Advanced Diagnostic Imaging Studies

1. Advanced DiagnosticImaging Studies Theatre Imaging

2. Some Essentials • Principles of radiography/terminology • Basic anatomy • Operative procedures and radiographic technique • Dose limitation • Health & Safety

3. Major Directional Terms

4. AP Position? • Actually PA for supine patient as beam enters posteriorly

5. Imaging in Theatres • Discussion. • Mobile x-ray units. (CXR etc) • Image Intensifier units

6. Mobile Fluoroscopy units • Flexibility • Ease of use • Safety features • Cross infection issues • Radiation protection • Image quality • Transportation / storage • Image storage facilities

7. Mobile fluoroscopy units

8. Mobile fluoroscopy units • Flexibility • Ability to move in small environments • Accurate controls • Full isocentric movements • Clear measurement markings • Manual handling considerations • Low base height • Foot / hand exposure devices

9. Mobile fluoroscopy units • Ease of use • Laser marking facility • Accurate positioning • Hand rails Easy movement • Quick access interlocks • Simplistic design • Clear user features • Ability to manipulate data from base unit

10. Mobile fluoroscopy units • Image review / print • Ability to review data on dual monitor display • Freeze –transfer –archive features • Manipulate data remotely from unit base • Input patient demographics • Ability to review “thumbnail” images • Ability to play movie clips

11. Safety Features • Cable protection on wheels • Minimal trailing cables • Electro-mechanical brakes • Counter balance construction • “Glide” mode • Key operation (IR(ME)R) • Handles to pull / push unit • Earthed units • Monitor & Image intensification unit • Cable connections

12. Infection Control • Bodily fluids •Areas where bodily fluids may settle: –Crevasses (Rails) –Wheels –Screw heads –Cables •Easily cleaned surfaces •Ability to cover with sterile drapes

13. Infection Control

14. Radiation Protection • Pulsing option • Up to 70% dose reduction • Visual collimator blades –Iris –Semi-transparent • CARE dose facility • Image rotation facility • Integrated DAP device • Exposure time / dose reading • Warning light / audible warning

15. Limiting dose • X-rays are potentially harmful to patients and staff • All radiological procedures should seek to keep dose “as low as reasonably practicable” ( ALARP) • This is the principle of Optimisation as stipulated in the IRRs – therefore not optional; required by law

16. Limiting dose • Collimation – decreasing the size of the radiation field • Use of shutters or iris collimator • Keep intensifier face as close as possible to the patient • Reduces x-ray output necessary to achieve acceptable image • Reduces image magnification and blurring

17. Limiting dose • Try to position correctly before exposing • Think about whether the required area is under the intensifier face before pushing expose button • Use of laser positioning • Use of anatomical landmarks • Lead rubber coats for staff • Must be worn by all in controlled area i.e the operating theatre • Avoid staff hiding behind other • Lead rubber gonad shielding for patient

19. Contrast Difference between adjacent densities on a radiograph The number of black, white and grey tones that appear on a radiograph Controlled by the energy of the x-ray beam

20. kVp Main controlling factor in radiographic contrast Selected by radiographer for every exposure Has a major influence on quality of the radiograph

21. kVp and contrast Photoelectric absorption probability aZ3 E3 Z atomic number E beam energy As kVp increases absorption by photoelectric effect rapidly decreases causing a reduction in radiographic contrast

22. kVp Determines the energy of the x-ray beam Low energy beam is easily absorbed Differential absorption increases High contrast High energy beam penetrates body more easily Differential absorption decreases Low contrast

23. Interprofessional Working…. • Communication skills • Cooperative attitude • Space awareness • Professional performance • Compromise

24. I.P.W

25. Interpreting surgeon’s requirements • Flash • Shot • Picture • Yes • All can mean “Please expose the patient and show me an image”

26. Break time

27. Orthopaedic procedures • Hip pinning • Dynamic Hip Screw (DHS) • Cannulated screws

30. Hip Fractures

31. Purpose of DHS ?

33. Accuracy

34. Screws. E.g. ASOS

35. Nailing procedures • Femoral(most common), tibial, humeral nail • Intramedullary –often requires reaming (drilling) of medullary canal • Proximal and distal locking screws

36. Nailing stages

37. Locking screws • Proximal locking usually drill guide device • Distal locking trickier and done by manual location of where to drill • Needs to achieve round holes to enable correct angulation of drill

38. Guidance systems Designed to make life easier for surgeon to place locking screws with better accuracy. Reduces need for x-rays and reduces time under anaesthetic.

39. Discussion slide

40. Tibial Nailing • Less common as tends to be less successful than femoral nail • Tibia has less vigorous blood supply than femur, and drilling out tends to compromise further. Problems with non-union • External frames becoming more popular (Taylor spatial, Ilizarov)

41. Taylor spatial frame

42. Kirschner “K” wires

43. K wires

44. Open Reduction and Internal Fixation (ORIF)

45. ORIF

46. Tension band of Olecranon fracture

47. Other Procedures • Central Lines • Give long-term central venous access for patients requiring it e.g chemotherapy

48. Peripherally inserted central catheter (PICC line) Typical screening position –intensifier on top

49. Portacath & Central Lines

50. Facet Joint Injections