Upper Airway Imaging Flashcards
what makes up the upper airway
nasal cavity
pharynx
larynx
trachea
mainstem bronchi
what views are used to image the nasal cavity
DV
open mouth VD
intraoral DV
lateral
frontal (rostrocaudal)
what is viewed on standard DV imaging of the nasal cavity
nasal passages (has summation of mandible)
look for symmetry
what is viewed on open mouth VD imaging of the nasal cavity
maxilla, nasal septum, and nasal passages without summation of mandible
should see fine lined turbinates within the nasal passage
what is viewed on intraoral DV imaging of the nasal cavity
similar to open mouth VD but with a plate inside the mouth - image does not extend as far caudally
what is viewed on lateral imaging of the nasal cavity
frontal sinuses and bony structures (has summation of nasal passages)
may need wedge/spoon to keep face parallel to plate
what is viewed on frontal imaging of the nasal cavity
frontal sinuses - gas filled
summation excludes the nose from view
what factors do you evaluate on nasal radiographs
- nasal passage opacity
- turbinates
- frontal sinus opacity
- bone integrity (septum, frontal, maxillary)
hyperplastic rhinitis
- increased ST opacity in nasal passage
- loss of turbinate detail
- sinuses unaffected
usually BILATERAL
ddx for hyperplastic rhinitis
- infectious - viral or bacterial
- allergic/autoimmune
- foreign body
- dental disease
- hemorrhage
destructive rhinitis
- destruction of turbinates
- lucent areas in nasal passage
- focal areas of increased ST opacity
- frontal sinus plaques (“cotton ball” plaques in sinuses from fungal rhinitis)
ddx for destructive rhinitis
- chronic fungal rhinitis (dogs - aspergillus; cats - cryptococcus)
- chronic foreign body rhinitis
- severe lymphoplasmacytic rhinitis
nasal neoplasia
- ST mass
- turbinate destruction
- bony distortion/destruction
- facial swelling
usually UNILATERAL
ddx for nasal neoplasia
carcinoma (dogs)
lymphoma (cats)
what view is most often used to evaluate larynx and pharynx
lateral
what are normal radiographic changes in the larynx and pharynx
old dogs get mineralization of tracheal rings, epiglottis, and laryngeal cartilage
what are most common radiographic pathologies of the pharynx
- elongated/thickened soft palate
- foreign bodies
- ST swelling and tracheal displacement - trauma
- masses (neoplastic, polyps, lymphadenopathy, abscess)
- masses: displacement of soft palate, secondary gas in pharynx
- LNs: narrowing of pharynx, increased sT opacity pushing on dorsal pharyngeal wall
what are radiographic pathologies of the larynx
- edema/inflammation
- thickening of larynx
- increased opacity in area of larynx - neoplasia
- destruction of hyoid apparatus
- ST opacities - upper airway obstruction
- larynx and hyoid pulled caudally
- gas dilation of pharynx
- dogs: under-inflated chest
- cats: over-inflated chest
what views are used to evaluate the trachea
lateral
DV
normal trachea on lateral projection
diameter should be slightly smaller than the larynx
can get normal deviations with flexion/extension of the neck
normal trachea on DV projection
should run just to the right of the heart with constant diameter
pathologies causing tracheal deviation
- cranial mediastinal mass
- trachea deviates right w/ compressed lumen - hilar lymphadenopathy
- caudal trachea deviates ventrally - left atrial enlargement
- caudal trachea deviates dorsally - persistent R aortic arch
- trachea deviates ventrally and to the left
pathologies causing tracheal narrowing
- hypoplasia
- congenital malformation causing trachea to be 1/2 size of the larynx - collapse
- degeneration of tracheal cartilage; narrowing varies on inspiration/expiration - masses
- neoplasia uncommon - trauma
- pneumomediastinum and subcutaneous emphysema
