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x-rays

___ are a form of invincible radiant energy discovered by Wilhelm Conrad Roentgen on November 8,1895:

Crookes tube (Hittorf tube)

the first x-ray tube of Roentgen:

Crookes tube (Hittorf tube)

the ___ consisted of a pear shape glass tube filled with air under reduced pressure:

glass tube

the part of the x-ray tube that is evacuated to high vacuum:

cathode

the part of the x-ray tube that is negative and contains the filament and focusing cup:

anode

the part of the x-ray tube that is positive and contains the x-ray target:

Coolidge hot cathode x-ray tube

the ___ made the possible generation of a constant source of x-rays that could be easily duplicated at will:

Dr. W.D. Coolidge of the General Electric Company

Dr. William David Coolidge

the inventor of the Coolidge tube:

December 27, 1913

the date when the Coolidge tube was announced:

cathode (negative electrode)

the source of electrons:

anode (positive electrode)

the source of x-rays:

incandescent filament of tungsten wire

the ___ is incorporated in the cathode and is heated by a current of low voltage step-down transformer:

rotating anode tube

the ___ is shaped like a disc and is composed of a metal with good heat and electron conducting characteristics:

molybdenum

a metal with good heat and electron conducting characteristics used in the rotating anode tube:

tungsten and rhenium

the coating used on the front surface of the rotating anode tube:

rotor

the front surface of rotating anode tube is connected to the ___:

1) vacuum

2) heated cathode

3) rotating cathode

the three essential components to the modern x-ray tube:

tungsten (74)

rhenium (75)

___ are used as target material on the anode:

photon

the word that is often used to denote a single x-ray:

bremsstrahlung (braking) radiation

an interaction in the anode wherein the electron passing near the atomic nucleus slows down due to the positive attraction of the nucleus:

more than 95%

bremsstrahlung radiation accounts for ___ of the total x-ray beam:

characteristic radiation

> an interaction in the anode wherein the high speed electron interact with one of the orbital electrons in the atomic shell

> outer shell electrons fill inner shell vacancies

x-ray beam spectrum curve graph

the ___ are used plot the amount of x-ray against their energy and demonstrate the effects of different changes:

1) primary beam

2) remnant beam

the parts of the x-ray beam:

primary beam

the beam that is confined to the portion of the x-ray beam emitted from the x-ray tube:

remnant radiation

___ is the radiation that emerges from the body tissue to expose the x-ray film and record the radiographic image:

attenuation (absorption)

> the reduction in x-ray beam intensity that occurs when the x-ray beam transverses the body part

> influenced by atomic number, tissue density, thickness and wavelength of radiation

subject contrast (tissue differences)

> represent the difference in x-ray absorption occurring in an anatomical part

> the greater the absorption of tissue, the greater the ___, and vice versa

central ray (CR)

the center of the x-ray beam:

focal spot (FS)

the specific area on the target surface of the x-ray tube anode which is bombarded by the speed electron:

focus-film distance (FFD)

the entire distance transversed by the central ray:

kilovoltage-peak (kVp)

the energy level or pressure with which the electricity is being forced through the machine across the x-ray tube:

milliampere (mA)

the unit for measuring the flow rate of electricity passing through the x-ray machine and across the x-ray tube:

milliampere-seconds (mAs)

the total exposure to an x-ray film that is controlled by the product of mA and exposure time:

object-film distance (OFD)

the distance from the object or body part to the x-ray measured along the course of the central ray:

primary radiation (PR)

the beam projected from the focal spot of the x-ray tube to the object:

remnant radiation (RR)

the beam emanating from the object, exposing the radiographic film:

secondary radiation (SR)

scatter radiation:

time of exposure in seconds (s)

the amount of time during which the x-ray tube is activated for a particular exposure:

Roentgen (R)

the international unit of quantity for both x-rays and gamma rays:

1) electrical variables

- machine phase, kVp, mAs, s

2) geometrical variables

- distance, areas, focal spot size, angles and alignment

3) patient status

- patient condition, sex, age, body habitus, disease

4) image receptor system

- grids, Potter-Bucky diaphragms, intensifying screens, film holders, etc.

- passes through patient and recording medium

5) processing variables

- chemical concentrations, temperatures

6) viewing conditions

- ambient and peripheral lighting, adequate illumination, artifacts

the types of radiographic variables:

John H. Schultz (1872)

a German chemist that discovered that a paste of silver carbonate or chloride mixed with chalk became dark when it was exposed to light in a glass tube:

Joseph N. Niepce (1816)

He created a crude camera from a jewel box in which a lens from a microscope was inserted to secure an image:

William Henry Fox Talbot

> an Englishman, that used silver chloride paper in a camera obscura to create a visible image, which he made permanent with sodium chloride

> in 1840, he discovered the ability to develop a latent image after exposing the silver layer

> he produced negative images and created positive images by printing on sensitized paper

> the inventor of the negative-positive method of photography

Louis J.J. Danguerre (1839)

a Frenchman that discovered the phenomenon of development:

Richard I. Maddox of England (September 8, 1879)

the inventor of gelatin bromide dry plate which served as the basis for modern photography:

George Eastman (1879)

the inventor for the first mechanically coated glass plates:

Eastman Negative Paper

> sensitized paper with an emulsion used in cameras

> made transparent for printing by chemical treatment

> in 1889, it introduced a flexible transparent base of nitro cellulose coated with

sensitive silver halide emulsion

Thomas Edison

> he developed an intensifying screen composed of calcium tungstate fluorescent crystals

> his intensifying screen was first used by Professor Michael Pupin of Columbia University in 1896, to serve as

augment for the exposure effect of the x-rays

1924

the year when safety x-ray films were introduced:

base

the blue-tinted polyester support of the modern x-ray film:

emulsion

the functional part of the modern x-ray film which consist of silver bromide crystals suspended in gelatin:

supercoat or tough coating (T-coat)

the thin coating of varnish that protects the film emulsion from scratches:

processing

the chemical method of multiplying or exaggerating the effects of exposure:

sensitivity speck

the small silver spot which was originally formed from the exposure:

cracks or fractures

the damage in the silver bromide crystal at each point where an x-ray strikes:

wavelength

the difference between light and x-rays:

light

the flow of small energy called quanta or photon:

optimum

it is used to describe the ideal or intermediate level of contrast that an image should have:

noise

the undesirable information that interferes with the subject of interest:

fogging

the most common form of image noise in radiography that is caused by a random radiation known as scatter:

scatter

the random radiation that causes the fogging of the film:

contrast

the difference between the intensities of reflected light:

intensity

the amount of light photons flowing toward the eyes:

recognizable function (recognizability/geometric integrity)

a visible image is completely

worthless unless the information in it is capable of being recognized: