Elsevier items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. X-Ray Production Chapter 8

Kinetic Energy  The energy of motion  Where does the electron traveling from the cathode to the anode get it’s kinetic energy?  Kinetic energy is increased by raising the kVp Elsevier items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 2

Kiloelectron volt (keV) Used to measure the energies of x-rays. A unit to measure the kinetic energy of an individual electron in the high speed electron beam within the x-ray tube; equivalent to 1000 electron volts (1 keV = 1000 eV) Elsevier items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 3

Anode  How does the anode handle the heat?  Heat dispersion by: (99% is heat)  Rotation – high rotation  Larger anode  Tungsten 90% Rhenium 10% Elsevier items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 4

X-ray Production  Polychromatic beam – Mix of different x- ray energies.  Bremsstrahlung (70%) – wider range of energy (kVp)  Characteristic (30%) – Tungsten 69.5 kV (K shell - p. 142) Elsevier items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 5

6 X-Ray Emission Spectrum

Elsevier items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 7 Bremsstrahlung Radiation Production

Elsevier items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 8 Characteristic X-Ray Production

Elsevier items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 9 Factors Affecting X-Ray Emission Spectrums mAs kVp Filtration Voltage Generation

Elsevier items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 10 Factors Affecting Quantity and Exposure Factor Increased Beam Quantity Image Receptor Exposure mAs Increased proportionately Increased kVp Increased geometrically Increased Distance Reduced geometrically Reduced FiltrationReducedReduced

Heel Effect Elsevier items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 11