Large AnimalThorax and Neck Normal Anatomy

Dr. LeeAnn Pack

Safety

• Barns – People need to be out of barn– Pregnant?

• Radiation Protection– Lead aprons, gloves

• Take care of them in the truck – no folding

– Cassette holder, wooden blocks

• Sedation

Cervical Spine

• Indications– Trauma– Doesn’t want to flex neck

• Abnormal head posture

– Ataxia or if the horse can not stand– Stiffness, pain, swelling

Cervical Spine

• Things to consider– Most animals are radiographed in the

standing position• Why are they not “knocked down”• Recumbent under anesthesia (VD)

– Usually only take laterals– Use 14 x 17 size films– Usually takes multiple films to get all of the

spine

Cervical Spine• Technical considerations

– Portable machines• Shoot C1-C6 usually

– Permanent tube• C7-T1

– Use a rope halter– White tape to mark centering– Must be true laterals with beam

perpendicular to the neck

Cervical Spine

• Must have parts of different vertebra on the film to know which one you are looking at

• Generally need 4 separate views– Occiput – C1– C1 – C3– C3 – C5– C5 – C7– Sometimes need a more caudal one for C7

Cervical Spine

• C1• C2

– has large dens and large spinous process

• C3 – C5 – all look similar• C6

– Large trifid transverse process – ventral lamina projects ventrally and caudally

• C7 – Tallest spinous process

Dens Close Up

Cranial Cervical (note buckle)

Cranial Cervical Spine

Mid Cervical

Thorax – Large Animal• Adults = standing lateral

– Complete study is 8 films – 4 on each side– Need powerful machines

• Pony– Often get chest on 2 films

• Foals and calves – can do DV/VD too– Generally one or 2 films

• Can use portable machines for ponies and neonates

Thorax – Large Animal

• Films made on full inspiration

• 4 films per side– Caudodorsal– Caudoventral– Craniodorsal– Cranioventral

Caudodorsal

Caudoventral

Craniodorsal

Cranioventral

Thorax – Young/Neonate

• Can be take with patient recumbent

• Can use small animal table

• Heart of neonate generally large in chest

• Interstitial pattern often seen at birth due to incomplete inflation of lungs– Within 24 hours lungs become more lucent

Calf

Calf (has pneumonia)

Foal Chest

Thoracic Structures

• Heart chambers

• Vessels aorta, CVC, Pulm a, Pulm v

• Trachea and bronchial structures

• Diaphragm, gastric gas cap

• Humerus, scapula, ribs, spine

• Abdomen that’s on film

Bovine Adult