5 Sv= 250 REM

temporary sterelization

biological effects at 3.0 Sv= 300 REM

50% pass away in 30 days

biological effects at 6.0 Sv= 600 REM

death…

as low as reasonably achievable

ALARA

how safe is radiation?

cumulative, there is no threshold, no SAFE dose of radiation

dosimeters

device measure the quantity of radiation received based on the conditions which radiographer was placed

cardinal rules of radiation protection: time

for pt: minimize length of exposure in the exposure beam

for radiographer: minimize the length of exposure in room when radiation is active, FLUOROSCOPY

cardinal rules of radiation protection: distance

for pt: max distance to lessen enterance or skin dose; increase distance = increase technique(radiation exposure)

for radiographer: max distance between radiation source and me; 6ft away, never hold the pt

cardinal rules of radiation protection: shielding

for pt: collimation, gonadal shielding over gonad or reproductive organs

for radiographer: collimation; aprons an thyroid shield during Fluoroscopic studies, stand behind fixed and mobile barriers

fluoroscopy

dynamic imaging, live x-ray beam, for physiology

what is on the fluoro machine to protect the operator?

bucky slot shield at least 0.25mm lead

spot image device curtain at least 0.25mm lead

xray beam: primary radiation

emerges from tube directed toward pt

xray beam; attenuated radiation

radiation that bases though matter to be absorbed or scattered

xray beam: absorbed radiation

absorbed radiation that cease to exist, deposited within the material, cumulative exposure, causes biological damage

xray beam: scattered radiation

change in original direction (random), no longer traveling in straight path, dangerous bc unpredictable

xray beam: exit remnant radiation

attenuated x-ray beam that emerges from the patient and travels towards the image receptor; less intense compared to primary beam.