|
|
MRI - Interesting Cases 3 |
52 year old female presents with slow-onset left-sided hearing loss and positional tinnitus with a feeling of fullness in the left ear. She had no facial numbness or balance disturbance.
MRI reveals a well defined 4mm soft tissue lesion, of similar intensity to the pons, within the left internal auditory canal. The lesion markedly enhances with gadolinium. The diagnosis of an Acoustic Schwannoma was made.
Axial T2
Axial T2 with gadolinium
Acoustis Schwannomas are benign but expansile tumours of the nerve sheath, most frequently arising in the superior vestibular portion of the 8th cranial nerve. About 10% are associated with Neurofibromatosis Type 2.
MRI is the recommended diagnostic modality because:
- There is no characteristic symptom pattern making early diagnosis a challenge.
- MRI sensitivity is nearly 100%.
- MRI has superior contrast and spatial resolution for early diagnosis of intracanalicular lesions >1mm (compared with CT which can only diagnose lesions >5mm).
- MRI can often differentiate other lesions in the cerebello-pontine angle such as meningiomas or epidermoids.
|
|
|
|
