Head, Neck, and Spine Radiography 2024 PDF

Head, neck and spine radiography Georgina Catlow BVSc MRCVS Learning Objectives To describe the positioning of common species encountered in small animal practice in relation to generating interpretable radiographic views of the head, neck and spine, including dental radiography To be abl...

Head, neck and spine radiography Georgina Catlow BVSc MRCVS Learning Objectives To describe the positioning of common species encountered in small animal practice in relation to generating interpretable radiographic views of the head, neck and spine, including dental radiography To be able to describe the number and type of views required to achieve diagnostic quality films for a range of conditions and apply these to common examples To identify and recognise aspects of those views that may confound or prevent interpretation of films in relation to the head and neck #universityofsurrey 2 Head radiography Indications Deformity, swelling or discharging sinus Trauma Ear disease Exophthalmos or Horner’s syndrome Pain in the head area Problems with jaw mobility Nasal or nasopharyngeal disease Dental disease #universityofsurrey 3 Radiographic appearance of the head Varies with skull type Dolichocephalic (long-nosed) Mesaticephalic (cranium and nose equal length) Brachycephalic (short-nosed) #universityofsurrey Images courtesy of BSAVA manual of musculoskeletal imaging 4 Radiographic appearance of the head Brachycephalic (short-nosed) Crowding of teeth Reduced frontal sinus Lack of occipital crest Small thick walled tympanic bullae Curved, elongated mandible Increased soft palate #universityofsurrey Images courtesy of BSAVA manual of musculoskeletal imaging 5 Radiographic Positions Special Views Indications Oblique lateral views Lesion orientated view of a swelling Dorsoventral intra-oral Nasal cavities Ventrodorsal intra-oral Ramus of mandible, mandibular teeth Ventral 20o rostral-dorsocaudal oblique Nasal cavities more caudally and laterally Rostrocaudal open mouth Tympanic bullae (dog) Rostral 10o ventral-caudodorsal oblique Tympanic bullae (cat) Rostrocaudal and caudodorsal closed Skyline calvarium and frontal sinus mouth #universityofsurrey 6 What view is this???? #universityofsurrey 7 What view is this???? #universityofsurrey 8 Which view is this???? #universityofsurrey 9 Which view is this???? #universityofsurrey 10 Which view is this???? #universityofsurrey 11 Which view is this???? #universityofsurrey 12 Alternative Imaging Techniques Ultrasonography o Ocular and orbital structures Retinal detachment Cataract and retinal detachment (arrow) Ocular ultrasonography in companion animals: a pictorial review In Pract. November 2007;29(10):604-610. #universityofsurrey 13 Alternative Imaging Techniques Computed Tomography o Boney structures o Can re-create 3D images Magnetic Resonance Imaging o Superior soft tissue imaging #universityofsurrey Images courtesy of BSAVA manual of musculoskeletal imaging 14 Abnormal findings on head radiography - some examples Fractures o Cranium, maxillae, mandible, zygomatic arch Congenital/Developmental conditions o Hydrocephalus Neoplasia o Cranium, maxillae, mandible Craniomandibular osteotomy o Periosteal reaction on mandibles, tympanic bullae Ear disease? o Changes in bullae may indicate ear disease o Radiography insensitive Images courtesy of BSAVA manual of musculoskeletal imaging #universityofsurrey 15 Dental radiography #universityofsurrey 16 Dental radiography Specific dental plates and processor improve image resolution Xray machine has fixed kV and MA #universityofsurrey 17 Dental Radiography Indications Dental trauma Jaw fractures Anodontia (absence of teeth) Retained deciduous dentition Periodontal disease Endodontic disease Extraction of teeth Malocclusions Nasal discharge Swellings, cysts, neoplasms #universityofsurrey 18 Dental Radiography – Bisecting Angle Technique #universityofsurrey Images courtesy of RVC 19 Dental radiography – Standard Views #universityofsurrey 20 Three simple rules…. All positioning errors involve the three parameters of tube angulation, tube position and film position. Three simple rules serve to identify and correct any errors. 1. If the image is foreshortened or elongated, adjust the tube angle. To make the roots longer, move the tube head more laterally. 2. If you cut the target off at the edge of the beam (cone cut), simply move the beam over toward the area of cone cut. 3. If you cut the target off at the edge of the film, move the film over toward the area you cut off. #universityofsurrey 21 Dental radiography - Interpretation Enamel Dentine Pulp cavity (radiolucent) Alveolar bone Lamina dura (radiopaque) Periodontal ligament space (radiolucent) Mandibular canal Alveolar bone height (should extend to just below enamel/cementum junction) #universityofsurrey 22 #universityofsurrey 23 FORL – Feline Odontoclastic Resorptive Lesions On visual inspection: inflamed gingiva over lesion. Common 108,208,309,409 Radiography is only definitive diagnostic test and should be used when visual and tactile examination give rise to suspicion of disease #universityofsurrey 24 #universityofsurrey 25 Dental pathology Another example of a periapical abscess #universityofsurrey 26 What do the arrows indicate? Periodontal ligament space (normal) Enlarged periodontal ligament space around root due to marked vertical bone loss at the distal root of 408 and mesial root 409 Start of a resorptive lesion Loss bone at furcation (between roots) #universityofsurrey 27 Neck and Spine Radiography Images courtesy of IMV-Imaging #universityofsurrey 28 Neck and Spine radiography Indications Top Tips Mono-, para – and quadriplegia Paresis or paraparesis General anaesthesia Ataxia Use a grid Accurate collimation Spinal pain Position over area of suspected pathology Stiffness Take orthogonal views Suspected vertebral deformities Sinus tracts in lumbar region #universityofsurrey 29 Standard Views Lateral View Ventrodorsal view Spine must be parallel to table top Dorsal recumbency Foam wedges: Support with radiolucent trough o under neck, between limbs, under lumbar spine Foam wedges to prevent rotation o Cervical spine: under nose Forelimbs o Cervical spine: drawn caudally #universityofsurrey Images courtesy of IMV-Imaging 30 Centring points Area of interest Centring point Upper cervical C2-C3 Lower cervical C5-C6 Mid-thoracic T8 Thoracolumbar junction T13-L1 Mid-lumbar L4-L5 Lumbosacral L7-S1 Good lateral views will have superimposition of: Good ventrodorsal views will have: Wing of the atlas Oval central opacities of the spinous processes Transverse processes of C6 Equally sized transverse processes Rib origins Lumbar transverse processes Wings of ilia #universityofsurrey 31 Evaluation of a spinal radiograph Vertebral alignment Length, shape, opacity vertebral bodies Contour and opacity of vertebral end plates Intervertebral disc space width and opacity Intervertebral foramen size, shape and opacity Articular process joints Paravertebral soft tissues #universityofsurrey Spondylosis from T11 to L6 32 #universityofsurrey 33 Intervertebral disc disease Calcified disc material is seen in the intervertebral disc space Location: T12-L3 This can often be hard to see on radiography and MRI indicated #universityofsurrey 34 #universityofsurrey 35 Intervertebral disc disease Location: T12-13 Disruption of spinal canal Calcified discs Hansen Type I disc extrusion #universityofsurrey 36 Advanced Imaging Myelography Contrast injected into subarachnoid space Need plain films first Risk seizures Magnetic resonance imaging Excellent soft tissue contrast Limited by availability and cost Requires prolonged anaesthesia Computed Tomography Sensitive for subtle bone lysis, new bone Images courtesy of C.Rusbridge Can identify disc mineralisation Can be combined with CT myelography Images courtesy of BSAVA #universityofsurrey 37 38