Upper Limb (Extremity)

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Chapter 2

Upper Limb (Extremity)

• Technical factors and radiation protection

Fingers

PA fingers (R)

PA oblique fingers (R)

PA and PA oblique critique

Lateral fingers (R)

Thumb

AP (R)

Lateral finger and AP thumb critique

PA oblique (R)

Lateral (R)

PA oblique and lateral thumb critique

AP axial (modified Roberts method) (S)

Hand

PA (R)

AP axial thumb and PA hand critique

PA oblique (R)

Lateral (“fan”) (R)

PA oblique hand and “fan” lateral hand critique

AP oblique bilateral (Norgaard/ball-catcher’s) (S)

AP oblique bilateral critique

Wrist

PA (R)

PA oblique (R)

PA and PA oblique critique

Lateral (R)

Lateral critique

PA axial ulnar deviation (15° and Modified Stecher) (S)

Scaphoid projections (15° and Modified Stecher) critique

PA radial deviation (S)

PA wrist radial deviation critique

Tangential carpal canal (Gaynor-Hart method) (S)

Tangential carpal canal critique

Forearm

AP (R)

Lateral (R)

AP and lateral critique

Elbow

AP (R)

AP critique

AP partially flexed critique

AP oblique (medial and lateral) (R)

AP medial and lateral elbow critique

Lateral elbow (R)

Lateral elbow critique

Trauma axial lateral (Coyle method) (S)

Trauma axial lateral (Coyle method) critique

Pediatric Upper Limbs

AP (S)

Lateral (S)

(R) Routine, (S) Special

Upper Limb (Extremity)^*

Technical Factors

The following technical factors are important for all upper limb procedures to maximize image sharpness.

• 40-44″ (102-113 cm) SID, minimum OID

• Small focal spot

• Nongrid or TT (tabletop), detail (analog) screens

• Digital imaging requires special attention to accurate CR and part centering and close collimation.

• Short exposure time

• Immobilization (when needed)

• Multiple exposures per imaging plate: Multiple images can be placed on the same IP. When doing so, careful collimation and lead masking must be used to prevent pre-exposure or fogging of other images.

• Grid use with digital systems: Grids generally are not used with analog (film-screen) imaging for body parts measuring 10 cm or less. However, with certain digital systems, the grid may or may not be able to be removed from the receptor. In those cases, it is departmental protocol that determines if a grid is left in place or removed. Important: If a grid is used, the anatomy must be centered to it to avoid grid cutoff.

Radiation Protection

Collimation

Close collimation is the most effective practice for preventing unnecessary radiation exposure to the patient.

Patient Shielding

Erect Patients:

Patients seated at the end of the table should always have a shield over radiosensitive organs to prevent exposure from scatter radiation and from the divergent primary beam.

Recumbent Patients:

A good practice to follow for upper limb examinations for patients on a stretcher or table is to always have shielding in place, especially the gonadal region.

PA Fingers ^*

Alternative routine: Include entire hand on PA finger projection for possible secondary trauma to other parts of hand (see PA Hand).

• 18 × 24 cm L.W. (8 × 10″)

• Nongrid

• Lead masking with multiple exposures on same IR

PA Oblique Fingers ^*

• 18 × 24 cm L.W. (8 × 10″)

• Nongrid

• Lead masking with multiple exposures on same IR

Fig. 2-2 PA oblique, 2nd digit (parallel to IR). Inset: Minimized OID.

Position

• Patient seated, hand on table, elbow flexed 90° (lead shield over lap)

• Align fingers to long axis of portion of IR being exposed.

• Rotate hand 45° medially or laterally (dependent of digit examined), resting against 45° angle support block.

• Separate fingers; ensure that affected finger(s) is (are) parallel to IR.

Central Ray:

CR ⊥, centered to PIP joint

SID:

40-44″ (102-113 cm)

Collimation:

On four sides to area of affected finger(s) and distal aspect of metacarpal

PA Finger

Evaluation Criteria

Anatomy Demonstrated:

• Distal phalanx to distal metacarpal and associated joints

Position:

• Long axis of digit parallel to IR with joints open

• No rotation of digit with symmetric appearance of shafts

Exposure:

• Optimal density and contrast (brightness and contrast for digital images)

• Soft tissue and bony trabeculation clearly demonstrated; no motion

Fig. 2-3 PA finger.

PA Oblique Finger

Evaluation Criteria

Anatomy Demonstrated:

• Distal phalanx to distal metacarpal and associated joints

Position:

• Interphalangeal and MCP joints open

• No superimposition of adjacent digits

Exposure:

• Optimal density and contrast (brightness and contrast for digital images)

• Soft tissue and bony trabeculation clearly demonstrated; no motion

Fig. 2-4 PA oblique finger.

Lateral Fingers ^*

• 18 × 24 cm L.W. (8 × 10″)

• Nongrid

• Lead masking with multiple exposures on same IR

Fig. 2-5 4th digit.

Fig. 2-6 2nd digit (digit parallel to IR).

Position

• Patient seated, hand on table (lead shield over lap)

• Hand in lateral position, thumb side up for 3rd to 5th digits, thumb side down for 2nd digit

• Align finger to long axis of portion of IR being exposed.

Central Ray:

CR ⊥, centered to PIP joint

SID:

40-44″ (102-113 cm)

Collimation:

On four sides to area of affected finger and distal aspect of metacarpal

AP Thumb ^*

• 18 × 24 cm L.W. (8 × 10″)

• Nongrid

• Lead masking with multiple exposures on same IR

Position

• Patient standing or seated, hand rotated internally with palm out to bring the posterior surface of thumb in direct contact with IR

• Align thumb to long axis of portion of IR being exposed.

Central Ray:

CR ⊥, centered to lst MP joint

SID:

40-44″ (102-113 cm)

Collimation:

Collimate closely to area of thumb (include entire 1st metacarpal extending to carpals).

Fig. 2-7 AP thumb, CR to 1st MP joint.

Lateral Fingers

Evaluation Criteria

Anatomy Demonstrated:

• Distal phalanx to distal metacarpal and associated joints

Position:

• True lateral: joints are open and concave appearance of anterior surfaces of shaft of phalanges

Exposure:

• Optimal density and contrast (brightness and contrast for digital images)

• Soft tissue margins and bony trabeculation clearly seen, no motion

Fig. 2-8 Lateral finger.

AP Thumb

Evaluation Criteria

Anatomy Demonstrated:

• Distal phalanx to proximal metacarpal and trapezium

Position:

• Long axis of thumb parallel to IR with joints open

• No rotation of thumb with symmetric appearance of shafts

Exposure:

• Optimal density and contrast (brightness and contrast for digital images)

• Soft tissue and bony trabeculation clearly demonstrated; no motion

Fig. 2-9 AP thumb.

PA Oblique Thumb ^*

• 18 × 24 cm L.W. (8 × 10″)

• Nongrid

• Lead masking with multiple exposures on same IR

Position

• Patient seated, hand on table, elbow flexed (shield over lap)

• Align thumb to long axis of portion of IR being exposed.

• With hand pronated, abduct thumb slightly. This position tends to naturally rotate thumb into 45° oblique.

Central Ray:

CR ⊥, centered to 1st MCP joint

SID:

40-44″ (102-113 cm)

Collimation:

Collimate closely to area of thumb (include entire 1st metacarpal extending to carpals).

Fig. 2-10 Oblique thumb, CR to 1st MCP joint.

Lateral Thumb ^*

• 18 × 24 cm L.W. (8 × 10″)

• Nongrid

• Lead masking with multiple exposures on same IR

Position

• Patient seated, hand on table, elbow flexed (shield across lap)

• Align thumb to long axis of portion of IR being exposed.

• With hand pronated and slightly arched, rotate hand medially until thumb is in true lateral position.

Central Ray:

CR ⊥, centered to lst MCP joint

SID:

40-44″ (102-113 cm)

Collimation:

Collimate closely to area of thumb (include entire 1st metacarpal extending to carpals).

Fig. 2-11 Lateral thumb, CR to 1st MCP joint.

PA Oblique Thumb

Evaluation Criteria

Anatomy Demonstrated:

• Distal phalanx to proximal metacarpal and trapezium

Position:

• Long axis of thumb parallel to IR with joints open

Exposure:

• Optimal density and contrast (brightness and contrast for digital images)

• Soft tissue and bony trabeculation clearly demonstrated

Fig. 2-12 PA oblique thumb.

Lateral Thumb

Evaluation Criteria

Anatomy Demonstrated:

• Distal phalanx to proximal metacarpal and trapezium

Position:

• True lateral position

• Interphalangeal and MCP joints open

• Anterior surfaces of first metacarpal and proximal phalanx equally concave shaped; posterior surfaces are relatively straight

Exposure:

• Optimal density and contrast (brightness and contrast for digital images)

• Soft tissue and bony trabeculation clearly demonstrated, no motion

Fig. 2-13 Lateral thumb.

AP Axial Thumb ^*

(Modified Roberts)

Note: This is a special projection to better demonstrate the first carpometacarpal joint region.

• 18 × 24 cm L.W. (8 × 10″)

• Nongrid

• Lead masking with multiple exposures on same IR

Fig. 2-14 AP axial thumb for 1st CMC joint (CR 15° proximally).

Position

• Patient seated or standing, hand rotated internally placing posterior surface of thumb directly on IR

• Align thumb to long axis of portion of IR being exposed.

• Extend fingers and hold back with other hand to prevent superimposing base of thumb and 1st CMC joint region (a key positioning requirement).

Central Ray:

CR angled 15° proximally, centered to 1st CMC joint

SID:

40-44″ (102-113 cm)

Collimation:

Collimate closely to entire thumb, including the trapezium carpal bone.

PA Hand ^*

• 24 × 30 cm L.W. (10 × 12″)

• 18 × 24 cm L.W. (8 × 10″) smaller hand

• Nongrid

• Lead masking with multiple exposures on same IR

Position

• Patient seated, hand on table, elbow flexed (shield across lap)

• Align long axis of hand and wrist parallel to edge of IR.

• Hand fully pronated, digits slightly separated

Central Ray:

CR ⊥, centered to 3rd MCP joint

SID:

40-44″ (102-113 cm)

Collimation:

Collimate on four sides to outer margins of hand and wrist. Include proximal and distal row of carpals.

Fig. 2-15 PA hand.

AP Axial Thumb (Modified Roberts)

Evaluation Criteria

Anatomy Demonstrated:

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