Small Animal Soft Small Animal Soft TissueTissueRadiologyRadiology

Chapter 17Chapter 17

IntroductionIntroduction► Soft Tissue describes areas of the body that Soft Tissue describes areas of the body that

surround the skeletal structures.surround the skeletal structures. Visualization can be difficult because it involves only slight Visualization can be difficult because it involves only slight

differences in radiographic density.differences in radiographic density. Considerations include:Considerations include:

► High kVp’s and low mAs’ are used.High kVp’s and low mAs’ are used.► Grid is necessary for areas of dense tissue to maintain image Grid is necessary for areas of dense tissue to maintain image

clarity and radiographic detail.clarity and radiographic detail.► Exposure time of 1/30 second or less is necessary for thorax Exposure time of 1/30 second or less is necessary for thorax

radiography to minimize motion caused by cardiac and radiography to minimize motion caused by cardiac and respiratory movement.respiratory movement.

► Proper penetration is necessary for abdominal radiography. Proper penetration is necessary for abdominal radiography. Patient should be fasted 12-24 hours and given an enema Patient should be fasted 12-24 hours and given an enema prior to radiography.prior to radiography.

► Exposure of the thorax and abdomen must be taken during Exposure of the thorax and abdomen must be taken during the correct phase of respiration: inspiration for the thorax and the correct phase of respiration: inspiration for the thorax and expiration for the abdomen.expiration for the abdomen.

PharynxPharynx►Lateral ViewLateral View

Patient is placed in lateral recumbency. Patient is placed in lateral recumbency. Head and neck are extended cranially and Head and neck are extended cranially and

placed in true lateral position.placed in true lateral position. Field of view should include the entire Field of view should include the entire

area of the neck between the lateral area of the neck between the lateral canthus of the eye an the third cervical canthus of the eye an the third cervical body. body.

ThoraxThorax► Dorsoventral ViewDorsoventral View

Preferred for evaluation of heart because heart is closure Preferred for evaluation of heart because heart is closure to sternum and is in the near-normal suspended position to sternum and is in the near-normal suspended position within the thorax.within the thorax.

May be difficult to position larger dogs due to deep chest.May be difficult to position larger dogs due to deep chest. Patient is in sternal recumbency with thoracic vertebrae Patient is in sternal recumbency with thoracic vertebrae

superimposed over the sternum.superimposed over the sternum. Forelegs are pulled forward, rear legs are in natural Forelegs are pulled forward, rear legs are in natural

crouched position.crouched position. Head is placed between two forelimbsHead is placed between two forelimbs View should include entire thorax, which is all of the ribs.View should include entire thorax, which is all of the ribs. Exposure should be taken at peak of inspiration to allow Exposure should be taken at peak of inspiration to allow

complete radiographic visualization of the lung tissue.complete radiographic visualization of the lung tissue.

ThoraxThorax

►Dorsoventral thoraxDorsoventral thorax

ThoraxThorax►Lateral ViewLateral View

Sometimes do both lateral views in order Sometimes do both lateral views in order to check for mets.to check for mets.

Patient is placed in lateral recumbency Patient is placed in lateral recumbency with front legs extended cranially. with front legs extended cranially.

Head is extended slightly.Head is extended slightly. View should include entire thoracic cavityView should include entire thoracic cavity View should be taken at peak of View should be taken at peak of

inspiration.inspiration.

►Lateral ThoraxLateral Thorax

ThoraxThorax►Lateral View with Horizontal BeamLateral View with Horizontal Beam

Used to confirm the presence of fluid or Used to confirm the presence of fluid or free air in the thoracic cavity and to assist free air in the thoracic cavity and to assist in its quantification.in its quantification.

Can use a standing lateral view or a Can use a standing lateral view or a sternally recumbent view.sternally recumbent view.

See textbook for examples and diagrams.See textbook for examples and diagrams.

ThoraxThorax► Lateral Decubitus View (Ventrodorsal View Lateral Decubitus View (Ventrodorsal View

with Horizontal Beam)with Horizontal Beam) Used to confirm quantitative thoracic fluid or air.Used to confirm quantitative thoracic fluid or air. Animal is in lateral recumbency on top of a foam Animal is in lateral recumbency on top of a foam

pad. This allows visualization of both sides of pad. This allows visualization of both sides of thorax. thorax.

Forelimbs and head are extended cranially.Forelimbs and head are extended cranially. Thorax is centered on the cassette.Thorax is centered on the cassette. View includes entire thorax. View includes entire thorax. Can also be used for the abdomen. Can also be used for the abdomen.

AbdomenAbdomen►Ventrodorsal ViewVentrodorsal View

Patient is placed in dorsal recumbencyPatient is placed in dorsal recumbency View includes entire abdomen from the View includes entire abdomen from the

diaphragm to the level of the femoral head.diaphragm to the level of the femoral head. Large patients may need this view split in Large patients may need this view split in

half.half. Radiograph is taken during expiratory pause Radiograph is taken during expiratory pause

so that the diaphragm is in cranial position so that the diaphragm is in cranial position and not placing compression on the and not placing compression on the abdominal contents. abdominal contents.

► Ventrodorsal ViewVentrodorsal View

AbdomenAbdomen►Lateral ViewLateral View

Patient is in right lateral recumbency with hind Patient is in right lateral recumbency with hind limbs extended in caudal direction.limbs extended in caudal direction.

Right lateral view is chosen to assist in Right lateral view is chosen to assist in longitudinal separation of the kidneys.longitudinal separation of the kidneys.

Abdomen should be centered on the cassette.Abdomen should be centered on the cassette. View should include diaphragm to femoral View should include diaphragm to femoral

head.head. Exposure is during expiratory pause so that Exposure is during expiratory pause so that

the diaphragm is displaced cranially.the diaphragm is displaced cranially.

►Lateral ViewLateral View

Uterine Rupture, Dead FetusUterine Rupture, Dead Fetus

Abdominal DystociaAbdominal Dystocia