AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
Internal auditory meatus11/30/2023 The VIIIth (white thick arrow) and VIIth (thick black arrow) nerves in the cisternal portion are seen in B (slightly cranial to A). The VIIIth nerve and its cochlear and vestibular divisions are noted (arrowhead in A). ![]() The modiolus is visible in A as a hypointense triangular area. 8Īxial high-resolution 3D T 2WI of the labyrinth showing a normal cochlea with well-formed interscalar septum dividing the different cochlear turns (arrows in A) and the lamina spiralis dividing scala vestibuli and scala tympani (thin arrow in B). Depiction of the latter is of paramount importance as although similar appearing anomalies have comparable therapeutic options, it is the integrity of the cochlear nerve which ultimately governs functional outcome. As expected, neural structures are well delineated on MRI, namely the facial (VIIth), vestibular and cochlear branches of the VIIIth cranial nerves. High resolution, three-dimensional T 2W ( T 2 weighted) images on MRI (with a spatial resolution approaching 0.4 mm) enables visualization of tiny cochlear structures such as the interscalar septum and lamina spiralis (since minor malformations with subtle osseous abnormalities are not always visualized on CT). This is particularly relevant in the diagnosis of different subtypes of cochlear hypoplasia’s, where the identification of subtle abnormalities can be challenging, and small cochleae may be overlooked. A recent review 7 summarizes the usefulness of normative values in identifying and classifying anomalies, rather than relying on visual inspection alone. The otic capsule and inner ear structures are fully formed at birth and remain stable in size over time. ![]() Newer cone beam techniques offer superior imaging resolution but at lower radiation doses compared to traditional multidetector CT an obvious advantage in the paediatric setting and in the presence of very small anatomical structures such as the ossicles. MRI is critical in the assessment of the cochlear nerve, in addition to identifying the labyrinthine portion of the inner ear and any associated brain anomalies. 4 CT enables accurate anatomical surgical planning visualizing the bony structures of the inner, middle and external ear and anatomical variants that may influence surgery. MRI and CT are complementary in the pre-operative work-up.
0 Comments
Read More
Leave a Reply. |