1Normal Radiographic Anatomy of the Spinal ColumnSarah Tibbs, BVetMedRadiography of the Spinez Anatomy is complex z Many structures overlap complicating interpretationz Because of beam divergence the edges of film are effected by obliquity z Radiographic interpretation is compromised by poor positioningRadiography of the Spinez Always take orthogonal views – lateral and ventrodorsal (VD) z Add oblique views if necessaryz Consider dynamic views (extended and flexed) in the cervical and lumbo-sacral regionsz Image each region separately, with the beam centered over the middle of that region z Image certain areas with more collimation (i.e. caudal cervical, thoracolumbar, lumbo-sacral) Positioningz Vertebral column must be parallel to the table topz The transverse process of the vertebrae should be perpendicular to the tablezProper patient positioning is CRITICALzProper positioning requires anesthesia, ties for the limbs and sponge wedges zIntervertebral disc spaces must be perpendicular to the table top (not oblique)Vertebral Anatomyz Example here is a cervical vertebraz Think z Lamina as the roofz Pedicles as the wallsz Body as the floorz Vertebral appearance varies somewhat by region, but basic parts are the sameHow to Count the Cervical Vertebrae6754321z Landmarksz Atlas C1z Axis C2z C6 with large transverse processes2How to Count the Thoracic Vertebraez Landmarksz T1 is actually just caudal to the first rib headsz T13 is the one with the last rib heads11312710981165432L1L2L3C7C6How to Count the Lumbar Vertebraez Landmarksz Use the sacrum to help you find L7 and then count backwardsz Or find T13 and count forwards4376521T13T12SacrumGeneral Spinal Anatomy1. Body2. Vertebral endplates3. Lamina4. Spinous process 5. Transverse processes6. Cranial articular process7. Caudal articular process1234567General Spinal AnatomyGeneral Spinal AnatomyArticular facet joint spaceSpinal canal Intervertebral disc spaceIntervertebral foramen1. Cranial articular process2. Caudal articular process3. Intervertebral disc space4. Body5. Endplates6. Spinous process 7. Transverse processes8. Pedicles12345678General Spinal Anatomy3General Spinal Anatomy Cervical Spinez Positioningz head extendedz front limbs pulled caudallyz wedge under mid-cervical regionLateral Cervical Spine Positioning in Cervical SpineWell positionedPoorly positionedVD Cervical Spine Cervical Spinez Seven vertebrae with variable structurez C1 or atlasz wide wingsz C2 or axisz long thin dorsal spinous processz dens with special ligamentsz No disc between C1-C24Cervical Spinez C3-C7 similar in shapez C6 has expanded transverse processesz Intervertebral disc spaces at C2-3 and C7-T1 are relatively narrow***Thoracic Spinez Positioningz front limbs pulled craniallyz hind limbs pulled caudallyz wedge under sternumLateral Thoracic Spine VD Thoracic SpineThoracic spinez Thirteen vertebrae uniform in shapez Variable dorsal spinous processesz Anticlinal vertebra T 11 *z Articular facet conformation changes at T10-11z Intervertebral disc space narrowest at T10-11*Lumbar Spinez Positioningz front limbs pulled craniallyz hind limbs pulled caudally5Lateral Lumbar Spine VD Lumbar SpineLumbar spinez Seven lumbar vertebraez Accessory processz Cranioventrally angled transverse processesz L3* and L4* site of attachment of diaphragmatic crura**Feline Differencesz Curvature of spinez Shape of vertebral bodiesz Very prominent accessory processCanineMyelogramz A special procedure to evaluate the spinal cord, when survey radiography is inconclusive z Aqueous non ionic iodinated contrast media is injected into the subarachnoid spacez Standard lateral and VD views, as well as oblique VD’s are obtained of the area of interestHerniated disc T13 – L1Clinical Correlation6Spinal Column Fracture and LuxationSpinal Column Subluxation and Vertebral body fractureDiscospondylitisSpondylosis and Articular Facet Osteoarthitis13.5 y old GoldenMineralized Disc Material (IVDD- Intervertebral Disc Disease)Vertebral AnomaliesBlock VertebraeButterfly Vertebra7Aplastic