Radiology exam 2 study guides 6-7?

What areas of the body are “soft tissue” films referring to?

Areas like the abdomen or thorax that contain “softer” tissues as opposed to dense, thick tissues like the bones.

What are some general guidelines that should be used when taking soft tissue films?

To attain long scale of contrast: high kVp and low mAs. Exposure on inspiration for thorax and expiration for abdomen.

An abdominal film should be taken when the animal inhales or exhales? Why?

Exhales, because there is more room in the abdomen because the diaphragm is relaxed.

A thoracic film should be taken when the animal inhales or exhales? Why?

Inhales, because there is more room in the thorax, and it is easier to see the lung field.

Where should you measure the animal for a VD thorax and where should the beam be centered?

You should measure at the thickest part of the thorax. The beam should be centered at the caudal portion of the scapula. Include the whole ribcage

What is the field of view for a VD thorax radiograph?

Include the whole ribcage. Central ray at the caudal end of the scapula.

When reviewing a VD thoracic radiograph, how can you tell the patient was in a true VD posture?

If the sternum is superimposed over the spine.

When should a DV thorax be considered instead of a VD?

If the animal is respiratory distress.

How will the patient be positioned for a lateral thorax radiograph?

Lateral recumbency, forelimbs pulled cranially, hindlimbs pulled slightly caudally. Ensure Sternum is at the same plane as the thoracic vertebrae.

Where should you measure the animal for a lateral thorax and where should the beam be centered?

The thickest part of the thorax, include the whole ribcage. The central ray should be at the caudal border of the scapula.

Why should the sternum be elevated in a lateral thoracic view?

To ensure that there is no rotation.

What is the field of view for a lateral thorax radiograph?

The whole ribcage.

When would you take both a right and left lateral thorax of an animal?

To detect atelectasis.

How will you restrain an animal for a VD abdomen film?

Dorsal in a V-trough, pulling the forelimbs cranially, the hindlimbs can be kept in a frog-leg position.

Where should you measure the animal for a VD abdominal film and where should the beam be centered?

Measure at the thickest part of the abdomen. Should be centered on the midline at the 13th rib. Field is the xiphoid process, and the femoral head.

What is the field of view for a VD abdomen radiograph?

Field is the xiphoid process, and the femoral head/greater trochanter.

Should the animal have their left or right side down on the table when taking a lateral abdominal film?

The right lateral.

When taking a lateral abdominal film, where should you measure the animal, and where should the beam be placed?

You should measure the the thickest part of the abdomen. And aim the central ray should be over the 13th rib. The borders are the xiphoid and the femoral head.

What is the field of view for a lateral abdominal radiograph?

The xiphoid process to the femoral head.

Where might you want to place foam pads on a lateral abdominal radiograph? What is the purpose of these pads?

Under the sternum to ensure that the sternum and the spine are on the same field and avoid any rotation.

What kind of restraint is usually required for taking skull films? And what is important to remember with this restraint?

Most animals will need to be sedated or anesthetized for skull films. If an endotracheal tube is used, it is important to be careful when positioning so the trachea is not damaged, and make sure to remove the tube at times if needed so it does not become an artifact.

The end goal of a skull film is precision and symmetry. That being said, should these films be taken in the bucky or tabletop?

Bucky because it decreases film fog from the scatter radiation and makes a sharper image.

How will an animal be positioned for a lateral view of the skull? Where should a foam pad be placed and why? Where might a second foam pad be placed and why?

They will positioned in lateral recumbency. A foam pad should be placed under the cranial portion of the neck and under the mandible to prevent rotation and keep the skull all on the same plane.

What is the field of view for a lateral skull film?

From the tip of the nose to the AO joint.

Where should you measure and place the beam center for a lateral skull film?

You should measure the thickest part of the skull, and place the central beam over the lateral canthus of the eye.

You will know if the skull is straight for a lateral skull view if the nasal septum is in what position relative to the cassette?

If it is parallel to the cassette it is correct.

Why would a DV view of the skull be recommended over a VD?

Because it is easier to obtain true symmetry and less rotation. The area of interest is also closer to the image receptor, reducing geometric distortion.

Why would a sand bag be placed over the cervical region when taking a DV skull film? And if you do use one, what do you need to make sure to do?

It is placed there for support. Be sure you put it on right before the exposure, and take it off immediately after. You don’t want to leave the sandbag on this area for long.

What is the field of view for a DV skull film?

Same as lateral, tip of the nose to the AO joint.

Where should you measure for a DV skull film and where should you center the beam?

Thickest point of the skull, and central beam on the lateral canthus of the eye.

What is the main goal of positioning the vertebral column when taking spinal films?

Making the animal straight, so making sure the vertebral column parallel to the tabletop in lateral by putting foam pads under the sternum or using a V-trough to help superimpose the sternum over the spine in VDs.

When taking a VD view of the cervical spine, where do you want to place a positioning device and why?

Placing them in a V-trough is helpful because it supports them underneath and on the sides. You can also use tape, straps or a sand bag if needed. You want to support their heads straight because if their head is rotated their spine will be too.

 Where should you measure and place the beam center for a VD cervical spine shot?

At the bottom of the neck, more at C6. The central beam should be at C3 and C4.

When taking lateral views of the cervical spine what views might you need to take?

You might need to take an extended view, a flexed view, and a hyperextended view so the doctor can fully evaluate the neck.

What is important to do with the forelimbs while taking lateral shots of the Cervical spine?

It is important to pull the front limbs caudally. And hen want to use something to pull the neck out while keeping the vertebra parallel to the cassette.

You need to include all 7 cervical vertebrae. Where should you measure and center the beam to make this happen?

You should measure at C6 and center the beam on C3 and C4.

What is necessary when taking the flexed lateral view of the cervical vertebrae?

You will need to use stretch gauze or something to hook around the mandible and then pull the head down so the neck is in a flexed position. Careful here if the animal has an endotracheal tube placed. You will need to include the base of the skull to the first few thoracic vertebrae in your shot.

True or false?: The goal of a VD shot in general is to have the sternum superimposed over the spine.

True

When taking a VD thoracic spine film, where should you measure and place the beam center?

You should measure the highest point of the sternum (Xiphoid process and where T6 and T7 are). Place the beam at T6 and T7.

What is important about Thoracic spine radiograph positioning?

Being sure to get the sternum and spine parallel to the cassette. You might need a positioning device for this.

Where should you measure and place the beam center for a lateral thoracic spine film?

You should measure the highest point of the sternum (Xiphoid process and where T6 and T7 are). Place the beam at T6 and T7.

Where should you measure and place the beam center for lateral and VD views of the lumbar spine? *Your textbook says the hind limbs can assume a normal position, but know that typically in practice you will pull them caudally.

Measure at L1 and place the central beam at L3 and L4.

When taking radiographs of an animal with a possible spinal injury what is important to remember?

Don’t pull on the limbs to stretch that animal out! You can cause further damage. Simply use positioning devices to get the animal straight and /or parallel, and then just let the legs be in a normal position.