(P) Hand/Wrist/Digit Anatomy and Positioning

What is the main image criteria for a lateral hand?

superimposition starting in the phalanges all the way to the distal arm bones.

How do you rotate the hand/wrist for a PA oblique wrist projection?

45-degree external or lateral rotation - easily achieved with a wedge sponge.

What is the proper position of the hands for the AP oblique projection (Norgaard method)?

45-degree semisupination ("open-book")

This is a benign bone tumor made of cartilage

Enchondroma

T/F: Fingers should be close together for a PA hand projection?

False. Best practice is to try to avoid soft-tissue overlap of the fingers as that can obscure bony anatomy of interest.

T/F: For a PA oblique wrist projection you should direct the CR to the long axis at the base of the metacarpals.

False. Center CR to long axis at midcarpals.

T/F: The ulnar (medial) surface of the hand is always placed flat down on the IR for a lateral projection of the hand.

False. To achieve true lateral you superimpose the styloid processes of the ulna and the radius perpendicular to the IR. This sometimes means a slight external rotation is required.

There are 2 positioning options for achieving a lateral hand. what are they?

Fan Lateral and Lateral with full extention.

What is the part position for a radiograph of the carpal bridge?

Position palm upward. Hand is positioned at right angle to forearm.

A fracture of the distal radius with anterior displacement (towards the palm) is called what?

Smiths Fracture

What is the consequence of the fingers being flexed or rested on the IR while taking a PA oblique projection of the hand?

joint spaces will be closed and the phalanges foreshortened.

Where do you direct the CR for a PA Digit

long axis of digit at the PIP or *P*roximal*I*nter*P*halangeal joint

What surface of the hand is placed flat on the IR for a lateral projection of the 5th digit?

medial or ulnar.

For a PA hand projection where do you center the CR?

the 3rd MCP joint

If the scaphoid or navicular bone was of interest, how would you alter the standard PA projection?

with extreme ulnar deviation and the CR directed at the scaphoid bone at the base of the thumb.

An injury to the ulnar collateral ligament that affects the first metacarpophalangeal (MCP) joint might be demonstrated with the:

"Folio Method" The PA projection of the first MCP joint demonstrates the ulnar collateral ligament and the joint.

The fingers are flexed for the PA wrist projection to reduce what?

OID

What is the Stecher Method?

PA Axial. Place hand on IR on wedge sponge to achieve appropriate angle.

Which of the following methods is used to demonstrate the trapezium carpal bone?

PA axial oblique (Clements-Nakayama method)

A wedge sponge is often helpful in decreasing motion for this 45-degree projection of a single digit, what is it?

PA oblique

Describe the proper light field for an AP projection of the first digit.

- CR at long axis of MCP joint - 1" collimation on all sides of digit

Describe the ideal light field for a PA hand projection.

- Center CR to long axis of third digit at MCP joint - Collimate to 1 inch on all sides of the hand, including 1 inch proximal to the ulnar styloid.

Describe the proper position for an AP projection of the first digit.

- extreme internal rotation - dorsal surface of thumb resting on IR - thumb is fully extended.

What is the proper part position for a PA oblique hand?

1) Externally rotate hand until MCP joints are at 45-degree angle to IR. 2) Support hand on wedge or stair-step sponge. 3) Fingers fully extended.

How do you place the hand for a lateral projection?

1) Position patient with lateral surface of hand and wrist resting on IR. 2) Extend digits and abduct thumb

Image criteria for a PA oblique of digits 2-5 includes what?

1) open joint space 2) no superimposition of adjacent fingers over the MCP joint or proximal phalanx. 3) 45-degree rotation of affected digit and adjoining distal metacarpal

Where does the CR enter for a carpal canal exam?

Angle CR 25 to 30 degrees to long axis of hand. CR should enter palm 1 inch distal to the base of third metacarpal. Near the center of the palm.

What is the appropriate collimation field for the PA, lateral and oblique projections of a single digit?

Collimate to 1 inch on all sides of the digit, including 1 inch proximal to the *M*eta*C*arpo*P*halangeal joint or MCP.

Describe the proper collimation for the PA/lateral/oblique wrist projection?

Collimate to 2.5 inches proximal and distal to the wrist joint and 1 inch on the palmar and dorsal surfaces.

Lateral digits two through five. Major critique criteria?

Concave anterior surfaces of the phalanges and open joint space

No rotation of the digit, 2-5, is confirmed by what?

Concavity of the phalangeal shafts and an equal amount of soft tissue on both sides of the phalanges

The tangential projection (Gaynor-Hart method) is used to demonstrate the:

Carpal canal

Where do you direct the CR for a PA oblique hand?

Center CR to long axis of third digit at MCP joint.

Which method is used for the trapezium?

Clements-Nakayama method PA axial oblique, CR at trapezium

Osteoarthritis

Degenerative Joint Disease

Dislocation

Displacement of a bone from the joint space

For the joint spaces to be demonstrated on the PA oblique projection of the hand, the fingers must be:

Extended and placed parallel with the image receptor

What is the difference between a lateral projection of digits 2 or 3 and 4 or 5.

For digits 2/3 you rotate the internally or onto the radial lateral surface. For digits 4/5 the rotation is external or onto the ulnar lateral surface. This places the affected digit closer to the IR and reduces OID.

Colle's Fracture

Fracture of the distal radius with posterior displacement

Boxers Fracture

Fracture of the metacarpal neck (generally the 5th metacarpal)

This projection is used to open the carpal canal, what is it?

Gaynor-Hart Method. Place the hand palmar side down on the IR. Hyperextend the wrist upwards. Place the hand vertical to IR.

In the PA/PA axial projections scaphoid radiographic series (Rafert-Long method), the wrist is positioned:

In extreme ulnar deviation

Osteomyelitis

Inflammation of bone resulting from a pyogenic infection

What is unique about part positioning for a PA oblique projection of the first digit?

It is the same position as the PA hand.

What is the purpose of positioning the upper limb in the same plane when performing radiographic procedures?

It opens the joint spaces and reduces distortion.

This special projection of the hand shows displacement of metacarpals.

Lateral hand in flexion. ulnar side down. fingers relaxed into natural arch but superimposed. thumb parallel to IR.

Osteoporosis

Loss of bone density

The Folio Method is most effective at imaging what?

MCP joints. (upside down book hands - thumbs together not touching)

How is the hand positioned for the PA projection of the wrist?

Pronated with fingers flexed

What is the method that is used as the scaphoid series?

Rafert-Long Method. PA and PA axial with extreme ulnar deviation.

What is the position of the styloid processes for the lateral projection of the wrist?

Superimposed and perpendicular to the image receptor

which method is used to demonstrate early changes associated with rheumatoid arthritis.

The AP oblique projection (Norgaard method) is used to demonstrate early changes associated with rheumatoid arthritis.

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acronym for the carpal bones

This bone is the largest carpal bone

capitate

The joint spaces of the digits are demonstrated when the fingers are [flexed or extended] and parallel with the IR.

extended

How must the hand be positioned to obtain an AP radiograph of the thumb?

extreme internal rotation

For a PA projection of the hand, should the part of interest be pronated or supinated?

pronated

Where do you center the CR for a lateral single digit exam?

the long axis of the finger, centered at the PIP joint.

carpal bone between lunate and pisiform is what?

triquetrum