Learning objectives
To learn the normal anatomy of the inner ear.
To Know imaging protocols for styding the inner ear by computed tomography and magnetic resonanace imaging.
To know the imaging features of the main congenital,
infectious,
dystrophic,
traumatic and tumoral pathologies of the inner ear.
Background
The labyrinth or the inner ear is the sensorineural organ of the temporal bone.
It consists of an osseous labyrinth that encloses membranous labyrinth.
When imaging the labyrinth,
the HR-CT allows to stydy the ossoues labyrinth and the MRI allows the minitious study of the fluid filled spases of the membranous labyrinth.The high magnetic field (3 Tesla) allows through improved spatial resolution to separate the endolymphatic and perilymphatic content.
Having a perfect knowledg of the anatomy of the inner ear makes easier the diagnosis of...
Findings and procedure details
1- Computed tomography imaging protocol
We use a General electric 64 slices VCT machine.
The exams are aquired with the following imaging parameters:120 kV,250 mAs,
collimation 0.5 mm or 0.625 mm,
scan time 1s.
After acquiring,
the raw dataset images are reconstructed with a slice thickness of 1 mm ,
by using an ultra high resolution reconstruction mode.
The reconstructions of the axial images are made in a plane parallel to the lateral semicircular canal.
The coronal imaging set is reconstructed exactly perpendicular to this...
Conclusion
High-resolution computed tomography and magnetic resonance imaging provide excellent delineation of the intricate anatomy of the inner ear,
CT depicts the minute details of osseous structures,
and MR imaging allows visualization of the fluid-filled spaces and the vestibulocochlear nerve.
Together,
these complementary modalities can aid the diagnoses and the characterization of most inner ear deseases.
References
(1) Curtin HD,
Sanelli PC,
Som PM.
Temporal bone: embryology and anatomy.
Head and neck imaging,2003;2:1057–75.
(2) VarshaM Joshi,
DNB Shantanu K.
Navlekar DMRD.
CT and MR imaging of the inner ear and brain in children with congenital sensorineural hearing loss.
RadioGraphics 2012;32:683–98.
(3) Jackler RK,
Luxford WM,
House WF.
Congenital malformations of the inner ear: a classification based on embryogenesis.
Laryngoscope 1987;97: 2–14.
(4) Bela Purohit & Robert Hermans & Katya Op de beeck Imaging in otosclerosis: A pictorial review Insights Imaging2014;5:245–52.
(5) F...
