CT anatomy of Neck Spaces RV

Dr Roshan ValentinePG ResidentDept of RadiodiagnosisSt Johns Medical College

CT ANATOMY OF NECK SPACES

NORMAL ANATOMY • Neck has a complex anatomy

• Compartmentalisation of anatomic structuresSuperiorly : Mandible & mylohyoid anteriorly Skull base posteriorly

Inferiorly: Thoracic inlet centrally Scapula posteriorly

INTRODUCTION• Clinicians : anterior and posterior triangles• Anatomists : pioneered the work on fascial spaces and

anatomy• Cross sectional imaging helped clinicians , anatomists

and surgeons in dividing it into fascial compartments

• Basis for dividing neck into spaces and compartments : arrangement of superficial and deep layers of cervical fascia• The importance of this spaces is that they may limit to

some degree the spread of most infections and some tumors• A proper understanding of their anatomy will also aid in the

diagnosis of various conditions

INTR0DUCTION

NECK SPACESDescribed in relation to the hyoid bone.• Suprahyoid Spaces.• Infrahyoid Spaces.• Spaces extending up to the entire

length of the neck.

SUPRAHYOID SPACES• Sublingual Space. • Submandibular Space.• Buccal Space. • Masticator Space.• Parotid Space.• Pharyngeal mucosal Space.• Parapharyngeal Space

INFRAHYOID SPACES• Visceral Space.• Anterior

cervical Space.• Posterior

cervical Space.

SPACES COMMON TO BOTH• Carotid Space.

• Retropharyngeal Space.

• Prevertebral Space.

• Danger Space.

Fascia

Superficial

Deep

Superficial

Middle

Deep

CERVICAL FASCIAE

SUPERFICIAL FASCIA• Composed of subcutaneous tissues that

encircle the neck like a collar.• Encircles the deep fascia• Components:

• Platysma and muscles of facial expression.

• Subcutaneous veins , nerves and fat• Superficial lymph nodes.

SUPERFICIAL LAYER/INVESTING LAYER• Complete collar around the neck• Attachments• Splits to cover SCM and Trapezius• Capsule : parotid and

Submandibular gland• Spaces : Masticator space ,parotid

space, submandibular space and sublingual space.

DEEP CERVICAL FASCIAE

SUPERFICIAL LAYER/INVESTING LAYER

MASTICATOR SPACEFormed by splitting of

the SLDCF.

Extends from skull base to the inferior edge of the mandible.

Contents: mandible, muscles of mastication, and mandibular division of the Vth nerve.

MASTICATOR SPACE

MTL

PAROTID SPACE• Boundary : Investing fascia(SLDCF) splitting at the angle of mandible.• Extends : Superiorly external acoustic meatus Inferiorly up to the mandible.• Contents: Parotid Gland, proximal part of the parotid duct, intraparotid

lymph nodes and vessels.• Parotid gland is divided by facial nerve into superficial and deep.• Division identified on imaging by retromandibular vein.

PAROTID SPACE

PAROTID SPACE

BOUNDARY•Investing fascia splitting at angle of mandible

EXTENT•Sup:EAM•Inf : Mandible

CONTENTS•Parotid gland•Facial N•Retromandibular vein•ECA•LN

PAROTID SPACE

SUBMANDIBULAR SPACE• Extend : Mylohoid superiorly &

hyoid bone inferiorly.• Communicates freely with

sublingual space.• Contents : superficial portions of the

Submandibular gland,submental and submandibular LNs, facial artery and vein, fat and ant belly of digastric.

SUBMANDIBULAR SPACE

SUBMANDIBULAR SPACE

Extent : Above the mylohyoid muscle

Contents : Sublingual gland and their ducts , LNs, hypoglossal muscle , lingual artery and vein , hypoglossal N and deeper portion of submandibular gland.

SUBLINGUAL SPACE

SUBLINGUAL SPACE

Visceral /pretracheal layerExtent: Hyoid bone to sup mediastinum SHN : Continues as buccopharyngeal fascia(BPF)Contents : Trachea, esophagus , larynx , thyroid and parathyroid gland

Spaces : Pharyngeal mucosal space , retropharyngeal space , parapharyngeal space and buccal space

MIDDLE LAYER OF DCF

MIDDLE LAYER OF DCF

MIDDLE LAYER OF DCF- SPACES

PHARYNGEAL MUCOSAL SPACE

• Located on the airway side of the Buccopharyngeal fascia in the

nasopharynx and oropharynx.

• No fascial boundaries on the airway side.

• Extend from skull base to the Cricoid cartilage.

• Contents: Mucosa, lymphoid tissue of Waldeyer’s ring, minor salivary

glands, and pharyngeal constrictor muscles.

PHARYNGEAL MUCOSAL SPACE

PARAPHARYNGEAL SPACE• Central fat filled spaces in

lateral SHN.• Extends on the either side of

neck from the skull base to the submandibular space inferiorly

• Surrounded by PMS , MS , PS , CS AND RPS.

• Contents : Mainly fat , pharyngeal venous plexus , Mandibular N , Int mammary A , ascending pharyngeal artery.• Direction of

displacement of PPS – space of origin of the lesion

PARAPHARYNGEAL SPACE

PARAPHARYNGEAL SPACE

BUCCAL SPACE• Extent : Medially -

Buccinator and max alveolar ridge

Post Laterally : Masticator space

• Contents: Buccal fat pad

BUCCAL SPACE

• Extent : Skull base to T4 level• 2 parts

• Ant : True RPS• Post : Danger space

• Contents : • SHN : LN and fat• IHN : Fat

• pathway for spread of infections / tumors into the mediastinum from the neck.

RETROPHARYNGEAL SPACE

RETROPHARYNGEAL SPACE

RETROPHARYNGEAL SPACE

DANGER SPACE

• Posterior to the RPS.

• Bounded by the Alar fascia anteriorly and Prevertebral portion proper

posteriorly.

• Extends from the skull base up to the diaphragm.

• Content : loose areolar tissue which provides easy pathway for the

spread of infections.

• Extent : skull base to superior mediastinum T4 level.• Encircles : Paravertebral and

paraspinal muscles, vertebral body , vertebral A and Vn , phrenic nerve and brachial plexus trunk• Spaces : involve both SHN and

IHN – CS , RPS, DS , PVS and posterior cervical space.

: Involving only IHN - Visceral spaces and anterior cervical space

DEEP LAYER OF DCF(Prevertebral fascia)

• Paired tubular structure traversing SHN and IHN• Skull base to superior

mediastinum• Lateral to RPS• Enveloped by carotid

sheath : all 3 layers of DCf• Contents : SHN – ICA IJV ,

CN9-12, :IHN - CCA, IJV , CN10 trunk ( vagus)

CAROTID SPACE

CAROTID SPACE

CAROTID SPACE

IHN

SHN

CAROTID SPACE

• Posterior midline space of SHN and IHN• Enclosed by deep

layer of DCF• Extent : base of skull

to level of coccyx• 2 compartments :Prevertebral and Paraspinal

PERIVERTEBRAL SPACE

PERIVERTEBRAL SPACE- CONTENTS

CERVICAL SPACES

• ANTERIOR CERVICAL SPACE : Hyoid to clavicle• Content : Only fat

• POSTERIOR CERVICAL SPACE : Extend from the skull base to the clavicles.

• Deep and posterior to sternocledomastoid• Content : fat, spinal accessory nerves and spinal accessory chain of deep cervical lymph

nodes.

CERVICAL SPACES

CERVICAL SPACES