anatomy of neck , cross sectional anatomy ,radi0logy of neck

1. CROSS SECTIONAL ANATOMY OF
NECK SPACES
Dr Raman Ghimire
Resident Radiology
NAMS

2. INTRODUCTION
• The neck is composed of :
 Cervix(anteriorly)-means “neck”: cylinder of soft tissue
 Nucha(posteriorly) :vertebral column and its associated musculature
• Extent:
 Superior: line connecting the occiput and the tip of the chin
 Inferior :course of the first rib at the thoracic inlet.
• The neck has a complex anatomy where many critical anatomic structures are
compartmentalized into a small space.
• The traditional classification of the head and neck into nasopharynx, oropharynx
and hypopharynx is useful in the evaluation of superficial mucosal lesions but is
much less helpful in localizing deep-seated head and neck lesions.
• Clinicians divide the superficial structures of the neck into anterior and posterior
triangles using superficial musculature as landmarks.
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3. Sagittal T2-weighted image of the extracranial head and neck showing the division of the
anatomical and functional units of the upper aerodigestive tract
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4. cross sectional anatomy of neck spaces 4
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5. cross sectional anatomy of neck spaces 5
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6. FASCIA AND SPACES
• Anatomists pioneered the work on fascial anatomy and spaces.
• With the advent of cross-sectional imaging clinicians, surgeons and
radiologists adopted the spatial organization of the head and neck into fascial
compartments.
• The basis for dividing the neck into spaces and compartments is the arrangement
of the superficial and deep layers of the cervical fascia.
• The importance of these spaces is that they limit to some degree the spread of
most infections and some tumors.
• This concept can be used to formulate differential diagnosis, determine the extent
of disease and facilitate surgical and therapy planning.
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7. FASCIAE OF NECK
Fascia
Superficial
Deep
Superficial
( Investing)
Middle
(Visceral)
Deep
(Prevertebral)
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8. Superficial cervical fascia (SCF)
• Layer of fatty loose
connective tissue that
encircles the neck like a
collar.
• Encircles the deep fascia.
• Contains:
 Platysma muscles
 Muscles of facial expression
 Subcutaneous nerves and
lymphatics
 Portions of the anterior and
external jugular veins
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9. Deep cervical fascia (DCF)
• Made up of thinner but
denser, better-defined layers.
 Superficial layer (SLDCF)
 Middle layer (MLDCF)
 Deep layer (DLDCF)
All three layers contribute to
the carotid sheath.
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10. Superficial layer of deep cervical fascia (SLDCF)/
Investing layer
• Forms a complete collar around the
neck and envelops the
sternocleidomastoid, trapezius and
attaches to the skull base, mandible,
hyoid, clavicle, sternum and scapula.
• Capsule: parotid and submandibular
gland
• Spaces:
 Masticator space (including Buccal
space)
 Submandibular space (sub
mental,sub lingual ,submaxillary
sapce)
 Parotid space
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11. cross sectional anatomy of neck spaces 11
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12. • Caudally in the midline the SLDCF splits into two layers enclosing the
manubrium. This creates the variably sized suprasternal space of Burns
(or Gruber).
• Contains fat and a communicating vein between the left and right
anterior jugular veins.
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13. Middle layer of deep cervical fascia (MLDCF)
/Visceral/Pre-tracheal layer
• The MLDCF encloses the
anterior neck.
• Extent:
 IHN: from hyoid bone to
superior mediastinum.
 SHN: continues as
buccopharyngeal fascia and
encloses naso/oropharynx
• Muscular part: encases the
infrahyoid strap muscles
• Visceral part : envelops the
trachea, larynx, pharynx,
esophagus, and the thyroid
gland
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14. • Spaces:
 Pharyngeal mucosal space.
 Parapharyngeal space.
 Visceral space
 Retropharyngeal space
(along with DLDCF)
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15. Deep layer of deep cervical fascia (DLDCF)
/Prevertebral layer
• DLCF extends from the skull base to the T4 vertebra where it fuses with the anterior
longitudinal ligament in the posterior mediastinum.
• The deep layer encircles the vertebrae, paravertebral and paraspinal muscles,
vertebral artery and vein, phrenic nerve and trunks of the brachial plexus.
• The vertebrae are completely enclosed by this layer which attaches firmly to the
transverse processes dividing the space into an anterior prevertebral and posterior
paraspinal portion.
• Anteromedial to the scalene muscles, the deep layer splits into two leaves; the
ventral leaf being the alar fascia, and the dorsal leaf being the prevertebral fascia
• Alar layer blends with the visceral layer along the posterior margin of the
esophagus at the level between the C6 and T4 vertebrae; the prevertebral layer
extends from the skull base to the coccyx.
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16. • This fascia separates the
lower neck from the
thorax and is called
Sibson’s fascia.
Spaces:
 Perivertebral space
 Danger space
 Retropharyngeal space
(MLDCF+DLDCF)
 Carotid space.
(all 3 layers)
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17. SPACES OF NECK
Suprahyoid Neck (SHN)
• Parotid space
• Masticator space
(+ buccal space)
• Submandibular space
(+ sublingual space
and submental space)
• Pharyngeal mucosal
Space
• Parapharyngeal
space(or prestyloid
parapharyngeal space )
Infrahyoid Neck (IHN)
• Visceral space
• Anterior cervical space
Entire length of neck
(SHN+IHN)
• Carotid space (SHN:
poststyloid
parapharyngeal space,
IHN: carotid sheath)
• Retropharyngeal space
• Danger space
• Perivertebral space
• posterior cervical space
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18. SPACES OF SUPRAHYOID NECK
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19. 8/29/2021 cross sectional anatomy of neck spaces 19

20. SPACES OF INFRAHYOID NECK
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21. MASTICATOR SPACE
• Paired
• Suprahyoid space
• Enclosed within SLDCF
• Contains :
 Ramus and body of mandible
 Trigeminal nerve(mandibular
division)
 Muscles of mastication.
MS
PPS
PS
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22. Contents Pathology
Muscle Rhabdomyosarcoma
CN V3 Schwannoma,neurofibroma
Mandible Dental tumors ,cysts ,abscesses
and osteomyelitis.
Vessels Hemangiomas, lymphangiomas
Fat Lipoma
Extension of SCC
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• Masticator space malignancy or infection can spread perineurally via the
foramen ovale and along the course of the mandibular division of
the trigeminal nerve into the middle cranial fossa.

23. PAROTID SPACE
• Paired
• Suprahyoid space
• Enclosed within SLDCF
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24. Contents Pathology
Parotid Parotitis, Hemangiomas ,Calculi
Benign tumors:pleomorphic adenomas, Warthin’s tumors
Malignant tumors: Mucoepidermoid carcinoma
CN VII Nerve sheath tumor
Embryological First branchial cleft cysts
Fat Lipoma
Lymph node Lymphoma
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25. 8/29/2021 cross sectional anatomy of neck spaces 25
SUBMANDIBULAR SPACE
• Paired
• Suprahyoid space
• Enclosed within SLDCF
• Submental space and sublingual
space also considered within SMS as
these spaces communicate freely
Anatomy of the submandibular and sublingual spaces in the coronal plane: picture illustration
and T2-weighted MR image

26. Contents Pathology
Submandibular gland Sialolithisis and sialadenitis
Benign:pleomorphic adenomas,
malignant masses :mucoepidermoid and adenocystic carcinomas
Sub mental
Ia/submandibular Ib
Lymph nodes
Lymphoma ,Metastasis,TB
Facial artery /vein Vascular malformations
Embryological Branchial cleft cysts, cystic hygromas, dermoids, epidermoids and
thyroglossal duct cysts
Fat Lipoma,liposarcoma
Ranula
Abscess, ludwig angina
Squamous cell carcinoma extension
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27. PHARYNGEAL MUCOSAL SPACE(PMS)
• Single midline
• Suprahyoid space
• Enclosed within MLDCF
• PMS is the area of nasopharynx
and oropharynx on the inner side
of the buccopharyngeal fascia.
• More inferior hypopharynx is in
the visceral space of the
infrahyoid neck, which is an
inferior continuation of the PMS
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28. PMS
PPS
RPS
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29. Contents Pathology
Squamous mucosa SCC
Tornwaldt cyst
lymphoid tissue of
Waldeyer's ring
Tonsillitis , Peritonsillar abscess
non-Hodgkin’s lymphoma (NHL)
Minor salivary glands Benign and malignant tumor
Pharyngeal constrictor
muscle
Cartilaginous portion
of the Eustachian
tube
Juvenile Angiofibroma
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30. 8/29/2021 cross sectional anatomy of neck spaces 30
PARAPHARYNGEAL SPACE(PPS)
• Paired
• Suprahyoid space
• Enclosed within MLDCF
• Its a inverted pyramid space
from inferior surface of
petrous bone to the hyoid
bone

31. CONTENTS Pathology
Fat Lipoma
Vessels: pharyngeal venous plexus,
internal mammary artery and ascending
pharyngeal artery
Branch of mandibular nerve Trigeminal schwannoma
Minor or ectopic salivary gland/rests Salivary gland tumor pleomorphic
adenoma
Embryological Cystic hygroma/lymphangioma
second branchial cleft cyst
Parapharyngeal abscess
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32. cross sectional anatomy of neck spaces 32
VISCERAL SPACE
• The visceral space includes all
structures within the confines of
the MLDCF .
• The visceral space extends from
the hyoid bone superiorly to
the superior mediastinum (level
of aortic arch / T4
• Infrahyoid continuation of PMS
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33. cross sectional anatomy of neck spaces 33
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34. RETROPHARYNGEAL SPACE
• Boundaries:
Anterior: MLDCF
Posterior:DLDCF(alar)
• Extends from the skull base upto
T4 level.
• Contents:
 Suprahyoid RPS :Nodes and fat
 Infrahyoid RPS : fat
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35. cross sectional anatomy of neck spaces 35
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36. DANGER SPACE (DS)
• The DS is formed by the splitting of
the deep layer into an anterolateral
alar slip and a posterior prevertebral
portion.
• Boundaries:
 Anterior: Alar fascia
 Posterior: Prevertebral fascia
 Superior: clivus
 Inferior: posterior mediastinum at
the level of the diaphragm
• Contents :Small amount of loose
fatty connecctive tissue
• In healthy patients, it is
indistinguishable from
the retropharyngeal space
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37. cross sectional anatomy of neck spaces 37
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38. PERIVERTEBRAL SPACE(PVS)
• Posterior midline space
• Enclosed by DLDCF
• Extends from the base of the skull
to the level of coccyx (SHN+IHN)
• Prevertebral space: prevertebral
and scalene muscle, roots of
brachial plexus ,vertebral bodies
and pedicles, phrenic nerve,the
vertebral arteries and veins.
• Paraspinal Space: paraspinal
musculature, vertebral laminae
and spinous processes.
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39. cross sectional anatomy of neck spaces 39
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A.Contrast-enhanced axial CT shows fluid in RPS and posterior displacement of the longus
capitis muscles (B) Axial contrast-enhanced axial CT shows anterior displacemnet of longus
capitis muscles with fluid collection within the prevertebral space

40. • Prevertebral soft tissue thickness(PVST):
 RPS and PVS should not exceed >7 mm at C2 for adult and children
 C6 soft-tissue space should no be >4 mm (children) and >22 mm for
(adults)
A 24-year-old patient after a motor vehicle crash with closed head injury; no fracture
was identified in the cervical spine or craniocervical junction. A, Midsagittal MDCT
image of the cervical spine demonstrates abnormal PVST thickening at C1 and C2
(asterisks). B, Correlation with midsagittal short τ inversion recovery MR image
obtained the next day confirms the presence of extensive PVST edema and/or
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41. cross sectional anatomy of neck spaces 41
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42. CAROTID SPACE
• Carotid space is a paired space
defined by the carotid sheath.
• Carotid sheath is formed by all
three layers of DCF.
• This space extends from the skull
base to the aortic arch at the
thoracic inlet/T4.
• The suprahyoid CS is also known as
the poststyloid PPS.
• Contents:
SHN: CN IX-XII, ICA,IJV
IHN: CN X, CCA,IJV
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43. cross sectional anatomy of neck spaces 43
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44. POSTERIOR CERVICAL SPACE
• Fat filled deep spaces of the
neck located posterolaterally.
• Posterolateral part of the neck
extending from the mastoid tip
and base of skull to the clavicles
• Most of the volume is in the
infrahyoid neck, with some
extension into the suprahyoid neck .
• Between SLDCF and DLDCF
• Lesion in PCS typically cause
anteromedial displacement of the
carotid space and posteromedial
displacement of the prevertebral
space
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45. cross sectional anatomy of neck spaces 45
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46. ANTERIOR CERVICAL SPACE
• The anterior cervical space is a
small infrahyoid compartment of
the head and neck.
• It is a fat containing space and is
not enclosed by fascia.
• Content : Fat
• Pathology : lipoma , second
branchial cleft cyst
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47. REFERENCES
• CT AND MR IMAGING OF THE WHOLE BODY;6TH EDITION
• GRAINGER & ALLISON’S DIAGNOSTIC RADIOLOGY; 6TH EDITION
• https://radiologyassistant.nl/head-neck/infrahyoid-neck
• https://radiopaedia.org/articles/deep-cervical-fascia
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48. THANK YOU
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