positioning of the hand and wrist

how is the patient positioned in a hand or wrist projection?

1. seated

2. hand and forearm on tabletop

3. elbow flexed at 90 degree

how is the hand positioned in the PA projection?

palmar surface on IR and fingers are flat

where is the CR pointed at during a PA projection of the hand?

perpendicular to 3rd MCP joint

how is the thumb positioned in the PA projection?

oblique

what is the criteria for evaluation for a PA projection of the hand?

1. long axis of hand and wrist should be aligned with long axis of IR

2. digits slightly separated

3. no rotation of the hand. symmetric appearance of both sides of shaft of MC and phalanges

4. thumb is in the oblique position

5. an equal amount of soft tissue on each side of 2nd-5th phalanges

6. open IP and MCP joints

what are positioning errors in the PA hand?

1. wrist not in alignment with long axis of IR, causing rotation of metacarpals

2. first and second MCP joints are not open

how should the part be positioned in a PA oblique of the hand?

1. MCP joints form a 45 degree angle to IR

2. fingers straight (parallel to IR if possible) and spread slightly

3. pronated hand, rotated entire hand and wrist 45 degree

what are PA oblique projection of the hand used to show?

supplemental view for pathologic or fracture investigation

what is the criteria for evaluation for a PA oblique projection of the hand?

1. IP and MP joints should be visible as open spaces and the phalanges should be demonstrated without foreshortening

2. the finger should be parallel with the IR

3. the 2nd and 3rd metacarpals heads should not be superimposed

4. the 3rd through 5th metacarpal heads should slightly superimposed

how is the part be positioned in a lateral projection (in flexion)?

1. fingers in natural flexion and superimposed

2. thumb parallel to IR

3. hand in true lateral position

what structures are shown in a lateral projection (in flexion)

1. flexed lateral projection of the hand

2. used to show anterior and posterior displacement or fractures

how is the patient positioned in a lateral projection (extension) of the hand?

1. fingers extended and superimposed

2. thumb at right angle to palm

3. hand in true lateral position

what is the purpose of the lateral projection in extension?

used for foreign body localization

where is the CR pointed in both lateral positions?

perpendicular to the 2nd MCP joint

what is the purpose of the "fan" lateral projection?

1. can show displacement or fractures

2. foreign bodies

3. arthritis and gout

what is the criteria for evaluation for a lateral extension projection?

1. distal ulna and radius should be superimposed

2. 2nd-5th metacarpals should be superimposed

3. the 2nd-5th phalanges should be superimposed

what is another name for the AP oblique projection?

norgaard method or ball-catcher's projection

how is the AP oblique projection positioned of the hand?

45 degree rotation with posterior aspect of the hand closest to the IR

what is the AP oblique projection of the hand used for?

rheumatoid arthritis

how should the part be positioned on a PA projection of the wrist?

1. hand pronated; fingers arched

2. midcarpal area centered to IR

what structures are shown during a PA projection of the wrist?

carpals, distal radius and ulna, and proximal metacarpals

what does the AP projection of the wrist demonstrate?

carpal interspace

what is the criteria for evaluation for a PA projection of the wrist?

1. the radius and ulna are separated, the distal radioulnar joint is open

2. the scaphoid (radial) fat stripe (pad) is demonstrated, ulnar styloid in profile

3. there is equal concavity on each side of the shaft of the proximal MC

4. the navicular is foreshortened

5. trapezoid is superimposed on the trapezium

displacement on the wrist

the fat pad/stripe may be the only indicator of a fracture on the lateral aspect of the wrist; displaced due to swelling

how should the patient be positioned on a PA oblique projection of the wrist?

1. seated, elbow flex 90

2. hand and forearm resting palm down

3. shoulder, elbow, and wrist are in the same plane

how should the parts be positioned on a PA oblique projection of the wrist?

1. from pronated position, rotate wrist laterally to form 45 degree angle with IR

2. wrist in semipronated

what should be shown on the PA oblique projection of the wrist?

carpals on lateral (radial) side of wrist; shows navicular and trapezium

what is the criteria for evaluation for a PA oblique projection of the wrist?

1. the trapezium and trapezoid should be demonstrated without superimposed

2. the tuberosity of the scaphoid should be demonstrated

3. ulnar styloid should be in profile and the medial carpal bones superimposed

4. the long axis of the 3rd metacarpal and midforearm should be aligned with the long axis of the collimated field

How should the part be positioned in a lateral projection of the wrist?

1. medial aspect of the arm is adjacent to the IR

2. wrist is in true lateral (distal radius and ulna superimposed)

3. carpals centered to IR

what is the criteria for evaluation for a lateral projection of the wrist?

1. the distal end of the scaphoid and the pisiform should be superimposed

2. the radius and ulna should be superimposed

3. the anterior (pronator) fat stripe should be seen

4. the ulnar styloid should be demonstrated in profile posteriorly

if the wrist is rotated internally, the distal scaphoid is visible anterior to the pisiform and the radius is anterior to the ulna how should it be corrected?

need to externally rotated wrist

if the long axis of the first metacarpal is not aligned parallel with forearm, how should it be corrected?

align the long axis of the 1st metacarpal parallel with the midforarm

if the joint space between the trapezium and the base of the 1st metacarpal is not free of superimposed how should it be corrected?

the thumb on the same level as the 2nd metacarpal

how should the part be positioned on a PA projection in ulnar deviation

1. hand pronated

2. evert hand (turned outward), flexed toward ulna

where should the CR be pointed during a PA projection in ulnar deviation

centered at the scaphoid

what structures should be shown on the PA projection in ulnar deviation?

1. scaphoid not foreshortened; open carpal interspaces on radial of the wrist

2. ulnar flexion best method to demonstrate scaphoid bone

a radiograph of the PA scaphoid projection in ulnar deviation reveals extensive superimposition of the scaphoid and adjacent carpals

insufficient ulnar flexion/deviation can lead to this problem

where is the CR pointed at for wrist projections?

perpendicular to midcarpal area