Small Animal Soft Tissue Radiology Chapter 17

Introduction ► Soft Tissue describes areas of the body that surround the skeletal structures.  Visualization can be difficult because it involves only slight differences in radiographic density.  Considerations include: ► High kVp’s and low mAs’ are used. ► Grid is necessary for areas of dense tissue to maintain image clarity and radiographic detail. ► Exposure time of 1/30 second or less is necessary for thorax radiography to minimize motion caused by cardiac and respiratory movement. ► Proper penetration is necessary for abdominal radiography. Patient should be fasted hours and given an enema prior to radiography. ► Exposure of the thorax and abdomen must be taken during the correct phase of respiration: inspiration for the thorax and expiration for the abdomen.

Pharynx ► Lateral View  Patient is placed in lateral recumbency.  Head and neck are extended cranially and placed in true lateral position.  Field of view should include the entire area of the neck between the lateral canthus of the eye an the third cervical body.

Thorax ► Dorsoventral View  Preferred for evaluation of heart because heart is closure to sternum and is in the near-normal suspended position within the thorax.  May be difficult to position larger dogs due to deep chest.  Patient is in sternal recumbency with thoracic vertebrae superimposed over the sternum.  Forelegs are pulled forward, rear legs are in natural crouched position.  Head is placed between two forelimbs  View should include entire thorax, which is all of the ribs.  Exposure should be taken at peak of inspiration to allow complete radiographic visualization of the lung tissue.

Thorax

► Dorsoventral thorax

Thorax ► Lateral View  Sometimes do both lateral views in order to check for mets.  Patient is placed in lateral recumbency with front legs extended cranially.  Head is extended slightly.  View should include entire thoracic cavity  View should be taken at peak of inspiration.

► Lateral Thorax

Thorax ► Lateral View with Horizontal Beam  Used to confirm the presence of fluid or free air in the thoracic cavity and to assist in its quantification.  Can use a standing lateral view or a sternally recumbent view.  See textbook for examples and diagrams.

Thorax ► Lateral Decubitus View (Ventrodorsal View with Horizontal Beam)  Used to confirm quantitative thoracic fluid or air.  Animal is in lateral recumbency on top of a foam pad. This allows visualization of both sides of thorax.  Forelimbs and head are extended cranially.  Thorax is centered on the cassette.  View includes entire thorax.  Can also be used for the abdomen.

Abdomen ► Ventrodorsal View  Patient is placed in dorsal recumbency  View includes entire abdomen from the diaphragm to the level of the femoral head.  Large patients may need this view split in half.  Radiograph is taken during expiratory pause so that the diaphragm is in cranial position and not placing compression on the abdominal contents.

► Ventrodorsal View

Abdomen ► Lateral View  Patient is in right lateral recumbency with hind limbs extended in caudal direction.  Right lateral view is chosen to assist in longitudinal separation of the kidneys.  Abdomen should be centered on the cassette.  View should include diaphragm to femoral head.  Exposure is during expiratory pause so that the diaphragm is displaced cranially.

► Lateral View

Uterine Rupture, Dead Fetus

Abdominal Dystocia