See if you can identify the parts of the incus on the scan with the colours switched off. Check whether you are correct buy switching the colours on.

Incus

The incus transmits sound energy from the malleus to the stapes . Its body articulates with the head of the malleus in the epitympanum. It has a short process facing posteriorly, positioned in the fossa incudis which is its only site of ligamentous attachment. Its long process passes inferiorly. A 90 degree turn forms the small lenticular process which articulates with the stapes head.

The long and lenticular processes have a poor blood supply and are the most common sites of incus erosion.

Practical Tip

Always identify the presence of the incus as the posterior of the two ossicular “dots” on axial CT scans.