XRAY basics

Date of xray discovery

Nov 8th 1895

First radiation fatality

Clarence dally

first xray image

Wifes hand ; 15 min

Material that had fluoresce

barium platinocyanide

first xrays were known as

Roentgen rays

Skin reddening from radiation

erythema

2 properties of xrays

electrical and magnetic ; electromagnetic spectrum (constant velocity)

3 x 10*8 m/s; c=fw is the formula for the

speed of light

Individual xray Photon energy is measured in:

electron volts (eV)

V=fw (velocity = frequency x wavelength)

is the equation for

wavelength

wavelength ranges from

0.1 - 1 A

Frequency is measured in:

 Hertz (Hz); 1 cycle per second

Frequencies range from:

 3 x 10*19 to 3 x 10*18 HZ

Frequency and Wavelength have an

inverse relationship

unit that measures occupational exposure

dose equivalent

The unit that expresses the relative risk to humans of exposure to ionizing radiation:

effective dose

Angstrom A =

10*10

Meter =

10*-8

vows that there is less intensity on the anode side and more on the cathode side

anode heel effect

vows that the smaller the anode angle, the smaller the effective focal spot size

line focus principal

the flow of electrons from cathode to anode in the tube and is what mA measures

tube current

increasing kVp will

Increases beam penetrability and increases electron speed

During x-ray production the energy of moving electrons is converted into:

electromagnetic energy (99% heat, 1% energy)

Diagnostic x-ray exposures range from:

30 to 50 kVp

Doubled tube current, xray photon quantity and thermionic emission is the result of

Doubling mA

Primary radiation:

radiation that leaves tube

Remnant radiation:

Reaches IR after passing through patient

Scatter radiation:

decreases visibility of anatomic structures

How the x-ray beam interacts with the anatomic tissue

Differential absorbtion