Radiography (quiz 1)

questions i got wrong

A circular collimator produces a cone-shaped beam that is how many inch(es) in diameter?

2.75inches

Where is a film badge worn?

is worn at waist level by the operator.

What is a radiograph defined as?

an image or picture produced on a receptor by exposure to ionizing radiation

what does mpd stand for in radiation

maximum permissable dose

what does msv stand for and what is it used to measure?

millisieverts, a unit used to measure the amount of ionizing radiation absorbed by the body

whats the current mpd for an occupationally exposed pregnant woman?

5 millisieverts annually or 0.5 per month

According to the dose-response curve, when dose and damage are plotted on a graph, what type of relationship is seen and why?

a linear nonthreshold relationship, because a linear relationship indicates that the response of the tissues is directly proportional to the dose and a nonthreshold relationship indicates that a threshold dose level for damage does not exist

what is the latent period in regards to radiation?

the time between exposure to ionizing radiation and the manifestation of symptoms or a disease

what cellular injuries may follow the latent period after radiation?

cell death, cessation of mitotic activity, abnormal mitotic activity

what is mitotic activity?

the presence of actively dividing cells or the making of new cells

Current fast radiographic film requires ____% less exposure time than the initial exposure times used in 1920

98 percent

Explain to your patient the steps, in order, in the formation of hydrogen peroxide, a toxin that will cause damage to living tissues

4. X-ray photons are absorbed by water in the cells (ionization), 2. Free radical formation which is the creation of highly reactive molecules , 1. Free radicals combine with each other to stabilize themselves, 3. Cellular dysfunction and biologic damage is done by putting oxidative (loss of electrons) stress on the cells

What is the conversion of 1 gray to rads?

100 rads

Radiation is defined as

a form of energy carried by waves or streams of particles

State and federal laws require that dental x-ray machines operating above 70 kVp have a minimum total (inherent plus added filtration) of ____ mm of aluminum filtration.

2.5mm

what are stochastic biological effects?

they occur as a result of exposure, but severity is not determined by dose

ex. a cancer caused by a low dose of radiation is no less severe than a cancer caused by a high dose

The ALARA concept states that all radiation must be kept

as low as reasonably achievable

The SI equivalent of the conventional unit rem is ___, and what is it measuring?

the sievert, Biological risk or dose equivalent

The SI equivalent of the conventional unit rad is ___, and what is it measuring?

gray, Absorbed radiation dose

The SI equivalent of the conventional unit roentgen is ___, and what is it measuring?

coulomb per kilogram, Radiation exposure

The acronym for the maximum dose equivalent that a body is permitted to receive within a specific period is the

MPD, max permissable dose

why was the bomb at nagosaki and hiroshima considered longterm and somatic for radiation exposre

survivors of the bombings were exposed to a single, high-dose event. While many died immediately from the blast and heat, others received high enough doses of radiation to cause health problems that developed over a long period, which is known as a long latency period, somatic because the damage occurred in the somatic cells (body cells) of the exposed individuals, rather than their germ cells (sperm or egg), meaning the effects are limited to the exposed person and are not inheritable

The potential risk of dental radiography inducing a fatal cancer in an individual is about _________ the risk of a person developing cancer spontaneously

1/1000

The thyroid collar is recommended for

all intraoral exposures

what is the difference between the traditional units of rad and roentgen?

rad is the traditonal unit of dose while roentgen is the traditional unit of exposure for xrays,

The use of F-speed film instead of D-speed film reduces the absorbed dose by ____%.

60 percent

Who was the xray discovered by on nov 8, 1895?

William Roentgen

who built the first vacuum tube in 1838?

Heinrich Geissler

Who observed in 1870 that discharges emitted from the negative electrode of a vacuum tube traveled in straight lines, produced heat, and resulted in a greenish fluorescence?

Johann Hittorf

Who discovered in the late 1870s that cathode rays were streams of charged particles?

William Crookes (was before the discovery of the xray)

Uranium is an example of __________ radiation.

terrestrial (comes from earth/dry land)

Which discovery was the precursor to the discovery of x-rays?

cathode rays

Which of the following can you do after x-ray receptor exposure to reduce(s) the amount of x-radiation your patient receives?

Proper instrument technique

Which of the following cells would be the most sensitive to x-rays?

blood cells

what is a sign or symptom of acute radiation syndrome (ARS)?

hair loss

what is an example of stochastic effects?

cancer

what is associated with long-term radiation effects?

small amounts of radiation absorbed over a long period

what is true of somatic effects of irradiation?

Changes are not transmitted to future generations

what is true of the average dose of background radiation received by an individual in the United States?

Geographic areas at higher elevations are associated with increased amounts of cosmic radiation

what type of position-indicating devices (PIDs) produce excess scatter radiation?

conical but it is not longer used in dentistry

Which type of PID would be most effective in reducing patient exposure?

A 16-inch rectangular PID

Which types of cells are more sensitive to radiation: (1) rapidly dividing, (2) slowly dividing, (3) young, and/or (4) old?

1 and 3, this si because cells are more vulnerable during cell division and young cells are more sensitive than mature or specialized cells

Who exposed the first dental radiograph in the United States using a live person

Edmund Kells

Who modified the paralleling technique with the introduction of the long-cone technique?

F. Gordon Fitzgerald, this led to less distortion and better images

You are 36 years old. What is your cumulative occupational dose recommended by the National Council on Radiation Protection and Measurements (NCRP)?

360 mSv

Your patient is receiving radiation treatments for breast cancer. She reports having a burning sore throat and great difficulty swallowing. Which stage of the radiation injury sequence is your patient in?

injury

___________ refers to the total amount of radiation that is received or absorbed.

Total dose

________________ is/are the single largest contributor to artificial radiation exposure (0.00053 Sv/year).

Medical radiation