Lecture 5- Skull and Spine

What are skull radiographs used to evaluate?

Tympanic bullae, nasal sinuses, teeth, foramen magnum, bone lesions, trauma, and tumors.

Why is heavy sedation or anesthesia recommended for skull radiographs?

Manual restraint is challenging and precise positioning is important.

What can create summation over the area of interest on skull radiographs?

The ET tube, tongue, and ear pinnae.

Why is symmetry important when taking skull radiographs?

It is important for creating diagnostic-quality images.

What is typically included in a skull radiograph?

The entire skull.

What are the 3 standard views of the skull?

VD, DV, and lateral.

What does VD stand for?

Ventrodorsal.

What does DV stand for?

Dorsoventral.

How is the animal positioned for a lateral skull view?

Right or left lateral recumbency.

What can be placed underneath the mandible and cervical region during a lateral skull view?

Foam pads to prevent rotation.

How are the forelimbs positioned for a lateral skull view?

Pulled caudally.

Where is the lateral skull measured?

Over the zygomatic arch at the lateral canthus of the eye.

Where is the lateral skull centered?

On the midline over the lateral canthus of the eye.

How is the lateral skull collimated?

From the tip of the nose to the base of the skull.

How is the animal positioned for a VD skull view?

Dorsal recumbency.

What is used to prevent head rotation in the VD skull view?

A foam pad under the cervical region and tape across the mandibles rostrally.

How are the forelimbs positioned for a VD skull view?

Extended caudally.

Where is the VD skull measured and centered?

Over the zygomatic arches at the lateral canthus of the eye.

What is the VD skull collimation?

Tip of nose to base of skull, including the entire skull on both sides.

How is the animal positioned for a DV skull view?

Sternal recumbency.

What is used to prevent head rotation in the DV skull view?

A foam pad under the mandible and tape across the maxilla rostrally.

Where are the forelimbs positioned for a DV skull view?

Caudally and out of the collimated area.

Where is the DV skull centered?

On the midline over the zygomatic arches at the lateral canthus of the eye.

What is the DV skull collimation?

Tip of nose to base of skull, including the entire skull on both sides.

How is the patient positioned for an oblique skull view?

Laterally, with head ventral aspect angled toward or away from the tabletop.

What is the oblique view called when the ventral aspect is AWAY from the tabletop?

VDLR.

What is the oblique view called when the ventral aspect is TOWARD the tabletop?

DVLR.

How are oblique skull views labeled?

According to recumbency and the direction of the X-ray field.

What are spinal radiographs used to evaluate?

Bony lesions, intervertebral disc spaces, neurological changes, paresis/paralysis, and trauma.

Why are correct positioning and adequate collimation important for spinal radiographs?

To create diagnostic radiographs.

What should you do if a spinal column injury is suspected?

Use alternative views for the VD views.

Why should extra care be taken when a spinal injury is suspected?

To avoid further injury to the spinal cord and nervous tissues.

What are the 5 segments of the spine?

Cervical, thoracic, lumbar, sacral/lumbosacral, and caudal/coccygeal.

What are the standard 2 views of the spine?

Lateral and VD.

What is the usual lateral side used for spinal radiographs?

Right lateral.

How is the cervical spine positioned for a lateral view?

Right or left lateral recumbency.

What is used to prevent rotation of the skull and spine in lateral cervical views?

Foam pads under the mandible and sternum.

Where is the cervical spine measured for a lateral radiograph?

At the thoracic inlet.

Where is the cervical spine centered for a lateral radiograph?

Midway between the base of the skull and spine of the scapula.

What is the lateral collimation field for the cervical spine?

Base of skull to spine of scapula, including full dorsal aspect.

What vertebrae make up the cervical spine?

C1-C7.

What are C1 and C2 called?

Atlas (C1) and Axis (C2).

How is the cervical spine positioned for a VD view?

Dorsal recumbency.

What is used to prevent rotation of the sternum?

A V-trough.

Where is the cervical spine centered on the VD view?

Midway between the base of the skull and thoracic inlet on the midline.

What should the VD cervical view include?

The base of the skull, thoracic inlet, and entire body wall on both sides.

How is the thoracic spine positioned for a lateral view?

Right or left lateral recumbency.

How are the limbs positioned?

Forelimbs cranially and hind limbs caudally.

Where is the thoracic spine measured?

At the thickest part of the thorax.

Where is the thoracic spine centered?

Caudal to the scapula.

What should thoracic spine collimation include?

Thoracic inlet and last rib, including the entire dorsal aspect.

What vertebrae are in the thoracic spine?

T1-T13.

What is used to keep the thoracic spine parallel with the tabletop?

A V-trough.

Where is the thoracic VD view centered?

On the midline caudal to the scapula.

What should the thoracic VD view include?

Thoracic inlet, last rib, and a margin on both sides.

Where is the lumbar spine measured?

Over the xiphoid process.

Where is the lumbar spine centered?

Caudal to the last rib.

What should lumbar spine collimation include?

Xiphoid process to greater femoral trochanters.

What is used to prevent rotation during lumbar imaging?

A foam pad/V-trough and foam wedges depending on the view.

What vertebrae make up the lumbar spine?

L1-L7.

Where is the lumbar VD view centered?

On the midline caudal to the last rib.

What should the lumbar VD view include?

Xiphoid process to greater femoral trochanters, with margins on both sides.

Where is the lumbosacral spine measured?

Over the greater femoral trochanters.

Where is the lumbosacral spine centered?

Caudal to the wing of the ilium at the lumbosacral junction.

What is the lumbosacral lateral collimation?

Cranial to the wing of the ilium and caudal to the ischiatic tuberosities.

What should the lumbosacral VD view include?

The coxofemoral joints on each side.

Where is the coccygeal spine measured?

At the base of the tail, usually the thickest part.

What is used to keep the tail parallel with the tabletop during a lateral view?

A foam block under the tail.

Where is the coccygeal spine centered?

Midway between the wing of the ilium and tip of the tail over the area of interest.

What is the coccygeal spine collimation?

Cranial to the wing of the ilium and caudal to the tip of the tail.

How is the tail positioned for a coccygeal VD view?

Extended and straightened caudally.

What is used to prevent rotation during the coccygeal VD view?

A V-trough and foam wedges along the sternum.

What does IVDD stand for?

Intervertebral disc disease.

What is Hansen Type I IVDD associated with?

Small breeds, ruptured discs, and dogs around 3-6 years old.

What is Hansen Type II IVDD associated with?

Large breeds, bulging discs, and dogs around 8-10 years old.

What spinal location is specifically shown with IVDD in the lecture?

T13-L1 and L2-L3.