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 7
| Question | Answer |
|---|---|
| What is the primary mechanism of x-ray production in the tube? | High-speed electrons interacting with the target anode. |
| What are the two types of x-rays produced? | Bremsstrahlung and characteristic radiation. |
| What is Bremsstrahlung radiation? | X-rays produced when electrons are decelerated by the nucleus of target atoms. |
| What is characteristic radiation? | X-rays produced when an outer-shell electron fills a vacancy in an inner shell. |
| Which type of x-ray production is most common in diagnostic imaging? | Bremsstrahlung radiation. |
| What determines the energy of Bremsstrahlung x-rays? | The kinetic energy of the incident electrons. |
| What determines the energy of characteristic x-rays? | The difference in binding energies between electron shells. |
| Which shell is involved in diagnostic range characteristic x-rays in tungsten? | K-shell. |
| 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? | Controls electron acceleration and maximum photon energy. |
| What is the role of mA in x-ray production? | Controls the number of electrons emitted from the filament. |
| What is the efficiency of x-ray production? | Less than 1% of electron energy is converted to x-rays. |
| What happens to the remaining electron energy? | 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 material? | High atomic number, high melting point, and good thermal conductivity. |
| What is the function of the rotating anode? | To spread heat over a larger area and increase tube capacity. |
| What is the focal spot? | The area on the anode where electrons strike and x-rays are produced. |
| What is the difference between actual and effective focal spot? | Actual focal spot is physical; effective focal spot is projected area seen by the IR. |
| What is the anode heel effect? | Variation in x-ray intensity across the beam due to absorption in the anode. |
| Which side of the x-ray beam is more intense? | Cathode side. |
| How can the anode heel effect be minimized? | Use smaller anode angles or place thicker anatomy under the cathode. |
| What does the x-ray emission spectrum show? | Continuous Bremsstrahlung spectrum with superimposed characteristic peaks. |
| What determines the maximum photon energy in the spectrum? | 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? | Aluminum or other materials added to 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 primary radiation? | X-rays emitted directly from the tube. |
| What is secondary radiation? | Scatter or leakage radiation. |
| What is scatter radiation? | X-rays that change direction after interacting with matter. |
| Which factors increase scatter radiation? | Large field size, high kVp, and thicker body parts. |
| How does scatter radiation affect image quality? | Reduces image contrast. |
| What is differential absorption? | Difference in absorption between tissues producing image contrast. |
| Which interaction contributes to differential absorption? | Photoelectric absorption. |
| Which interaction contributes 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)? | 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, and shielding. |
| What is a protective barrier? | A wall, lead apron, or shield that absorbs x-rays. |
| What is backscatter radiation? | Scatter radiation 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? | 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 ensure patient safety. |
| 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