Dr Ahmed Esawy IMAGING OF ADENIOD ENLARGMENT different modalities PLAIN X RAY CT MRI

1. Dr. Ahmed Esawy
MBBS M.Sc MD

2. Anatomy
• The lymphoid tissue of the nasopharynx and
oropharynx is composed of the adenoids, the tubal
tonsils, the lateral bands, the palatine tonsils, and
the lingual tonsils.
• There are also lymphoid collections in the posterior
pharyngeal wall and in the laryngeal ventricles.
• These structures form a ring of tissue named
Waldeyer’s ring after the German anatomist who
described them.

4. The adenoid, also known as
a pharyngeal
tonsil or nasopharyngeal
tonsil, is the superior -most of
the tonsils . It is a mass of
lymphatic tissue situated
posterior to the nasal cavity,
in the roof of the nasopharynx
it forms a soft mound in the
roof and posterior wall of the
nasopharynx , just above and
behind the uvula .

7. Lateral neck radiograph
• The main imaging study to evaluate the
adenoid is a lateral neck radiograph, as in the
images below.
ENLARGED ADENIOD
AVERAGE SIZE ADENIOD

8. Requirement of Lateral neck radiograph
in adenoid
• 1-true lateral view not oblique
• 2-adjust X ray factors to differentiate between
soft tissue density of adenoid and bone density of
mandible . high voltage lead to false –ve ,low
voltage give false +ve
• 3-extend neck to pull mandible anteriorly away
from adenoid bed prevent overlap on adeniod
shadow
• 4-open mouth to clear identify air column
• 5-no movement of patient to prevent haziness
,blurring

9. • The lateral neck x-ray is the main imaging
study. The size of the adenoids is less of a
consideration than the degree to which they
encroach on the nasopharyngeal airway
(adeniod grades) :
• if no adenoidal tissue after 6 months, suspect
immune deficiency
• if enlarged adenoids well after childhood,
suspect lymphatic malignancy

10. Method of assessing adenoid enlargement on lateral neck radiography. In this method the
adenoidal measurement (A) represents the distance from the point of maximal convexity of
the adenoid shadow to a line along the anterior margin of the basiocciput. The
nasopharyngeal measurement (N) is the distance between the posterior border of the hard
palate and the antero-inferior edge of the sphenobasioccipital synchondrosis.
Minimal (AN ratio < 0.50)
Mild (0.50 ≤ AN ratio < 0.62)
Moderate (0.63 ≤ AN ratio < 0.75)
Severe (0.76 ≤ AN ratio < 0.88)

15. CASE 1
ENLARGED ADENIOD

16. CASE 2
ENLARGED ADENIOD

17. CASE 3
ENLARGED ADENIOD

18. CASE 4
ENLARGED ADENIOD

21. Three-dimensional (3D) measurements of the nasopharyngeal airway on the adenoid plane
in this study. A, The nasopharyngeal airway on the midsagittal view. The most enlarged
adenoid was tangential; the nasopharyngeal airway’s narrowest part is identified as Ad-En;
and the nasopharyngeal airway is shown as the yellow area. B, The cross-sectional image of
the nasopharyngeal airway in the frontal plane, in which the most enlarged adenoid was
included (adenoid plane).
Minimal (AN ratio < 0.50)
Mild (0.50 ≤ AN ratio < 0.62)
Moderate (0.63 ≤ AN ratio < 0.75)
Severe (0.76 ≤ AN ratio < 0.88) group

24. No enlarged adenoid and palatine tonsils
Enlarged adenoid and palatine tonsils

25. Axial T1-weighted contrast-enhanced MR image in a 56-year-old man shows smooth, thin,
hyperenhancing tissue along the posterior nasopharyngeal wall (white long arrows). The right
pharyngeal recess is collapsed (white short arrows), whereas the left recess is patent (black
arrows), but both recesses show symmetric wall thickness.

26. Axial T1-weighted, A, nonenhanced and, B, contrast-
enhanced MR images of the nasopharyngeal roof in a 34-
year-old man show vertically aligned dark and bright stripes
(arrows) within a grossly enlarged nasopharyngeal adenoid

27. C, Axial T1-weighted contrast-enhanced
MR image in a 29-year-old man
shows an enlarged adenoid composed
of a central wedge of predominantly
dark tissue (black arrow), flanked
on each side by a thin stripe of bright
tissue (white arrows).
D, Axial T1-weighted contrast-enhanced MR
image in a 51-year-old woman shows small
tags of tissue protruding from the
nasopharyngeal roof (arrows),which probably
represent tissue remnants after adenoid
involution.

28. Axial T1-weighted, A, nonenhanced and, B, contrast-
enhanced MR images in a 30-year-old man show a uniform
hypoenhancing band of tissue in the posterior wall
(arrows).

29. A, Axial T1-weighted contrast-enhanced MR image, and, B, axial T2-
weighted fat-suppressed MR image in 45-year-old woman show
numerous mucus retention cysts, which are hypointense and markedly
hyperintense, respectively. A few cysts are indicated (arrows).