X-Rays in Medicine

Discovery of X-Rays -Wilhelm Conrad Roentgen-1895 -Electrical discharges in a vacuum tube -Caused a phosphoric screen to fluoresce -Formed an image of bone -First x-ray photograph of wife’s hand/ring

X-rays in Medicine One year later British doctors were already using x- ray imaging. Prolonged exposure to x-rays caused tissue burns. Wounds were abnormal- took time before appearing.

ENERGY

PHOTONS -The energy of a light-wave is carried by packets called photons -The energy of a photon depends on the light’s wavelength -Smaller wavelengths have larger energies

Photon energies are usually given in units of electron volts (eV) ENERGY Photon energies are usually given in units of electron volts (eV) 1 eV = 1.602x10-19 Joules Need 56,000,000,000, 000,000,000,000 eV to cook an egg.

X-Ray Tube

X-Ray Tube

X-Ray Tube

X-Ray Tube X-ray tube consists of the following major parts 1- Filament: made from tungsten wire which is heated electrically at a potential difference of 8 to 12 V to a high temperature so that electrons ‘boiled off’ from its surface. These electrons form the tube beam. The filament is located within a negatively charged nickel cathode which is shaped so that a precise beam geometry is obtained.

X-Ray Tube 2- Cathode: this houses the filament and is manufactured from nickel . The filament is located within a cup having sharp contoured edges which electrostatically focus the electron beam. The cathode cup is independently supplied with a high negative voltage 3- Anode: is manufacture from tungsten (high melting metal). Dental units and small mobile X-ray units use stationary or fixed anode design. The most efficient design however uses a rotating-disk anode which enables higher X-ray output owing to more effective cooling.

Rotary X-Ray Tube

Diagnostic X-Ray Spectra

Therapeutic X-Ray Spectra

X-ray Image Two Forks, Ball pin, and teeth brush in the intestine

X-Ray image of a Gun