Basic Properties of X-ray Photons and Radiation Protection

1. Basic Properties of X-ray Photons and Radiation Protection Radiation Physics #1

2. Properties of X-ray X-rays travel in a straight line and diverge from their point of origin. X-ray photons have many different energies. X-rays are highly penetrating. X-rays are invisible. X-rays travel at the speed of light.

3. Properties of X-ray X-rays produce scatter radiation when they enter-act with matter. X-rays affect radiographic and photographic film. X-rays cause fluorescence of some materials. X-rays cause biologic damage.

4. Properties of X-ray X-rays respond according to the inverse square law.

5. X-ray Protection Because x-rays cause biologic damage, the operator of the machine and the patient must be protected from the radiation. Lead is used to absorb radiation.

6. X-ray Hazards In the early days of radiography, the patient often was burned by the radiation. With proper operation of equipment, x-rays are relatively safe today.

7. X-ray Injuries Still Occur These are serial photographs on a patient that had multiple long fluoroscopic examination. Last image is after skin graphs.

8. Patient Radiation Protection Radiographers have an ethical and professional responsibility to keep the exposure to the patient as low as possible. “As low as reasonably achievable” (ALARA)

9. X-ray Hazards With early x-ray machine, there was a real possibility of electrocution. Today with proper safety precautions, radiography is very safe for the operator.

10. X-ray Hazards X-ray was also very hazardous for the operator in those early years. X-ray operators would use their hands to make sure the machine was working .

11. X-ray Hazards It was not uncommon for both the operator and patient to receive burns. Today, with proper precautions, x-ray is safe for the operator.

12. The X-ray Room The radiographic equipment consists of: The Tube Stand, Tube & Collimator Grid Holder or Bucky Controls in the Control Booth.

13. The X-ray Room The wall of the x-ray room and door are shielded with lead to protect the operator and staff.

14. Operator X-ray Protection The Door to the X-ray Room contains lead. It must be closed during exposures.

15. Operator X-ray Protection The wall of the control booth is leaded. Stand completely behind the wall during exposures.

16. Operator X-ray Protection Observe the patient or experiment through the lead glass window. No peeking around the wall!

17. X-ray Tube X-rays are produced inside the x-ray tube. Many properties of light and x-ray are the same.

18. Modern X-ray Tube This is a modern rotating anode general radiographic x-ray tube. The leaded glass holds the vacuum in the tube. Anode rotated to cool tube.

19. X-ray Collimator Using light in the collimator, lead shutters are moved to restrict the area of exposure.

20. X-ray Collimator Collimation is our best tool for reducing radiation exposure to the patient.

21. Observations 1. Does the light field match the x-ray beam? Yes 2. What principle does this demonstrate? X-rays travel in a straight line and diverge from the point of origin. X-rays have similar properties to light.

22. Observations 3. Did the intensity of the fluorescence of the screen change when the kVp was increased? Yes 4. Would this indicate that the intensity of the beam changed? Yes 5. During the exposure could you see inside the phantom? Yes

23. Observations 6. What property of x-ray did this demonstrate? X-rays are highly penetrating. 7.After the tone from the control terminated, did the screen continue to fluoresce? No 8.If the screen did not fluoresce, was there any radiation coming from the tube after the tone stopped? No

24. Observations 9. Did you hear any noise coming from the tube after the tone stopped? Yes the rotor continued to rotate. 10. What did you see on the film that was sitting near the phantom? A blurry image. 11. What principle did this demonstrate? X-rays produce scatter radiation. Scatter radiation is not divergent.