2. Portable Mobile Equipment and Applications RTEC 124 – WEEK 12 SPRING 2011 1

3. Portable Objectives 2 1) Recommend methods for accomplishing acceptable variations of standard radiographic projections 2) Assess the radiation protection rules for mobile radiography

4. Objectives Continued 3) Identify factors contributing to the difficulty of mobile radiography 4) Explain appropriate communications methods for mobile examinations 5) Describe items that must be considered when arranging a patient room for a mobile examination 3

5. 4 First “Portable “ Unit

6. Portable - DDR 5

7. THREE Basic types of Units Portable - refers to a small hand held unit, first designed by Picker for WW I 15 ma generator Chest & extremities Mobile - Full powered institutional units much heavier - motor or muscle driven Fluoroscopic: C-arm and “Mini C-arm” or Fluoroscan PORTABLE is accepted terminology 6

8. MOBILE XRAY UNIT 7

9. Basic Types of Mobile Radiography Battery Powered Unit Capacitor-discharge Unit High Frequency Units Mobile Fluoroscopic ( C-ARM) 8

10. Portable Units - Special Features Battery Powered uses Ni-Cd rechargeable batteries, DC high frequency pulsed power Capacitor-Discharged - uses 110 outlet. High voltage transformer - Capacitor discharges at time of exposure -voltage drops 1kv/mas during exposure High Frequency- converts hf AC to DC - resulting in high voltage ripple 60hz-500 hz (square vs sine wave) *Techniques are equivalent to 3Ø 12 p (like in a standard Radiographic room) 9

11. 10 BATTERY POWERED

12. 11 12 VOLT BATTERIES CAR BATTERY Silver or Nickel Cadmium

13. Power Drive Self-propulsion for mobile unit Dead-man switch Must use caution when piloting equipment Weight of Equipment Areas: – safe and not safe to use 12

14. 13

15. 14 “PLUG –IN” : Capacitor DISCHARE UNIT

16. Plug in – Light weight Cap. Discharge 15

17. 16

18. Types of Equipment Power supplies Generators Power drive Power Supplies: Portable light duty units – 220V or 110V outlet Full power mobile institutional units – Capacitor discharge – Battery operated 17

19. Generators Capacitor discharge – Constant potential output Battery operated – 3 phase output THEREFORE – Technique is consistant with x-ray room Grid is different 18

20. Milliampere-Seconds Low power units not capable of high mAs techniques needed for grid radiography (300 mA) Double or triple exposure – Be careful not to overload tube – EX: X-table L5 S1 SPOT (in surgery) 19

21. 20  This paddle with one or two cells  Placed behind the patient and cassette  Position of cells critical  Control Panel  Selection of density  back up time  cells AEC and Portables

22. NEW – Mobile DIGITAL UNITS 21

23. 22 DIGITAL UNITS

24. 23

25. 24

26. COMPARISONS Battery Powered Uses 9 - 10 12V batteries - (heavy) Battery supplies power for all inst. operations Motor Driven Wt - +1,000 lbs ? Constant potential Some have AEC Needs recharging - holds 8 hr charge 3Ø 12pulse techniques Can double expose + 110 V Capacitor DC Uses 110 outlet Capacitors stores up charge - then exposure discharges “Muscle Driven” Wt - + 450 lbs ? Constant potential Some have programmed memory Must be plugged in to store up charge ? Not for large parts 25

27. HIGH FREQUENCY UNITS Very Expensive – – not many in use Smaller – more compact units High voltage transformer 1/10 the size Minimal voltage ripple – higher efficiency 26

28. 27

29. MinXray High Frequency Portable Units 28 Designed for use in: nursing homes, private homes, correctional facilities, field clinics, or hospitals, Maximum of 80 mAs 70 lbs

30. SUMMARY Battery Powered Uses batteries 3Ǿ 12p (4%ripple) Capacitor Discharge Needs wall outlet Constant Potential (1 % ripple) C-Arm Fluoroscopic Digital, Subtraction, Last Image Hold 29

31. “PREP” GETTING READY FOR EXAMS YOUR PATIENT THE ROOM YOURSELF 30

32. Special Patient Considerations Communication Manipulating equipment Positioning and pathology 31

33. THE TECHNOLOGIST The “ultimate test” of skill, competency and resourcefulness Urgency and Tension Patient’s inability to cooperate Technical Considerations – – varying SID, – grid alignment – patient positioning 32

34. THE PATIENT More acutely ill and/or unable to transport More lines and tubes – Cardiac Monitoring – Ventilators – traction – Respirators Levels of consciousness Can they hear you or understand you? 33

35. Patient Considerations Pre- portable rapport Rearrange equipment/furniture Leave it the way it was before you got there Locks on bars – bed rails – Table trays – Chairs – Pillows – Blankets – TV – etc 34

36. Other considerations Overhanging TV’s and the X-ray tube can be hazardous to your head! Don’t bump the bed or your head Place cassette in a pillowcase when possible 35

37. GRIDS: lower ratio / more latitude 36 Consider direction of grid lines to tube

38. Grid Ratio Higher grid ratio – More efficient in removing scatter Typical grid ratio range is 5:1 to 16:1 37 Watch positioning of CR to grid

39. Cassettes with Grid Caps 38

40. Grid Frequency The number of lead strips per inch or cm Frequency range – 60-200 lines/in – 25-80 lines/cm Typically higher frequency grids have thinner lead strips 39

41. 40

42. KUB With and Without GRID 41

43. CR GRIDS 42 Lower grid ratio = CR is more sensitive to scatter

44. Special Technical Factor Selection Considerations Kilovoltage Milliampere-seconds Distance Grids Film/screen combinations Other factors 43

45. Distance Measurements For technique – 40” – 56” – 63” – 72” 44

46. ALARA Patient You Staff Friends and family 45

47. Legal Radiation Protection It’s your duty Politely ask whoever can, to leave the area – Provide aprons to those who cannot leave – Always carry 2 Announce your intent to make an exposure 46

48. Ethical Radiation Protection Never be in primary beam Achieve maximum distance from the patient and tube – stand 90° from the patient Minimum 6 foot exposure cord for radiography Label and handle cassettes carefully 47

49. 48

50. MOVE ARTIFACTS WHEN POSSIBLE 49

51. Artifact under pt abd 50 Move artifacts when possible

52. Types of Exams Chest – AP, Lateral and LLD Abdomen – AP or LLD Cross table Hip Extremities – 2 VIEWS - 90° Cross table C-spine Cross table T-spine Shoulder (Y- view) 51

53. 52 ?? QUESTIONS??