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144
4 Ultrasound of the Neck
Fig. 4.4 Glands and tonsils. Normal parotid gland, note the normal slightly prominent hypoechoic,
nodular-shaped tonsil below the echogenic triangular gland as often observed in infants and children, adjacent normal homogenously echogenic tongue
Fig. 4.5 Larynx US. Normal US appearance of yet non-ossifi ed larynx
4.2.3.4 Para- and Retropharyngeal Spaces
Only meaningfully assessable in case of pathology, such as parapharyngeal abscess
or paravertebral tumour. Otherwise not a routine target of US investigation, retropharyngeal space is diffi cult to visualise.
4.2.3.5 Larynx
Especially in infant/younger children, laryngeal US often diffi cult due to limited
patient cooperation.
Cartilaginous structures nicely assessable – helpful for assessing congenital malformations (e.g. cysts, haemangioma), posttraumatic changes (e.g. haematoma of
vocal cord) and similar queries (Fig. 4.5 ).
NOTE : It is important to know age-dependent anatomic appearance (varies with
progressive calcifi cation).
4.2.4 Cervical Vessels
Normal anatomy with respective US and Doppler fi ndings of major vessels shown
in Fig. 4.1 .
4.2 Normal Findings
145
ab
Fig. 4.6 Cervical vessels. Anatomy + typical US appearance of carotid artery ( a ) using aCDS and
the vertebral artery with accompanying vein ( b ) on CDS (note shadowing from transverse process
of cervical vertebra)
US Findings :
Vessel – anechoic tubular structure
• Artery – multilayered thick wall.
• Vein – usually thin wall, valves may be visible and more easily compressible:
– Veins show signifi cant variation in diameter depending on respiratory cycle
and intrathoracic/transducer pressure – used for assessing patency.
NOTE : Physiologic venous ectasia may be present, particularly during valsalva
manoeuvre.
CDS (Fig.
4.6 )
• In arteries – biphasic unidirectional fl ow towards head.
• In (jugular) veins – usually three-phase modulated fl ow, inspiratory and expira-
tory velocity variations can be bidirectional.
Spectral Analysis
Essential – typical fl ow patterns can be demonstrated in individual arteries (see
4.1 ):
Fig.
• CCA – intermediate resistive fl ow pattern, relatively low antegrade diastolic
velocity and RI = 0.7–0.9.
• ICA – low-resistant fl ow pattern, higher diastolic velocity and RI = 0.6–0.7.
• ECA – fl ow profi le resembles any peripheral high-resistance vessel with low,
potentially missing or inverted end-diastolic fl ow, RI = 0.9–1.1.
• VA – may resemble CCA or ICA fl ow, depending on area of measurement and
head position as well as dominant/nondominant vessel; fl ow velocities usually
slightly lower than CCA; fl ow profi le may change with altered head position
(particularly in fi rst year of life – see Fig.
3.12b–e ).
• All vessels: sharp systolic upstroke, short acceleration time and narrow Doppler
envelope (i.e. narrow band of velocities, no spectral broadening).
• Flow velocities: vary with age (peak systole = 40 cm/s in newborn, 150 cm/s in
adolescents), vessel part and head position (particularly VA).
NOTE : Flow profi le and velocities also depend on many other systemic factors.
Venous fl ow pattern is described above.
146
4 Ultrasound of the Neck
4.3 Pathologic Findings
4.3.1 Lymph Nodes
US Findings
Enlargement, changed echotexture (inhomogenicity, missing hilus, increased or
decreased echogenicity), focal structural alterations (infi ltration, abscess formation), irregular or spherical shape, diameter >1 cm and length-to-diameter ratio
>0.8. Conglomeration, large bulk of nodes, focal large spherical anechoic node,
changed architecture (Fig. 4.7 ).
Potential dorsal enhancement, particularly after anechoic or necrotic parts
NOTE : In enlarged nodes always assess adjacent soft tissue structures and glands
in search for complications or origin (e.g. tumour, secondary abscess formations
in paratonsillar/pharyngeal region). Furthermore, there may be fi stula tracts
(e.g. in MOTT, mycobacteria infection other than tuberculosis, dental origin)
(Fig. 4.8 ).
CDS
For potential disruption of vascular architecture, focal non-perfused areas in granulomatous or tumorous infi ltration/abscess formation (see Fig. 4.2 ).
• In infl ammation hypervascularity and hyperaemia (increased diastolic velocity
with reduced RI).
• 3DUS may be particularly useful for demonstrating disrupted vascular
architecture.
NOTE : Though various criteria indicate suspicion of malignancy, US cannot reli-
ably defi ne entity; some infl ammatory nodes look similar to malignant nodes (e.g.
granulomatous disease), whereas some malignant nodes (e.g. hypervascular lymphoma) may resemble hyperaeremic infl ammatory changes.
4.3.2 Pathology of Cervical Soft Tissue
4.3.2.1 Malformations
Cervical Cyst
Congenital malformation and positioned medially (median cyst – remnant of thyreoglossal duct) or lateral (remnant of embryological branchial arches/clefts).
US Findings
Complicated or simple cyst may contain echogenic debris. May get infected and
then resemble abscess with complicated fl uid, perifocal oedematous changes of
adjacent soft tissue and dorsal sound amplifi cation – but cyst wall is thinner, more
regular and sharper than abscess (Fig. 4.9 ).
Dermoid Cyst
Subcutaneous cyst may contain echogenic material, but no specifi c US criteria.
Duplication Cysts
Arise from trachea or oesophagus (usually lower neck) and may get infected.
4.3 Pathologic Findings
Fig. 4.7 US in lymph node
pathology. ( a ) Split image, sagittal
lateral neck – grouped spherical
enlarged lymph nodes ( LK ). ( b )
Extended fi eld of view, similar
region: a large node (….) with
multiple smaller adjacent
conglomerated lymph nodes
147
a
b
a b
Fig. 4.8 Fistula tact in necrotising node infl ammation/abscess. ( a ) Large suppurated lymph node
with fi stula tract to skin in infection with atypical mycobacteria. ( b ) Fistula tract deriving from
mandibula – from dental infection
ab
Fig. 4.9 Cervical cysts. ( a ) Lateral branchial cleft cyst. ( b ) Median cervical (ductus thyreoglossus)
cyst adjacent to larynx, with clinical signs of secondary infection, dorsal through transmission
cause increased echogenicity behind the complex cyst with sedimentations confi rming its liquid
nature. Note : US alone cannot always differentiate between an old or infl amed cyst/abscess
US Finding
• Cyst-like appearance and may cause compression of adjacent structures.
• Some wall structure (with respective gut/bronchial signature) depictable, often
with complex contents, air within if connection to structure of origin.
148
4 Ultrasound of the Neck
ab
Fig. 4.10 Cervical thymus. ( a ) Cervical ectopic thymus adjacent to thyroid gland. No connection
to mediastinum. ( b ) Large neonatal thymus that reaches up into lower median cervical space
Thymic Cyst
Positioned (para-)median, inferior to thyroid gland, on entire pathway down to
mediastinum.
Vary in size, otherwise undistinguishable from any other uncomplicated cyst.
Cervical Ectopic Thymus
Either isolated or connected to thymus, resembling typical thymal echotexture (see
Chap. 6 ) (Fig. 4.10 ). Intermittent cervical herniation of thoracic thymus may occur
with crying or valsalva.
4.3.2.2 Tumours
Haemangioma
Cavernous or capillary haemangioma, positioned superfi cially and show typical
skin discolouration.
US Findings
• Depending on anatomy and entity, more or less homogeneous, echogenic,
tumour-like lesions, potentially with hazy margins and some infi ltrating aspects
and tubular anechoic structures (representing dilated vessels).
• Central thrombosis may be present (Fig. 4.11 , also see Chap. 11 ).
CDS
• Hyperaemia and hypervascularisation.
• Often some major feeding vessels can be depicted.
Spectral Analysis
• Differentiates lesions into high- and low-fl ow vascular or arterial/venous malfor-
mations; arteriovenous shunts can be identifi ed.
NOTE : Same phenomena and classifi cation/imaging appearance as anywhere else
in body.
Lymphatic Malformation
US Findings
• Mass of septated cysts, potentially with some nodular tissue.
• Tend to bleed – then show mixed echogenicity, sometimes with fl uid-fl uid levels
(see also Chap. 11 ) (Fig. 4.12 ).
aCDS
• Potentially some high-resistance vessels within septae.
4.3 Pathologic Findings
Fig. 4.11 Cervical masses –
haemangioma. ( a ) Gray scale
image shows nonspecifi c
echogenic, well-demarked mass
below an area with only minor
skin discoloration, as the
tumour is mainly positioned
subcutaneously. ( b ) CDS shows
hypervascularisation – consistent
with a haemangioma
149
a
b
ab
Fig. 4.12 Cervical cystic lymphatic malformation. ( a ) Gray scale image of a cystic “lymphangi-
oma” (lymphatic vascular malformation) with central complex cyst that exhibits echoes with fl uid
levels and sedimentation after haemorrhage. ( b ) aCDS demonstrates vascularised septae without
any fl ow in cystic parts
NOTE : Often mixed tumours (containing haemangiomatous and lymphangioma-
tous as well as other mesenchymal tissue) can be encountered; defi nite differentiation only by histology. Look similar everywhere in the body.
Other Mesenchymal Tumours
Various tumours: lipoma, fi broma, fi brolipoma and sarcomatous variants
US Findings
• No specifi c US features.
• Aggressive fi bromatosis more invasive, infi ltration with destruction of borders
and may exhibit inhomogenous echogenicity.
NOTE : Same appearance as everywhere else.
150
4 Ultrasound of the Neck
Neuroblastoma, (Ganglio-)Neuroma, Neurofibroma and Other Nerve (Sheath) Tumours
See respective chapters, defi nitive diagnosis of entity often requires histology.
NOTE : Neuroblastoma tends to invade spinal canal, particularly in the neck, and
may have calcifi cations.
Teratoma
US Findings
• US appearance varies with its components. May be purely cystic or may have
fatty or calcifi ed compartments, with more or less large solid components.
• Same appearance as everywhere else.
• Details discussed with genital tumours (see Chap. 10 ).
Other Malignant Tumours
Commonly rhabdomyosarcoma, but also liposarcoma, metastases and lymphoma.
US Findings
• Usually tumour depictable.
• Sometimes origin and affected space can be defi ned.
Diagnosis usually by histology.
NOTE : Imaging appearance varies – specifi c diagnosis of underlying entity often
impossible.
Role of US
Shows lesion, defi nes relation to surrounding structures, potentially guides biopsy
and serves for follow-up.
4.3.2.3 Abscess Formations
All infl ammatory changes may also manifest in neck, resembling fi ndings in other
body compartments (cellulitis/phlegmon, abscess).
US Findings
Originates from phlegmonous soft tissue (increased echogenicity of swollen tissue
with more or less fl uid collections, particularly along septae, hypervascularisation –
may also be seen around abscess) or other infl ammatory conditions.
Abscess formation – central complex fl uid with fl oating echoes and dorsal
through transmission, surrounding membrane-like abscess wall with perifocal
infl ammatory changes (Fig. 4.13 ).
CDS
• Hypervascular wall (no vessels in central necrotic part).
• Potentially secondary vascular involvement – particularly of jugular vein –
always includes assessment of ipsilateral, particularly venous, structures.
NOTE : US insuffi cient for deeply located abscesses, cannot exactly defi ne anatomy
and extension (e.g. mediastinal or skull-base extension) – additional cross- sectional
imaging advisable especially preoperatively. Differentiation of primary abscess
from infected pre-existing cystic formation (cervical cyst, lymphatic malformation)
sometimes impossible/diffi cult.
4.3 Pathologic Findings
151
a
b
c
Fig 4.13 Cervical abscess. ( a ) Gray scale image of a complex cystic mass with fl uid levels and
debris (+ +) – together with the clinical fi ndings consistent with an abscess. ( b ) CDS: vascularised
capsule, no central vessels and compression of adjacent vein in a superfi cial lymph node abscess.
( c ) CDS, axial section: abscess (+ +) of the deeper parapharyngeal space
All abscesses, e.g. from lymph nodes, tonsils and other soft tissues, exhibit no
other imaging criteria than mentioned above and have same appearance everywhere
else in the body.
4.3.2.4 Traumatic Changes
Haematoma (Including Sternocleidomastoid Muscle “Haematoma”)
US Findings
• Initially echogenic, later hypoechoic, potentially inhomogenous.
• May eventually develop into cyst-like appearance (seroma).
• Typically seen in muscles as well as subcutaneously, rarely in larynx.
• May be diffi cult to differentiate perifocal (reactive) changes/swelling from
haematoma.
NOTE : The typical sternocleidomastoid muscle “ haematoma ” in newborns with resul-
tant torticollis – usually after birth trauma, also called/consistent with benign fi broma-
tosis colli of unclear origin resulting from contracture of muscle – can be identifi ed as
fusiform sternocleidomastoid muscle enlargement in continuity within fascial and
muscle borders. Echogenicity may vary depending on age and insonation angle (from
152
4 Ultrasound of the Neck
a b
c
Fig. 4.14 US images of a fi bromatosis colli. ( a ) Oblique section, preserved muscle structure and
septae (+ +). ( b ) Large tumour-like appearance – the entire length only depictable by extended
view US (+ +) may sometimes be huge and frightening; however, other imaging has no higher
specifi city, biopsy not indicated. ( c ) Typical confi guration aligning along the fascia of the sterno-
cleidomastoid muscle
hypoechoic to slightly hyperechoic) (Fig. 4.14 ). Sometimes typical muscular septae
preserved. Small calcifi cations occur hypervascularisation may be present on CDS.
NOTE : Does not need (additional) imaging; do not mistake for rhabdomyoma,
aggressive fi bromatosis and other (malignant) tumours.
4.3.3 Thyroid Gland
4.3.3.1 Cystic Changes
Cysts may be normal and may be congenital, posttraumatic or regressive cysts – the
latter after/in thyroid disease. Many focal, partially cystic lesions exist – for a DDx
list, see Table 4.1 .
US Findings
• Anechoic spaces with thin membrane and sharp borders.
• If proteinaceous component, secondary haemorrhage or infection – fl oating
echoes.
• Can be differentiated from nodular solid lesions by typical dorsal through trans-
mission and no vessels on aCDS.
4.3.3.2 Malformations
Typical query in newborn: is there (ectopic) thyroid tissue?
• Gland may be hypoplastic or hypertrophic, asymmetric, etc. – numerous form
and shape variations. (Fig. 4.15 ).
• Size does not necessarily correspond with function.
4.3 Pathologic Findings
153
a
c
Fig. 4.15 Thyroid shape and position variations. ( a ) Thyroid agenesis – no thyroid tissue depict-
able. ( b ) Ectopic thyroid situated at base of tongue (+ +). ( c ) Only one single, but hypertrophic
thyroid lobe – the left lobe is absent
b
4.3.3.3 Inflammation
Either focal or diffuse. Typically thyroid gland enlarged with slightly altered
echotexture; echogenicity can be increased, sometimes (also focally) decreased –
inhomogenous appearance possible.
US Findings (Fig. 4.16 )
• Subacute thyroiditis: typically anechoic patchy changes.
• Lymphocytic thyroiditis (Hashimoto): more globally patchy anechoic disruption
of echotexture.
• Morbus Basedow/Graves’ disease (hyperthyroidism)/immune processes, pronounced
swelling of isthmus, diffusely swollen and more or less homogeneous gland:
– CDS: signifi cant hypervascularisation (“thyroid inferno”).
• Sclerosing thyroiditis: gland eventually gets smaller, rather inhomogenously
hypoechoic, sharp contours with regional bumpy alterations of surface.
CDS
Hypervascularisation – unspecifi c, in late phases (atrophy) reduced vascularity.
– Corresponds more with function/treatment than underlying entity.
4.3.3.4 Other Conditions
Hypothyroidism/Struma Diffusa/Colloides (Fig. 4.17 )
Slightly enlarged gland with patchy structure, potentially increased echogenicity.
The neonatal goiter with maternal hypothyroidism usually is slightly enlarged and
with only slight hypervascularity; huge goiters and hypervascularity hint towards
(genegtic) thyroid hormon synthesis defects.