OSCE Notes in Otoradiology by drtbalu

Station 1:

View this x-ray

xray_mas.jpg

1. Name the view

2. Write down the differential diagnosis

X-ray both mastoids Laws view (lateral oblique)

Differential diagnosis:

1. Large antral cell - This is usually bilateral

2. Cholesteatomatous cavity - Radiologically this cavity will be surrounded by a rim of sclerosis

3. Operated cavity - Pt will give h/o mastoid surgery. The cavity margins will be irregular and will not show sclerosis

4. Secondaries

5. Multiple myeloma

6. Tuberculosis

7. Eosinophilic granuloma

Station 2:

choles.jpg

Read this CT scan

This is a CT scan of temporal bone.

Soft tissue shadow seen occupying the middle ear cavity, it even extends to involve mastoid air cell system.

Possible diagnosis - Cholesteatoma

Station 3:

mastoiditis.jpg

1. What view is this CT scan ?

2. What could be the probable diagnosis ?

This is a plain CT axial view of temporal bone.

It shows sclerosis of mastoid air cells on the right side - possibly due to mastoiditis

Mastoid air cell pneumatization is normal on the left side

Station 4:

Read this CT scan temporal bone axial view

What could be the clinical manifestation seen in this patient ?

lon_fra.jpg

This CT scan temporal bone axial view shows longitudinal fracture of temporal bone

Haematoma could be seen filling the middle ear cavity

These patients commonly manifest with conductive deafness due to the presence of hematoma in the middle ear, or disruption of ossicular continuity.

Station 5:

Comment on the CT displayed

Describe the cochlear deformity

mondini.jpg

This is a HRCT of temporal bone, axial view.

It shows a deformed cochlea with less than 2 1/2 turns. This is a classical feature of Mondini deformity

Station 6:

Shown below is the CT scan of a patient before cochlear implant procedure.

Identify the pathology

Discuss its relevance to cochlear implant procedure

laby_ossi.jpg

This is a HRCT of temporal bone showing ossified labyrinth. (Labyrinthitis ossificans).

In these patients since the round window is totally obliterated due to ossification it will be difficult to place the cochlear implant electrode.

A third window will have to be drilled for placement of cochlear implant electrodes.

Station 7:

atresia.jpg

Name the pathology seen in this CT scan.

What type of hearing loss this patient will have ?

This is a axial CT of temporal bone.

It shows atresia of left external auditory canal

Cochlea appears normal

Deafness could be conductive in nature

Station 8:

scutum_ero.jpg

This 30 year old patient had C/O left ear discharge - 5 years

Discharge was scanty, blood tinged and foul smelling

Axial CT (plain) of temporal bone is displayed

1. Identify the pathology

2. Why is the discharge foul smelling ?

This CT shows erosion of the outer attic wall on the left side.

This could most probably be due to cholesteatoma.

Foul smelling discharge is caused due to bone erosion

Station 9:

10 year old boy with h/o grommet insertion left ear one month back.

C/O pain in the left ear

Pt underwent CT scan

grommet.jpg

Identify the structure shown by the arrow

Ear drum can be clearly seen.

There is a communication between the external canal and middle ear cavity as pointed by the white arrow.

The site of this communication indicates that it could be the site of grommet insertion

Station 10:

20 year old male patient had c/o Hard of hearing in right ear

There were no other otologic complaints like tinnitus / vertigo / facial nerve dysfuntion etc

There was a bony mass arising from the medial aspect of external auditory canal on the right side

The ear was completly dry

CT scan temporal bone :

osteoblastoma.jpg

Name the view

Describe the saliant features of this CT scan

What could be the probable diagnosis

This is Axial CT scan plain of both temporal bones

There is a well demarcated bone dense tumor involving the right temporal bone

Middle ear cavity obliterated

No bony erosion of petrous apex

Probable diagnosis - Benign osteoma of right temporal bone

Station 11:

15 years old boy presented with c/o:

1. foul smelling ear discharge left side - 15 days

2. Fever - 2 days

3. Intense headache - 2days

4. There was tenderness / oedema over left mastoid process

Temperature chart:

picket.jpglat_sinus.jpg

Name the type of temperature chart

Comment on MRI scan of the patient

What could be the probable diagnosis ?

Temperature chart shows classic picket fence appearance. The temperature does not touch normal at any given point of time.

MRI shows clot in the left lateral sinus.

Diagnosis - Otogenic lateral sinus thrombosis

Station 12:

cong_chol.jpg

30 year old female patient came to the OPD with C/O mild hard of hearing right ear - 3 years

She gave no h/o ear discharge / pain

O/E: Ear drum was found intact in the right ear.
Mobility was also normal.

CT scan of temporal bone was taken

Comment on the CT scan

This is a CT scan of temporal bone.
Soft tissue shadow is seen occupying the middle ear cavity close to the long process of incus.
Possible diagnosis is cholesteatoma ?? congenital.

Derlacki and Clemis criteria for the diagnosis of congenital cholesteatoma:

1. The patient should not have previous episodes of middle ear disease

2. Ear drum must be intact and normal

3. It is purely an incidental finding

Station 13:

Comment on the CT brain displayed.

Which condition commonly cause this problem?

temp_abs.JPG

This CT scan brain shows hypodense mass in the right temporal lobe. This mass is surrounded by thickened
capsule. Probable diagnosis is temporal lobe abscess. Commonest cause of temporal lobe abscess is chronic suppurative
otitis media.

Station 14:

glomus3.jpg

Shown here is the CT scan (axial cut) of petrous bone area showing glomus jugulare as marked there. How do you differentiate it from high jugular bulb and aberrant internal carotid artery?

In patients with glomus jugulare and high jugular bulb the jugular fossa is enlarged. But in glomus jugulare the cortex of the jugular fossa appears eroded while in patients with high jugular bulb this erosion is not seen.

To rule out aberrant carotid artery a coronal CT of temporal bone is a must. If the carotid canal is normally placed then glomus tympanicum should be considered, whereas if the same is placed laterally then aberrant internal carotid artery is a good diagnostic possibility.

Station 15:

petromastoid_canal.jpg

Name the structure pointed out by the arrow.

This is petromastoid canal also known as subarcuate canal.
It connects the mastoid antrum with cranial cavity. It houses
subarcuate artery and vein. It may be 0.5 mm wide and may be
confused with that of fracture line.

Station 16:

cochlear_aque.jpg

Name the structure pointed out by the arrow.

It is a cochlear aqueduct. It connects perilymph with the subarachnoid space.
This canal runs towards the cochlea in the same direction as that of internal acoustic meatus, but
more caudally. It is through this duct infections from brain reaches the inner ear. This is how
labyrinthitis ossificans is caused in a patient with meningitis.

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