Lavin: Chapters 22 Chart on page 305 Small Animal Spine Lavin: Chapters 22 Chart on page 305

Objectives: Spine/Skull Identify normal spinal anatomy on a radiograph Know the common principles & positions for radiographing the spine Understand radiographic concerns Safely & accurately position an animal for spinal radiographs Understand alternative views & their usage lateral radiograph of lumbar spine. There is extensive, bridging spondylosis of ventral spine with evidence of loss of mineralization within the L7-S1 ...

Skeletal Anatomy Review: Vertebral Column Separated into 5 areas: 1. Cervical Includes atlas and axis 2. Thoracic 3. Lumbar 4. Sacral 5. Caudal or coccygeal

Reasons to radiograph the spine… Trauma – be careful! Paralysis Neurological changes Suspected IVDD

Radiographic Concerns & Strategies: Spine General anesthesia is often indicated Use extreme care with possible spinal cord injuries! kVp _______________ mAs _______ mA ________ Use of a grid can help Common views – Lateral & VD DV view not as accurate (increases object-film distance)

Radiographic Concerns & Strategies: Spine (cont.) Positioning aids are helpful Keep spine parallel to receptor with padding Avoid body rotation Tape along the spine can help with alignment Use smaller cassettes & multiple views Limits number of vertebrae so can keep anatomy parallel to film Elevate the nose if possible Head should be in a true lateral position (important)

Cervical Vertebrae: Lateral View Head must be in true lateral Requires a positioning device under nose AND sternum Superimpose transverse processes Measure at C3-C4 Margins: base of skull to just past shoulder joint True for all cervical views

Atlas & Axis

Atlas & Axis

Cervical Vertebrae: Hyperextended Lateral View All cervical vertebrae extended dorsally Hyperextend neck & head until resistance – careful! Used during myelography to visualize spinal cord impingement

Cervical Vertebrae: Flexed Lateral View Tape or thin rope can be used to apply traction Place around nose All cervical vertebrae are flexed Beware of airway restriction

Atlantoaxial Luxation

Cervical Vertebrae – Ventrodorsal View Sternum & vertebrae should be superimposed Align nose, body, and base of tail Forelimbs pulled caudally

Cervical Vertebrae – Ventrodorsal View

Intervertebral Disc Disease (IVDD)

Thoracic Vertebrae: Anatomy

Thoracic Spine

Thoracic Vertebrae: Lateral View Considerations: Maintain thoracic vertebra on same horizontal plane as sternum without rotation Ribs should be superimposed over each other Larger dogs may require two views Margins: include C7 and L1 *About the shoulder joint to the last rib

Thoracic Vertebrae: V/D View Considerations: Symmetrically arrange all limbs Spinous processes should be evident and equal on film Nose parallel to table & equidistant between limbs Superimpose sternum and vertebrae No rotation Measure at the thickest part of the sternum

Lumbar Vertebrae: Lateral View Margins: On film: Invertebral foramina should be visible & symmetrical “Horse heads” Transverse processes should be superimposed “Nike swoosh”

Lumbar Spine - Feline

Lumbar Vertebrae: Lateral View

Lumbar Vertebrae: V/D View Note: Enemas are suggested before radiography, as feces can cause artifacts for lumbar spine

Lumbosacral Vertebrae: Lateral View Considerations: Fully extend front limbs and place foam pad between them Ensure wings of ilia are superimposed & parallel to cassette Legs can hyperextended or hyperflexed Forelimbs slightly cranial Padding under sternum/lumbar vertebrae to keep parallel Use pelvis technique chart

Lumbosacral Vertebrae: Lateral View

Lumbosacral Vertebrae: V/D View Can be true V/D or frog-leg Same as pelvis but more tightly collimated

Caudal Vertebrae (Tail) Lateral View

Caudal Vertebrae (Tail) V/D View Split cassette so both views are on one film Use extremity settings Must capture all vertebrae!