✨✨✨✨DH103 Dental Radiology quiz# 3 Module #4

Radiation is defined as

a form of energy carried by waves or streams of particles.

A radiograph is defined as

a picture on film produced by the passage of x-rays through an object or body.

Your patient asked you why dental images are important. Which of the following is the correct response?

Many dental diseases are typically discovered only through the use of dental images.

The x-ray was discovered by

Wilhelm Roentgen

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

Which of the following is an advantage of digital imaging?

Increased speed for viewing images

The fundamental unit of matter is the

atom.

The nucleus of an atom contains

protons and neutrons.

Which subatomic particle carries a negative electrical charge?

An electron

Which of the following statements is true of orbits or shells in the atom?

The orbiting shell closest to the nucleus has the highest energy level.

The binding energy or binding force of an electron is

determined by the distance between the orbiting electrons and the nucleus.

Which of the following statements is true of ionization?

An atom that gains an electron has a negative charge, and an atom that loses an electron has a positive charge.

An ion pair results when

an electron is removed from an atom.

Which of the following statements is true of ionizing radiation?

It is radiation that is capable of producing ions by removing or adding an electron to an atom.

Which of the following forms of electromagnetic radiation are capable of ionization?

X-rays

Photons are

a component of the particle concept of electromagnetic radiation.

Which of the following statements is true of the wave concept of electromagnetic radiation?

Frequency and wavelength are inversely related.

Which of the following components of the x-ray machine would have two indicator lights?

The control panel

Heat is a byproduct of x-ray production. Which component of the x-ray tubehead dissipates the heat created by the production of x-rays?

Insulating oil

Within the x-ray tube, electrons are generated by the

tungsten filament in the cathode.

The purpose of the anode is to

convert electrons into x-ray photons.

In the dental x-ray tube, the number of electrons created is controlled by

milliamperage.

Thermionic emission of electrons occurs at the

tungsten filament in the cathode.

Approximately what percentage of the kinetic energy of the electrons is converted to x-rays at the anode?

Less than 1%

The lead collimator

restricts the size of the x-ray beam.

Which of the following statements is true of characteristic radiation?

It only occurs at 70 kV and above.

Which form of the x-ray beam is most detrimental to the patient and operator?

Scatter radiation

Which is the most common possibility when an x-ray photon interacts with matter?

Compton scatter

Which of the following four possibilities that can occur when an x-ray photon interacts with matter is responsible for producing densities on a dental receptor that make dental radiography possible?

No interaction

(1) X-ray photon production occurs as a result of both general and characteristic radiation. (2) General radiation accounts for a small number of x-ray photons produced because it takes high kV to dislodge the electrons from the K shell.

The first statement is true; the second statement is false.

Interaction with the x-ray photon as a result of the photoelectric effect is harmful to the patient because ionization occurs.

The statement is true.

Which would you adjust if you wanted to create a larger electron cloud?

Milliamperage

Which would you adjust if you wanted to produce characteristic radiation?

Kilovoltage

Which property of x-rays allows for the image on the receptor?

Penetrating power

In dental radiography, the term ________ is used to describe the mean energy or penetrating ability of the x-ray beam.

quality

Which of the following statements is true of wavelength in reference to radiation?

X-rays with longer wavelength have less penetrating power.

______________ is a measurement of force that refers to the potential difference between two electrical charges.

Voltage

When contrasted with the use of 70 kV for dental x-rays, the use of 60 kV produces

less penetrating dental x-rays with longer wavelength.

When kilovolt is increased, a

higher energy x-ray beam with increased penetrating ability results.

(1) Density is the overall darkness or blackness of a dental image. (2) When the kilovoltage is increased while other exposure factors remain constant, the resultant image exhibits a decreased density and appears lighter.

The first statement is true; the second statement is false.

Milliamperage regulates the _________ of electrons produced at the cathode filament.

quantity

In regard to increasing density

an increase in either kV or mA will increase density.

Which of the following changes will increase x-ray beam intensity?

Decreasing the source-to-film distance

Aluminum filters are used to remove _______-energy, ________ wavelength x-rays.

low; longer

Aluminum filters

reduce the intensity of the x-ray beam.

You have been using a dental x-ray machine that has a 4-inch PID. Your new machine has an 8-inch PID. Given that all exposure factors remain the same, according to the inverse square law, the resultant beam would be ___________ as intense.

one quarter

(1) As kilovoltage, milliamperage, and time increase, x-ray beam intensity decreases. (2) As distance and filtration increase, the intensity of the x-ray beam increases.

Both statements are false.