Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Physics
Ch 5
| Question | Answer |
|---|---|
| What is the primary source of x-ray production in the tube? | The interaction of high-speed electrons with the anode target. |
| What are the two types of x-ray production? | Bremsstrahlung and characteristic radiation. |
| What is Bremsstrahlung radiation? | X-rays produced when high-speed electrons are decelerated by the nucleus of target atoms. |
| What is characteristic radiation? | X-rays produced when an inner-shell electron is ejected and an outer-shell electron fills the vacancy. |
| Which type of x-ray production is most common in diagnostic radiography? | Bremsstrahlung radiation. |
| What determines the energy of Bremsstrahlung x-rays? | The kinetic energy of the incident electrons and the degree of deceleration. |
| What determines the energy of characteristic x-rays? | The difference in binding energies between electron shells. |
| Which shell electrons produce diagnostic range characteristic x-rays in tungsten? | K-shell electrons. |
| What is the minimum energy required to produce K-shell characteristic x-rays in tungsten? | 69 keV. |
| What is the role of kVp in x-ray production? | It accelerates electrons toward the anode and determines maximum photon energy. |
| What is the role of mA in x-ray production? | It controls the number of electrons emitted from the filament. |
| What is the efficiency of x-ray production? | Less than 1% of electron kinetic energy is converted to x-rays. |
| What happens to the remaining energy from electrons? | Converted to heat in the anode. |
| What is the target material commonly used in x-ray tubes? | Tungsten. |
| Why is tungsten used as a target? | High atomic number, high melting point, and good thermal conductivity. |
| What is the function of the rotating anode? | To spread heat over a larger surface and increase tube capacity. |
| What is the focal spot? | The area of the anode where electrons strike and x-rays are produced. |
| What is the difference between the actual and effective focal spot? | Actual focal spot is the physical area hit by electrons; effective focal spot is the projected area seen by the image receptor. |
| What is the anode heel effect? | Variation in x-ray intensity across the beam due to absorption in the anode. |
| Which side of the beam is more intense? | Cathode side. |
| How can the anode heel effect be minimized? | Using smaller anode angles or placing thicker anatomy under the cathode side. |
| What is the typical x-ray emission spectrum? | Continuous Bremsstrahlung spectrum with characteristic peaks superimposed. |
| What is the maximum photon energy in the spectrum determined by? | The kVp applied to the tube. |
| What is the average photon energy in a diagnostic x-ray beam? | About one-third of the kVp. |
| How does filtration affect the x-ray beam? | Removes low-energy photons, increases beam quality, and reduces patient dose. |
| What is inherent filtration? | Filtration provided by the tube housing, glass envelope, and oil. |
| What is added filtration? | Additional materials, usually aluminum, placed in the beam path. |
| What is total filtration? | The sum of inherent and added filtration. |
| What is the purpose of collimation? | To restrict the x-ray beam to the area of interest and reduce patient dose. |
| What is the difference between primary and secondary radiation? | Primary radiation is the beam from the tube; secondary radiation is scatter or leakage. |
| What is scatter radiation? | X-rays that change direction after interacting with matter. |
| What factors increase scatter radiation? | Large field size, high kVp, and thicker body parts. |
| How does scatter radiation affect image quality? | Reduces contrast. |
| What is differential absorption? | The difference in absorption between tissues producing contrast on the image. |
| Which interactions contribute to differential absorption? | Photoelectric absorption. |
| Which interactions contribute to image fog? | Compton scatter. |
| How does tissue atomic number affect absorption? | Higher atomic number tissues absorb more x-rays. |
| How does tissue thickness affect absorption? | Thicker tissues absorb more x-rays. |
| How does photon energy affect absorption? | Higher energy photons penetrate more, reducing absorption. |
| What is half-value layer (HVL)? | The thickness of material that reduces beam intensity by half. |
| What does HVL indicate? | Beam quality or penetration. |
| How does kVp affect HVL? | Higher kVp increases HVL. |
| How does filtration affect HVL? | Added filtration increases HVL. |
| What is the primary factor controlling patient dose? | Beam quantity and quality (mAs and kVp). |
| What is the main source of occupational exposure? | Scatter radiation. |
| How can occupational exposure be reduced? | Time, distance, shielding. |
| What is a protective barrier? | A wall, lead apron, or shield that absorbs x-rays. |
| What is backscatter radiation? | Scatter radiation that is reflected back toward the source. |
| What is the photoelectric effect? | Complete absorption of an x-ray photon by an inner-shell electron. |
| What is the probability of the photoelectric effect dependent on? | Photon energy and atomic number of tissue. |
| What is Compton scattering? | Partial energy transfer to an outer electron with photon deflection. |
| How does Compton scattering affect image quality? | Produces fog and reduces contrast. |
| What is pair production? | Photon energy creates an electron-positron pair (not diagnostic). |
| What is photodisintegration? | Photon absorbed by nucleus causing particle emission (not diagnostic). |
| What is off-focus radiation? | X-rays produced outside the focal spot. |
| What is the effect of off-focus radiation on image quality? | Creates unwanted exposure and reduces image contrast. |
| What is tube rating? | The maximum safe combinations of kVp, mA, and exposure time. |
| Why is tube cooling important? | Prevents overheating and damage to the anode. |
| What is the unit of heat in x-ray tubes? | Heat units (HU). |
| What is the main cause of x-ray tube failure? | Excessive heat. |
| What is the effect of a small focal spot on tube capacity? | Lower heat capacity but higher image sharpness. |
| What is the effect of a large focal spot on tube capacity? | Higher heat capacity but lower image sharpness. |
| What is characteristic peak in the emission spectrum? | Discrete energy levels corresponding to target atom electron shells. |
| What is Bremsstrahlung continuum? | Range of energies from 0 up to maximum photon energy. |
| What is tube filtration required for? | To meet federal regulations and patient safety standards. |
| What is the main source of x-ray tube heat? | Conversion of electron kinetic energy into thermal energy. |
| How does anode rotation speed affect heat capacity? | Faster rotation spreads heat over larger area, increasing capacity. |
Created by:
user-1983814