Imaging the equine distal limb- common studies

What is the lateral (lateromedial) view of the distal phalanx used to evaluate?

The distance between the hoof wall and the dorsal border of P3.

How should the hoof be positioned for a lateral view of the distal phalanx?

On the medial edge of the block next to the film.

Where is the beam centered for P3 on a lateral view?

Below the coronary band over the hoof wall.

Where is the beam centered for the navicular bone on a lateral view?

Below the coronary band over the hoof wall at the palmar/plantar aspect.

What abnormality can be evident on a lateral view of P3?

Rotation of P3.

Does the limb need to be weight-bearing for the lateral distal phalanx view?

Yes.

What is required for the dorsopalmar/dorsoplantar view of the distal phalanx?

The limb needs to be weight-bearing.

How should the hoof be positioned for a dorsopalmar/dorsoplantar view?

Heel bulbs at the edge of the block.

Where is the beam centered for the dorsopalmar/dorsoplantar view of P3?

Over the middle of P3, just below the coronary band.

What is the purpose of the 65° dorsopalmar/dorsoplantar oblique view?

To evaluate the size, number, and character of vascular channels and the distal border of the navicular bone.

Where is the beam centered for the 65° oblique view?

Over P2, just above the coronary band.

What are the three standard views of the navicular bone?

1. Lateral (lateromedial)

2. Dorsopalmar/dorsoplantar oblique 65°

3. Palmaroproximal/palmarodistal or plantaroproximal/plantarodistal flexor view.

What is another name for the palmaroproximal/palmarodistal view?

The flexor view.

When is the navicular series commonly performed?

As part of a pre-purchase exam.

Which navicular view is best for evaluating the cortex, medulla, and ridge?

The flexor view.

What are the standard views of the metacarpus/metatarsus?

Dorsopalmar/dorsoplantar, lateral and medial oblique views, and lateral (lateromedial).

How should the limb be positioned for metacarpus/metatarsus radiographs?

In the normal standing position.

Where is the tube pointed for metacarpus/metatarsus radiographs?

At the midpoint of the metacarpus/metatarsus.

Where is the cassette placed for the dorsopalmar/dorsoplantar view?

Palmar or plantar.

Where is the cassette placed for the oblique views?

Medial or lateral palmar/plantar at 45°.

Where is the cassette placed for the lateral view?

Medial.

How is the hoof positioned for a lateral distal phalanx view?

On a wooden block, close to the edge.

How is the hoof positioned for a dorsopalmar/dorsoplantar distal phalanx view?

On a wooden block with the heel at the edge.

How is the hoof positioned for the dorsopalmar/dorsoplantar oblique navicular view?

In the center of the block or in a specialty-designed block.

How is the hoof positioned for the flexor view?

On top of the block; ideally the fetlock is in an extended position.

Where is the cassette placed for the lateral distal phalanx view?

On the medial side of the foot, on the floor or in the cassette groove.

Where is the cassette placed for the dorsopalmar/dorsoplantar distal phalanx view?

Behind the hoof on the floor or in the cassette groove, perpendicular to the floor.

Where is the cassette placed for the navicular oblique view?

In the tunnel cassette holder; with a specialty block, behind the heels.

Where is the cassette placed for the flexor view?

Within the cassette tunnel.

What should be included when collimating the hoof?

The entire hoof.

Where is the beam centered for the lateral distal phalanx view?

Hoof wall below the coronary band.

Where is the beam centered for the dorsopalmar/dorsoplantar distal phalanx view?

Middle of the pedal bone, below the coronary band.

Where is the beam centered for the navicular oblique view?

Middle of the hoof wall, below the coronary band.

Where is the beam centered for the flexor view?

Middle of the heel bulbs.

What is important about the leg being radiographed for the hoof views?

It must be weight-bearing.

What angle is used for the x-ray tube for the navicular oblique view with a traditional block?

65° toward the middle of the second phalanx.

How is the beam directed when using a specialty navicular block?

Parallel to the specialty block.

What angle should the x-ray tube be positioned at for the flexor view?

65° to the floor, behind the hoof.

What should be included in the collimation for the proximal phalanges?

The 1st and 2nd phalanges.

Where is the cassette placed for the lateral proximal phalanx view?

Medial side of the hoof, perpendicular to the floor.

Where is the cassette placed for the dorsopalmar/dorsoplantar proximal phalanx view?

Behind the leg, parallel to the phalanges.

How should the fetlock be positioned for a dorsopalmar/dorsoplantar view?

Directly under the animal and weight-bearing.

How should the fetlock be positioned for a lateral view?

Directly under the animal and weight-bearing.

What should be included in the collimation for a fetlock view?

The entire fetlock and 1/3 or less of the bones on either side of the joint.

Where is the beam centered for a dorsopalmar/dorsoplantar fetlock view?

Over the fetlock joint at a right angle to the cassette.

What is important about the limb during proximal phalanx radiographs?

It needs to be weight-bearing.

What should be minimized during proximal phalanx radiographs?

Motion.

How much may the x-ray tube need to be tilted for the dorsopalmar/dorsoplantar proximal phalanx view?

30°-45° to the floor.

What can slightly tilting the beam do during a fetlock view?

Allow the joint to be seen more clearly.

How is the fetlock positioned for a flexed lateral view?

The fetlock joint should be flexed.

Where is the cassette placed for the flexed lateral fetlock view?

Against the medial aspect of the joint.

What must NOT be included in the collimated area during a flexed lateral fetlock view?

The assistant's hand holding the animal's leg.

What do DLPMO and DMPLO views of the fetlock allow you to visualize?

The medial and lateral sesamoid bones.

What angle is the beam centered at for DLPMO/DMPLO of the fetlock?

Approximately 30°-45° from the dorsal midline of the joint.

What is the standard positioning for metacarpus/metatarsus views?

Normal weight-bearing position.

What should be included in metacarpus/metatarsus collimation?

The joints proximal and distal to the metacarpus/metatarsus.

Where is the beam centered for metacarpus/metatarsus views?

Midway over the metacarpus/metatarsus.

What are DLPMO and DMPLO views of the metacarpus/metatarsus used to view?

The splint bones.

How should the animal be positioned for standard carpal views?

Normal weight-bearing position.

How is the carpus positioned for a flexed lateral view?

The carpus is flexed by elevating the limb.

Where is the cassette placed for a dorsopalmar carpal view?

Perpendicular to the floor on the palmar aspect of the carpus.

Where is the cassette placed for a lateral carpal view?

Perpendicular to the floor on the medial aspect of the carpus.

Where is the cassette placed for a flexed lateral carpal view?

Perpendicular to the floor on the medial aspect of the carpus.

Where is the beam centered for a dorsopalmar carpal view?

Middle of the carpal joint, perpendicular to the cassette.

Where is the beam centered for a lateral carpal view?

Lateral aspect of the leg at the middle of the carpus.

Where is the beam centered for a DLPMO/DMPLO carpal view?

On the carpus, 45° off the dorsal midline.

What should NOT be in the primary beam during carpal radiography?

The assistant's hand.

How should the animal be positioned for the dorsoplantar tarsal view?

Normal weight-bearing position with the limb slightly "toed-out."

Where is the cassette placed for the dorsoplantar tarsal view?

Perpendicular to the floor against the plantar aspect of the tarsus.

Where is the cassette placed for the lateral tarsal view?

Perpendicular to the floor against the medial aspect of the tarsus.

Where is the cassette placed for the DLPMO/DMPLO tarsal view?

On either the lateral or medial side of the plantar surface of the tarsus.

What should be included in the collimation for tarsal views?

The tarsal joint and 1/3 or less of the bones on either side.

Where is the beam centered for the dorsoplantar tarsal view?

Middle of the joint, perpendicular to the floor.

Where is the beam centered for the lateral tarsal view?

Middle of the joint, about 4 inches distal to the calcaneal tuberosity.

Where is the beam centered for the DLPMO/DMPLO tarsal view?

Middle of the joint, about 4 inches distal to the calcaneal tuberosity.

What angle is used for the x-ray tube during a DLPMO/DMPLO tarsal view?

Approximately 45° lateral or medial from the dorsal midline.

What is a major safety rule when taking tarsal radiographs?

NEVER stand directly behind a horse.

What other tarsal view can be taken?

A flexed lateral view.