Lesson 1: X-ray Discovery and Early Medical Imaging

A vocabulary-style set of flashcards covering key terms and concepts from the lecture on X-ray discovery, early imaging technologies, and the advent of diagnostic ultrasound.

X-ray

A highly penetrating, invisible form of electromagnetic radiation that is electrically neutral, polyenergetic, capable of ionizing matter, travels at the speed of light, can affect photographic film, and cannot be focused by a lens.

Roentgen (X-ray discovery)

Wilhelm Conrad Roentgen’s 1895 discovery of X-rays; first radiographs; led to the term ‘X-ray’; Nobel Prize in Physics in 1901.

Crookes tube

A partially evacuated glass tube used in early cathode-ray experiments; capable of producing X-rays and a forerunner of modern X-ray tubes.

Barium platinocyanide screen

A fluorescent screen that glows when struck by X-rays, used to visualize X-rays in Roentgen’s experiments.

Intensifying screen (IS)

A screen that emits light when hit by X-rays, increasing image brightness and allowing lower X-ray exposure.

Double emulsion film

A radiographic image receptor with two emulsion layers, increasing sensitivity and image quality.

Fluoroscopy

Imaging technique using a fluorescent screen to view live X-ray images without film development.

Image receptor (IR)

Device that records the X-ray image (e.g., film with intensifying screens).

X-ray energy range (polyenergetic)

X-rays can be produced over a wide range of energies and wavelengths, known as polyenergetic radiation.

X-ray ionization and effects

X-rays can ionize matter and cause chemical/biological changes in tissues.

Fluorescence (emission of light)

X-rays induce fluorescence in certain crystals, such as barium platinocyanide.

Nobel Prize for Physics (1901)

Roentgen received the first Nobel Prize for Physics for the discovery of X-rays.

Snook Transformer

A high-voltage power supply used to generate X-rays efficiently.

Coolidge X-ray Tube

Vacuum tube with a hot cathode allowing independent control of X-ray energy and intensity (advancement over the Crookes tube).

Collimation

Restriction of the useful X-ray beam to the body part of interest to image; reduces exposure and improves image quality.

Filtration

Insertion of metal filters (e.g., aluminum or copper) in the tube housing to absorb low-energy X-rays before reaching the patient.

Gustav Bucky

Physicist associated with grid development in radiography; contributed to stationary grids.

Hollis E. Potter

Inventor of the moving grid used to reduce scatter in radiography.

Potter-Bucky grid

Grid system combining Potter’s moving grid with Bucky's stationary grid to reduce scatter; introduced around 1921.

First X-ray fatality (1904)

The first recorded death resulting from X-ray exposure, highlighting radiation hazards.

Clarence Dally

Edison's assistant; experienced a severe X-ray burn leading to amputations; early radiation injury case.

William Rollins

Early radiologist who emphasized collimation and filtration to minimize patient exposure.

Homer Clyde Snook

Pioneer in radiology associated with early X-ray equipment development (including the Snook Transformer).

Diagnostic Ultrasound

Imaging modality appearing in the 1960s that uses high-frequency sound waves (>20 MHz); non-ionizing, portable, inexpensive, and good for soft tissues.

Michael Pupin

demonstrated the use of intensifying screen

Charles Leonard

he demonstrated the use of double emulsion film

Thomas A. Edison

invented fluoroscopy

Clarence Dally

edison’s assistant and first xray fatality

William Rollins

he demonstrated collimation and filtration

Homer Clyde Snook

he introduced the Snook Transformer

William Coolidge

Invented the coolidge tube

Gustav Bucky

stationary grid

Hollis E. Potter

moving grid

1950s

appearance of diagnostic ultrasound

On a New Kind of Rays

Roentgen’s original paper

Hand of his wife, Set of weights, compass, piece of metal

first four radiograph

December 28, 1895

publication of Roentgen’s paper

Polyenergetic

variety of energy

Low Energy Xrays

what does filtration absorb?

Anna Bertha Ludwig

wife of Roentgen

30-150 keV

common for diagnostic xrays

200-250 keV

common for orthovoltage xrays

phosphor

other term for screen

November 8, 1895

discovery of xrays

Wurzburg University

roentgen’s university

anode

positive

cathode

negative

Lead

protection to radiation

Primary, Scatter, Leakage

types of radiation