Anatomy of Fluoroscopy & CT Fluoroscopy Equipment L04

1. IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy Anatomy of Fluoroscopy & CT Fluoroscopy EquipmentL04

2. Educational objectives • How is fluoroscopy equipment designed? • What are the different factors that influence the X ray output from a fluoroscopic system? • What are the new developments in fluoroscopy equipment? IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

3. Early (Screen Only) Fluoroscopy Fluorescent screen with leaded glass IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

4. Modern Image Intensifier based fluoroscopy system IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

5. Components of C-arm equipment IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

6. Bi-plane C-arm setup From: R Kruger et al, Spine 2003 IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

7. A Modern Bi-Plane C-Arm with Flat Panel Detectors Flat panel Image Receptors X ray Tubes IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

8. Multi-purpose C-arm Fluoroscopy System Image Intensifier X ray tube IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

9. Over-couch vs Under-couch X ray Tubes Image Intensifier X ray Tube fixed under table X ray Tube fixed over table Image Intensifier IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

10. Over-couch vs Under-couch X ray Tubes • Under-Table X ray tube system subject the operator to much less scattered radiation than do over-table X ray tube systems. • It is therefore preferable to have the X ray tube mounted below the table when purchasing fixed configuration systems. IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

11. The Image Intensifier (II) Its function is to • Convert X rays into visible light • Increase the image brightness so it is visible to the camera and recording devices IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

12. Automatic Brightness Control (ABC) • Adjusts X ray intensity to produce image of predefined brightness • Adjusts kV and mA in various ways to achieve predefined image brightness. • Normally adjusts kV with associated adjustment in mA IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

13. Theory of Operation – ABC Monitor Camera Iris/Diaphragm Optics Image Image Intensifier Brightness Feedback Grid Table Reference Brightness Collimator Filter Automatic Generator X ray Tube K kV,mA Brightness Control IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

14. Automatic Exposure Control and Patient Thickness Pulse Width Focal Spot Size Filtration mA kV Very Large Very Small Small Large Medium Patient size

15. Imaging modes Fluoroscopy versus Acquisition,Magnification, Dose level

16. Magnification Synonyms: MAG Zoom Field View (FOV) Image Intensifier field size IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

17. 6” 9” Magnification Smaller Image Intensifier Mode (“MAG”) has better resolution 0.15 mm / pixel vs. 0.23 mm/pixel … but higher exposure to patient and staff IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

18. Radiation Output and Mag Modes • Exposure Rate change = (old FOV)2/(new FOV)2 • Example: go from 40 cm to 30 cm • 402/302 = 1.77 • So the smaller FOV will need 1.77x more radiation for the same image brightness IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

19. ABC increases patient dose for increased MAG Normal, 40 cm FOV,1 dose unit MAG 1, 33 cm FOV,1.46 dose units IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment MAG 3, 17 cm FOV,5.5 dose units MAG 2, 23 cm FOV,3.0 dose units

20. High Fluoro, MAG 2 Low Fluoro, No MAG > 10 fold more exposure rate 13 cm 17 cm 23 cm (+) mode increases dose by 50% compared to normal.(-) mode decreases dose by 50% compared to normal. IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

21. Fluoroscopy vs Image Acquisition Can you tell ………. Which image is FLUOROSCOPY, which one is ACQUISITION? IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

22. Fluoroscopy Continuous display of images, normally without recording, except last image hold (LIH) Image Acquisition Discrete or multiple images recorded in sequence. Commonly known as runs or cine runs > 10 fold more exposure rate IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

23. Better image quality with higher radiation dose reaching the image receptor. Tradeoff: higher patient and staff dose!! Image Quality Radiation Dose IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

24. ALARA No known safe limit of magnitude of radiation exposure As Low As Reasonably Achievable Physicians Patients Professional staff IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

25. Pulsed Fluoroscopy

26. Pulsed fluoroscopy IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

27. Effect of filtration • What is beam filtration? • Absorber placed between source and object • Will preferentially absorb the lower energy photons • Patient skin dose reduction IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

28. Effect of filtration For equal kVp Increased mean beam energy Increased Mean Energy With increased filter and increased mA Intensity Low Filtration Spectrum kVp Photon energy, keV IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

29. Effect of filtration • Additional Cu filters can reduce the skin dose by more than 70%. • Some systems offer variable extra filtration (0.2 mm - 0.9 mm) that is automatically set according to patient weight and angulation of the C-arm. IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

30. Other important elements Collimator Dose Area Product (DAP) meter IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

31. Collimator IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

32. Collimator Collimation confines the X ray beam to an area of the user’s choice. IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

33. Collimator Why is narrowing the field-of-view beneficial? • Reduces exposure to patient by reducing volume of tissue at risk • Reduces scatter radiation at image receptor to improve image contrast • Reduces scatter radiation to in-room personnel • Reduces potential overlap of fields when beam is reoriented IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

34. Dose Rates and Aging Equipment • Image Intensifier efficiency at converting X rays to light reduces over time. Thus the image becomes dimmer. • Via the ABC, Image Intensifier input doses rates go up to compensate. (Patient and staff doses also increase.) • A service engineer can open optical iris of TV camera to compensate, but at some stage no further adjustment available & image intensifier replacement needs to be considered. IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

35. C-arm Control Panel kVp , mA display “Radiation on” warning Tube temperature alarm Image transfer controls Procedure timer Fluoro dose mode Low / high On Off Manual fluoro Automatic fluoro Pulsed fluoro Image acquisition/ Manual controls MAG/Zoom/ II field size IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

36. New developments • Flat panel detectors • CT fluoroscopy • Mobile CT in operation theatre IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

37. Flat panel detector Flat panel detector instead of image intensifier For the user, dose level, MAG, filters and other parameters remain more or less the same IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

38. Flat panel detector: bi-plane system IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

39. CT Fluoroscopy – real-time CT • Staff enters CT room during acquisition Biopsy mediastinal mass Needle holder IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

40. CT Fluoroscopy – real-time CT Applications Core biopsies, precise needle placement, fluid collection aspirations, drainage, local drug injection, RF ablation, lumbar nerve root blocks, vertebroplasty, arthrography, etc Users Radiologist, pneumologist, orthopedic surgeon, anesthetist Patient skin dose rates typical > 10 times higher than in C-arm fluoroscopy IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

41. CT Fluoroscopy – real-time CT Typical tube current settings in CTF 10 mA paediatrics, 10-40 mA chest, 40-50 mA abdominal Staff protection Standoff needle device to increase distance to primary beam IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

42. CT in the operating theatre • CT based surgical navigation – mobile system • Staff leaves room during acquisition IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

43. CT in the operating theatre • Also works in 2D conventional fluoroscopy mode 3D mode delivers radiation dose to patients that is comparable to that of a 64 slice CT scanner. 2D mode delivers radiation dose to patients and staff comparable to that of a conventional C-arm system IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment

44. Thank you IAEA Training Course on Radiation Protection for Doctors (non-radiologists, non-cardiologists) using Fluoroscopy L04. Anatomy of Fluoroscopy & CT Fluoroscopy Equipment