Basic views of scaphoid and wrist

it all about basic x ray views of scaphoid and wrist
positioning and

1. BASIC VIEWS OF SCAPHOID AND WRIST MAAJID MOHI UD DIN MALIK LECTURER COPMS ADESH UNIVERSITY BATHINDA,PUNJAB

2. Postero-anterior – ulnar deviation Imaging of the carpal bones is most commonly undertaken to demonstrate the scaphoid. The projections may also be used to demonstrate other carpal bones, as indicated below. Four projections may be taken to demonstrate all the carpal bones using a 24 X 30-cm cassette, each quarter being used in turn, with the other three-quarters masked off using lead rubber. For scaphoid fractures, three projections are normally taken: Postero-anterior, anterior oblique and lateral.

3. Position of patient and cassette The patient is seated alongside the table with the affected side nearest the table. The arm is extended across the table with the elbow flexed and the forearm pronated. If possible, the shoulder, elbow and wrist should be at the level of the tabletop.

4. CONT… The wrist is positioned over one-quarter of the cassette and the hand is adducted (ulnar deviation). Ensure that the radial and ulnar styloid processes are equidistant from the cassette. The hand and lower forearm are immobilized using sandbags

5. DIRECTION AND CENTRING OF THE X-RAY BEAM The vertical central ray is centred midway between the radial and ulnar styloid processes.

6. ESSENTIAL IMAGE CHARACTERISTICS The image should include the distal end of the radius and ulna and the proximal end of the metacarpals. The joint space around the scaphoid should be demonstrated clearly.

7. Antero-posterior radiograph of wrist

8. POSITION

9. POSITION

10. NORMAL POSTERO-ANTERIOR RADIOGRAPH OF SCAPHOID IN ULNAR DEVIATION

11. ANTERIOR OBLIQUE – ULNAR DEVIATION Position of patient and cassette From the Postero-anterior position, the hand and wrist are rotated 45 degrees externally and placed over an unexposed quarter of the cassette. The hand should remain adducted in ulnar deviation. The hand is supported in position, with a non-opaque pad placed under the thumb. The forearm is immobilized using a sandbag.

12. DIRECTION AND CENTRING OF THE X-RAY BEAM The vertical central ray is centred midway between the radial and ulnar styloid processes.

13. ESSENTIAL IMAGE CHARACTERISTICS The image should include the distal end of the radius and ulna and the proximal end of the metacarpals. The scaphoid should be seen clearly, with its long axis parallel to the cassette.

14. ANTERIOR OBLIQUE RADIOGRAPH OF SCAPHOID

15. POSITION

16. NORMAL ANTERIOR OBLIQUE RADIOGRAPH OF SCAPHOID

17. POSTERIOR OBLIQUE Position of patient and cassette From the anterior oblique position, the hand and wrist are rotated externally through 90 degrees, such that the posterior aspect of the hand and wrist are at 45 degrees to the cassette. The wrist is placed over an unexposed quarter of the cassette, with the wrist and hand supported on a 45-degree non-opaque foam pad. The forearm is immobilized using a sandbag.

18. Direction and centring of the X-ray beam The vertical central ray is centred over the styloid process of the ulna.

19. ESSENTIAL IMAGE CHARACTERISTICS The image should include the distal end of the radius and ulna and the proximal end of the metacarpals. The pisiform should be seen clearly in profile situated anterior to the triquetral. The long axis of the scaphoid should be seen perpendicular to the cassette.

20. Posterior oblique radiograph of wrist

21. POSITION

22. NORMAL POSTERIOR OBLIQUE RADIOGRAPH OF WRIST

23. Lateral Position of patient and cassette From the posterior oblique position, the hand and wrist are rotated internally through 45 degrees, such that the medial aspect of the wrist is in contact with the cassette. The hand is adjusted to ensure that the radial and ulnar styloid processes are superimposed. The hand and wrist are immobilized using non-opaque pads and sandbags.

24. DIRECTION AND CENTRING OF THE X-RAY BEAM The vertical central ray is centred over the radial styloid process .

25. ESSENTIAL IMAGE CHARACTERISTICS The image should include the distal end of the radius and ulna and the proximal end of the metacarpals. The image should demonstrate clearly any subluxation or dislocation of the carpal bones.

26. RADIOLOGICAL CONSIDERATIONS Fracture of the waist of the scaphoid may be very poorly visible, if at all, at presentation. It carries a high risk of delayed avascular necrosis of the distal pole, which can cause severe disability. If suspected clinically, the patient may be re-examined after 10 days of immobilization, otherwise a technetium bone scan or magnetic resonance imaging (MRI) may offer immediate diagnosis.

27. LATERAL RADIOGRAPH OF WRIST

28. POSTION

29. NORMAL LATERAL RADIOGRAPH OF WRIST

30. BASIC VIEW OF WRIST Postero-anterior Position of patient and cassette The patient is seated alongside the table, with the affected side nearest to the table. The elbow joint is flexed to 90 degrees and the arm is abducted, such that the anterior aspect of the forearm and the palm of the hand rest on the cassette. If the mobility of the patient permits, the shoulder joint should be at the same height as the forearm.

31. CONT… The wrist joint is placed on one half of the cassette and adjusted to include the lower part of the radius and ulna and the proximal two-thirds of the metacarpals. The fingers are flexed slightly to bring the anterior aspect of the wrist into contact with the cassette. The wrist joint is adjusted to ensure that the radial and ulnar styloid processes are equidistant from the cassette. The forearm is immobilized using a sandbag.

32. Direction and centring of the X-ray beam The vertical central ray is centred to a point midway between the radial and ulnar styloid processes.

33. Essential image characteristics The image should demonstrate the proximal two-thirds of the metacarpals, the carpal bones, and the distal third of the radius and ulna. There should be no rotation of the wrist joint.

34. POSITION

35. Normal Postero-anterior radiograph of wrist

36. LATERAL – METHOD 1 Position of patient and cassette From the Postero-anterior position, the wrist is externally rotated through 90 degrees, to bring the palm of the hand vertical. The wrist joint is positioned over the unexposed half of the cassette to include the lower part of the radius and ulna and the proximal two-thirds of the metacarpals. The hand is rotated externally slightly further to ensure that the radial and styloid processes are superimposed. The forearm is immobilized using a sandbag.

37. Direction and centring of the X-ray beam The vertical central ray is centred over the styloid process of the radius.

38. Essential image characteristics The exposure should provide adequate penetration to visualize the carpal bones. The radial and ulnar styloid processes should be superimposed. The image should demonstrate the proximal two-thirds of the metacarpals, the carpal bones, and the distal third of the radius and ulna.

39. POSITION

40. NORMAL LATERAL RADIOGRAPH OF WRIST, METHOD 1

41. Lateral – method 2 This projection will ensure that both the radius and the ulna will be at right-angles, compared with the Postero-anterior projection. Position of patient and cassette From the Postero-anterior position, the humerus is externally rotated through 90 degrees. The elbow joint is extended to bring the medial aspect of the forearm, wrist and hand into contact with the table.

42. CONT… The wrist joint is positioned over the unexposed half of the cassette to include the lower part of the radius and ulna and the proximal two-thirds of the metacarpals. The hand is rotated externally slightly further to ensure that the radial and styloid processes are superimposed. The forearm is immobilized using a sandbag.

43. Direction and centring of the X-ray beam The vertical central ray is centred over the styloid process of the radius.

44. Essential image characteristics The exposure should provide adequate penetration to visualize the carpal bones. The radial and ulnar styloid processes should be superimposed. The image should demonstrate the proximal two-thirds of the metacarpals, the carpal bones and the distal third of the radius and ulna.

45. Notes If the patient’s limb is immobilized in plaster of Paris, then it may be necessary to modify the positioning of the patient to obtain accurate Postero-anterior and lateral projections. Increased exposure factors will be necessary to penetrate the plaster, and the resultant image will be of reduced contrast. Light-weight plasters constructed from a polyester knit fabric are radio-lucent and require exposure factors similar to uncasted areas.

46. POSITION

47. NORMAL LATERAL RADIOGRAPH OF WRIST, METHOD 2

48. Postero-anterior radiograph of wrist through conventional plaster

49. Postero-anterior radiograph of wrist through light-weight plaster

50. Oblique (anterior oblique) Position of patient and cassette The patient is seated alongside the table, with the affected side nearest to the table. The elbow joint is flexed to 90 degrees and the arm is abducted, such that the anterior aspect of the forearm and the palm of the hand rest on the tabletop.

51. CONT… If the mobility of the patient permits, then the shoulder joint should be at the same height as the forearm. The wrist joint is placed on the cassette and adjusted to include the lower part of the radius and ulna and the proximal two-thirds of the metacarpals. The hand is externally rotated through 45 degrees and supported in this position using a non-opaque pad. The forearm is immobilized using a sandbag.

52. Direction and centring of the X-ray beam The vertical central ray is centred midway between the radial and ulnar styloid processes.

53. Essential image characteristics The exposure should provide adequate penetration to visualize the carpal bones. The image should demonstrate the proximal two-thirds of the metacarpals, the carpal bones, and the distal third of the radius and ulna.

54. Radiological considerations Fracture of the distal radius can be undisplaced, dorsally angulated (Colles’ fracture) or ventrally angulated (Smith’s fracture). The importance of Smith’s fracture lies in the fact that it is less stable than Colles’ fracture. Dislocations of the carpus are uncommon, but again they carry potential for serious disability. One manifestation of lunate dislocation is an increased gap between it and the scaphoid, which will be missed if the wrist is rotated on the posteroanterior projection.

55. POSTION

56. Normal anterior oblique radiograph of wrist

57. To change the projection of the ulna, the arm must be rotated as shown in the three photographs above