Hand Part 2

RADIOGRAPHIC OF THE HAND PART 2 (special consideration)

PART: 2

BOTH HANDS

dorsi-Palmar-BOTH HANDS

This projection is often used to demonstrate subtle radiographic changes associated with early rheumatoid arthritis and to monitor the progress of the disease.

Dorsi-palmar

• Position of patient and cassette

Ideally, the patient is seated alongside the table.

However, if this is not possible due to the patient’s condition, the patient may be seated facing the table Both forearms are pronated and placed on the table with the palmer surface of the hands in contact with the cassette The fingers are separated and extended but relaxed to ensure that they remain in contact with the cassette The wrists are adjusted so that the radial and ulna styloid processes are equidistant from the cassette.

A sandbag is placed over the lower forearms for immobilization. Direction and centering of the X-ray beam

Direction and location of the X-ray beam

The vertical central is centered over a point midway between the inter-phalangeal joints of both thumbs.

Essential image characteristics

The image should demonstrate all the phalanges, including the soft tissue of the fingertips, the carpal and metacarpal bones and the distal end of the radius and ulna.

The exposure factors selected must produce an accurate EI and optimally demonstrate joint detail.

Antero-posterior oblique both

• hands (ball catcher’s or Norgaard
• projection)
• This projection may be used in the diagnosis of rheumatoid arthritis.
• It can also be used to demonstrate fractures of the base of the 5th metacarpals.

CR a 24 × 30 cm cassette is employed.

Position of the patient and image receptor

Ideally the patient is seated alongside the table. However, if this is not possible, due to the patient’s condition, the patient may be seated facing the table Both forearms are supinated and placed on the table with the dorsal surface of the hands in contact with the image receptor.

From this position both hands are rotated internally (medially) 45° into a ‘ball catching’ position.

The fingers and thumbs are separated and extended but relaxed to ensure that they remain in contact with the image receptor.

• The hands may be supported using 45° non-opaque pads.

A sandbag is placed over the lower forearms for immobilisation.

Direction and location of X-ray beam

The collimated vertical beam is centered to a point midway between the hands at the level of the 5th metacarpophalangeal joints (MCPJ).

Essential image characteristics

The image should demonstrate all the phalanges, including the soft tissue of the finger tips, the carpal and metacarpal bones and the distal end of the radius and ulna.

The exposure factors selected must produce an accurate EI and optimally demonstrate joint detail.

The heads of the metacarpals should not be superimposed.

Radiation protection

If it has been necessary to position the patient facing the table it is essential to provide radiation protection for the lower limbs and gonads.

This may be achieved by placing a lead-rubbersheet on the table underneath the image receptor to attenuate the primary beam

Lateral – hand

In the lateral position the metacarpals overshadow and obscure each other.

However, this projection is essential to demonstrate anterior or posterior displacements of fracture fragments.

This projection is also used to determine the position of foreign bodies in the palmar or dorsal aspect of the hand.

Position of patient and image receptor

From the postero-anterior (DP) position, the hand is externally rotated 90°.

The palm of the hand is perpendicular to the image receptor, with the fingers extended and the thumb abducted and supported parallel to the image receptor on a non-opaque pad.

The radial and ulnar styloid processes are superimposed.

Direction and location of the X-ray beam

The collimated vertical beam is centered over the head of the 2nd metacarpal.

Essential image characteristics

The image should include the fingertips, including soft tissue, and the radial and ulnar styloid processes.

• The heads of the metacarpals should be superimposed.

The thumb should be demonstrated clearly without superimposition of other structures

Radiological considerations

The hand and wrist (like the ankle and foot) have many accessory ossicles, which may trap the unwary into a false diagnosis of pathology.

‘Boxer’s fracture’ of the neck of the 5th metacarpal is seen easily, but conspicuity of fractures of the bases of the metacarpals is reduced by over-rotation and underexposure.