Normal Radiographic Anatomy of the Spinal Column Normal ...

General Spinal AnatomyConsiderations for SpinalRadiographs• Always take orthogonal views – lateral andventrodorsal (VD)• Add oblique views if necessary• Consider dynamic views (extended and flexed)in the cervical and lumbo-sacral regions• Image each region separately, with the beamcentered over the middle of that region• Image certain areas with more collimation (i.e.caudal cervical, thoracolumbar, lumbo-sacral)Proper patient positioning isCRITICAL•Proper positioning requires sedation oranesthesia and sponge wedges•Intervertebral disc spaces must beperpendicular to the table top (not oblique)•Vertebral column must be parallel to the tabletop•The transverse process of the vertebraeshould be perpendicular to the table9

• Positioning• head extended• front limbs pulledcaudally• wedge undermid-cervical regionCervical SpineLateral Cervical SpinePositioning in Cervical SpineWell positionedPoorly positioned10

VD Cervical SpineCounting the Cervical Vertebrae• Seven vertebrae with variable structure• Landmarks• C1 - Atlas• C2 - Axis• C6 with large transverse processes123456 7• C1 or atlas• wide wings• C2 or axis• long thin dorsalspinous process• dens with specialligaments• No disc between C1-C2Cervical Spine11

Features of the cervical spine• C3-C7 similar in shape• C6 has expanded transverseprocesses• Intervertebral disc spaces atC2-3 and C7-T1 are relativelynarrow ***• Positioning• front limbs pulledcranially• hind limbs pulledcaudally• wedge under sternumThoracic SpineLateral Thoracic Spine12

VD Thoracic SpineCounting the thoracic vertebrae• Thirteen vertebrae uniform in shape• Landmarks• T1 is actually just caudal to the first rib heads• T13 is the one with the last rib headsL1L2L3C6C712345678911101213Features of the thoracic spine• Variable dorsal spinous processes• Anticlinal vertebra T 11 *• Articular facet conformation changes at T10-11• Intervertebral disc space narrowest at T10-11*13

• Positioning• front limbs pulledcranially• hind limbs pulledcaudallyLumbar SpineLateral Lumbar SpineVD Lumbar Spine14

Counting the Lumbar Vertebrae• Seven lumbar vertebrae• Landmarks• Use the sacrum to help you find L7 and then count backwards• Or find T13 and count forwardsT12T131234567SacrumFeatures of the lumbar spine• Accessory process• Cranioventrally angled transverse processes• L3* and L4* site of attachment of diaphragmaticcrura**Feline Differences• Curvature of spine• Shape of vertebral bodies• Very prominent accessory processCanine15

Clinical CorrelationMyelogram• A special procedure to evaluate the spinal cord,when survey radiography is inconclusive• Aqueous non ionic iodinated contrast media isinjected into the subarachnoid space• Standard lateral and VD views, as well asoblique VD’s are obtained of the area of interestHerniated disc T13 – L1Spinal Column Fracture andLuxation16

Spinal Column Subluxation andVertebral body fractureDiscospondylitisSpondylosis and Articular FacetOsteoarthitis13.5 y old Golden17

Mineralized Disc Material(IVDD- Intervertebral Disc Disease)Vertebral AnomaliesButterfly VertebraBlock VertebraeAplastic DensNormal18

Questions?19