Projections of carpal tunnel and wrist

Basic and Supplementary Projection of Carpal Tunnel
and Wrist. IT GIVES INFORMATION'S ABOUT PROJECTIONS OF WRIST . IT IS MORE HELPFUL FOR IMAGING STUDENTS TO KNOW ABOUT WRIST AND ITS RADIO-GRAPHIC POSITIONS.

1. Don Benny BMIT- ii year basic and supplementary projection of carpal tunnel And wrist

2. The carpal tunnel refers to the tunnel-like structure of the wrist in which 9 tendons and the median nerve pass through a narrow passage under a tight band of tissue known as the transverse carpal ligament. ANATOMY

3. The boundaries of carpal tunnel are the Carpal bones and the flexor retinaculum. Carpal tunnel syndrome is the compression of the median nerve as it passes into the hand through carpal ligaments  

4. Carpel Tunnel

5. INDICATIONS Suspected metacarpal dislocation Foreign body detection and localisation. Investigation of joint pain/ Hand pain. Investigation of Carpal tunnel syndrome.

6. CARPAL TUNNEL BASIC PROJECTIONS Supero-inferior (Axial) SUPPLIMENTARY PROJECTIONS Infero -superior (Axial) The  carpal tunnel view  is an axial projection to demonstrate the medial and lateral prominences and the concavity. 

7. Patient is standing facing away from the table. The detector is placed level with the edge of the table top . palmar surface of hand is pressed into the detector, with the wrist joint dorsiflexed to approximately 135º. The fingers are curled around under the table to assist in immobilisation. Patient Position SUPERO – INFERIOR (AXIAL)

8. Carpal Carpal Tunnel Carpal Bones

9. Axial projection Centring point M id carpal region The central ray is vertical and will be centered to the midpoint of the dorsiflexed wrist Collimation Laterally to the skin margins Dorsal to the skin margins  Ventral to the carpometacarpal joint  TECHNICAL FACTORS

10. Orientation    portrait Detector size 18 cm x 24 cm E xposure 50-60 kVp 3-5 mAs

11. 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. IMAGE CHARACTRISTICS

12. Patient Position The patient is seated alongside the table. The detector is placed on top of a plastic block approximately 8 cm high The lower end of the forearm rests Against the edge of the block, with the Wrist adducted and dorsiflexed to 135º This position is assisted using a traction bandage held by the patients other hand INFERO – SUPERIOR (AXIAL)

13. Centring point M id carpal region The central ray is vertical and will be centered to the midpoint of the dorsiflexed wrist Collimation Laterally to the skin margins Dorsal to the skin margins  Ventral to the carpometacarpal joint   Axial projection TECHNICAL FACTORS

14. Orientation     Portrait Detector size 18 cm x 24 cm E xposure 50-60 kVp 3-5 mAs

15. The image should demonstrate clearly the pisiform and the hook of the hamate medially and the tubercle of the scaphoid and the tubercle of the trapezium laterally. IMAGE CHARACTERISTICS

16. The wrist is a complex joint that bridges the hand to the forearm. It is actually a collection of multiple bones and joints. The bones comprising the wrist include the distal ends of the radius and ulna, 8 carpal bones, and the proximal portions the 5 metacarpal bones. WRIST ANATOMY

17. The radius articulates with the scaphoid laterally and the lunate medially. The lunate  is connected to the scaphoid via the scapholunate ligamen t, and provides stability to the radiocarpal joint. 

18. Its a complex joint that bridges the hand to the forearm  Assessment of trauma To find any kind of Bone fracture Suspected metacarpal dislocation Foreign body detection and localisation Investigation of joint pain or deformity INDICATIONS

19. BASIC PROJECTIONS Postero-anterior (PA) Oblique Lateral Horizontal Beam Lateral Wrist Carpal Bridge view Radial deviation view PROJECTIOS SUPPLIMENTARY PROJECTIONS

20. patient is seated alongside the table the affected arm if possible is flexed at 90° so the arm and wrist can rest on the table the affected hand is placed, palm down on the image receptor shoulder, elbow, and wrist should all be in the transverse plane, perpendicular to the central beam the wrist and elbow should be at shoulder height which makes radius and ulna parallel Patient position WRIST PA

21. Postero-anterior projection Centring Point mid carpal region / Between the radial and ulnar styloid processes. Collimation laterally to the skin margins distal to the midway up the metacarpals proximal to the include one-quarter of the distal radius and ulna TECHNICAL FACTORS

22. Orientation     portrait Detector size 18 cm x 24 cm Exposure 50 - 60 kVp 3 - 5 mAs

23. IMAGE CHARACTERISTICS The ulna head and distal radius are slight superimposed . The proximal metacarpals 3 to 5 also being partly superimposed. The image should demonstrate the proximal 2/3 of the Metacarpals , the carpal bones , and the distal 1/3 of the radius and ulna. There should be no rotation of the wrist joint .

24. patient is seated alongside the table From the PA position the wrist is externally rotated through 90 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 2/3 of the metacarpals. The hand is rotated externally slightly further to ensure that the radial and styloid processes are superimposed. Patient Position WRIST LATERAL

25. TECHNICAL FACTORS Lateral Projection Centring point mid carpal region Collimation Antero-posterior to the skin margins distal to the midway up the metacarpals proximal to include one-quarter of the distal radius and ulna

26. Orientation   portrait Detector size 18 cm x 24 cm Exposure 50-60 kVp 3-5 mAs

27. patient is seated alongside the table the affected arm if possible is flexed at 45 ° so the arm and wrist can rest on the table the affected hand is placed, palm down on the image receptor shoulder, elbow, and wrist should all be in the transverse plane, perpendicular to the central beam wrist and elbow should be at shoulder height which makes radius and ulna parallel from the positioning of the PA projection, the wrist is externally rotated 40° - 45°; a sponge can be placed under the wrist to aid stability. Patient Position WRIST OBLIQUE

28. TECHNICAL FACTORS Postero -anterior Projection Centring point mid carpal region Collimation laterally to the skin margins distal to the midway up the metacarpals proximal to the include one-quarter of the distal radius and ulna.

29. Orientation     portrait Detector size 18 cm x 24 cm Exposure 50-60 kVp 3-5 mAs

30. The ulna head and distal radius are slight superimposed . The proximal metacarpals 3 to 5 also being partly superimposed. IMAGE CHARACTERISTICS

31. patient is supine affected arm is placed by the patient's side on a pillow or foam block image receptor is placed leaning against the aforementioned foam block or pillow with the long axis of the image receptor in line with the long axis of the affected limb Patient Position WRIST - HORIZONTAL BEAM LATERAL VIEW

32. TECHNICAL FACTORS Lateral Projection Centring point The ulnar aspect of the mid carpal region Collimation Antero-posterior to the skin margins distal to the mid way up the metacarpals proximal to include one quarter of the distal radius and ulna

33. Orientation     landscape Detector size 24 cm x 30 cm Exposure 50-60 kVp 3-5 mAs

34. IMAGE CHARACTERISTICS There is superimposition of the carpal bones, including the distal portion of the scaphoid and the pisiform. The radius and ulna are also superimposed.

35. The patient is seated alongside the table. Dorsal aspect of affected wrist is placed on the detector in flexion. Flex the wrist as much as tolerable to the patient . Patient position WRIST - CARPAL BRIDGE VIEW

36. TECHNICAL FACTORS Tangential projection Centring point midcarpal region the central ray is angled approximately 45 degrees to the long axis of the forearm   Collimation laterally to the skin margins dorsal to the skin margins  ventral to the carpometacarpal joint  

37. Orientation     Portrait Detector size 18 cm x 24 cm Exposure 50-60 kVp 3-5 mAs

38. IMAGE CHARACTERISTICS There should be a clear outline of the dorsal aspect of the carpal bones with no superimposition.

39. patient is seated alongside the table the affected arm if possible is flexed at 90° so the arm and wrist can rest on the table the affected hand is placed, palm down on the image receptor with hand in radial deviation shoulder, elbow, and wrist should all be in the transverse plane, perpendicular to the central beam the wrist and elbow should be at shoulder height which makes radius and ulna parallel Patient Position WRIST - RADIAL DEVIATION VIEW

40. Postero -anterior Projection Centring point central carpal zone Collimation laterally to the skin margins distal to the midway up the metacarpals proximal to the include one-quarter of the distal radius and ulna TECHNICAL FACTORS

41. Orientation     Portrait Detector size 18 cm x 24 cm Exposure 50-60 kVp 3-5 mAs

42. hand is in radial deviation minor superimposition of the metacarpal base IMAGE CHARACTERISTICS

43. REFERENCE CLARK’S POSITIONING IN RADIOGRAPHY