Foot 1 Dorsi plantar normal

Question 1

What equipment is required for the dorsi-plantar projection?

Answer 1

A: 24 x 30 cm image receptor (split into two parts),
lead rubber sheet,
sandbag,
lead protective waist apron.

Question 2

What is the centering point for the dorsi-plantar projection?

Answer 2

Over the cuboid-navicular joint, midway between the palpable navicular tuberosity and the tuberosity of the fifth metatarsal.

Question 2

What is the direction of the central ray for the dorsi-plantar projection?

Answer 2

Angle the central ray 10° to 15° posteriorly (toward the heel).

Question 2

How should the patient be positioned for the dorsi-plantar projection?

Answer 2

• Seat the patient on the X-ray couch with knees flexed,
• Place the plantar aspect of the affected foot on the image receptor,
• Align and center long axis of the foot to the long axis of the and IR.
• Use a sandbag to prevent IR from slipping from on the table.
• Support the knee of the affected food by putting the other knee of the unaffected side for immobilization.

Question 3

Why should the CR be angled 10 degrees on normal AP of the foot.

Answer 3

• When a 10⁰ posterior angle is used, the central ray is perpendicular to the metatarsals, reducing foreshortening.
• The tarso-metatarsal joint spaces of the midfoot are better shown

Question 4

Special features of when doing an x-ray exam of AP foot

Answer 4

A wedge filter placed under the toes may be used to
give a uniform range of densities, especially if the image
is acquired using film/screen technology.