Head/neck (not including brain) Flashcards
What are the 5 classifications for caudal aberrant turbinates in English bull dogs?
Vilaplana, F., et al. “Gender, weight, and age effect on prevalence of caudal aberrant nasal turbinates in clinically healthy english bulldogs” Vet rad 2015 (pre-publish)
- No turbinates in ventral nasal meatus
- Turbinates in VNM, but not nasopharyngeal meatus
- Turbinates in NPM, but not extending into choanae
- Turbinates in choanae but not to the rostral border of the nasopharynx
- Turbinates visible in the nasopharynx
According to the article “Gender, weight, and age effect on prevalence of caudal aberrant nasal turbinates in clinically healthy english bulldogs” - what is prevalence of caudal aberrant nasal turbinates in healthy English bull dogs? What is significance of grades 0-3?
Prevalence is 100% in these healthy dogs (no signs of respiratory disease). These dogs were scored 1-3. No significance of gender, weight, or age. Suggests that severe cases are grade 4 - but more studies needed!
How are the nasal conchae form, and what problem occurs in English bulldogs that lead to caudal aberrant turbinates?
Vilaplana, F., et al. “Gender, weight, and age effect on prevalence of caudal aberrant nasal turbinates in clinically healthy english bulldogs” Vet rad 2015 (pre-publish)
Post-natal development and growth of the nasal conchae is normal in healthy animals - conchae grow until the nasal cavity is occupied. In brachycephalic breeds - mechanisms fail, favourin aberrant extension of conchae (they do not stop growing once they touch each other).
Which imaging characteristics were pathognomonic for carcinoma vs sarcoma vs melanoma of the pharynx?
Carozzi, G., “CT features of pharyngeal neoplasia in 25 dogs.” VRU Pre-publish.
NONE. (shape, margins, mass effect, infiltration, grade/pattern of enhancement, potential distant metastasis, enlargement/shape, enhancement of lymph nodes.”
What characteristics of lymph nodes were consistent with metastatic disease from a pharyngeal neoplasia. What % of lymph nodes with these findings were consistent with metastasis?
Which lymph node was most commonly affected?
Carozzi, G., “CT features of pharyngeal neoplasia in 25 dogs.” VRU Pre-publish.
Enlarged, round, heterogeneous contrast enhancement.
75%
Medial retropharyngeal lymph nodes. Mandibular lymph nodes also were commonly affected, but to lesser degree.
According to the article: Apparent wall thickening in fluid filled vs air filled tympanic bulla in CT - what is ideal protocol and algorithm to view the tympanic bulla?
VRU 34.6
It is best to use a bone algorithm (with a very wide window - between 2 and 4000), with thin slices to prevent volume averaging
What algorithms/windows will make the tympanic bulla appear thicker?
Will fluid or air in the bulla make it look thicker?
Apparent wall thickening in fluid filled vs air filled tympanic bulla in CT. VRU 34.6
Soft tissue algorithm/window, thicker slices, narrow windows,
Fluid will make the bulla look thicker
What are high spatial frequency objects?
Apparent wall thickening in fluid filled vs air filled tympanic bulla in CT. VRU 34.6
Small size, well defined borders, high degree of contrast with surrounding structures.
Examples: Bone, pulmonary vessels, pulmonary nodules
What are low spatial frequency objects?
Apparent wall thickening in fluid filled vs air filled tympanic bulla in CT. VRU 34.6
Large size, poorly defined borders, low contrast with surrounding structures.
Examples: Abdominal viscera and fat.
What happens to the bulla when fluid is added into the tympanic cavity? (relate to the high/low spatial frequency of these objects)
Apparent wall thickening in fluid filled vs air filled tympanic bulla in CT. VRU 34.6
The bulla will appear thicker.
Tympanic bulla is a high spatial frequency structure (thin walled, small, high contrast with air in the cavity). When fluid cavity - there is less contrast and spatial frequency decreases and information is transferred better. (IE - HU # of bulla will be closer when fluid filled than when air filled)
What are indications for evaluation of the nasolacrimal system?
chronic epiphora, orbital trauma, nonresponsive conjunctivitis, proptosis, congenital malformations, neoplasia, factial fractures
What are the components of the nasolacrimal drainage system?
CT anatomy of normal feline nasolacrimal drainage system VRU 47.1
upper and lower lacrimal puncta, lacrimal canaliculi, lacrimal sac, and nasolacrimal duct
What are the osseous structures in vicinity of drainage system of nasolacrimal duct?
CT anatomy of normal feline nasolacrimal drainage system VRU 47.1
lacrimal fossa,
Which part of the lacrimal system is not covered by osseous structures?
CT anatomy of normal feline nasolacrimal drainage system VRU 47.1
the lacrimal sac (approximately 2mm) - between lacrimal and maxillary bones. Approximately 2mm rostral to the maxillary recess
Where is the origin of the nasolacrimal duct at approximately?
CT anatomy of normal feline nasolacrimal drainage system VRU 47.1
At the same level of the infraorbital foramen - at the caudal border of the maxillary 3rd premolar
What surrounds each portion of the nasolacrimal duct? (proximal, middle, distal)
CT anatomy of normal feline nasolacrimal drainage system VRU 47.1
Proximal - maxillary bone
Middle - ventral to basal lamina of the ventral nasal concha. Medial portion covered by respiratory epithelial mucosa
Distal - runs towards midline without osseous protection.
Whole canal is formed by maxilla and the basal lamina of ventral nasal concha
At what level could the lacrimal sac be identified?
CT anatomy of normal feline nasolacrimal drainage system VRU 47.1
At the level of the maxillary foramen (caudal end of infraorbital canal).
What are the 5 types of paragangliomas in the head and neck? (NOT SUBGROUPS)
CT and MR features of carotid body paragangliomas in 16 dogs. VRU 56.4
1) Carotid body tumors - paraganglioma cells at the carotid bifurcation
2) Vagal paragangliomas - arise from paraganglionic tissue within the vagal nerve (near skull in the jugular fossa)
3) Tympanic paraganglioma - tympanic branch of glossopharyngeal nerve (anyhwere aong this nerve)
4) Jugular paraganglimomas within adventitia of jugular bulb
5) Chemodectomas - aortic bodies
Where is the most common form of paragangliomas located at?
CT and MR features of carotid body paragangliomas in 16 dogs. VRU 56.4
aortic bodies - close to heart base, less commonly at bifurcaiton of common carotid vessel
What is typical behavior of paragangliomas?
CT and MR features of carotid body paragangliomas in 16 dogs. VRU 56.4
Slow growing, nonsecreting tumors, 30% of dogs have metastasis at time of diagnosis (lungs, nodes, liver, pancreas, kidneys and vertebrae).
What breed and sex are predisposed to paragangliomas?
CT and MR features of carotid body paragangliomas in 16 dogs. VRU 56.4
Brachycephalics (boston terriers specifically)
Males
What are common characteristics of paragangliomas? (Both CT and MR)
CT and MR features of carotid body paragangliomas in 16 dogs. VRU 56.4
1) Splaying of carotid bifurcation
2) Lateral/ventrolateral displacement of external carotid vessels
3) Entrapment of external carotid artery
4) strongly contrast enhancing (usually homogeneous)
5) similar to musculature on CT, hyperintense on MRI
6) T2* hemorrhage
7) Invasion into adjacent structures 9/16 dogs
Where do paragangliomas invade into?
CT and MR features of carotid body paragangliomas in 16 dogs. VRU 56.4
Invasion was seen in 9/16 dogs
1) Basilar portion of the skull - widening of petro-occipital fissure - some with invasion into cranial vault through jugular foramen
2) Erosion/lysis of ipsilateral tympanic bulla with or without invasion into middle ear
3) Vascular invasion (external jugular vein, maxillary, linguofacial vein)
4) Effacement / enlargement of medial retropharyngeal lymph nodes
In previous literature, what has behavior or paragangliomas been?
CT and MR features of carotid body paragangliomas in 16 dogs. VRU 56.4
Typically benign, well encapsulated tumors. No tumors were seen invading osseous structures
In this study, 9/16 were invasive (bias?)
Osseous invasion seen in 6/16 patients
What do patients with paragangliomas usually present for?
CT and MR features of carotid body paragangliomas in 16 dogs. VRU 56.4
Most tumors are incidental, but some dogs have respiratory/swallowing difficulties, Horner’s syndrome, other neurologic signs
Why may paragangliomas cause Horners, facial nerve paralysis, hypoglossal deficits?
CT and MR features of carotid body paragangliomas in 16 dogs. VRU 56.4
Invasion into petrooccipital fissure causes compression of nerves through this structures: glossopharyngeal, vagus, spinal accessory nerves.
Hypoglossal foramen is immediately dorsal to this area.
What are classic MR findings of a paraganglioma?
Imaging diagnosis - paraganglioma of hte cauda equina: MR findings VRU 56.1
T2w hyperintense
T1w - hypointense
T1w +C - stronghly enhancing (very hypervascular)
Hypointense well defined rim on both T2 and T1
T2* no magnetic susceptibility
Edematous spinal cord
What are 4 subgroups of paragangliomas?
Imaging diagnosis - paraganglioma of hte cauda equina: MR findings VRU 56.1
1) Branchiomeric - aortic/carotid body
2) Intravagal - along the vagus nerve
3) Aortico-sympathetic - in retroperitoneal space
4) visceral-autonomic: thyroid, middle ear, GI tract, pancreas, prostate, larynx, gallbladder, intrathoracic region, peripheral blood vessels
What is percentage of metastatic potential of paragangliomas?
Imaging diagnosis - paraganglioma of hte cauda equina: MR findings VRU 56.1
6.5%
What are distinguishing characteristics of small tympanic bone spicules and hyperostotic tympanic bone spicules?
Prevalence and characterization of small tympanic bone spicules and drumstic-like hyperostotic tympanic bone spicules in the middle ear cavity of dogs. VRU 56.1
Small tympanic bone spicules: smaller, needle like bone spicules arising from the inner wall of the bulla with a length of 1mm and diameter 1mm
These are considered to be a continuation!!
Where are the most common sites to see small tympanic bone spicules and hyperostotic tympanic bone spicules?
Prevalence and characterization of small tympanic bone spicules and drumstic-like hyperostotic tympanic bone spicules in the middle ear cavity of dogs. VRU 56.1
Small tympanic bone spicules - free wall of the bulla septae
Hyperostotic tympanic bone spicules - free wall of the bulla septae, roof of the tympanic cavity, and caudoventral wall.
What is prevalence of HTBS in cadaver vs CT studies?
Prevalence and characterization of small tympanic bone spicules and drumstic-like hyperostotic tympanic bone spicules in the middle ear cavity of dogs. VRU 56.1
Cadaver - 48% prevalence
CT study - 20%
When is HTBS more likely to be seen?
Prevalence and characterization of small tympanic bone spicules and drumstic-like hyperostotic tympanic bone spicules in the middle ear cavity of dogs. VRU 56.1
Dogs with increased weight
No correlation with sex or age
What is prevalence of bilateral vs unilateral HTBS in cadaver vs CT studies?
Prevalence and characterization of small tympanic bone spicules and drumstick-like hyperostotic tympanic bone spicules in the middle ear cavity of dogs. VRU 56.1
Cadaver - 66-80% bilateral
CT studies - 40%
Discrepancy may be due to slice thickness
What animals were likely to have increased # of HTBS and STBS?
Prevalence and characterization of small tympanic bone spicules and drumstick-like hyperostotic tympanic bone spicules in the middle ear cavity of dogs. VRU 56.1
Increased weight - increased numbers - larger bulla wall to have spicules along.
Which imaging characteristic of middle ear disease was the only characteristic that had a significant correlatoin with PRESENCE of disease on histopath for BOTH modalities?
Comparative performance of radiography and CT in diagnosis of middle ear disease in 31 dogs VRU 47.1
Increased opacity of the bulla
Which imaging characteristics showed a strong correlation with histopathology SEVERITY?
Comparative performance of radiography and CT in diagnosis of middle ear disease in 31 dogs VRU 47.1
increased opacity within the bulla, bulla proliferation
NOT bony lysis
Are CT/radiographs better at predicting how severe a disease process is, or whether there is disease or not?
Comparative performance of radiography and CT in diagnosis of middle ear disease in 31 dogs VRU 47.1
Severity of disease
Both modalities still had a lot of false ngatives
Do CT and radiographs over or under-estimate the presence of middle ear disease?
Comparative performance of radiography and CT in diagnosis of middle ear disease in 31 dogs VRU 47.1
Underestimate
What were approximate sensitivity/specificity/PPV/NPV of CT for detecting middle ear disease?
Comparative performance of radiography and CT in diagnosis of middle ear disease in 31 dogs VRU 47.1
Histopath vs surgery Sens: 64/86 Spec: 100/89 PPV: 100/93 NPV: 29/80
What were approximate sensitivity/specificity/PPV/NPV of radiographs for detecting middle ear disease?
Comparative performance of radiography and CT in diagnosis of middle ear disease in 31 dogs VRU 47.1
Histopath vs surgery Sens: 54/55 Spec: 100/83 PPV: 100/84 NPV: 24/54
How do cat tympanic bulla differ from canines?
MRI of the normal and diseased feline middle ear VRU 41.5
Larger ventromedial and smaller dorsolateral compartment
Compartments are separated by very thin bony lamella
How did mucous differ on MRI from inflammatory polyp and thickened mucosa?
MRI of the normal and diseased feline middle ear VRU 41.5
Contrast enhancement of polyp and thickened mucosa
mucosa/fluid retention did not enhance
What are CT characteristics of feline inflammatory polyps?
Pathologic basis for rim enhancement in CT images of feline nasopharyngeal polyps VRU 57.2
Mass within the tympanic bulla, nasopharynx, or external ear canal (any of these can have extension into the other via the auditory canal), enlargement of tympanic cavity, lysis of bulla or petrous temporal bone, enhancement of whole polyp with increased rim enhancement
What is the pathologic difference between the core and superficial stroma of a nasopharyngeal polyp?
Pathologic basis for rim enhancement in CT images of feline nasopharyngeal polyps VRU 57.2
Core: Edematous
Stroma: inflammatory, hemorrhagic, vascularity was not significant
What is underlying reason for rim enhancement of nasopharyngeal polyps?
Pathologic basis for rim enhancement in CT images of feline nasopharyngeal polyps VRU 57.2
Inflammation
What CT and histologic correlations were seen in the study: Pathologic basis for rim enhancement in CT images of feline nasopharyngeal polyps VRU 57.2
Positive correlation:
Post contrast HU rim and grade of inflammatory infiltration in superficial stroma
Increase in HU of rim and grade of inflammatory infiltration of superficial stroma
Extent of rim observed on CT wwith grade of inflammatory infiltration
Negative correlation:
HU of rim and grade of edema
What effects did hemorrhage, vascularization and edema have on enhancement of the superficial layers of the polyp?
Pathologic basis for rim enhancement in CT images of feline nasopharyngeal polyps VRU 57.2
None
Inflammatory infiltration was only correlation.
How does tympanic cavity thickness and volume differ between brachycephalic and non-brachycephalic breeds?
Comparison between CT characteristics of the middle ear in non-branchycephalic and brachycephalic dogs with obstructive airway syndrome VRU 57.2
Tympanic bulla thickness: thicker rostro-ventral (3mm), and thinner caudoventral (2mm) in brachycephalics. Brachycephalics are static in thickness throughout (1mm)
Tympanic cavity volume: smaller in brachycephalic breeds (0.41mL) vs (0.85mL)
What was difference between soft palate thickness and presence of fluid in the ears between groups?
Comparison between CT characteristics of the middle ear in non-branchycephalic and brachycephalic dogs with obstructive airway syndrome VRU 57.2
Brachycephalics were more likely to have fluid filled tympanic cavities. The dogs with thicker soft palates were significantly more likely to have fluid within the tympanic cavity.
Non-brachycephalic - none had fluid within the ear canal.
What is significance of a thickened soft palate and presence of subclinical ear disease?
Comparison between CT characteristics of the middle ear in non-branchycephalic and brachycephalic dogs with obstructive airway syndrome VRU 57.2
Accumulation of soft tissue/fluid in affected dogs occurred as a result of Eustachian tube dysfunction or obstruction. This was seen in similar report in Cavalier king charles
What did authors propose as the cause for increased subclinical ear disease in brachycephalic breeds?
Comparison between CT characteristics of the middle ear in non-branchycephalic and brachycephalic dogs with obstructive airway syndrome VRU 57.2
Combination of a thickened soft palate, smaller tympanic vulla volume, tortuous conformation of their external ear producing Eustachian tube dysfunction
According to this article:
Association of middle ear effusion with trigeminal mass lesions in dogs. Vet Record 2013
What will a mass withint he trigeminal nerve lead to?
Larger trigeminal lesion = more severe Ipsilateral muscle wasting
Middle ear effusion = more severe ipsilateral muscle wasting
NO correlation between size of trigeminal lesion and presence/absence of middle ear effusion
Tensor veli palatini muscle wasting
Which muscles does the trigeminal nerve innervate?
Association of middle ear effusion with trigeminal mass lesions in dogs. Vet Record 2013
tensor veli palatini
masseter, temporalis, medial and lateral pterygoid, rostral digastricus, myelohyoideus, tensor tympani muscles
What effect does the tensor veli palatini muscle have on middle ear effusion?
Association of middle ear effusion with trigeminal mass lesions in dogs. Vet Record 2013
Tensor veli palatini - innervated by trigeminal nerve
Opens the pharyngeal orifice of the auditory tube (allows for drainage).
Without innervation, drainage cannot occur, and there is increased pressure within the middle ear - leading to sterile transudate to be drawn in from the secretory epithelium of the middle ear
In this report: Association of middle ear effusion with trigeminal mass lesions in dogs. Vet Record 2013, as well as CE-CT of the auditory tube in mesaticephalic dog -
How do you achieve enhancement of the auditory canal?
Application of 10cc of 1:1 dilution of contrast agent into the tympanic cavity via a urinary catheter tube and either a balloon dilation/ear plugs to prevent drainage of contrast
What are imaging characteristics of a trigeminal nerve tumor?
Association of middle ear effusion with trigeminal mass lesions in dogs. Vet Record 2013
Ipsilateral muscle wastage Unilateral, well-circumscribed, extra-axial mass at the level of the trigeminal ganglion T2 iso/hyperintennse T1 - isointense Enhancement following contrast
