Chapter 1

List five clinical skills required by the ARRT.

-Patient Care -Radiation Protection -Equipment Operation -Image Production -Equipment Maintenance -Radiographic Procedures **See pages 24 & 25 in the book for the full list

What is the velocity of the mobile x-ray imaging system if the hospital elevator travels 20 meters to the next floor in 30 seconds?

Distance divided by time = 20 m/30 s = 0.67 m/s.

Define or otherwise identify the following: Fluoroscopy

Imaging modality that provides a continuous image of the motion of internal structures while the x-ray tube is energized, with continuous low mA. Real-time imaging.

Match the following dates with the appropriate event: 1895

Roentgen discovers x-rays

Define or otherwise identify the following: The term applied to the chemistry of the body

Biochemistry.

Describe how weight is different from mass.

Weight is determined by the force of gravity. Weight changes in value with position in a gravitational field such as that of the Earth or the moon. Mass is constant. It is the quantity of matter contained in any physical object, and is independent of position and is determined by the object's energy equivalence.

A radiographer has a mass of 58 kg. What is her weight on Earth? On the moon?

Weight on Earth = 58 kg × 9.8 m/s2 = 568 N. Weight on the moon = 58 kg × 1.6 m/s2 = 93 N.

Place the following chronological order of appearance: a. Digital fluoroscopy b. American Society of Radiologic Technologists (ASRT) c. Computed Tomography (CT) d. Radiographic grids e. Automatic film processing

1. Radiographic Grids 2. American Society of Radiologic Technologists (ASRT) 3. Automatic film processing 4. Computed Tomography (CT) 5. Digital fluoroscopy

What percentage of average radiation exposure to a human is attributable to medical x-rays?

51% according to an estimate made in 2006 by the NCRP (National Council on Radiation Protection).

Define or otherwise identify the following: Barium Platinocyanide

A phosphor that glows when excited with x-rays. This is the phosphor with which Roentgen (while using the Crookes tube) was experimenting when he discovered x-rays.

Define or otherwise identify the following: Derived Quantity

Also known as secondary quantities, they are derived from a combination of one or more of the three base quantities (mass/length/time). Examples of derived quantities are energy, power, work, momentum, force, velocity, and acceleration.

Describe the process that results in the formation of a negative ion and a positive ion.

An x-ray, for instance, interacts with an orbital electron of an atom of tissue. The electron absorbs some energy from the x-ray and is released/ejected from the orbit of the atom. The orbital electron and the atom from which it was separated are called an ion pair; one electron is negative, and the remaining atom is positive.

Define or otherwise identify the following: Ionizing Radiation

Any electromagnetic or particulate radiation that has sufficient energy to remove an electron from an atom.

Define or otherwise identify the following: The average level of natural environmental radiation.

Approximately 300 mrad/yr. or 3 mSv/yr. It consists of four components - cosmic rays, terrestrial radiation, internally deposited radionuclides, and radon.

The acronym ALARA stands for what?

As Low As Reasonably Achievable.

What are the three natural sources of whole-body radiation exposure?

Cosmic rays, terrestrial radiation, and internally deposited radionuclides.

What are the four special quantities of radiation measurement?

Exposure Air Kerma Gya (R); Absorbed Dose Gyt (rad); Effective Dose Sv (rem); and Radioactivity Bq (Ci).

Name devices designed to minimize radiation exposure to the patient and the operator.

Filtration, collimation, intensifying screens, protective apparel, gonadal shielding, protective barriers.

What naturally occurring radiation source is responsible for radiation dose to lung tissue?

Radon 222, a gas.

Match the following dates with the appropriate event: 1901

Roentgen wins the first Nobel Prize in physics.

Liquid hydrogen with a boiling temperature of 77 K is used to cool some superconducting magnets. What is this temperature in degrees Celsius? In degrees Fahrenheit?

Temperature in °C = 77K - 273 = -196 °C. Temperature in °F = [(-196) × 1.8] -32 = -385 °F.

Match the following dates with the appropriate event: 1913

The Coolidge hot-cathode x-ray tube is introduced.

Match the following dates with the appropriate event: 1907

The Snook transformer is developed.

Define or otherwise identify the following: Energy

The ability to do work or physically influence surroundings because of position, chemical state, or nuclear state.

Define or otherwise identify the following: The Coolidge Tube

The first heated filament x-ray tube was developed by a physicist, William Coolidge, in 1913, allows x-ray intensity and energy to be selected separately and accurately.

Define or otherwise identify the following: Air Kerma

The kinetic energy transferred from photons to electrons during ionization and excitation; 1/1000 of a rad, where the rad (radiation absorbed dose) is 100 ergs (a unit of work or energy, equal to the work done by a force when its point of application moves one centimeter in the direction of action of the force.) of energy absorbed per gram of tissue.

Define or otherwise identify the following: Acceleration

The rate of change of velocity (speed and/or direction) with time.

What are the three units common to the SI (International System of Units) and MKS systems?

The three fundamental units of measurements common to the SI and MKS systems are: length (meters, m), mass (kilograms, kg), and time (seconds, s).

How would you define the term "radiation"?

The transfer of energy from one area or medium to another.

What is the purpose of x-ray beam filtration?

To keep low-energy x-rays from reaching the patient. Such x-rays do not reach the image receptor. Filtration results in lower patient radiation dose.

How is x-ray interaction different from that seen in other types of electromagnetic radiation?

X-rays interact at the electron level or nuclear level, ionizing an atom or ejecting a nuclear particle, respectively. Lower-energy electromagnetic radiation interacts with molecules, cells, and larger objects in a way that will usually elevate the temperature of the object.

Name four examples of electromagnetic radiation.

X-rays, gamma rays, visible light, radio waves (also microwaves, infrared radiation, ultraviolet radiation).