Skull and Nasal Cavity

1. Skull and Nasal Cavity Dr. LeeAnn Pack Dipl. ACVR

2. Radiography of the Skull • Anesthesia required • Perfect positioning is critical (especially for lateral and DV) • Evaluate for asymmetry • Obtain special views as needed • Radiographs are nice but they are no CT or MRI image :-)

3. Skull Types

4. Lateral Views of the Skull and Nasal Cavity

5. Closed Mouth DV

6. Special or Additional Views • Intraoral DV or VD/ open mouth VD • Eliminates superimposition of mandibles/ maxilla

7. Intra Oral DV Open Mouth DV

8. Special or Additional Views • Rostrocaudal frontal sinus • Neoplasia, sinusitis, trauma

9. Open mouth rostrocaudal Evaluation of bullae Variation (30 degree VD) in Cats Special or Additional Views

10. Special or Additional Views • Oblique views • Bullae, maxilla, mandible • Left dorsal-right ventral • Right dorsal-left ventral • Labeling can get confusing

11. Shots Summary • Nasal Series • Minimum = *VD open mouth and lateral • Special = rostro-caudal frontal sinus • Special = *intra –oral • * these provide the best evaluation of the nasal cavity in general • Knowing normal anatomy is critical

12. Nasal Disease • Neoplasia, infection, foreign body, fracture, fungal • History of nasal discharge • Unilateral or bilateral • Serous, purulent, hemorrhagic

13. Radiographic Interpretation • Change in opacity • Bony lysis • Increased soft tissue or fluid • Or BOTH • Are the nasal turbinates still visualized? • Use the opposite side for comparison of increased opacity • Radiographic changes are not always specific for a specific disease

14. Frontal Sinuses

15. Rhinitis / Infectious • Acute • Viral, bacterial, allergic, FB (usu. not seen) • Increased opacity (exudate in nasal cavity or thickening of mucosal turbinate covering) without turbinate destruction • Chronic • Usu. seen in cats with a viral upper respiratory disease • Turbinates may be deformed but not destroyed

16. Rhinitis

17. Destructive Rhinitis • Aspergillus sp. Infection • Young animals • Medium and long nosed dogs • Rarely seen in brachycephalic • Fungal rhinitis usually causes focal turbinate destruction

18. Destructive Rhinitis • Nasal aspergillosis • Saprophytic fungal organism • Destructive rhinitis/ sinusitis • Radiographic findings • Lysis of turbinates • Increased intranasal ST • Ddx neoplasia usu= ST mass, adjacent bony lysis, frontal sinus opacity • Cryptococcus neoformans • Usually cats and nondestructive

19. Neoplasia – Nasal Tumors • Nasal Tumors • 1-2% of all tumors in dogs and cats • 2/3 are carcinomas (Adenocarcinoma, SCC) • 1/3 are sarcomas (FSA, OSA, chondrosarcoma) • Intranasal lymphoma (more commonly cats) • Diagnosis usually occurs late • Hemorrhage often seen

20. Aspergillosis

21. Nasal Tumors • Radiographic findings • Increased intranasal soft tissue opacity • Soft tissue mass or accumulation of nasal exudate • Lysis of nasal turbinates • +/- Lysis of cribriform plate= extent into brain • Does it involve one side or has it crossed the nasal septum? • Often begin in the region of the ethmoid turbinates • CT great for nasal tumors

22. Moderate Maxillary Lysis

23. Nasal Tumors

24. Nasal Adenocarcinoma Septal Deviation

25. Nasal Adenocarcinoma

26. Shots Summary - Skull • Minimum = lateral and DV view • Special = obliques • Special = teeth, tympanic bullae, TMJ’s, foramen magnum, nasal cavity and frontal sinus (as per nasal shots) • Knowing anatomy is critical • Very complex area • Does not evaluate the brain

27. Hydrocephalus • Excess CSF within skull • Congenital or acquired • Maltese, Yorkie, Chihuahua • Radiographic Signs • Doming and cortical thinning of calvarium • Open fontanelle • Lateral projection best • Ground glass look

28. Occipital Dysplasia • Congenital malformation of the foramen magnum (keyhole shape) – may be seen with AA sub lux and hydrocephalus • Mini and Toy breeds • Special view = rostrodorsal – caudoventral of foramen magnum

29. Feline Mucopolysaccharidosis • Inherited lysosomal storage disease • Siamese (VI) • Skull deformity – broad flat face with widely spaced eyes • Epiphyseal dysplasia, short maxilla, small frontal sinus, thick nasal turbinates, small dens and hyoid bones • Also have vertebral abnormalities

30. Neoplasia - Skull • Osteosarcoma – 10-15% arise from the skull • Usually productive, well marginated • Osteoma • Slow growing, benign • Dense, homogenous, well marginated

31. Osteosarcoma

32. Multilobular Osteochondrosarcoma • Neoplasia • Aka Multilobular tumor of bone, Multilobular osteoma • Often arise from temporo-occipital area • Granular, osteoproductive mass with lysis

33. Skull Trauma • HBC, fights, gunshot wounds • Often see depression skull fractures • May cause cerebral edema, epistaxis and neurologic signs • Fairly rare to see skull fractures

34. Trauma – Depressed Skull Fx

35. Metabolic Abnormalities • Primary hyperparathyroidism • Parathyroid nodule or parathyroid hyperplasia • Secondary hyperparathyroidism • Nutritional or renal causes (Ca and P levels messed up) • Both situations lead to increased PTH and bone resorption • Radiographic findings • Loss of lamina dura • Demineralization of mandible and maxilla = “floating teeth” “rubber jaw”

36. Hyperparathyroidism

37. Neoplasia Mandibular or Maxillary • Squamous Cell Carcinoma • More aggressive/ worse prognosis in cats • Rostral mandible - dogs • FSA, OSA, Chondrosarcoma • Malignant melanoma • Epulis= benign tumor of periodontal ligament (dogs) • Fibromatous, Ossifying= Osteoproductive • Acanthomatous= Invasive, Lytic

38. Dentigerous Cyst - Odontoma

39. Acanthomatous Epulis

40. Otitis Externa • Otitis externa • Stenosis or mineralization of external ear canal • VD view best

41. Otitis Externa

42. Mineralized Ear Canals

43. Otitis Media • Otitis media • Increased opacity in bulla • Thickening of bulla walls • Obliques or open mouth rostrocaudal views • **25% of dogs with normal bulla rads had otitis media at surgery • Nasopharyngeal polyp • Cats - sneezing

44. Nasopharyngeal Polyp • Non neoplastic • Originate from mucous membrane of auditory tube or middle ear • Younger cats – can extend into external ear canal, osseous bulla or the nasopharynx

45. Tooth Root Abscess • Tooth root (periapical) abscess • Lysis of periapical alveolar bone • Resorption of tooth root • Widening of periodontal space • Sclerosis surrounding apex • Loss of lamina dura • Dogs - 4th maxillary premolar (carnassial tooth) • External fistulous tract below eye

46. Normal Dental Formulas • Cat • Deciduous 2 x (I 3/3 C 1/1 P 3/2) = 26 • Permanent 2 x (I 3/3 C 1/1 P 3/2 M 1/1) = 30 • Dog • Deciduous 2 x (I 3/3 C 1/1 P 3/3) = 28 • Permanent 2 x ( I 3/3 C 1/1 P 4/4 M 2/3) = 42

47. Root Canal

48. More Trauma • Fractures • Additional views as needed • Temporomandibular joint (TMJ) luxations • Often rostrodorsal and concurrent with fractures • Usu. unilateral • Malocclusion

49. Cranial Mandibular Osteopathy • Westies, Scotties, Cairn, Boston terriers • Autosomal recessive in Westies • +/- Link to hypertrophic osteodystrophy (HOD) • Young dogs (3-8 months) • Mandibular swelling • Difficulty/ pain chewing • Pyrexia, Self- limiting • Radiographic signs • Bony proliferation on mandibles, bulla, petrous temporal bone, calvarium

50. CMO