17th May 2021

ICRI CASE OF THE WEEK

Contributed By : Dr. Richa Gautam, Dr Jyoti Kumar

Copyright of the Case belongs to : Dr Jyoti Kumar
Professor, Department of Radiology
MAMC, New Delhi

Clinical Details

A 16 year old adolescent presented to ENT OPD with complaints of small
deformed right auricle and decreased hearing in the right ear.

On auditory examination (Pure tone audiometry), conductive type of
hearing impairment was found on right side.

On otoscopic evaluation, there was no meatal opening/ auditory canal
on right side. Left auricle, external auditory canal and tympanic
membrane were normal on examination.

Patient was referred for HRCT of temporal bone to see other temporal
bone structures.

Axial (A) and coronal (B & C) HRCT
images of bilateral temporal bones

• What are the findings marked by arrows?

• What is the diagnosis?

• What are the critical temporal bone
structures that need evaluation in this case?

• White arrow- atresia of right external auditory canal & non-pneumatized bony atretic plate
• Yellow arrow- normal left external auditory canal
• Red arrow- normal tympanic membrane
• Image C- Right sided tympanic cavity is smaller (measuring <3mm in coronal plane from

promontory to the atretic plate) as compared to left side.

Other critical temporal bone structures to be looked
for in EAC atresia

1. Ossicles- presence or absence of stapes, malleus-incus complex,
incus-stapes complex, epitympanic fixation

2. Windows – oval and round windows

3. Facial nerve course

4. Mastoid pneumatization

OSSICLES AND ROUND WINDOW

Axial HRCT images of
right temporal bone (A-D
from superior to
inferior).

What are the findings
marked by arrows?

Key:
Il- long process of incus;
Ib- body of incus;
S- stapes

OSSICLES AND ROUND WINDOW • Il is dysplastic

• Yellow arrow- dysplastic ice-
cream cone appearance

• Incudo-stapedial joint
between Il and S (in Fig A)
appears mal-aligned.

• Red arrow- fixation of Ib with
lateral epitympanic wall

• Blue arrow- open round
window

• * -absent manubrium in
mesotypanum

FACIAL NERVE AND OVAL WINDOW

Axial (A-C, from superior to
inferior) and coronal (D)
HRCT images of right
temporal bone.

What are the findings
marked by arrows?

Key:
Fl- labyrinthine segment
of facial nerve;
Ft- tympanic segment;
Fm- mastoid segment.

FACIAL NERVE AND OVAL WINDOW

• Normal course of Fl and
Ft

• Anterolateral
displacement of Fm
exiting through the bony
atretic plate (red arrow)
at the level of oval
window (blue arrow)

• Green arrow- normal
pneumatization of
mastoid

• What is the common CT scoring system used?
• What is its significance?

• Jahrsdoerfer scoring system (1)- 10 point CT scoring system
• Used to establish surgical candidacy

JAHRSDOERFER SCORING

JAHRSDOERFER SCORING NORMAL SCORE IN JAHRSDOERFER SCORE TYPE OF SURGICAL
SYSTEM SCORE OUR CASE CANDIDATE
2
Stapes normal 1 2 ≤5 poor
Appearance of external ear 1 0
1 0 6 Marginal
Middle ear space 1 0
Malleus-incus complex 1 0 7 Fair
Incus-stapes connection 1 0
1 1 8 Good
Facial nerve 1 1
Open oval window 10 1 9 Very good
Open round window 5
Mastoid pneumatization 10 Excellent

TOTAL SCORE

Discussion

• Congenital aural atresia (CAA) characterized by malformations of external and middle ear
• Rarely involves inner ear.

• Occurs in 1 in 10,000-20,000 live births
• Bilateral > unilateral
• Males > Females

• Most often sporadic
• Syndromic association with Goldenhaar syndrome, Treacher Collin syndrome, Crouzon

syndrome may be seen.

• Jahrsdoerfer scoring system- used to decide surgical candidacy and predict post-operative
hearing outcome.

• Important structures to be examined for this score are- external ear, middle ear size &
aeration, ossicles, facial nerve, windows, mastoid pneumatization

• Other less common scoring systems used are-
 Modified grading system (2)
 Active Middle ear implant (aMEI)score (3)

• Facial nerve course to be inspected carefully to avoid undesirable but avoidable complication
of facial nerve paralysis.

• Pre-operative HRCT temporal bone- an essential investigation to delineate the anomalies
and to decide the management strategy (4).

References

1. Jahrsdoerfer RA, Yeakley JW, Aquilar EA, Cole RR, Gray LC. Grading system for the
selection of patients with congenital aural atresia. Am J Otol 1992;13:6–12

2. Yellon RF, Branstetter IV BF. Prospective blinded study of computed tomography in
congenital aural atresia. Int J Pediatr Otorhinolaryngol 2010;74(11):1286-91.

3. Frenzel H, Sprinzl G, Widmann G, Petersen D, Wollenberg B, Mohr C. Grading system for
the selection of patients with congenital aural atresia for active middle ear implants.
Neuroradiology 2013;55(7):895-911. 10.

4. Gautam R, Kumar J, Pradhan GS, Passey JC, Meher R, Mehndiratta A. High-resolution
computed tomography evaluation of congenital aural atresia–how useful is this?. J
Laryngol Otol 2020;134(7):610-22.