The document provides a detailed overview of the carpal tunnel and its anatomy, focusing on the median nerve and associated syndromes. It outlines various imaging techniques and patient positioning for radiographic assessment of wrist conditions, including carpal tunnel syndrome and fractures. The document emphasizes the complex structure of the wrist, detailing various views and exposure settings necessary for effective imaging.

1. DON BENNY
BMIT- II YEAR

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.

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

6.  Supero-inferior (Axial)
 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

8. Carpal
Carpal TunnelCarpal Bones

9. Axial projection
Centring point
 Mid 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

10. Orientation
 portrait
Detector size
 18 cm x 24 cm
Exposure
 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.

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

14. Centring point
 Mid 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

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

16. 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.

17.  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.

18. The radius articulates with
the scaphoid laterally and
the lunate medially. The lunate
is connected to the scaphoid via
the scapholunate ligament,
and provides stability to the
radiocarpal joint.

19. 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

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

21.  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

23. 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

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

25.  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 .

26.  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

28. 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

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

30.  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

32. 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.

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

34.  The ulna head and distal radius are slight superimposed. The
proximal metacarpals 3 to 5 also being partly superimposed.

35. 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

37. 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

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

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

40.  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

42. 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

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

44.  There should be a clear outline of the dorsal aspect of the
carpal bones with no superimposition.

45.  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

47. 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

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

49.  hand is in radial deviation
 minor superimposition of the metacarpal base

50. REFERENCE