ANATOMY AND IMAGING OF AUDITORY OSSICLES

1. Dr S.KRITHIKA MDDr I.GURUBHARATH MD PhD

2. MALEUS
 The malleus is made up
of the head, neck, lateral
(short) process,anterior
process and handle
(manubrium).
 The lateral process and
handle of the malleus are
embedded in the TM

3. CORONAL HRCT

4.  The malleus articulates with the larger body of the
incus at the synovial diarthrodial malleoincudal joint
within the attic and is best visualized on axial or
sagittal obliqueimages.
 On axial images the malleoincudal joint resembles an
ice cream (head of malleus) sitting on a cone (body of
incus) and on sagittal reformatted images a molar
tooth

7. INCUS
 Th e incus consists of a
body and short, long and
lenticular processes.
 The short process
extends posteriorly
within the fossa incudis
just inferior to the aditus
ad antrum

8.  The long and lenticular processes meet at an angle of
approximately 90°. This ‘hockey stick’ appearance is best
demonstrated in the coronal plane

9.  The cup-shaped
lenticular process of the
incus articulates with the
head (capitulum) of the
stapes at the
incudostapedial joint
(ISJ), which is again a
synovial diarthrodial
articulation

11. Stapes
 The stapes consists of the
head (capitulum) anterior
and posterior crura and the
tympanic portion of the
footplate
 These components
together are described as
the stapes superstructure.
 The space between the
stapes crura is called the
obturator foramen.

12. AXIAL
The base of the stapes rocks in and out against the oval window. The
vibrations are transmitted via the endolymph to the hair cells of the organ
of Corti of the cochlea.

13.  The superior, lateral and anterior malleal ligaments,
supporting the malleus, can be seen on HRCT.
 Prussak’s space is the most common site of origin for
acquired cholesteatoma and is located between the
lateral mallear ligament superiorly,
 the lateral (short) process of the malleus inferiorly,
 the pars flaccida of the TM laterally and the neck of
the malleus medially

15. PRUSSAC’S SPACE

16. I am the
smallest bone
in the human
body
-STAPES
THANK YOU