Introduction to Radiography

A set of vocabulary flashcards covering the history of radiography, x-ray production, electromagnetic energy, and radiographic equipment based on the provided lecture notes.

Wilhelm Conrad Roentgen

The physicist who discovered x-rays on November 8, 1895, at the University of Würzburg.

Crookes tube

A cathode ray tube used by Roentgen during his initial experiments with x-radiation.

H.C. Snook

An x-ray pioneer who developed the interrupterless transformer for use with alternating current generators.

Thomas Edison

The inventor of the first fluoroscope who experimented with many different fluorescent materials.

Clarence Dally

Assistant to Thomas Edison and the first recorded x-ray fatality in the United States, dying in 1904 from radiation exposure.

Michael Pupin

The individual who demonstrated the use of fluorescent screens, now called intensifying screens, to reduce x-ray exposure time.

William Coolidge

Designer of the hot cathode x-ray tube, introduced in 1910, which became the prototype for modern x-ray tubes.

George Eastman

The inventor who produced the first radiographic film in 1914, using cellulose nitrate instead of glass.

Image receptor (IR)

A device that receives the radiation exiting the patient and records the latent image.

Latent image

The pattern of exposure on the image receptor that exists before it is processed into a visible radiographic image.

Cathode

The electrically negative end of the x-ray tube that serves as the source of electrons.

Filament

A wire made of tungsten located in the cathode that releases electrons when heated.

Space charge

The electron cloud formed around the filament when electrons are released from tungsten atoms.

Anode

The electrically positive end of the x-ray tube containing the target where x-rays are generated.

Tungsten

The element used for both x-ray tube filaments and targets due to its high melting point and large atomic number of $74$.

High-voltage transformer

The component that provides the high potential difference (voltage) required for x-ray production.

Amplitude

The height of a wave, measured as the distance from the resting position to the crest or valley.

Wavelength ($\lambda$)

The distance between corresponding points on consecutive waves, such as crest to crest.

Frequency

The number of waves passing a specific point per second.

Inverse relationship

The relationship between wavelength and frequency where a short wavelength results in a high frequency.

Photon

The smallest unit or quantum of electromagnetic energy, often described as a tiny bundle of energy.

Ionizing radiation

Electromagnetic radiation, including x-rays and gamma rays, with enough energy to cause ionization of atoms.

Wave-particle duality

The principle that x-rays possess characteristics of both waves and particles.

Attenuation

The reduction of the x-ray beam intensity as it passes through matter due to absorption.

Remnant radiation

Also known as exit radiation, this is the radiation that remains after passing through the body to reach the image receptor.

Fluorescence

The process by which certain crystals produce visible light when exposed to x-rays.

Primary radiation

The usable x-ray beam that is produced at the focal spot of the x-ray tube and travels toward the patient.

Central ray (CR)

The imaginary line through the geometric center of the x-ray beam and perpendicular to the tube axis.

Radiation field

The cross-sectional area of the x-ray beam.

Collimator

A device attached to the tube housing that uses lead shutters to restrict the size and shape of the radiation field.

Scatter radiation

Radiation that is created when the primary beam interacts with matter and travels in unpredictable directions with less energy.

Detent

A mechanism that stops a moving part, such as the x-ray tube, at a specific preset position for alignment.

Trendelenburg position

A position achieved with a tilting table where the patient's head is lowered at least $15^{\circ}$ below the feet.

Grid

A device placed between the patient and the IR to absorb scatter radiation and prevent image fog.

Bucky

A moving grid device that includes a tray to hold the image receptor and prevents grid lines from appearing on the image.

Milliamperage (mA)

The control that sets the rate of x-ray production and determines the focal spot size.

Kilovoltage peak (kVp)

The control that determines the wavelength, energy, and penetrating power of the x-ray beam.

mAs

The product of milliamperage and exposure time, which determines the total quantity of radiation produced.

Fluoroscopy

A technique that allows the visualization of internal anatomy and movement in real time using a continuous x-ray beam.

Fluoroscopy timer

A safety device that triggers an alarm after $5\,minutes$ of fluoroscopy to encourage the reduction of radiation exposure.