Supra Hyoid Neck

7/29/2019 Supra Hyoid Neck

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Head & Neck Imaging

Parapharyngeal Spaces

Para - pharyngeal spaces

Definition

Fatfilled triangular space lateral the pharynx Extends from the skull base to the oropharynx

Parapharyngeal spaces

Contents

Fat Arteries [ascending pharyngeal, internal

maxillary]

Veins [ pharyngeal veins] Nerves [ branches of the mandibular nerve]

PPS

Scanning An anatomic landmark for the adjacent spaces Imaging plane is directed for the site pathology

CT and MRI

5 mm slices Axial and coronal planes Contrast injection

Coronal

Axial


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CT

Calcification Bone erosions Hyperostosis

MRI

Superior contrast resolution Direct multiplanar imaging Vascular imaging without contrast injection No bone artifacts

MRI Open

MRI Closed

Extremity MRI Dynamic Magnet

The bed rotates fromUpright to Recumbent,

stopping at any angle in between


3/10

PPS

Clinical aspects Is difficult to be evaluated clinically Presenting symptoms

Sore throat Dysphagia

Change of voice Nasal obstruction Cranial nerves IXXII A mass bulges posterior to the angle of mandible

PPSAnatomic relations

Anterior Posterior Medial Lateral

Patient with Low Back Pain AfterSurgery

Does a Lie-Down-Only Scanner see the patients problem ?

NO
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PPS anatomyAntro -lateral aspect [ Infratemporal fossa ]

Masticator space Parotid space

Masticator Space Muscles of mastication

[ masseter, temporalis, pterygoid muscles]

Mandibular ramus Mandibular nerve branches Fat behind the antral wall

PPS anatomy

Antro -lateral aspect

[ Parotid space ]Stylo mandibular tunnel

Parotid gland (deep lobe) External carotid artery Retromandibular vein Facial nerve Lymph nodes

PPS anatomy

Postro -lateral aspect [ Post styloid space ][ extends from the skull base to aortic arch

Carotid canal

Internal carotid artery Internal jugular vein Cranial nerves 9 to 12, sympathetic plexus Lymph nodes [Internal jugular + lateral retropharyngeal

PPS anatomy

Medial aspect [ Pharyngeal mucosal space ]

The pharyngeal mucosal space is separated from thePPS by the pharyngo - basilar fascia

The PBF is a tough membrane Maintains patent airway Crossed only by aggressive lesions


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PPS Pathology Medial aspect [ Pharyngeal mucosal space ]

Displacement of the PPS fat laterally 98% of masses are carcinomas

80% squamous cell type Other carcinomas [ adenoid cystic & mucoepidermoid]

Lymphomas and sarcomas (children) Angiofibroma, plasmacytoma, melanoma

Nasopharyngeal carcinoma

N1 = Unilateral single or multiple nodes all 6 cm N2 = Bilateral multiple all 6cm N3a = Single or multiple nodes > 6 cm N3b = Supra clavicular nodes

Nasopharyngeal carcinomaClinical triadA symptomatic mass due to LN

Hearing loss due to otitis media

Bloody nasal discharge

NB T4 has multiple cranial nerve palsies

Mass in the lateral wall of the naropharynx Before age 50 Y M: F = 2.5: 1 Strong relation ship with EpsteinBarr virus

Nasopharyngeal Carcinoma

MRI

Obliteration of the fat strip between the tensorand levator veli palatini muscles on T1 WIs

Extension into the PPS fat Obliteration of the fat plane between the

nasopharynx and prevertebral muscles


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Nasopharyngeal carcinomaStaging

T1 Confined to the nasopharynx T2 Extension to Oropharynx or nasal fossa (axial) T3 Invasion of bones or sinuses (axial) T4 Intracranial extension or hypo pharynx or orbit

Nasopharyngeal carcinoma

ExtensionsEffacement of the FR and ET

Heterogeneously enhancing mass in the lateral wall of the nasopharynx

Anteriorly nasal fossa, maxillary sinus, infratemporal fossa Posteriorly prevertebral muscles, carotid sheath Laterally Para pharyngeal space, mastecator space

Nasopharyngeal carcinomaExtensions

Medially nasopharyngeal air space, retropharyngeal to the contra lateral side Inferiorly Oropharynx, tongue Superiorly skull base, intracranial extension


7/10

Other malignanciesLymphomas 20%

Others 10%

Rhabdomyosarcoma

Adenoid cystic carcinomaMelanoma, plasmacytoma,..

Rhabdomyosarcoma

The most common sarcoma of the head and neck Arise from the primitive mesenchymal cells 70% arise before the age of 12 years Orbit > nasopharynx >temporal bone > sinuses Presents by pain and cranial nerve palsies Soft tissue mass with bone destruction Deposits to the lung and bones DD nasopharyngeal carcinoma , angiofibroma ,NHL

Tornwaldts cyst

Benign lesions

A mucous retention cyst Occurs in the midline nasopharynx Low signal in T1 and high signal in T2 WIs

Nasopharyngeal angiofibroma

Arises near the sphenopalatine foramen Almost exclusively in adolescent boys Epistaxis


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Nasopharyngeal angiofibroma

Hyper vascular lesion with intenseenhancement

Supplied by the ascending pharyngeal &ascending palatine branches of the

internal maxillary artery Forward displacement of the posterior wall of

the maxillary sinus [Holman- Miller sign]-

classical

Grading of nasopharyngeal AngiofibromaI Confined to the nasopharynx

II Extension into pterygopalatine fossa or masticator space

III Intracranial or intraorbital extension

PPS anatomyPostro -lateral aspect

[ Post styloid space ]

[ extends from the skull base to aortic arch

Carotid canal

Internal carotid artery Internal jugular vein Cranial nerves 9 to 12,

sympathetic plexus

Lymph nodes [Internal jugular + lateralretropharyngeal nodes]

Glomus Nodes Neurofibroma


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Glomus tumor

Rare, slowly growing hypervasculer tumor Incidence 1: 1,300,000 Male : female 1: 3 40 - 60 Y Arise from the glomus bodies in and

around the jugular bulb

Benign hyper vascular lesion supplied byAscending pharyngeal

Carotico -tympanic [ICA]Anterior tympanic [ECA]

Stylomastoid [ECA]

Meningeal branches [ vertebral]

Glomus tumor

Mass in the jugular fossa with bone destruction Large at presentation 2-6 cm, intense enhancement Intracranial and extra cranial extension Metastases in 4%, Lung , nodes, liver, bones Salt and pepper appearance on MRI


10/10

Lymphadenopathy Reactive homogenous ,young patient less than

1cc

Lymphoma bulky homogenous Direct invasion from nearby malignancy Inflammatory septic focus abscess formation

Metastatic nodes

The most common nodal disease Any malignancy can spread to the retro-pharyngeal nodes Enlarged nodes > 0.8 cm with central necrosis and stranding of the perinodal

fat

75% of nasopharyngeal carcinoma , 20% of oropharyngeal ,5% of thyroid carcinoma have metastatic nodes at presentation

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Supra Hyoid Neck