Imaging of the Infrahyoid neck spaces.pdf

MENURadiopaedia.org
SEARCH
ARTICLES
CASES
COURSES
LOG IN
REGISTER NOW
ADVERTISEMENT: Supporters see fewer/no ads

Deep spaces of the head and neck
Last revised by Daniel MacManus on 26 Aug 2022

Citation, DOI, disclosures and article data
The deep spaces of the head and neck refer to compartments delimited by the deep cervical fascia. While these concepts overlap with traditional anatomical descriptions, their existence highlights the importance of fascia in confining various pathologies.

A knowledge of these spaces not only allows for better communication between radiologists and specialists familiar with imaging of this region but also aids in diagnosis as each space has a distinct group of pathologies.

Gross anatomy
Three layers of deep cervical fascia form the boundaries of the deep spaces in the neck 5,6:

superficial layer: investing fascia of the sternocleidomastoid and trapezius muscles, fascia of the muscles of mastication, fascia between the hyoid and mandible that forms the floor of the submandibular space, at least some of the fascia covering the parotid gland
middle layer: strap muscle fascia, visceral fascia that encloses the thyroid gland and aerodigestive tract (pharynx, larynx, trachea, esophagus)
deep layer: perivertebral fascia of the prevertebral and paraspinal muscles, alar fascia
All three layers contribute to the carotid sheath.

Contents
The compartmental definitions vary somewhat by source 1,5-7. The neck spaces are often divided into the suprahyoid (between the base of the skull and hyoid bone) and infrahyoid (between the hyoid bone and clavicles) spaces, as the anatomy of the deep cervical fascia is slightly different above and below the hyoid bone. Some spaces cross the hyoid bone and course the entire neck.

suprahyoid neck
parotid space
masticator space, including or contiguous with the buccal space
infrazygomatic masticator space (sometimes simply called the masticator space) 8
pterygomandibular space
submasseteric space
suprazygomatic masticator space (or temporal fossa 8)
superficial temporal space
deep temporal space
submandibular space, including or contiguous with the sublingual space and submental space
(prestyloid) parapharyngeal space
suprahyoid and infrahyoid neck
carotid space (or poststyloid parapharyngeal space in the suprahyoid neck, carotid sheath in the infrahyoid neck 7)
visceral space (infrahyoid in some definitions 7), including or contiguous with pharyngeal mucosal space (suprahyoid)
retropharyngeal space, including or contiguous with danger space
perivertebral space, including prevertebral space
posterior cervical space
sternocleidomastoid‐trapezius compartment 5
infrahyoid neck
anterior cervical space
suprasternal space
strap muscle compartment 5
Relations
Many of the deep neck spaces can be described in relation to the (prestyloid) parapharyngeal space, which lies in a central location on each side of the deep face and suprahyoid neck. Directional deviation of the parapharyngeal fat helps l

1. IMAGING OF INFRA-HYOID NECK SPACES
Presenter : Dr. Suhas Bhoovanahalli
Moderator : Dr. Vinodh

2. Suprahyoid
Infrahyoid

3. FASCIAS OF NECK
The neck has 2 layers of fascia.
•The superficial fascia.
•The deep fascia.

4. FASCIAS OF NECK

5. FASCIAS OF NECK

6. Superficial cervical fascia
•Thin layer of subcutaneous fat tissue
that surrounds the neck between the
dermis and the superficial layer of the
deep cervical fascia.
•Extends from the head to the thorax
and the shoulders to the axilla.

7. Superficial cervical fascia
•Thin layer of subcutaneous fat tissue
that surrounds the neck between the
dermis and the superficial layer of the
deep cervical fascia.
•Extends from the head to the thorax
and the shoulders to the axilla.

8. Superficial cervical fascia
•Contains the platysma, muscles of
facial expression, cutaneous nerves,
blood vessels, and lymphatics.

9. DEEP CERVICAL FASCIA (FASCIA COLLI)
•The deep cervical fascia is subdivided into
three layers – which provide a supporting
role for the viscera, muscles, vessels and
deep lymph nodes.
•Superficial /Investing layer of deep
cervical fascia.
•Middle layer of deep cervical fascia.
•Deep layer of deep cervical fascia.

10. Investing /Superficial layer of deep cervical
fascia
•Arises deep to the superficial fascia.
•In the suprahyoid neck – it splits to enclose
the parotid, masticator & submandibular
spaces.

11. Investing /Superficial layer of deep cervical
fascia
•Arises deep to the superficial fascia.
•In the suprahyoid neck – it splits to enclose
the parotid, masticator & submandibular
spaces.
•In the infrahyoid neck – It invests the neck
completely. It arises posteriorly from the
nuchal ligament and splits to encircle the
SCM & trapezius muscles.

12. Investing /Superficial layer of deep cervical
fascia
•Forms the roof of posterior triangle

13. Investing /Superficial layer of deep cervical
fascia
•This layer is pierced by cutaneous branches
of cervical plexus and EJV.
•The cutaneous branches pierce this layer
just behind the SCM and enter the
superficial cervical fascia.

14. Investing /Superficial layer of deep cervical
fascia
Boundaries/Attachments
•Anteriorly – Mandible, hyoid and sternal
manubrium.
•Laterally – Clavicle and scapular spine and
acromion.
•Posteriorly – Nuchal line of occipital bone,
nuchal ligament and trapezius
•Postero-superiorly – mastoid processes
and the zygomatic arches.

15. The middle layer of deep cervical fascia
•Extends from the skull base superiorly to
the mediastinum inferiorly and anteriorly
from the hyoid bone to the thoracic inlet.
•It is divided into the muscular division and
visceral division.
•The muscular division surrounds the strap
muscles, the omohyoid, sternothyroid,
sternohyoid and thyrohyoid and forms a
pulley through which the intermediate
tendon of the digastrics muscles passes to
suspend the hyoid bone. Over the
sternocleidomastoid, it fuses with the
superficial layer of deep cervical fascia.

16. Pretracheal - Middle layer of deep cervical
fascia
•It is limited to the anterior part of the neck.
•Runs on the deep surface of the strap
muscles.
•Extends from the hyoid bone to thorax
where it fuses with the pericardial sac
(along with deep layer of dcf ).
•Anteriorly it merges with the superficial
layer of deep cervical fascia.

17. Pretracheal - Middle layer of deep cervical
fascia
•It splits to encircle the viscera including
thyroid gland, esophagous and trachea.
•Posterior border of pretracheal fascia is called
buccopharyngeal fascia. – It encircles the
buccinator and pharyngeal constrictor
muscles.

18. Pretracheal - Middle layer of deep cervical
fascia
•It splits to encircle the viscera including
thyroid gland, esophagous and trachea.
•Posterior border of pretracheal fascia is called
buccopharyngeal fascia. – It encircles the
buccinator and pharyngeal constrictor
muscles.

19. Pretracheal - Middle layer of deep cervical
fascia
•Anteriorly –Hyoid and sternum
•Laterally – Clavicle and scapula
•Posteriorly – base of skull

20. Deep layer of deep cervical fascia
•Surrounds the deep muscles of the neck and
the cervical vertebrae.
•Extends from the skull base into the
mediastinum.
•Has 2 divisions
The prevertebral layer.
The alar layer.

21. Prevertebral layer - Deep layer of deep
cervical fascia
•Circumscribes and defines the
perivertebral space, enveloping the
prevertebral and para spinal muscles,
scalene muscles & vertebrae.
•It also surrounds the vertebral artery
and vein, phrenic nerve and trunks of
brachial plexus with the cervical
sympathetic trunk fixed into the
anterior part of the fascia.

22. Prevertebral layer - Deep layer of deep
cervical fascia
•Circumscribes and defines the
perivertebral space, enveloping the
prevertebral and para spinal muscles,
scalene muscles & vertebrae.
•It also surrounds the vertebral artery
and vein, phrenic nerve and trunks of
brachial plexus with the cervical
sympathetic trunk fixed into the
anterior part of the fascia.

23. Prevertebral layer - Deep layer
of deep cervical fascia
The deep layer of deep cervical
fascia attaches to the transverse
process, subdividing the
perivertebral space into anterior
and posterior areas.
Anterior : The prevertebral
aspect of the perivertebral space.
Posterior : The paraspinal aspect
of the perivertebral space.

24. Prevertebral layer - Deep layer of deep
cervical fascia
•Forms axillary sheath
•Forms floor of posterior triangle

25. Alar fascia – deep layer of deep cervical
fascia
•Anterior subdivision of deep layer of
deep cervical fascia.

26. Alar fascia – deep layer of deep cervical fascia
•Anterior subdivision of deep layer of deep
cervical fascia.
•Fuses with the buccopharyngeal fascia
between T1-T4.
•The alar layer forms the posterior and
lateral walls of the retropharyngeal space
and bridges the transverse processes of the
vertebrae.

27. Carotid sheath
•All three layers of deep cervical fascia
contributes to carotid sheath
•Forms the vascular compartment.
•Carotid sheath has ansa cervicalis within
the wall

29. Deep spaces of the neck
•The fascial layers in the neck
define some potential spaces
•In healthy patients most of these
spaces are closed
•However infection can widen
these spaces and serve as
conduits
•Extends from the base of the skull
to the anterior superior
mediastinum

31. DEEP SPACES OF THE NECK
Cervical spaces defined by the three layers of deep cervical fascia
Suprahyoid spaces (Exclusively) Both Infrahyoid spaces (Exclusively)
•Parapharyngeal space (PPS) •Carotid space (CS) •Visceral space (VS)
•Pharyngeal mucosal space (PMS)•Retropharyngeal space (RPS)
•Masticator space (MS) •Perivertebral space (PVS)
•Parotid space (PS) •Posterior cervical space (PCS)
•Sublingual space (SS)
•Submandibular space (SMS)

34. THE INFRAHYOID NECK

35. VISCERAL SPACE
•A cylindrical, central, infrahyoid
space enclosed by the middle
layer of deep cervical fascia.
•Largest space in the infrahyoid
neck and the only space that is
found entirely in the infrahyoid
neck.
•Extent
•The visceral space extends from
the hyoid bone down into the
mediastinum.

36. VISCERAL SPACE
•Anatomic relationships
•Laterally: Paired anterior
cervical spaces
•Posterolaterally: Paired
carotid spaces
•Posteriorly: Retropharyngeal
space.

37. VISCERAL SPACE
CONTENTS PATHOLOGIES
Viscera of the larynx, trachea, hypopharynx &
esophagus
•Tracheal adenoid cystic carcinoma
•Tracheal diverticulum
•Cervical esophageal carcinoma
Thyroid and parathyroid glands. •Inflammation of thyroid
•Tumours of thyroid and parathyroids
•Infrahyoid thyroglossal duct cyst
•Colloid cyst of thyroid
•Parathyroid cyst
Nerve(s):
•Recurrent laryngeal nerve, which, on the left,
recurs at the level of the aortic arch where it
passes through the aortopulmonic window
and, on the right, recurs around the right
subclavian artery in the tracheoesophageal
groove up to the larynx
•Schwanomma
The level VI groups of lymph nodes, the
paratracheal, prelaryngeal, and pretracheal nodes,
are all found within the visceral space as well as in
the infrahyoid strap muscles.
•Lymphoma
•Metastasis

40. Laryngocele
• Laryngocele refers to dilatation of the saccule of the laryngeal
ventricle and is unilateral in the vast majority of cases .
•• On imaging, these lesions are generally characterized as well-
defined, thin-walled, fluid or air-filled cystic lesions inthe paraglottic
space. The communication with the laryngeal ventricle is not always
identified, and an extra laryngeal extension through the thyro-hyoid
membrane may or may not be present.

43. Thyroglossal duct cyst
•Thyroglossal duct cysts (TGDC) are the most common type of
congenital neck cysts and pediatric neck masses.
•They are typically located in the midline and are the most common
midlinecneck mass in young patients.•
•The cysts can occur anywhere along the course of the thyroglossal
duct from the foramen cecum to the thyroid gland although infrahyoid
location is most common:
•• suprahyoid: 20-25% (less common in adults ~5%)
•at the level of hyoid bone: ~30% (range 15-50%)
• infrahyoid: ~45% (range 25-65%)

45. Multinodular goitre

46. THE ENTIRE NECK

47. RETROPHARYNGEAL SPACE
•It is a fat-filled space formed between
the middle layer of deep cervical fascia
anteriorly and the alar layer of deep
layer of deep cervical fascia posteriorly
and laterally.
•Extent
•The retropharyngeal space extends from
the skull base to the level of the T4
vertebral body posteriorly or approximately
the level of the tracheal bifurcation in the
mediastinum anteriorly.
•The alar fascia, which is a thin fascial layer,
divides the RPS into two compartments:
the anterior and posterior.

48. •Anatomic Relationships
–In the suprahyoid neck, the
retropharyngeal space is found
posterior to the visceral space,
anterior to the danger space
and perivertebral space, and
medial to the carotid space.
–In the infrahyoid neck, the
retropharyngeal space is
posterior to the hypopharynx
and cervical esophagus, medial
to the carotid space, and
anterior to the danger space,
into which it empties inferiorly
at T3.

49. RETROPHARYNGEAL SPACE
CONTENTS PATHOLOGIES
Fat - Main component of RPS.
Deep cervical lymph nodes (in the suprahyoid
compartment) - a/k/a nodes of Rouviere
•typically atrophy in childhood, beginning
around age 4.
•Abscess - These lymph nodes travel on the lateral
sides of the retropharyngeal space and can become
infected in childhood, leading to retropharyngeal
abscesses. In adults, retropharyngeal abscesses are
caused by penetrating injuries or infectious spread
from other neck spaces.
•Lymphomas
•Metastasis
A mass in the RPS pushes the prevertebral muscles posteriorly whereas a mass in the prevertebral
space lifts the prevertebral muscles anteriorly

50. DANGER SPACE
•Named the danger space because of the potential for rapid spread of
infection to the posterior mediastinum through its loose areolar
tissue.
•It is a potential space between the alar and prevertebral layers of the
deep layer of deep cervical fascia.
•Contents: Fat

52. Extent
•Extends from the skull
base to the diaphragm.
•Bordered anteriorly by
the alar fascia
•Posteriorly by the
prevertebral fascia
•Laterally by the
transverse processes.
Anatomic Relationships
•Posterior to the
retropharyngeal space
•Anterior to the
prevertebral space.

53. Retropharyngeal abscess

55. PERIVERTEBRAL SPACE
•Large midline space enclosed entirely
by the deep layer of deep cervical
fascia.
•Extent
•Formed by the prevertebral fascia
anteriorly and the vertebral bodies
posteriorly.
•Extends from the clivus of the skull
base to the coccyx and is divided in to
2 main divisions, the prevertebral and
paraspinal spaces, by the lateral fascial
attachments to the vertebral
transverse processes.

56. PERIVERTEBRAL SPACE
•Anatomic Relationships
•Directly behind the danger space.
•Bounded anterolaterally by the carotid space and laterally by the
anterior aspect of the posterior cervical spine.
•The paraspinal space lies deep to the posterior cervical space and
posterior to the transverse processes of the cervical spine.

57. PERIVERTEBRAL SPACE
CONTENTS PATHOLOGIES
Within the prevertebral portion :
•Muscle(s):
•Prevertebral muscles - the longus colli and longus
capitis
•Anterior, middle, and posterior scalene muscles
•Nerve(s):
•Roots of the brachial plexus
•Phrenic nerve
•Vessel(s)
•Vertebral artery and vein
•Vertebral bodies
•Myosistis, abscess, sarcoma
•Schwanomma, neurofibroma
•Aneurysm, dissection, thrombosis
•Osteomyelitis, primary bone tumour,
metastais
Within the paraspinal portion:
•Muscle(s):
•Paraspinal muscles
•Nerve(s):
•Proximal brachial plexusVessel(s)
•Posterior vertebral column
•Myosistis, abscess, sarcoma
•Schwanomma, neurofibroma
•Osteomyelitis, primary bone tumour,
metastais

60. PERIVERTEBRAL SPACE
•The C5-T1 roots of the brachial plexus travel in a
complex route through the prevertebral space.
•Theses roots exit the cervical neural foramina and pass
between the anterior and middle scalene muscles
before going through an opening in the deep layer of
deep cervical space.
•From there they enter the posterior cervical space
while heading toward the axilla.

66. CAROTID SPACE
•The area enclosed by the carotid sheath, a structure formed
from all 3 layers of the fascia.
•The fascia is incomplete in the area above the angle of the
mandible, so its contents lie within the greater area of the
parapharyngeal space.
•This area of the carotid space is sometimes referred to as the
retrostyloid portion of the parapharyngeal space.
•A vitally important fact about the carotid space is its role as
the so-called Lincoln Highway of the neck. The carotid space
is a route of travel of infection or malignancy from the neck
into the mediastinum, such as descending necrotizing
mediastinitis, or from the mediastinum into the neck.

67. CAROTID SPACE
•Extent
•The carotid space begins at
the aortic arch and extends
to the inferior margin of
the jugular foramen-
carotid canal. It is divided
into 4 major segments:
nasopharyngeal,
oropharyngeal, cervical,
and mediastinal.

68. CAROTID SPACE
•Anatomic Relationships
•The carotid space abuts:
⮚Retropharyngeal space
medially
⮚Visceral space
anteromedially
⮚Parapharyngeal space and
anterior cervical space
anteriorly
⮚Parotid space laterally
⮚Posterior cervical space
posterolaterally
⮚Prevertebral space
posteromedially.

69. CAROTID SPACE

70. CAROTID SPACE

71. CAROTID SPACE
CONTENTS PATHOLOGIES
Vessels:
•Carotid arteries
•Internal jugular vein
•Carotid artery
•Aneurysm
•Dissection
•Arteritis
•Jugular vein thrombosis and thrombophlebitis
Nerves:
•CN IX
•CN X
•CN XI
•CN XII
•Sympathetic chain
•Neurogenic tumours
•Paragangliomas
Lymph nodes are located lateral to the CS - The
internal jugular nodal chain is associated with but
not in the infrahyoid neck carotid space.
•Neoplastic or inflammatory causes - located
lateral to but closely approximating the CS.
•Neoplastic causes (contiguous or from
perineural spread of tumor - most commonly
SCC.)
•2
nd branchial cleft cyst

76. Paraganglioma
•Carotid body tumor, also known asa chemodectoma or carotid body
paraganglioma, is a highly vascular glomus tumor that arises from the
paraganglion cells of the carotid body. It is located atthe carotid
bifurcation with characteristic splaying ofthe ICA and ECA.
•Carotid body tumors are located at the carotid bifurcation with
characteristic splaying of the ICA and ECA, described as the lyre sign.
In all modalities, the dense vascularity of these tumors is manifested
as prominent contrast enhancement.

81. CERVICAL SPACES
•The anterior cervical space and the posterior cervical
space are 2 well-defined spaces that are not enclosed
by their own fascia.
•They extend from the skull base to the clavicles and
are composed primarily of fat.

82. CERVICAL SPACES
Anterior cervical space:
The anterior cervical space
is a small space in the
anterolateral neck. It is
not enclosed by fascia and
contains only fat.
The anterior cervical space
lies lateral to the visceral
space and anterior to the
carotid space.

83. CERVICAL SPACES
Posterior cervical space: The posterior cervical space lies
posterolateral to the carotid space and lateral to the paraspinal
space. It contains mostly fat as well as the spinal accessory nerve
and spinal accessory chain of deep cervical lymph nodes.

84. CERVICAL SPACES

85. CERVICAL SPACES

86. CERVICAL SPACES

88. Lymphoma

89. Lipoma

90. Lymphangioma

91. SUMMARY

93. THANK YOU