Head and Neck Imaging

Post-treatment imaging appearances in head and neck cancer

2011-01-19T03:41:00.000-08:00

Clinical information:
Histopathology:
TNM staging:
Surgery: Radical/ modified radical neck dissection, laser, no surgery
Reconstruction surgery: yes/ no
If yes, flap details:
Radiotherapy: yes/ no
If yes, type of radiotherapy

Primary site review:
Residual disease/ recurrence/ post-op change
Radiation induced sarcoma: latent period is 5 years, radiation induces SCC, lymphoma and meningioma

Post RT changes:
Acute post-RT changes (within 2-4 weeks): skin, platysma, neck space edema, enhancing salivary glands, enhancement of mucosal lining, increased attenuation of paralaryngeal fat
Subacute post-RT changes (few months to 18 months): chronic mucositis (polyps), chronic sialadenitis, i.e, loss of volume (virtually in ALL), especially parotids, fibrosis (may or may not enhance, stop enhancing after 18 months), persistent reactive nodes

Radionecrosis:
Sites: larynx, mandible, temporal bone, basisphenoid, maxillary bone
6- 15 months
Sclerosis, fragmentation, mottled appearance, sloughing, break of cartilage and bone with sequestration, pathological fracture, loss of trabeculae. Subluxation/ dislocation (of arytenoids). Soft tissue thickening, abscess, fistula, gas in the soft tissue. Enhancement of the adjacent muscles and fat.

Neurological changes:
Radiation cerebral necrosis: Deep white matter of medial and inferior temporal lobes or frontal lobes (depending on site of RT)
Brainstem encepahlopathy, myelopathy and transverse myelitis
RT induced brachial plexopathy
Traumatic neuroma
Denervation od V, XI and XII nerves

Reference:
Post-treatment imaging appearances in head and neck cancer patients

Vestibular schwannoma

2009-11-26T09:27:00.000-08:00

85% of CP angle mass

90% from inferior division (superior division 6%) of vestibular nerve, within or near vestibular (Scarpa) ganglion, at porus acousticus, or just within IAC (near Obersteiner-Redlich zone = transition from glial cells to Schwann cells)

Surgerical approach:
Middle cranial fossa, translabyrinthine and suboccipital (retrosigmoid)

Reference:
http://radiographics.rsna.org/content/29/7/1955.abstract

Skull base foramen

2009-11-26T07:13:00.000-08:00

Optic canal: Optic nerve
Superior orbital fissure: Nerves III, IV, V1 and VI, superior ophthalmic vein
Inferior orbital fissure:

Foramen ovale: Mandibular divison of trigeminal (V3)
Foramen rotundum: maxillary division of trigeminal (V2)
Foramen spinosum: Middle meningeal artery
Foramen lacerum: Meningeal branches of ascending pharyngeal artery
Vidian canal: Vidian artery and nerve
Stylomastoid foramen: exit of facial nerve
Hypoglossal canal: XII cranial nerve

IAC: VII and VIII cranial nerves

Jugular foramen/fossa: IX, X, XI cranial nerves, IJV
Carotid canal: ICA

Imaging cholesteatoma

2008-12-29T07:23:00.000-08:00

Classification:

Congenital (2%)

Acquired (98%)

--Pars flaccida (82%)

--Pars tensa (18%)

---- Posterosuperior (78%)

---- Anteroinferior (22%)

Congenital cholesteatoma:

= Epidermoid Epithelial rest cells

Can be seen in middle ear, mastoid, squamous temporal, petrous apex, CP angle

Common in anterior middle ear cavity near ET tube and stepes

Acquired cholesteatoma:

= Prusaac's cholesteaoma, attic cholesteatoma

Sequele to middle ear infection

MRI:

Useful in evaluating post operative/ recurrent cholesteatomas; differentiating

Delayed post-Gd T1 SE is useful

Cholesterol granuloma: increased signal on T1, no change on delayed Gd T1, low signal on DWI

with b factor of 800 sec/mm².

Granulation tissue without recurrence: low signal on T1, high signal on T2, enhance on delayed

Gd T1, low signal on DWI b factor of 800 sec/mm²

Recurrent cholesteatoma: low signal on T1, no change on delayed Gd T1, and high signal on DWI

with b factor of 800 sec/mm²

Cholesteatoma shows increased signal on DWI, whereas granulation tissue, fibrous tissue, cholesterol granuloma, or serous fluid show low

signal intensity.

Reference:

http://radiology.rsnajnls.org/cgi/content/full/238/2/604

Diffusion-weighted MR Imaging Sequence in the Detection of Postoperative Recurrent Cholesteatoma

Radiology 2005;238:604-610

Imaging Neck

2008-09-18T04:43:00.001-07:00

Approach to ultrasound of the neck

2008-09-18T04:43:00.000-07:00

Start with submental region:
Structures to be identified: anterior belly of digastric, myelohyoid, geniohyoid, genioglossue from superfical to deep. Sublingual glands are more deep and lateral.
Lesions superficial to digastric will be submental space
Lesions superficial to myelohypoid will be submandibular space
Lesions deep to myelohypid will be sublingual space
There might be defect in the myelohyoid - from which sublingual lesions may plunge into submandibular space

Midline sagittal scan of the submental space:
Probe netween mandible and hyoid will show myelohyoid and anterior belly of digastric
Evaluate submental region

Then move laterally to submandibular space:
Trace the myelohyoid muscle laterally to its free border to come to submandibular gland and space
Myelohyoid is superficial and hyoglossus is deep. Between them is submandibular duct and lingual vein. The lingual artery lies deep to hyoglossus.
Evaluate submandibular gland and fat anterior to it for lymphnodes

Then image parotid glands:
Identify retrmandibular vein and extrenal carotid artery. Retromandibular vein is landmark for facial nerve.
parotid duct is seen as then echogenic line, pierces buccinator
Messeter is a landmark anteriorly and mandible posteriorly
Common to find accessory partotid along the cheek

Then scan cervical chain:
Identify IJV in cross section, follow it from superior to inferior to look for level 2, 3 and 4 nodes.
Look for thrombosis of IJV

Then scan posterior triangle:
Look for nodes in the superficial fat between trapezius and sternomastoid, superficial to scalene and splenius muscles

Then scan supraclavicular region:
Along the superior border of the clavicle
Identify sternomastoid, trepezius and omohyoid
Identify scalene muscles and brachail plexus

Then scan laryngeal region:
Identify thyroid lamina, strap muscles

Then do not scan thyroid and carotid:
Unless asked, do not ultrasound thyroid and carotids!

(images will be uploaded shortly...)

Differentials in petrous apex

2008-08-15T07:42:00.001-07:00

Pseudolesions:
Diploic fat marrow
Simple petrous effusion
Congenital:
Cephalocele
Benign:
Cholesterol granuloma
Mucocele
Cholesteatoma
Infection:
Petrous apicitis
Vascular:
Carotid artery aneurysm
Malignant:
Rhabdomyosarcoma
Metastasis
Lymphoma
Bone and cartilage tumors:
Osteosarcoma
Chondrosarcoma
Others:
Histiocytosis X
Paget's fibrous dysplasia

Reference:
Connor SEJ et al. Imaging of the petrous apex: a pictorial review. British Journal of Radiology (2008) 81, 427-435

Petrous apex

2008-08-15T07:22:00.000-07:00

IAM divides petrous apex into
1. anterior portions - contains marrow and air cells
2. posterior otic capsule

Aereated in 1/3rd by peritubal, posteromedial and subarcuate tracts which extend superior and inferior to cochlea to communicate with middle ear

Anterior compartment:
Contains horizontal portion of petrous carotid canal and foramen lacerum

Relations:
VI N medial and V N superomedial

Reference:
Connor SEJ et al. Imaging of the petrous apex: a pictorial review. British Journal of Radiology (2008) 81, 427-435

Imaging CSF rhinorrhoea

2008-08-14T04:23:00.000-07:00

Causes:
Trauma 90% (increased incidence in periorbital trauma)
Nontraumatic - Increased CSF pressure or primary nontraumatic CSF leaks

Sites:
Most common cribriform plate and ethmoid air cells
Frontal sinus
Sella turcica
Sphenoid sinus
Lateral lamella of cribriform plate
Posterior ethmoid roof near anterior and medial sphenoid wall

Natural history:
Most of CSF leaks resolve spontaneously
CSF fistulae > 7 days - increased risk of meningitis

Diagnosis:
Beta-2 transferrin assay is the test of choice (high sensitivity and specificity)

Anatomy of inner ear

2008-07-22T08:53:00.000-07:00

Basic anatomy

1. Membranous labyrinth

2. Bony laryrinth

3. Perilymphatic labyrinth

Membranous labyrinth (endolymph)
Utricle - within vestibule
Saccule - within vestibule
Semicircular ducts - within semicircular canals
Cochlear duct (scala media) - within cochlea
Endolymphatic duct - within proximal proximal vestibular aqueduct
Endolymphatic sac - within distal vestibular aqueduct
Bony laryrinth
Vestibule - contains urtcile and saccule
Semicircular canals - contain semicircular ducts
Cochlea - contains cochlear duct
Vesticular aqueduct - contains endolymphatic duct and endolymphatic sac
Medial aspect of cochlear aqueduct
Perilymphatic labyrinth
Located between membranous and bony labyrinth
Within vestibule surrounding the utricle and saccule
Within semicircular canal surrounding semicircular ducts
Within vestivular aqueduct surrounding endolymphatic duct
Within cochlea (called scala vestibuli and scala tympani) parallel (not surrounding) to cochlear duct (i.e. scala media - membranous labyrinth)
Cochlear aqueduct is purely perilymphatic labyrinth - runs parallel and inferior to IAC. Only the medial aspect is covered by bony laryrinth

Anatomy of 7th nerve

2008-05-29T07:48:00.000-07:00

Roots:
Motor - large, anterior
Sensory - smaller, N intermedius, posterior
Cisternal segment:
Both roots join and pass anterolaterally through CPA cistern
Intratemporal segment:
IAC: anterosuperior in position, superior to crista falciformis. Superior vestibular nerve is posteior to it. Cochlear nerve is inferior to it. Inferior vestibular nerve is posteroinferior to it.
Labyrinthine: Up to geniculate ganglion, superior to cochlea. Stops at anterior genu
Tympanic: Starts at anterior genu. Includes geniculate ganglion. Ends at posterior genu. passes inferior to L-SCC
Mastoid: up to stylomastoid foramen. Anteriorly facial nerve recess; medially stepedius, pyramidal eminence and sinus tympani (sinus tympani is medial to pyramidal eminence)
Extracranial:
Enters parotid, lateral to RMV

ANATOMIC LOCALIZATION BASED ON CLINICAL SYMPTOMS:
1. Paralysis of muscles of facial expression with forehead sparing: supranuclear, i.e. central
2. Paralysis of muscles of facial expression with forehead involvement: infranuclear, i.e from brain stem below
a. involvement of 6th CN - pons
b. involvement of 8th CN - CAP, IAC
c. involvement of lacrimation, sound and taste - proximal to geniculate ganglion
d. variable involvement of lacrimation, sound and taste - intratemporal
e. sparing of lacrimation, sound and taste - extracranial
b.

SCC dehiscence

2008-02-20T08:44:00.000-08:00

Most common in S-SCC, also seen in P-SCC

CT is investigation of choice, can also be assessed by MR

10% are asymptomatic

Vestibulocochlear nerve aplasia/ hypoplsia

2008-02-20T08:29:00.000-08:00

Within IAM, 8N splits into

1. Superior vestibular branch
2 Inferior vestibular branch
3. Cochlear branch

Anatomy:
Anterosuperior - VII
Anteroinferior - Cochlear
Posterosuperior - Superior vestibular
Posteroinferior - Inferior vestibular

MR is used to assess the aplasia/ hypoplasia

Large vestibular aqueduct

2008-02-20T08:25:00.000-08:00

Also known as widened vestibular aqueduct syndrome and enlarged endolymphatic sac
anomaly.

Clinical features:
Most common cause of SNHL in children/ teens
Gradual deterioration of HL
Usually bilateral
Sporadic
Associated with other cochlea malformations, like Mondini deformity, dilated vestibule and Pendred’s syndrome.

Anatomy:
Lies posterior and parallel to posterior semicircular canal
Joins labyrinth anteriorly at crus, enters extradural space of posterior cranial fossa on posterior
aspect of temporal bone.
Normally mid part of vestibular aqueduct measures less than 1.5 mm, and not bigger than posterior semicircular canal.
Contains endolymphatic sac
Axial images are used.

Imaging and pathology:
If > 1.5mm in the mid part; rule of thumb: if larger than P-SCC
No correlation between size and degree of hearing loss

CT:
Large vestibular aqueduct
Probably invariably a/w modilolar deficiency

MR:
Large Endolymphatic duct

Semicircular canal aplasia/hypoplasia

2008-02-20T08:21:00.000-08:00

a/w CHARGE syndrome
Most common L-SCC; most commonly a/e vestibular dysplasia. a/w Goldenhar's syndrome
P-SCC malformations are a/w Waardenburg syndrome, ALagille syndrome

Mondini deformity

2008-02-20T08:16:00.000-08:00

Middle and apical turns are fused, basal turn is present

a/w deformities of vestibule, SCC, endolymphatic duct, endolymphatic sac

Present with low frequency hearing loss

Cochlear implants are done. May be associated with defect of modiolus. Placing electrode can empty endolymph, hence it is important to assess modilous. Modilolus can be measured on MR.

May suffer with recurrent meningitis, due to spontaneous fistula between middle ear and subarachnoid space

Cochlear aplasia/ hypoplasia

2008-02-20T08:13:00.000-08:00

< 1 turn
Vestibule and SCC present

Common cavity

2008-02-20T07:37:00.001-08:00

Single cavity in the inner ear
Cochlear implants might be useful

CT:
To demonstrate the abnormality as well as course of facial nerve canal

MR:
shows single cavity

Congenital Anomalies of Inner Ear

2008-02-20T07:37:00.000-08:00

Michel (labyrinthine) Aplasia
Common cavity
Cochlear aplasia/ hypoplasia
Mondini deformity
Semicircular canal aplasia/hypoplasia
Large vestibular aqueduct
Vestibulocochlear nerve aplasia/ hypoplsia
SCC dehiscence

Michel (labyrinthine) Aplasia

2008-02-20T06:52:00.000-08:00

Complete absence of inner ear with flat cochlear promontory

CT:
Complete absence of inner ear structures
Flat Cochlear promontory
DD: Labyrinthitis ossificans secondary to meningitis (normal cochlear promontory)

MR:
Absent labyrinth on T2

Chondrosarcoma

2007-12-19T04:21:00.000-08:00

< 40yrs of age

CT:
Chondroid matrix

MR:
High T2 signal
Enhance

Reference:
Momeni et al. Imaging of Chronic and Exotic Sinonasal Disease: Review. AJR 2007; 189:S35-S45

Inverted papilloma

2007-12-19T04:11:00.000-08:00

Nearly 50% of all papillomas
Arise from lateral nasal wall/ max sinus
Significant malignant potential - SCC
40-70 years of age
20-40% recur

Staging:
Stage I: limited to nasal cavity
Stage II: limited to ethmoidal air cells and medial and superior part of max sinus
Stage III: extsnion into lateral/inferior aspect of max sinus
Stage IV: Spread outside nose and sinus, especially cribriform plate, skull base

CT:
Non specific mass centred in middle meatus
Bone remodelling +
Stippled calcification (20%) may help in diagnosis

MR:
Iso on T1, iso-to-hypo on T2 wrt muscle
Enhance (50%)
Convoluted cribriform plate on T2 is typical

Reference:
Momeni et al. Imaging of Chronic and Exotic Sinonasal Disease: Review. AJR 2007; 189:S35-S45

Nasopharyngeal angiofibroma

2007-12-19T04:04:00.000-08:00

Most common nasopharyngeal benign tumor
Locally agressive
Invades pterygopalatine fossa
Anterior bowing of the posteior maxiallary wall is charactersitic
Arterial supply from internal or externalcarotid; per-op embolization is needed
40-50% recur, if skull base invasion present

CT:
Intensely enhance

MR:
Abundant flowvoids

Differentials:
Hypervascular polyp, rhabdomyosarcoma, germ cell tumor, carcinoma, lymphangioma, encephalocele (later 2 do not enahnce)

Reference:
Momeni et al. Imaging of Chronic and Exotic Sinonasal Disease: Review. AJR 2007; 189:S35-S45

Osteomeatal complex

2007-12-19T03:20:00.000-08:00

Osteomeatal complex:
Ostium: opening within the maxillary sinus
Infundibulum: the canal like struture
Hiatus semilunaris: slit like air space, situated superior to uncinate process, anteroinferior to bulla ethmoidalis
Uncinate process: sickle shaped bone extension of the medial wall, rarely pneumatized
Bulla ethmoidalis: largest ethmoidal bulla, situated anteroinferiorly
Middle meatus: where hiatus semilunaris opens

Patterns of obstruction (Sonkens et al):
1. Infundibular pattern:
Sinus disease is limited to infundibulum and maxillary sinus; fromtal and ethmoidal sinuses are spared
Secondary to swollen mucosa, polyps, Haller cells
Rx - infundibulotomy

2. Osteomeatal unit pattern:
Middle meatus, anterior-middle ethmoidal air cells, maxillary and frontal sinuses are involved.
Secondary to swollen mucosa, polyp, concha bullosa, septal deviation, nasal tumor
Rx - infundibulotomy and ethmoid bullectomy

3. Sphenoethmoidal recess pattern:
Sphenoid and posterior ethmoid cir cells are involved.

4. Sinonasal polyp pattern:
Polyps fill nasal cavity and sinuses bilaterally

5. Unclassifiable pattern:
Secondary to retension cysts, mucocels, post-op changes

NHL in head and neck

2007-11-22T03:29:00.001-08:00

NHL accounts 5% of head and neck malignancies

2nd most common site for NHL

Most common extranodal site for NHL is Waldeyer's ring

Within Waldeyer's ring, tonsils are the most common site, follwoed by nasopharynx

Floor of mouth lesions

2007-10-24T03:47:00.001-07:00

Developmental:
Dermoid
Epidermoid
Lymphoepithelial cyst

Inflammatory:
Ranula - mucuc retension cyst

Tumor:
Lipoma
Salivary gland tumors
Mesenchymal tumors

Floor of mouth

2007-10-24T03:40:00.001-07:00

From lower gingiva and alveolar mandibular ridge to insertion of anterior tonsillar pillar into tongue
Medially bounded by inferior surface of the tongue
Sublingual and submandibular glands are in the floor
SMG duct is 5 cm long and courses between sublingual gland and genioglossus and opens in anterior floor of mouth near midline on papillae sublingualis
In midline, genioglossus and geniohyoid separate sublingual glands, which have several openings in addition to Bartholin duct on plica sublingualis.
Genioglossus, geniohyoid, mylohyoid, and anterior belly of digastric form muscular diaphragm of mouth floor
Lingual nerve (from posterior trunk of V3) suppplies sensation
Lingual artery (from ECA) and vein supply
Drain to L-I nodes (submandibular and submental), which lie inferior and lateral to the mylohyoid muscle close to submandibular gland

Differentials for the floor of mouth lesions

Auditory nerve vascular compression

2007-10-17T03:41:00.000-07:00

Location of abberent vessel within the IAM (from medial to lateral):
1. Root entry zone of auditory nerve to the brainstem
2. Cisternal
3. Porus - mouth of IAM
4. IAC - within canal

Vessels crossing:
AICA
PICA

Likelyhood of compression:
? subjective

Nasopharynx, nasal cavity and paranasal sinuses

2007-09-16T14:21:00.001-07:00

Osteomeatal complex

Infections:
Fungal sinusitis

Tumors:
Inverted papilloma
Nasopharyngeal angiofibroma
Chondrosarcoma

Fungal sinusitis

2007-09-16T13:59:00.000-07:00

Acute invasive:
Rapidly progressing infection
Seen commonly in immunocompromised patients, diabetec ketoacidosis
Mortality of 50%–80%
Primary site is nasal cavity with common involvement of middle turbinate
CT:
Mucosal thickening of paranasal sinus and nasal cavity
Complete opacification with expansion, erosion, remodelling, thinning
Calcification (70%) - primarily central (non fungal - peripheral), fine punctate (non fungal - eggshell, round)
More often unilateral with involvement of ethmoid and sphenoid sinuses
Bone destruction
Cavernous sinus thrombosis, or carotid artery invasion, occlusion or pseudoaneurysm may be seen
MR:
Low T2 signal
Orbital extension - inflammatory changes in periorbital fat, proptosis
Obliteration of periantral fat
Leptomengeal enhancement

Chronic invasive:
Usually immuno competent
CT:
Masslike soft tissue with destruction of sinus walls and extension beyond the sinus
May be bony sclerosis
MR:
Low on T1 and very low on T2-weighted

Allergic fungal sinusitis:
Young people
CT:
Opacification and expansion
MR:
Low or hig signal on T1, low signal on T2

Fungal ball:
Mass within sinus, common in maxillary sinus
CT:
High density
May be punctate calcifications
MR:
Low on T1 and T2

References:
1. Aribandi M et al. Imaging Features of Invasive and Noninvasive Fungal Sinusitis: A Review. RadioGraphics 2007;27:1283-1296

CPA meningioma

2007-08-12T08:25:00.000-07:00

2nd most common CPA lesion
2nd most common intracranial tumor
More common in women, 3:1
Middle aged people

CT:
Hyperdense (75%) lesion with intense enhancement (90%)
Calcium in 25%
IAM not usually enlarged
Sclerosis of adjacent bone
Surrounding edema may be seen

MR:
Iso to gray matter
May show cystic changes, necrosis or hemorhage
Intense enhancement
Dural tail sign in 60%
Surrounding edema may be seen

Acoustic schwannoma

2007-08-12T08:17:00.000-07:00

Arise from schwann cells
Most common CPA lesion
2nd most common extra axial lesion
85% of schwannomas found in this region
A/W arachnoid cyst in 0.5%
Bilateral is diagnostic of NF-2 (Chr 22q)

Clinical presentation:
SNHL, tinnitus, trigeminal or facial neuritis

MR:
Well defined
Oval or round
Low on T1, high on T2, intensely enhance (100%)
Cystic component present
Small lesions are seen as low signal lesions (filling defect ) in IAM on T2
Large lesions show stalk in the IAM (ice cream on cone)
Dural tail sign rare (cf. meningioma)

CT:
Mixed solid and cystic lesion with intense enhancement
No calcium (cf. meningioma)

CPA aneurysm

2007-08-12T08:13:00.000-07:00

1% of CPA lesions
PICA > VA > AICA

Clinical presentation:
SNHL in 70%, facial nerve palsy in 60%, SAH in 50%, hemifacial spasm
CT:
Ovoid lesion with calcium rim
Enhances

MR:
Complex layered signal, low flow void on T1, high on T2 (methHb)
Does not enter IAM

CPA arachnoid cyst

2007-08-12T08:09:00.000-07:00

Do not communicate with cisterns or ventricles
10% of arachnoid cyst occur in CPA
Most commonly incidental finding
75% occur in children

Clinical features:
Silent
Headache, dizziness, SNHL, trigeminal neuralgia, hemifacial spasm

MR:
Similar to CSF on all sequences, suppressed on FLAIR
No diffusion restriction (low signal)
Displaces the cisterns and vessels, do not encase (c.f. epidermoid)
No enhancement

CPA epidermoid cyst

2007-08-12T08:00:00.000-07:00

Congenital lesion arising from inclusion of ectodermal elements
3rd most common CPA lesion
Insinuating CP angle lesion, engulfs cranial nerves and vessels
Pathologically pearly white beautiful cauliflower tumor

Clinical presentation:
20-70 years (40)
Headache, trigeminal or facial neuralgia, SNHL
May be clinically silent

MR:
low on T1, high on T2 similar to CSF (dirty CSF signal)
No suppression on FLAIR
Restricted diffusion on DWI (high signal)
Irregular or scalloped margins
No enhancement

CT:
Low attenuation lesion
Calcium in 20%

Management:
Complete removal

CP angle differentials

2007-08-12T07:58:00.000-07:00

Acoustic schwannoma
CPA meningioma
CPA epidermoid cyst
CPA arachnoid cyst
CPA aneurysm

Cerebellopontine angle

2007-08-12T07:56:00.001-07:00

CP angle differentials

Acoustic schwannoma
CPA meningioma
CPA epidermoid cyst
CPA arachnoid cyst
CPA aneurysm

Auditory nerve vascular compression

Staging malignancies of larynx

2007-07-25T15:13:00.000-07:00

Supraglottis:
T1 - confined to one subsite
T2 - more than one subsite or glottis involvement without fixed cord or outside supraglottis, i.e., base of tongue, vallecula, medial wall of pyriform sinus
T3 - Fixed cord and/or invasion of post cricoid area, preepiglottic tissue, paraglottic space, thyroid cartilage inner cortex erosion
T4a - Invasion of thyroid cartilage and/or invasion beyond larynx, i.e., trachea, extrinsic tongue muscles, strap muscles, thyroid gland, esophagus
T4b - Invasion of prevertebral space, carotid artery encasement, mediastinal structures

Glottis:
T1a - Limited to one cord
T1b - Limited to both vocal cords with or without involvement of anterior or posterior commisure with normal cord mobility
T2 - supra and/or subglottic extension, and/or impaired cord mobility
T3 - Fixed cord and/or paraglottic space extension and/or thyroid cartilage inner cortex erosion
T4a - Invasion through thyroid cartilage and/or invasion beyond larynx, i.e., trachea, extrinsic tongue muscles, strap muscles, thyroid gland, esophagus
T4b - Invasion of prevertebral space, carotid artery encasement, mediastinal structures

Subglottis:
T1 - Limited to subglottis
T2 - Extends to vocal cord (s) without fixed cord
T3 - Vocal cord fixed
T4a - Invasion of cricoid ot thyroid cartilage and/or invasion beyond larynx, i.e., trachea, extrinsic tongue muscles, strap muscles, thyroid gland, esophagus
T4b - Invasion of prevertebral space, carotid artery encasement, mediastinal structures

Anatomy of Larynx

2007-07-25T14:56:00.000-07:00

Supraglottis:
Consists of epiglottis (both lingual and laryngeal aspects), laryngeal aspect of aryepiglottic folds, arytenoids, false cords (ventricular bands)

Glottis:
Consists of superior and inferior surfaces of true vocal cords, anterior and posterior commisures

Subglottis:
From lower boundary of glotiis to lower margin of cricoid cartilage

Staging malignancies of pharynx

2007-07-18T16:49:00.000-07:00

Nasopharynx:
T1 - confined to nasopharynx
T2a - extends to oropharynx, nasal cavity
T2b - with parapharyngeal extension
T3 - Bony involvement, paranasal sinus
T4 - Intracranial extension, cranial nerves, infratemporal fossa, hypopharynx, orbit, masticator space

Oropharynx:
T1 - < 2cm
T2 - 2-4 cm
T3 - > 4 cm
T4a - invasion of larynx, extrinsic tongue muscles, medial pterygoid plate, hard palate, mandible
T4b - invasion of lateral pterygoid muscle, pterygoid plates, lateral nasopharynx, skull base, carotid encasement

Hypopharynx:
T1 - Limited to one subsite and < 2 cm
T2 - More than one subsite of hypopharynx, or an adjacent site or 2-4 cm
T3 - > 4cm, but not fixed to hemilarynx
T4a - Invasion of thyroid or cricoid cartilage, hyoid bone, thryoid gland, central soft tissue compartment
T4b - Invasion of prevertebral fascia, encasement of carotid artery, mediastinal involvement

References:
AJCC Cancer staging handbook. 6th Edition. Springer

Anatomy of hypopharynx

2007-07-03T16:25:00.000-07:00

Extends from superior border of hyoid bone/ floow of vellacula to lower border of cricoid cartilage

Contents:
Pyriform sinuses
Lateral and posterior wall
Post cricoid region

Anatomy of oropharynx

2007-07-03T16:22:00.000-07:00

Extends from superior surface of soft palate to superior surface of hyoid bone/ floor of vallecula

Contents:
Tongue base
Inferior surface of soft palate
Uvula
Anterior and posterior tonsillar pillars
Glossotonsillar sulci
Pharyngeal tonsils
Lateral and spoterior pharyngeal wall

Anatomy

2007-07-03T16:13:00.001-07:00

Pharynx and Larynx:
Anatomy of nasopharynx
Anatomy of oropharynx
Anatomy of hypopharynx
Anatomy of Larynx

Salivary glands:
Anatomy of salivary glands

Ear and petrous:
Anatomy of inner ear
Anatomy of 7th nerve
Anatomy of Petrous apex

Anatomy of nasopharynx

2007-07-03T16:07:00.000-07:00

Relations:
Anterior: posterior choana
Floor: superior surface of soft palate

Include:
Vault
Lateral walls
Fossa of Rosenmuller
Mucosa covering torus tubaris
Posterior wall

Nasopharyngeal carcinoma

2007-07-03T16:03:00.000-07:00

Anatomy of nasopharynx

Staging head and neck cancers

2007-07-03T14:50:00.001-07:00

Staging lymph nodes
Staging malignancies of oral cavity
Staging malignancies of pharynx

Staging malignancies of oral cavity

2007-07-03T14:41:00.000-07:00

T1 - < 2 cm
T2 - 2-4 cm
T3 - > 4 cm
T4 (for lip) - Invasion of cortical bone, inferior alveolar nerve, floor of mouth, skin of face
T4a - Invasion of cortical bone, extrinsic muscles of tongue (genioglossus, hyogossus, palatoglossus, styloglossus), maxillary sinus, skin of face
T4b - Invasion of masticator space, pterygoid plate, skull base, encasement of ICA

References:
AJCC Cancer staging handbook. 6th Edition. Springer

Lymph node involvement: Pearls

2007-06-28T16:44:00.000-07:00

Closer the cancer to midline, greater risk of bilateral nodes
Previous surgery or radiotherapy may result in unusual nodal disease
Midline nodes are considered ispilateral

Oral cavity:

Nodal spread depends upon T staging. M spread is depends on N staging
Midline nodes are considered ipsilateral
Usually follow L2 to L4
Cancers of hard palate and alveolar ridges commonly spread to L1, L2, buccinator, and rarely L5 or supraclavicular
Cancers of anterior oral cavity may directly spread to L3
Oral tongue cancer may directly spread to L4

Nasopharynx:

Commonly spread to retropharyngeal, upper jugular and spinal accessory nodes
Often bilateral spread

Oropharynx:

Level II and III, less commonly level I nodes

Hypopharynx:

Parapharyngeal, paratracheal and level III and IV nodes

Supraglottis:

Rich bilaterally connected lymphatics, hence nodal disease is common
Commonly spread to Level II and III, less common to level I

Glottis:

Nearly devoid of any lymphatics, hence rarely spread to regional nodes

Subglottis:

Prelaryngeal, pretracheal, paralaryngeal, paratracheal nodes

Cancer of oral tongue

2007-06-28T16:38:00.000-07:00

Involves anterior 2/3rd of tongue

Nodal spread:
May directly to level 4 (lower jugular)

cancer of hard palate

2007-06-28T16:35:00.000-07:00

Arising from mucosa lining palatine process of palatine bones

Nodal involvement:
Low metastatic potential
Commonly involved: buccinator, submandibular, jugular
Occasionally involved: retropharyngeal

Cancer of floor of mouth

2007-06-28T16:31:00.000-07:00

Arising from mucosa over myelohyoid and hyoglossus to undersurface of tongue. Posteriorly extends up to anterior pillar of tonsil.
Floor of mouth contains ostia of submandibular and sublingual glands

Cancer of retromolar trigone

2007-06-28T16:28:00.000-07:00

Arising from mucosa overlying ascending mandibular ramus posterior to the last molar tooth

Upper alveolar ridge cancer

2007-06-28T16:27:00.000-07:00

Arising from mucosa overlying alveolar process of maxilla

Nodal involvement:
Low metastatic potential
Commonly involved: buccinator, submandibular, jugular
Occasionally involved: retropharyngeal

Lower alveolar ridge cancer

2007-06-28T16:25:00.000-07:00

Arising from mucosa overlying alveolar process of mandible

Nodal involvement:
Low metastatic potential
Commonly involved: buccinator, submandibular, jugular
Occasionally involved: retropharyngeal

Cancer of buccal mucosa

2007-06-28T16:23:00.000-07:00

Arising from inner surface of lip and cheek to mucosa of alveolar ridge

Malignancies in oral cavity

2007-06-28T16:15:00.000-07:00

Staging malignancies of oral cavity
Cancer of buccal mucosa
Lower alveolar ridge cancer
Upper alveolar ridge cancer
Cancer of retromolar trigone
Cancer of floor of mouth
Cancer of hard palate
Cancer of oral tongue

References:
AJCC Cancer staging handbook. 6th Edition. Springer

Staging lymph nodes

2007-06-28T16:01:00.000-07:00

(Note lymph node measurement is in greatest dimesion, not short axis)

N1: Single ipsilateral node, < 3cm
N2a: Single ipsilateral node 3-6 cm
N2b: Multiple ipsilateral nodes, none > 6 cm
N2c: Contralateral or bilateral nodes, none > 6 cm
N3: Node > 6 cm

References:
AJCC Cancer staging handbook. 6th Edition. Springer

Imaging in head and neck cancer

2007-06-28T14:35:00.000-07:00

Staging:
Staging head and neck cancers

Imaging lymph nodes:
Nodal levels
Staging lymph nodes
Lymph node involvement: Pearls
Ultrasound features of malignant lymphnodes

Sites:
Malignancies in oral cavity
Nasopharyngeal carcinoma

Ultrasound features of malignant lymphnodes

2007-06-20T15:59:00.000-07:00

Rounded shape
Increased size
No fatty hilum
Irregular margin
Heterogenous echo
Calcification
Vascularity through out

References:
Hoang JK et al. US Features of Thyroid Malignancy: Pearls and Pitfalls. RadioGraphics 2007;27:847-860

Ultrasound features of malignancy

2007-06-19T15:56:00.000-07:00

Microcalcification:
Most specific (90%) sign of malignancy, seen as hyperechoic foci without shadowing
Seen in approx. 40% of thyroid ca
Most common in papillary ca
Also seen rarely in other ca and adenoma and Hashimoto's
Other types of calcifications include, large calcification (necrosis of ca, goitre), Microcalcification with reverberation artefact (benign nodule), peripheral calcification (MNG)

Absence of halo:
Neither sensitive or specific
Complete halo is highly suggestive of a benign lesion
Halo is absent in more than 50% of benign lesion
15% of papillary ca have complete halo

Taller than wider(AP more than transverse):
As similar in breast ca
Specific sign (90%)

Vascularity:
More than 50% of solid hypervascular lesions are benign
Malignant lesions show marked central flow; peripheral flow is more common with benign lesions
Complete avascular nodule is very unlikely to be malignant

Hypoechoic solid nodule:
Sensitive but not specific
Marked low echogenicity is suggestive of malignancy

Size:
More than 4 cm are more likely to be malignant
Not a sensitive or specific sign
Direct invasion:
Specific sign of malignancy
Common with anaplastic ca, lymphoma, sarcoma

Lymph node involvement:
Occur in about 20%
Common with papillary ca, medullary ca

References:
Hoang JK et al. US Features of Thyroid Malignancy: Pearls and Pitfalls. RadioGraphics 2007;27:847-860

Thyroid malignancies: Pearls

2007-06-19T15:41:00.000-07:00

Papillary ca is the most comon (75%) and has the best prognosis with 20YS of 95%
Follicular ca is 2nd most common (10%) with 20YS of 75%
Medullary ca accounts for 5% of thyroid ca with 10YS of 60%
Anaplatic ca accounts for less than 5% of thyroid ca with 5YS of 5%
Common in less than 20yrs and more than 60yes
Risk factors include neck irradiation and family history

References:
Hoang JK et al. US Features of Thyroid Malignancy: Pearls and Pitfalls. RadioGraphics 2007;27:847-860

Thyroid nodules: Pearls

2007-06-19T15:15:00.000-07:00

Occur in 50% of population
93% are benign and only 7% are malignant
Most common cause is benign thyroid hyperplasia
Most specific USG sign is microcalcification; other specific signs are metastatic lymphadenopathy and adjacent organ invasion. Other USG signs of malignancy are marked hypoechotexture, AP dimesion more than trasverse, irregular illdefined margin, absence of hypoechoic halo
On scintigraphy, a hot nodule is rarely malignant; 77% of cold nodules are benign

References:
Hoang JK et al. US Features of Thyroid Malignancy: Pearls and Pitfalls. RadioGraphics 2007;27:847-860

Thyroid gland

2007-06-19T15:12:00.000-07:00

Thyroid nodules: Pearls
Thyroid malignancies: Pearls
Ultrasound features of malignancy

Adenoid cystic carcinoma

2007-06-18T14:34:00.000-07:00

2nd most common parotid malignancy
Tendency for perineural and perivascular extension

MR:
Gd-MRI demonstrates perineural extension

References:
Howlett DC. High resolution ultrasound assessment of the parotid gland.British Journal of Radiology (2003) 76, 271-277

Mucoepidermoid carcinoma

2007-06-18T14:31:00.000-07:00

Most common parotid malignancy (more than 80%)

US:
Smaller lesions may be similar to pleomorphic adenoma
May be irregular and illdefined with heterogeneous echotexture
Pulsewave may show raised RI

References:
Howlett DC. High resolution ultrasound assessment of the parotid gland.British Journal of Radiology (2003) 76, 271-277

Retention cyst

2007-06-17T17:08:00.000-07:00

Secondary to tumour, calculus or inflammation
Present with painless swelling
May be infected
Thin walled anechoic lesion with posterior enhancement
Multiple cysts are associated with HIV

References:
Howlett DC. High resolution ultrasound assessment of the parotid gland.British Journal of Radiology (2003) 76, 271-277

Lipoma

2007-06-17T17:06:00.000-07:00

Compressible
Oval or elliptical mass with regular margin
No signal on Doppler
MRI confirms fatty nature

References:
Howlett DC. High resolution ultrasound assessment of the parotid gland.British Journal of Radiology (2003) 76, 271-277

Oncocytoma

2007-06-17T16:59:00.000-07:00

Rare tumour
1% of parotid neoplasms
Arise from oncocytes
Present as slow growing mass
Common in superficial lobe
Imaging features are similar to pleomorphic adenoma

References:
Howlett DC. High resolution ultrasound assessment of the parotid gland.British Journal of Radiology (2003) 76, 271-277

Core needle biopsy of salivary glands

2007-06-16T21:03:00.000-07:00

15-mm cutting needle with 15-mm specimen notch
1-4 passes
14-20 G needle (16 or 18 more commonly used)

References:
Wan YL et al. Ultrasonography-Guided Core-Needle Biopsy of Parotid Gland Masses. American Journal of Neuroradiology 25:1608-1612, October 2004

Head and neck interventions

2007-06-16T20:59:00.000-07:00

FNA of salivary gland lesions
Core needle biopsy of salivary glands

FNA of salivary gland lesions

2007-06-16T20:55:00.000-07:00

Technique:
10- to 13-MHz linear probe
25-gauge needle
Samples evaluation by cytologist
If inadequate, 20 and 22 gauge needles

References:
Siewert B et al. Utility and Safety of Ultrasound-Guided Fine-Needle Aspiration of Salivary Gland Masses Including a Cytologist’s Review. J Ultrasound Med 23:777-783 • 0278-4297

Salivary gland tumors: Pearls

2007-06-16T15:15:00.000-07:00

The smaller the salivary gland, the higher the rate of malignancy
Most of the lesions in the parotid gland are likely to be benign (less than 30% of focal parotid lesions are malignant), 50% of focal submandibular gland lesions are malignant, and more than 70% of sublingual gland lesions are malignant.
80% of parotid benign lesions are pleomorphic adenomas
Multiple parotid masses are usually lymphadenopathy or Warthin tumors
Warthin tumor occurs almost exclusively in parotid gland, usually in tail in older men
Most common malignancy of parotid gland is mucoepidermoid carcinoma
Most common benign lesion of SMG is pleomorphic adenoma
Most common malignancy in SMG is adenoid cystic carcinoma
MR imaging in parotid gland tumors:
Virtually all parotid lesions are well seen on T1 because of hyperintense fatty background of the gland. T1 also shows margin, extent and infiltration
Fat sat post Gd T1 shows perineural spread, bone invasion, meningeal infiltration, bone marrow changes
Hyperintense mass on T2-weighted images is usually benign and a mass of low to intermediate signal intensity is usually malignant

References:
1. Yousem DM et al. Major salivary gland imaging. Radiology. 2000;216:19-29

Sialolithiasis

2007-06-16T14:47:00.000-07:00

Most are seen in submandibular gland (60%–90%)
Parotid gland is 2nd most common site (10%–20%)
20% are radiopaque
Cause mechanical obstruction resulting in recurrent swelling and may be complicated by bacterial infection

US:
Smaller stones may not cast shadow
Air bubbles within duct may mislead
Heterogenous gland due to recurrent infections

CT:
Smaller stones may not be visible

MR:
MR sialography is promising

Sialography and stone extraction:
Detailed anatomy with stone extraction

References:
1. BialekEJ etal. US of the Major Salivary Glands: Anatomy and Spatial Relationships, Pathologic Conditions, and Pitfalls. RadioGraphics 2006;26:745-763

Chronic Sclerosing Sialadenitis

2007-06-16T11:18:00.000-07:00

Also known as Kuttner tumor
May mimic malignant lesion both clinically and on imaging
Usually involves submandibular gland
Usg shows multiple small hypoechoic foci scattered on heterogeneous background
May be focal with focal hypoechoic heterogeneous lesion
FNA is recommended

References:
1. BialekEJ etal. US of the Major Salivary Glands: Anatomy and Spatial Relationships, Pathologic Conditions, and Pitfalls. RadioGraphics 2006;26:745-763

Imaging the complications of mastoiditis

2007-06-16T03:01:00.000-07:00

Subperiosteal abscess:
Common site is external mastoid cortex which shows osteolysis and subperiosteal abscess, usually extends towardsa EAM, along zygomatic bone

Bezold Abscess:
Osteolysis at mastoid tip with debris in the soft tissues of the neck

Perisinus Abscess:
Osteolysis in internal mastoid cortex leads to perisinus and epidural abscess
CT shows erosion of cortical plate overlying the sigmoid sinus

Apical petrositis:

Rare complication

Occurs in individuals with pneumatized petrous apex (30% of population)

Classic clinical triad: 6th nerve palsy, deep facial pain, ipsilateral otorrhea (Gradenigo syndrome) CT shows erosions of petrous apex with abnormal enhancement of adjacent meninges

Epidural abscess:
Most common intracranial complication
Common in posterior fossa due to destruction in Trautmann triangle over sigmoid sinus plate or in posterior cortex of petrous pyramid
Next common site is middle cranial fossa

Dural venous thrombophlebitis:
Due to extradural abscess
Common sinus involved is sigmoid sinus leading to thrombosis
May propogate to jugular vein, other dural sinuses

Subdural empyema:
More common with sinusitis than with otitis media

Carotid artery involvement:
Rare complication
ICA is commonly involved
Clinically present with recurrent hemorrhage from throat, nose, ear; Horner syndrome
MR and MRA show carotid spasm or arteritis

Brain (cerebral or cerebellar) abscess

Meningitis

Hydrocephalus

Encephalitis

Labyrinthitis

Facial nerve paralysis

Hearing loss

References:
Vazquez E et al. Imaging of Complications of Acute Mastoiditis in Children. Radiographics. 2003;23:359-372

Lymph nodes

2007-06-16T03:00:00.001-07:00

Nodal levels
Ultrasound features of malignant lymphnodes
Staging lymph nodes
Lymph node involvement: Pearls

Imaging temporal bone

2007-06-16T02:59:00.001-07:00

Anatomy:
Anatomy of inner ear
Anatomy of 7th nerve
Anatomy of Petrous apex

Congential:
Congenital Anomalies of Inner Ear

Infection:
Imaging the complications of mastoiditis

others:

Imaging cholesteatoma

Sjogren disease

2007-06-15T05:46:00.000-07:00

Imaging:
US shows heterogeneous punctate hyperechoic areas (mucus filled ducts) with hypoechoic foci (sialectasis)
CT shows enlarged hyperdense gland
MR shows salt and pepper or honeycomb appearance

Complications:
Increased risk of lymphoma

References:
Lowe LH et al. Swelling at the Angle of the Mandible: Imaging of the Pediatric Parotid Gland and Periparotid Region. Radiographics. 2001;21:1211-1227

Sarcoidosis

2007-06-15T05:44:00.000-07:00

Parotid is involved in up to 30%
Often bilateral
Nonpainful enlargement
CT and MR show multiple noncavitating masses

References:
Lowe LH et al. Swelling at the Angle of the Mandible: Imaging of the Pediatric Parotid Gland and Periparotid Region. Radiographics. 2001;21:1211-1227

HIV

2007-06-15T05:41:00.000-07:00

Imaging:
US shows multiple hypoechoic or anechoic areas without posterior enhancement in 70% and anechoic foci in 30%
CT and MR show bilateral parotid enlargement with cystic and solid areas
Associated with cervical adenopathy
Enlarged adenoids may be seen

References:
Lowe LH et al. Swelling at the Angle of the Mandible: Imaging of the Pediatric Parotid Gland and Periparotid Region. Radiographics. 2001;21:1211-1227

Sialadenitis

2007-06-15T05:34:00.000-07:00

Most common cause is mumps
Bacterial sialoadenitis is commonly due to Staph aureus

Imaging:
Us shows enlarged heterogeneous gland with hypoechoic foci and increased blood flow
CT shows enlarged gland with diffuse enhancement; may show abscess
MR shows enlarged gland which is low on T1 and high on T2

Management:
Antibiotics and surgical drainage if abscess.

References:
Lowe LH et al. Swelling at the Angle of the Mandible: Imaging of the Pediatric Parotid Gland and Periparotid Region. Radiographics. 2001;21:1211-1227

Salivary gland neurofibroma

2007-06-15T05:29:00.000-07:00

Benign nerve sheath tumours from facial nerve trunk or its branches
May be solitary or multiple
Associated with NF1

Imaging:
Oval shaped welldefined homogeneous isoattenuating lesions with or without multiple small cystic areas; show moderate enhancement
On MR low-to-int on T1 and high on T2; show intense enhancement

References:
Lowe LH et al. Swelling at the Angle of the Mandible: Imaging of the Pediatric Parotid Gland and Periparotid Region. Radiographics. 2001;21:1211-1227

Salivary gland angiolipoma

2007-06-15T05:23:00.000-07:00

Benign lesion
Welldefined (more common) or infiltrating

Imaging:
CT and MR shows lipid and blood components
On imaging it is difficult to distinguish between angiolipoma and hemangioma with fatty degeneration

Mangement:
Facial nerve preserving complete excision
Do not recur

References:
Lowe LH et al. Swelling at the Angle of the Mandible: Imaging of the Pediatric Parotid Gland and Periparotid Region. Radiographics. 2001;21:1211-1227

Warthin tumor

2007-06-15T05:20:00.000-07:00

Also known as papillary cystadenoma lymphomatosum, adenolymphoma, cystadenolymphoma 2nd most common benign tumour of parotid gland
5-10% of benign salivary tumors
Common in elderly males (50-60 yrs)
Common in superficial lobe or tail of parotid gland
Multiple or bilateral in 10–15%
Painless slow-growing mass
Increased incidence in smokers

Imaging:
US shows oval hypoechoic lesion with anechoic (cystic) areas, often show increased vascularity
CT and MR shows a welldefined, homogeneous cystic or solid mass
Tc-99 shows hot spot

Management:
Surgery
Recurrence not uncommon

References:
1. Lowe LH et al. Swelling at the Angle of the Mandible: Imaging of the Pediatric Parotid Gland and Periparotid Region. Radiographics. 2001;21:1211-1227
2. Howlett DC. High resolution ultrasound assessment of the parotid gland.British Journal of Radiology (2003) 76, 271-277
2. BialekEJ etal. US of the Major Salivary Glands: Anatomy and Spatial Relationships, Pathologic Conditions, and Pitfalls. RadioGraphics 2006;26:745-763

Pleomorphic adenoma

2007-06-15T05:16:00.000-07:00

General features:
Also known as benign mixed tumor
70-80% of all benign salivary tumors
Most occur in parotid gland (60%–90%)
90% superficial to facial nerve
40-60 yrs
More common in women
Usually solitary and unilateral
Slow growing painless mass
Most are in superficial lobe

Recurrence and malignant transformation:
Malignant transformation may occur - carcinoma ex pleomorphic adenoma (malignant mixed tumor), carcinosarcoma (true malignant mixed tumoe), metastasizing benign mixed tumor
If left untreated, 25 may undergo malignant transformation
Recurrence known to occur, more with enucleation
Recurrences - often multiple, around the original lesion (cluster of grapes)

US:
US shows round welldefined hypoechoic lobulated mass with posterior enhancement; May be heterogeneous or show cystic changes or calcification; May show peripheral, basket-like flow
USG used for FNA, FNAB or core biopsy

CT:
Smaller are homogeneous, well-defined, hyperattenuating (may be hypoattenuating or cystic)
Larger are illdefined, lobulated, heterogeneous due to necrosis and/or hemorrhage
Varibale mild enhancement
Dystrophic calcifications or ossifications - rarely seen - but highly suggestive of diagnosis
May be slightly illdefined, appearing aggressive - secondary to hemorrhage or surrounding inflammation

MR:
Low on T1, high on T2
Low signal capsule on T2, and fat sat post Gd T1 - often seen
Large ones may be heterogenous with various signals due to haemorrhage

Management:
Facial nerve–sparing partial parotidectomy
Often recur

Differentials:
Lymphnodal disease suggests malignancy
Low signal on T1 and T2 suggests malignancy in known pleomorphic adenoma
References:
1. Lowe LH et al. Swelling at the Angle of the Mandible: Imaging of the Pediatric Parotid Gland and Periparotid Region. Radiographics. 2001;21:1211-1227
2. BialekEJ etal. US of the Major Salivary Glands: Anatomy and Spatial Relationships, Pathologic Conditions, and Pitfalls. RadioGraphics 2006;26:745-763
3. Howlett DC. High resolution ultrasound assessment of the parotid gland.British Journal of Radiology (2003) 76, 271-277
4. Som PM and Curtin HD. Head and Neck Imaging. 4th Edition. Mosby

Salivary gland lymphangioma

2007-06-15T05:11:00.000-07:00

Congenital malformations
2/3rd are present at birth, 90% by 2 years
Soft asymptomatic neck mass with facial asymmetry
May be complicated by infection or hemorrhage
Rarely undergo spontaneous regression

Imaging:
US shows cystic lesion with thin septations with or without solid elements
CT shows heterogeneous lesion with septations and cystic areas; Often insinuates between adjacent structures; May contain fluid-fluid levels; Solid portions may enhance
MR shows heterogeneous lesion with multiple cystic areas; Hemorrhage is common causing fluid-fluid levels of variable signal; May show enhancement of solid portions

Management:
Surgical debulking or resection, sclerotherapy, interferon injection
Recurrence not uncommon

References:
Lowe LH et al. Swelling at the Angle of the Mandible: Imaging of the Pediatric Parotid Gland and Periparotid Region. Radiographics. 2001;21:1211-1227

Salivary gland hemangioma

2007-06-15T05:04:00.000-07:00

Most common benign salivary gland mass in children
Significant female predilection
Present 90% of parotid tumors in 1st year of life
Can be capillary or cavernous
Capillary hemangiomas present shortly after birth, grow rapidly up to 1–2 years, and then spontaneous regression by adolescence
Cavernous hemangiomas present in older children, do not undergo spontaneous resolution

Imaging:
Hypoechoic with flow on Doppler
CT shows well-defined mass with intense enhancement. Phleboliths may be seen
MR shows low to intermediate signal on T1 and bright on T2 with flow voids and show intense enhancement

Management:
Most capillary regress and hence surgical treatment is delayed
Cavernous hemangiomas are treated with surgery, sclerotherapy, laser ablation

References:
Lowe LH et al. Swelling at the Angle of the Mandible: Imaging of the Pediatric Parotid Gland and Periparotid Region. Radiographics. 2001;21:1211-1227

Anatomy of salivary glands

2007-06-14T16:36:00.000-07:00

Imaging appearances of salivary glands:
In young: homogeneous and hyper/ iso echoic relative to muscle on USG, same as muscle on CT, fatty on MRI
In adults: undergoes progressive fatty infiltration, hence low attenuation on CT and more fatty on MR

USG:
Homogeneously hyperechoic in comparison to adjacent muscles

Parotid gland:
Located in retromandibular fossa, anterior to ear and SCM
Located at mandibular angle wrapping it
Majority is superficial to masseter
Divided into superficial and deep lobes by the facial nerve; Since VII N is not seen on USG, retromandibular vein (lies directly above facial nerve) is used as landmark
Deep lobe lies deep to mandibular angle and very little is seen on USG
Drained by Stenson duct - exits above upper 2nd molar tooth; usually not seen on USG
Facial nerve is located lateral to posterior belly of digastric and retromandibular vein
Lymph nodes may be seen mainly in upper and lower poles

Accessory parotid gland:
Seen in 20%
Drains directly into parotid duct
Lies superficial to masseter, anterior to main parotid gland

Submandibular gland:
Seen in posterior part of submandibular triangle
Triangular in shape
May be connected with parotid or sublingual gland by glandular processes
Facial artery may cross submandibular gland
Facial vein runs along anterosuperior part of submandibular gland
Posteriorly, a branch connecting the retromandibular vein
Medially lingual artery and vein
Wharton duct runs from hilum at the level of mylohyoid muscle, bends around free part of mylohyoid, extends to its orifice at sublingual caruncle along the medial part of the sublingual gland

Sublingual gland:
Lies between muscles of floor of oral cavity, viz., geniohyoid, intrinsic muscles of tongue and hyoglossus and mylohyoid
Lies adjacent to mandible
Oval on cross section and lentiform on long axis
Medially there is Wharton duct

References:
1. Lowe LH et al. Swelling at the Angle of the Mandible: Imaging of the Pediatric Parotid Gland and Periparotid Region. Radiographics. 2001;21:1211-1227
2. BialekEJ etal. US of the Major Salivary Glands: Anatomy and Spatial Relationships, Pathologic Conditions, and Pitfalls. RadioGraphics 2006;26:745-763

Imaging salivary glands

2007-06-14T16:34:00.000-07:00

Anatomy of salivary glands

Infections:
Sialadenitis
Chronic Sclerosing Sialadenitis
HIV

Inflammations:
Sialolithiasis
Sarcoidosis
Sjogren disease

Salivary gland tumors: Pearls

Benign lesions:
Pleomorphic adenoma
Warthin tumor
Salivary gland neurofibroma
Oncocytoma
Lipoma
Paediatric lesions:
Salivary gland hemangioma
Salivary gland lymphangioma

Benign cystic lesions:
Retention cyst
Lymphoepithelial cyst
First branchial cleft anomaly
Ranula
Sialocele
Pseudocyst

Malignant lesions:
Mucoepidermoid carcinoma
Adenoid cystic carcinoma
Squamous cell carcinoma
Acinic cell carcinoma
Adenocarcinoma
Lymphoma
Leukemia
Metastatic lymphadenopathy: commonly seen with dermatologic malignancy (basal cell carcinoma, squamous cell carcinoma, melanoma), but also in upper digestive SCC
Metastasis: uncommon site, include head and neck malignancies, melanoma, breast, lung, renal cancer

Interventions:
FNA of salivary gland lesions
Core needle biopsy of salivary glands

Nodal levels

2007-06-14T08:07:00.001-07:00

Most simple way to remember:
L1: Bounded by digastric, mandible and hyoid. Submental and submandibular.
L2: Skull base to hyoid. Upper jugular
L3: Hyoid to cricoid. Mid jugular
L4: Cricoid to clavicale. Lower jugular
L5: Bounded by SCM, trepezius and clavicle. Posterior triangle. Divided into upper, mid and lower similar to the L2,3,4 levels
L6: Midline hyoid to sternoclavicular notch. Prelaryngeal, pretracheal and paratracheal
L7: Inferior to sternoclavicular notch. Upper mediastinal
Other groups: Suboccipital, retropharyngeal, parapharyngeal, buccinator (facial), preauricular, periparotid, intraparotid

Image gallery:
Click here for the external link or here in PDF

References:
AJCC Csncer staging handbook. 6th Edition. Springer

Parotid space

2007-06-13T16:39:00.000-07:00

(Link to Radiographics)
Illustration upper parotid space
CT upper parotid space
Illustration lower parotid space
CT lower parotid space

Central giant cell granuloma

2007-06-13T15:48:00.000-07:00

Common lesion
Present in adolescents and young adults (75% less than 30 years)
Common in mandible
Common anterior to 1st molar

Clinical features:
Painless swelling
May be tender

Imaging:
Bone expansion
Teeth displacement
Usually unilocular well defined lucency
May be multilocular
May cross midline, especially in maxilla
Resorption of lamina dura and roots may occur

Management:
Enucleation and curratage
Recurrence uncommon

Reference:
Scholl, RJ et al. Cysts and Cystic Lesions of the Mandible: Clinical and Radiologic-Histopathologic Review. Radiographics. 1999;19:1107-1124

Lingual salivary gland inclusion defect

2007-06-13T03:44:00.000-07:00

Also known as Stafne cyst
Well defined depression in lingual surface of posterior body of mandible near mandibular angle Associated with aberrant submandibular gland lobe
Typically asymptomatic and incidental

Imaging:
Oval or rectangular well-defined lucent lesion just above the inferior border of mandible, anterior to angle, inferior to mandibular canal, posterior to 3rd molar

No treatment is necessary

Reference:
Scholl, RJ et al. Cysts and Cystic Lesions of the Mandible: Clinical and Radiologic-Histopathologic Review. Radiographics. 1999;19:1107-1124

Traumatic bone cyst

2007-06-13T03:42:00.000-07:00

Also known as simple bone cyst
Present in 2nd decade
Commin in mandible
Usually asymptomatic and incidental
Unilocular lucent lesions with scalloped superior margin between the roots of teeth associated with thinning of mandibular cortex and osseous expansion

Differential diagnosis:
Vascular lesions
Central giant cell granuloma
Ossifying fibroma

Reference:
Scholl, RJ et al. Cysts and Cystic Lesions of the Mandible: Clinical and Radiologic-Histopathologic Review. Radiographics. 1999;19:1107-1124

Florid osseous dysplasia

2007-06-13T03:40:00.000-07:00

Most dramatic and extensive expression of cemento-osseous dysplasia
Diffuse, multifocal distribution of mixed lucent-opaque osseous lesions in mandible and maxilla
May complicate with osteomyelitis

Reference:
Scholl, RJ et al. Cysts and Cystic Lesions of the Mandible: Clinical and Radiologic-Histopathologic Review. Radiographics. 1999;19:1107-1124

Cemento-osseous dysplasia

2007-06-13T03:35:00.000-07:00

Common in mandible
Classically seen in periapical region of lower anterior teeth
Present in adult life as incidental findings
Localized discrete lesions
Round lucent lesions with varying opacity
Progressively become more opaque internally
Follow-up the lesion with radiographs for 18–24 months
Surgery or biopsy are indicated only if become symptomatic or significant clinical or radiographic change

Reference:
Scholl, RJ et al. Cysts and Cystic Lesions of the Mandible: Clinical and Radiologic-Histopathologic Review. Radiographics. 1999;19:1107-1124

Ossifying fibroma

2007-06-08T06:20:00.000-07:00

General features:
Encapsulated, well defined benign neoplasms of high cellular fibrous connective tissue with varying osteoid, bone, cementum
Can cause bone expansion with facial asymmetry

Types:
Conentional ossifying fibroma: asymptomatic, but may cause facial asymmetry and tooth displacement
Juvenile aggressive ossifying fibroma: locally destructive, tend to recur, but do not metastasize

Imaging:
Lucent, opaque, or mixed an ddemarcated by a thin line of lucency
Bone scans show intense focal increased uptake

Differenatial diagnosis:
Odontoma
Fibrous dysplasia
Vascular lesions

Management:
Enucleation

Reference:
Scholl, RJ et al. Cysts and Cystic Lesions of the Mandible: Clinical and Radiologic-Histopathologic Review. Radiographics. 1999;19:1107-1124

Odontogenic myxoma

2007-06-08T05:52:00.000-07:00

General features:
Uncommon benign lesion (5%)
From mesenchymal odontogenic tissue
Locally aggressive causing destruction of adjacent bone and soft-tissue infiltration
Associated with congenitally missing or unerupted teeth

Location:
More common in maxilla

Clinical presentation:
10–30 year

Imaging:
Lytic, multilocular (honeycomblike), expansile lesion with ill-defined borders and foci of irregular calcification
Scallop between roots of adjacent teeth with displcaement or resorption of the teeth

Differential diagnosis:
Malignancy
Traumatic bone cyst
Central giant cell granuloma
Other odontogenic tumors
Calcifying epithelial odontogenic tumor - more heavily calcified

Reference:
Scholl, RJ et al. Cysts and Cystic Lesions of the Mandible: Clinical and Radiologic-Histopathologic Review. Radiographics. 1999;19:1107-1124

Management:
Surgical excision

Odontoma

2007-06-08T05:44:00.000-07:00

General features:
Odontogenic hamartomatous malformation
Most common odontogenic tumor (70%)
2nd decade
May cause impaction, malpositioning, resorption of adjacent teeth.

Types:
Compound: more common, contain multiple teeth or toothlike structures.
Complex: . multiple masses of dental tissue, well-defined with amorphous calcifications

Differentials:
Focal cemento-osseous dysplasia
Ameloblastic fibro-odontoma
Adenomatoid odontogenic tumor

Treatment:
Surgical excision

Reference:
Scholl, RJ et al. Cysts and Cystic Lesions of the Mandible: Clinical and Radiologic-Histopathologic Review. Radiographics. 1999;19:1107-1124

Radicular cyst

2007-06-08T05:40:00.000-07:00

General features:
Also known as periapical cyst
Most common cyst of jaw
30 - 50 years
Painless
Periapical inflammatory lesion secondary to pulpal necrosis in tooth

Imaging:
Round, unilocular, lucent lesions in periapical region with thin rim of cortical bone
Associated tooth has deep restoration or large carious lesion
May displace adjacent teeth or mild root resorption

Management:
Enucleation and may be retrograde surgical endodontic treatment or toothe extraction of tooth or root fragment

Reference:
Scholl, RJ et al. Cysts and Cystic Lesions of the Mandible: Clinical and Radiologic-Histopathologic Review. Radiographics. 1999;19:1107-1124