HDR104 RADIOGRAPHIC EQUIPMENT AND IMAGE RECORDING 1 CHAPTER 1 MAJOR COMPONENTS OF X-RAY GENERATING UNIT PREPARED BY: MR KAMARUL AMIN BIN ABDULLAH SCHOOL OF MEDICAL IMAGING FACULTY OF HEALTH SCIENCES
LEARNING OUTCOMES At the end of the lesson, the student should be able to:- Describe what x-ray tube is. Identify the parameter selectors on control panel and their functions. Discuss the characteristics of x-ray couch. Describe the types of tube stand. Describe briefly the principle of Bucky. Slide 2 of 52
OUTLINES INTRODUCTION 1.1 X-ray Tube 1.4 Tube Stand 1.2 Control Panel 1.5 Bucky Tray 1.3 X-ray Couch (Table) 1.6 References Slide 3 of 52
INTRODUCTION Slide 4 of 52
INTRODUCTION Slide 5 of 52
1.1 X-ray Tube 1.1.1 Specifications It is attached to a tube support. It produces X-rays & Heat. It can operate at high voltage which ranges from 40-150 kvp. It has an insulation which is lead lined to avoid leakage of radiation. Oil is used to cool X-ray tube during exposures. It has an indicator such as height, kvp, mas and motion. Figure 1: The x-ray tube. Slide 6 of 52
1.1 X-ray Tube 1.1.1 Specifications (Continued) It is being incorporated with safety interlocks to avoid injury to staff and patients. It has Light Beam Diaphragm to include the area of interest. It also has an Integrated Collimation with various sizes according to the projection and cassettes/films. This equipment is Earthed (Shockproof). It is connected with high tension cables that supplies the high voltage current. Figure 1: The x-ray tube. Slide 7 of 52
1.1 X-ray Tube X-ray tube encased within LEAD lined case. Figure 2: The x-ray tube with diagram. Slide 8 of 52
1.2 Control Panel There are THREE primary control 1. kvp quality 2. ma 3. Time quantity Auxiliary control (anatomical programs @ AEC control) Slide 9 of 52
1.2 Control Panel Main Power AEC Bucky Selector kvp Selector ma selector Timer Selector Exposure Switch Focal Spot Selector Anatomical Part Selector Figure 3: The picture shows an example of control panel. Slide 10 of 52
1.2 Control Panel Figure 4: Control Panel (Somasundaram, 2009) Figure 5: Control Panel (Medilux, 2010) Slide 11 of 52
1.2 Control Panel 1.2.1 kvp(kilovoltagepeak) The energy (the penetrating power) of the x-ray beam is controlled by the voltage adjustment. It is labelled in kev (thousand electron volts) and sometimes the level is referred to as kvp (kilovoltage potential). The higher the voltage setting, the more energetic will be the beam of x-ray. It plays major part in affecting contrast of image. Slide 12 of 52
1.2 Control Panel 1.2.2 ma (MiliAmperage) The second control of the output of the x-ray tube is called the ma (milliamperage) control. This control determines how much current is allowed to flow through the filament which is the cathode side of the tube. The effect of the ma circuit is quite linear. It is more concerned in density aspect of the image. Slide 13 of 52
1.2 Control Panel 1.2.3 Timer (s) Control length of time machine produces x rays This is usually denoted as an "S" (exposure time in seconds) and is combined with the ma control. e.g using 10 milliampere seconds you could use a 10 ma current with a 1.0 second exposure or a 20 ma current for a 0.5 second exposure or any combination of the two which would result in the number 10. Both of these factors and their combination affect the film in a linear way. Slide 14 of 52
1.2 Control Panel 1.2.4 AEC (Automatic Exposure Chamber) Variable densities exist within subjects. AEC s monitor the beam of X-rays transmitted from the patient. Production of X-ray radiation can be measured. Located under patient but above cassette. Minimizes inaccurate exposures. Figure 6: Automatic Exposure Chamber Ionization Chamber. Slide 15 of 52
1.2 Control Panel Exposure terminates once a sufficient quantity of radiation has been received to produce a radiographic image of required density. Permit accurate exposures Usually three AED s incorporated in table tops and vertical chest stands. Markings usually on surface of table/chest stand. Individual chambers may be selected depending on the exam being performed. Slide 16 of 52
1.2 Control Panel Figure 7: The position of the chambers. Slide 17 of 52
1.3 X-ray Couch (Table) Figure 8: The picture shows the x-ray table/couch. Slide 18 of 52
1.3 X-ray Couch (Table) 1.3.1 Specifications It must be strong enough to support large patients or obese. It should have low attenuation materials (such as Carbon Fibre) as to improve quality of x-ray beam. It has Rise and Fall facilities. Figure 9: X-ray Couch Slide 19 of 52
1.3 X-ray Couch (Table) 1.3.1 Specifications (Continued) It has Kick buttons. Incorporated with an Integrated Bucky tray. Insulated to avoid electrical shocked. It is easy to clean as to reduce cross infection. Figure 9: X-ray Couch It is associated with pressure switches. Slide 20 of 52
1.4 Tube Stand Figure 10: Ceiling Mounted X-ray Tube Figure 11: Floor Mounted X-ray Tube Slide 21 of 52
1.4 Tube Stand Advantages Flexibility Ease of use and Durable Safety features/interlocks Specifications of modern X-ray tube Integral features Wide range of movements Disadvantages Expensive Interlock too sensitive Figure 10: Ceiling Mounted X- ray Tube Slide 22 of 52
1.4 Tube Stand Advantages Inexpensive. Can be used with upright Bucky. Require less space. Disadvantages Less flexible. Not user friendly for complicated cases. Figure 11: Floor Mounted X-ray Tube Slide 23 of 52
1.5 Bucky Tray Figure 12: Table Bucky Figure 13: Erect Bucky It actually acts as cassette holder. Slide 24 of 52
1.5 Bucky Tray Integrated within table top. Lock mechanism ensures cassette is secure. Grid mechanism incorporated within cassette tray. Grid reduces scatter radiation from certain examinations:- Abdomen Pelvis Hips Figure 14: Bucky Tray with Grid. Slide 25 of 52
1.5 Bucky Tray Important that X-ray tube and cassette tray are aligned Set distance between X-ray tube and Cassette tray Oscillating movement ensures scatter is absorbed before reaching film Figure 15: The x-ray tube and bucky. Slide 26 of 52
1.5 References No. REFERENCES 1 Richard R. Carlton, Arlene McKenna Adler (2005) Principles of Radiographic Imaging, Delmar 2 Bushong, S. C. (2008). Radiologic science for technologists. Canada: Elsevier. Slide 27 of 52
SUMMARY There are FIVE major components of x-ray generating unit:- 1. X-ray Tube 2. Control Panel 3. X-ray Couch 4. Tube Stand 5. Bucky Tray Slide 28 of 52
NEXT SESSION PREVIEW CHAPTER 2: ELECTROSTATIC Slide 29 of 52
APPENDIX FIGURE Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 SOURCE http://www.actors.co.ke/en/news/energy1.jpg http://intechweb.files.wordpress.com/2012/03/shutterstock_77399518.jpg http://iws.collin.edu/biopage/faculty/mcculloch/1406/outlines/chapter%206/s B7-2b.JPG http://www.physics4kids.com/files/art/motion_energy1_240x180.jpg http://www.sciencebuilder.com/michigan/science/images/p/potentialenergy.j pg http://www.solarenergybook.org/wp-content/uploads/2009/12/solar-energyexample.gif http://www.petervaldivia.com/technology/energy/image/potencial-andkinetic.bmp http://www.petervaldivia.com/technology/energy/image/potencial-andkinetic.bmp http://4.bp.blogspot.com/_v7dueo3c2e8/sb2pzfoxzi/aaaaaaaaadk/kkxoueyon2i/s1600/one-balanced-rock.jpg Slide 30 of 52
APPENDIX FIGURE Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 SOURCE http://im.glogster.com/media/2/6/1/15/6011523.jpg http://cse.ssl.berkeley.edu/bmendez/ay10/2002/notes/pics/bt2lf0403_a.jpg http://www.petervaldivia.com/technology/electricity/image/electron-flow.gif http://newsimg.bbc.co.uk/media/images/42340000/gif/_42340232_nuclear_fus ion_2inf416.gif http://freegrab.net/114284main_em_spectrum500.jpg http://myweb.cwpost.liu.edu/vdivener/notes/solid-liquid-gas.gif http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/inteng.html http://hop.concord.org/h1/h1pix/p2b.gif http://www.aos.wisc.edu/~aalopez/aos101/wk5/conduction.jpg http://www.gcse.com/energy/images/conduction.gif http://okfirst.mesonet.org/images/cond_conv_rad_small.jpg http://www.aos.wisc.edu/~aalopez/aos101/wk5/convection.jpg Slide 31 of 52
APPENDIX FIGURE Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 SOURCE http://okfirst.mesonet.org/images/cond_conv_rad_small.jpg http://www.aos.wisc.edu/~aalopez/aos101/wk5/radiation.jpg http://okfirst.mesonet.org/images/cond_conv_rad_small.jpg http://www.aos.wisc.edu/~aalopez/aos101/wk5/heatrans.jpg http://www.beodom.com/assets/images/education/principles-thermalinsulation/heat-transmittance-means.jpg http://www.drenergysaver.com/images/insulation/how-insulation-works.gif Slide 32 of 52
Activity Test Your Knowledge Answer the question. What is the push or pull of an object that can cause it to accelerate called? Mass Speed Force Slide 33 of 52