Imaging of neck: Anatomy and pathology

1. DR/ Wafik Ebrahim, MD
Assistant Professor of Rradiodiagnosis
Faculty of Medicine
Alazhar University

2. For proper studying of the neck it is
divided into compartments and spaces:
 Suprahyoid neck:
From skull base to the hyoid bone
 Infrahyoid neck:
Below hyoid bone to thoracocervical
junction. Some spaces continue to
mediastinum.

3. Suprahyoid neck spaces:
 Parapharyngeal space (PPS).
 Pharyngeal mucosal space (PMS).
 Masticator space (MS).
 Parotid space (PS).
 Carotid space (CS).
 Buccal space (BS).
 Retropharyngeal space (RPS).
 Perivertebral space (PVS).

4. Infrahyoid neck spaces:
 Visceral space (VS).
 Posterior cervical space (PCS).
 Anterior cervical space (ACS).
 CS.
 RPS.
 PVS.

5. Skull base relation to SHN

6. Skull base interaction with SHN
spaces:

7. Neck spaces:
are They true spaces
?

8. Deep cervical fascia:
 Superficial layer:
 SHN: Around MS, PS and contributes to CS.
 IHN: surrounding strap, sternocleidomastoid and trapezius
muscles.
 Middle layer:
 SHN: defines PMS and contributes to CS.
 IHN: defines VS and contributes to CS.
 Deep layer:
 SHN and IHN: surrounds PVS and contributes to CS.
 Alar fascia is a slip within the deep fascia.

9. Deep cervical fascia: three layers
cleave neck into spaces.
Axial Coronal

10. Suprahyoid neck

11. Infrahyoid neck

12. Deep fascia

13. Neck spaces

14. Suprahyoid neck:

15. Suprahyoid neck

16. Suprahyoid neck

17. Suprahyoid neck

18. Suprahyoid neck

19. Hyoid bone level

20. Infrahyoid neck

21. Infrahyoid neck

22. Lower level of infrahyoid
neck

23. Parapharyngeal space
(PPS):
 It is fat filled space (easily identified even
with large neck masses).
 Extends from the skull base to the cornue
of hyoid bone (SHN).
 According to direction of displacement, the
origin of a mass can be identified.
 Superiorly, interacts with skull base with no
foramina.
 Inferiorly, communicates with submand.
space. Mass in PPS can present at angle
of mandible

24. Parapharyngeal space
(PPS)
 Contents:
Fat, minor salivary glands and vessels (internal
maxillary and ascending pharyngeal arteries
and ptrygoid plexus of veins).
No mucosa, muscles, nodes, bones.
 Pathology:
Rarely diseases can originate within. Minor
salivary gland tumors, lipoma may be.
To say it is from PPS, it should be completely
surrounded by fat.

25. PPS

26. PPS

27. PPS

28. PPS

29. PPS

30. Pharyngeal Mucosal Space
(PMS)
 Nasopharyngeal, oropharyngeal and
hypopharyngeal surface structures on
the air way side of the middle layer of
deep cervical fascia.
 Superiorly, interacts with the skull
(basisphenoid and basiocciput).
Foramen lacerum is here (perivascular
spread of tumors around ICA ).

31. PMS

32. PMS:

33. PMS: Contents
 Mucosal surface of the pharynx.
 Lymphatic (Waldeyer) ring:
Nasopharynx Adenoid.
Oropharynx Palatine tonsils.
Lingual tonsils.
 Minor salivary glands.
 Fascia:
 Muscles:
 Cartilage:

34. PMS: Diseases
 Mass should:
Be medial to PPS.
Push PPS laterally.
Disrupts mucosal and submucosal architecture.
 Pathology:
Mucosa: SCC.
Lymphatic: NHL.
Salivary glands: Minor salivary glands tumors
(uncommon).
Muscles: Rabdomyosracoma (rare).

35. PMS:

36. PMS

37. PMS: Ba. swallow
•The hypopharynx extends from
the level of vallecula and
glossoepiglottic fold down to the
inferior margin of the pyriform
fossa.
• Three important subsites in
hypopharynx to be identified;
Postcricoid hypopharynx,
posterior wall of hypopharynx
and pyriform sinus.
• Remember The lower margin of
vallecula is the landmark where
hypopharynx starts.
•The lingual tonsil has irregular
outline resulting in irregularity of
contrast column.

38. PMS: MRI T1
Nasopharynx Oropharynx

39. PMS: MRI T2
Nasopharynx Oropharynx

40. PMS

41. PMS Coronal (graphic & MRI
Postcontrast T1)

42. Masticator space (MS)
 Large anterolateral space of the suprahyodid
neck containing muscles of mastication.
 Included within the superficial layer of deep
cervical fascia.
 Extends from high parietal calvarium to
mandibular angle.
 Surgical terms:
 Temporal fossa (Suprazygomatic MS).
 Infratemporal fossa (Infrazygomatic MS).
 Skull: MS abuts skull base including:
 Foramen ovale (CN V3).
 Foramen spinosum (middle meningeal A.).

43. MS: Contents:
 Muscles of mastications:
Masseter, Tempralis, Medial ptrygoid and lateral
prygoid muscles.
 Nerves: Mandibular division of trigeminal N:
Masticator: Motor to Msc of mastication.
Mylohyoid: Motor to mylohyoid and diagastric m.
Inferior alveolar: Sensory to chin and mandible.
Lingual: Sensory to anterior 2/3 tongue and mouth floor.
Auriculotemporal: Sensory to EAC and TMJ
 Bones:
Ramus and posterior body of the mandible, coronoid
process and condylar process as well as TMJ.
 Vessels:
Ptrygoid plexus of veins.

44. MS:
 Important note: tumors may spread
along CN V3 intracranially. So the
course of the nerve should be assessed.
 Pitfalls:
Ptrygoid venous plexus enhancement
(misinterpreted as a mass).
CN V3 motor atrophy of muscles
(misinterpreted as a contralateral mass)

45. MS

46. MS

47. MS:

48. MS: MRI

49. MS: Coronal MRI
T1 post-contrast

50. Mass in
MS

51. Mass in
MS

52. Parotid space (PS):
 It extends from the EAC and mastoid tip
down to below the angle of the
mandible.
 Skull interaction: stylomastoid foramen
is related to this space transmitting the
facial nerve.
 The space is enclosed within the
superficial layer of the deep cervical
fascia.

53. PS: Contents:
 Parotid gland:
 Superficial lobe (2/3 of the space).
 Deep lobe.
 Extracranial facial nerve:
 Ramifies within the PS.
 Forms a surgical plane between Superficial and
deep lobes.
 It is not detected by CT. It is plane is estimated
between just medial to mastoid process to just
lateral to the retromandibular vein.
 Vessels (just behind mandibular ramus):
 Retromandibular vein (lateral and larger)
 External carotid artery (medial and smaller).

54. PS: Contents:
 Lymph nodes:
Late embryonic encapsulation results in
intraparotid nodes.
About 20 in each PS.
1st order drinage of EAC, pinna and adjacent
scalp.
 Parotid duct:
Runs on the surface of masseter muscle.
Enters the buccal space and pierce the
buccinator to open opposiet 2nd premolar tooth.
 Accessory parotid gland:
20% of population.
Along the surface of masseter muscle.

55. PS:
 Important notes:
If inflammation is suspected: CECT with
angulations of the gantry to avoid artifacts from
dental filling.
If tumors are suspected: MRI+C and assess for
perineural spread (facial nerve).
Parotid tail mass should be identified as
intraparotid to avoid facial nerve injury during
excision. (tail is between platysma and
sternomastoid ms inferiorly).
 Pitfalls:
It is more fatty in elderly.
It is soft tissue like in children.

56. PS:

57. PS:

58. PS:

59. PS:
MRI T1

60. PS:
MRI T1

61. PS:
MRI T2 FS

62. Carotid space CS:
 Travels from the skull base (jagular
foramen and carotid canal) to aortic arch
(SHN and IHN)
 Contents:
SHN: IJV, ICA and cranial nerves (9-12).
IHN: IJV, CCA, and cranial nerve 10 (only).
Sympathetic chanin (between CS and RPS).
Internal jagular lymph node chain (closely
related).

63. CS
SHN IHN

64. CS

65. Retropharyngeal space
(RPS)
 Starts at the skull base and extends
down to mediastinum (T3 level). (SHN
and IHN)
 Contents:
SHN:
Fat
LNs: lateral (Nodes of Rouviere ) group and
medial group (rarely seen):
IHN:
only fat.

66. RPS:
 Fascia:
Anterior wall: middle layer DCF.
Posterior wall: deep layer DCF:
 Two slips present with Danger space in between.
Lateral wall: (Alar fascia).
 Danger space:
Infection or tumor can extend to diaphragm
(hence the name).
The RPS is locked inferiorly by trap door at level
of T3. Lesion that opens the door reaches DS
and down to diaphragm.

67. RPS:
 Imaging issues:
Nodal disease: localized.
Extranodal disease (infection or tumor) with
fill the space (reactangular lesion).
Mass here may mimic CS mass so look
carefully to the CS structures and their
displacement.
RPS and DS are indistinguishable from each
other by CT. just you have to consider the
danger.

68. RPS:
SHN IHN

69. RPS

70. RPS

71. RPS

72. Perivertebral space PVS:
 Perivertebral space: term dropped to
include all structures under the deep
layer of deep cervical fascia.
 Supra-infrahyoid neck. Down to T4 and
some authors consider it one space
down to coccyx.
 Divisions: by dipping of the deep facia
laterally toward transverse processes.
Prevertebral compartment.
Paraspinal compartment.

73. PVS
 Contents:
 Prevertebral space:
Bones: vertebral body.
Muscles: longus colis and capits and scalene Muscles
Nerves: Brachial plexus roots and phrenic nerve
Vessels: vertebral A&V
 Paraspinal space:
Paraspinal muscles.
Posterior elements of the vertebrae.
 Brachial plexus roots:
Pass between ant. and mid. Scalenei, to posterior
cervical space to axilla.

74. PVS

75. PVS

76. Posterior cervical space
(PCS)
 Posterolateral fat filled space.
 Triangular wit its tip at mastoid process
and base at clavicle.
 Contents:
Fat.
Spinal accessory nerve.
Spinal accessory nodes (group V).
Brachial plexus: Roots pass in way to axilla.
Dorsal scapular nerve.

77. PCS:
 How to differentiate spinal accessory
nodes from jagular nodes.
Infrahyoid neck:
IJ nodes Abut the carotid sheath.
SA node has surrounding fat separating it from CS.
Suprahyoid neck:
IJ nodes are anterior and lateral to CS. May be
posterior but should abut the CS.
SA nodes are posterior to CS only separated from it
by fat.

78. PCS

79. PCS

80. PCS

81. Visceral space (VS):
 Midline cylindrical space in IHN. Enclosed
in DL-DCF.
 Contents:
Thyroid and parathyroid (4) glands.
Cervical trachea and esophagus.
Lymph nodes: level VI (prelaryngeal and
pretrachesal)
Recurrent laryngeal nerve:
 Left: recurs at level of aortic arch.
 Right: recurs around right subclavian A. (low IHN).
Pass to larynx in tracheoesophageal groove.
Recurrent laryngeal nerve:

82. VS: Important notes:
 MRI is preferred in staging thyroid
malignancy to prevent iodine load delaying
iodine based nuclear therapy.
 VS imaging should include upper
mediastinum (to carina):
Group VII lymph nodes drain VS malignancy.
Left distal vagal neuropathy requires examination
down to carina.
Ectopic thyroid may be seen in superior
mediastinum.

83. VS:

84. VS:

85. VS:

86. VS:

87. Hypopharynx-Larynx:
 Hypopharynx: is continuation of PMS.
 Larynx: junction between upper and
lower airways.
 From glossoepiglottic and
pharyngoepiglottic folds to level of
cricoid cartilage.
Hypopharynx to esophagus.
Larynx to traches.

88. Hypopharynx-Larynx:
 Larynx: is the organ of phonation.
It consists of cartilagenous skeleton and mucosal
curtains. Ligaments and muscles fix structures in
place and produce movements responsible for
sound production.

89. Larynx: cartilagenous skeleton:
 Is the supporting framework of the larynx.
Epiglottis, thyroid cartilages, cricoid
cartilages, arytenoid cartilages, corniculate and
cuniform cartilages.
Thyroid cartilages: two lamina meeting anteriorly
at acute angle.
Cricoid cartilage: the only complete ring (signet
ring appearance).
Arytenoid (paired) cartilages: set on posterior
aspect of cricoid. Vocal process gives
attachment to TVC and is landmark in CT.
The interval between cartilages is closed by
ligaments(thyrohyoid and cricothyroid ligaments.

90. Larynx: mucosal folds
Two main mucosal folds are seen in the
endolarynx sweeping from front to back along the
lateral surface of larynx. (true and false vocal
cords). In between is the Laryngeal ventricle.
Consequntly the three compartments form;
supraglottis, glottic region and infraglottis.

91. Hypopharynx-Larynx: contents:
 Supraglottis:
 Extends from the tip of epiglottis above to the
laryngeal ventricle below.
Epiglottis: laryngeal lid. Has free edge (suprahyoid)
and attached portion (infrahyoid).
It is attached to the thyhroid lamina below by the
thyroepiglottic ligament.
The free edge is connected to the hyoid bone by the
hyoepiglottic ligament that is covered by
glossepiglottic midline mucosal fold.
Valleculae are air spaces formed between the base
of tongue and free part of epiglottis on both sides of
glossoepiglottic fold.
Preepiglottic space: fat filled space anterior to
epiglottis.

92. Hypopharynx-Larynx

93. Hypopharynx-Larynx

94. Hypopharynx-Larynx: contents:
 Aryepiglottic fold: Extends from the tip of
arytenoid cartilage to inferolateral margin of
epiglottis.
 It is the superolateral wall of the supraglottis
separating the supraglottis from the pyriform
sinus.
 Paraglottic space: paired spaces beneath
the false and true vocal cords. Filled with
fat in supraglottis and occupied by muscle
at the glottis (landmark)

95. Larynx:
 Glottis: True vocal cord, anterior
commissure and posterior commissure.
True vocal cord (TVC): the only soft tisue
structure in the larynx: comprised of
thyroarytenoid muscle (medial fibers are the
vocalis muscle).
Anterior and posterior commissures are the
midline meeting of both cords.
Conus elasticus: fibroelastic membrane
extending from medial aspect of TVC to the
cricoid cartilage.

96. Larynx:
 Subglottis: from the under surface of
TVC to inferior border of cricoid
cartilage.
Its mucosa is closely applied and merges
with the mucosal covering of trachea.

97. Hypopharynx:
 Pyriform sinus: (2) between the inner
surface of thyroid cartilage and thyrohyoid
ligment laterally and posterolateral surface
of the AE fold. Its apex is at level of TVC.
 Posterior wall: is the posterior continuation
of the posterior wall of oropharynx.
 Postcricoid space: interface between larynx
and hypopharynx (from level of
cricoarytenoid joint to lower margin of
cricoid cartilage.

98. Larynx- Hypopharynx CT

99. Larynx- Hypopharynx CT

100. Larynx- Hypopharynx CT

101. Larynx- Hypopharynx CT
(breath holding)

102. Larynx- Hypopharynx CT

103. Larynx- Hypopharynx CT

104. Larynx: MRI

105. Larynx: MRI

106. Thyroid and
parathyroid glands
oThyroid glands:
Two lobes connected by the isthmus
wrapped around the trachea.
Accessory pyramidal lobe may be seen.
It is located in the visceral space
enclosed within the middle layer of deep
cervical fascia.
o parathyroid gland:
Four lobes at the posterior surface of
thyroid gland. .

107. Thyroid gland:
Imaging with CT scan
and isotope scan should
be coordinated. The
iodinated contrast media
in CT scan interferes
with the iodine uptake of
isotope scan postponing
the study for 4-6 weeks.

108. Thyroid gland
US is the first line
of imaging
because the
gland is
superficial.

109. Thyroid gland
•Thyroglossal
duct cyst.
•Lymph drainage
of thyroid
malignancy./

110. Cervical trachea and
esophagus:
 Trachea (10-13cm): starts opposite C6
vertebra (continuation of larynx). And
ends at T5 vertebra (carina).
 Esophagus (25cm): starts opposite C6
(continuation of hypopharynx) down to
T11 vertebra. Its upper limit is identified
by the cricophryngeus muscle.
 Tracheoesophageal groove: Contains
parathyroid gland, recurrent laryngeal
artery and lymph nodes.

111. BA swallow:

112. Trachea and esophagus:

113. Trachea and esophagus: