Imaging and pathology of larynx (2)

IMAGING AND PATHOLOGY OF
LARYNX
DR.D.Sunil Kumar

• Imaging of the larynx can be an extremely difficult
endeavor. The anatomy is complex. The target moves
with every breath and every swallow. In certain
situations, however, imaging addresses questions that
the clinician has difficulty in answering and can make a
considerable difference in treatment planning.
• The mucosa can be examined thoroughly. To be
relevant, imaging must provide information that
cannot be obtained by direct visualization. Thus, the
usual intent of the radiologist is to evaluate the deeper
tissues.
• In some cases, a bulky lesion of the upper larynx may
block the view of the lower larynx, and imaging may
assist in defining caudal extent of disease.

Anatomy
• The larynx extends from the tip of epiglottis to the
inferior margin of the cricoid cartilage.
• Laryngeal Cartilages
– The laryngeal skeleton provides the framework by which
the supporting soft tissues function. The laryngeal skeleton
consists of three singular cartilages the thyroid, epiglottic,
and cricoid cartilages and three paired small cartilages: the
arytenoid, cuneiform, and corniculate cartilages.
– Understanding of the normal cross-sectional CT anatomy
of the larynx is aided by familiarity with these
cartilagenous structures at different anatomic levels.

• Thyroid Cartilage.
– The thyroid cartilage is a
shield-shaped structure
consisting of paired Iaminae
fused in the midline, forming
a more acute angle in males
than in females.
– In addition, the thyroid
cartilage has two superior
projections (cornu), which
extend toward the hyoid,
and two similar projections
interiorly, which articulate
with the cricoid.
– The broad thyroid cartilage
provides some protection
from trauma for the intrinsic
soft tissues of the larynx.

• The cricoid cartilage is
the foundation of the
larynx and is the only
complete ring.
• The posterior part is
larger than the anterior,
giving the cartilage the
appearance of a signet
ring facing posteriorly.
• The lower margin of the
cricoid cartilage
represents the lower
margin of the larynx.

• Epiglottis.
– This cartilaginous structure
is situated behind the body
of the hyoid.
– Its widest part is cephalad;
it then tapers to a point at
its inferior tip where it
attaches to the thyroid
laminae by the
thyroepiglottic ligament.
– At its cephalad, free
margin the epiglottis is
attached to the lateral
pharyngeal wall by the two
lateral glossoepiglottic
folds and in its midline
anchored by the medial
glossoepiglottic fold
extending toward the base
of the tongue

Normal anatomy of larynx
on axial contrast CT
images -
supraglottis. Axial contrast
CT image shows the tip of
the epiglottis in
the midline (thin arrow)
Paired valleculae
(curved arrows) on
either sides of
hyoepiglottic ligament
(elbow arrow). Epiglottis
is seen in the midline
(thin arrow)

• Arytenoids.
– The paired pyramidal structures lie
on top of the cricoid cartilage .
– Anteriorly projecting vocal processes
extend from the base of the
arytenoids to the origin of the true
vocal cord.
– Laterally projecting muscular
processes project toward the thyroid
lamina.
– During phonation, the arytenoid
cartilages slide medially allowing the
true vocal cords to oppose each
other.

• The vertical height of the arytenoid spans the
laryngeal ventricle. Because of this and its
characteristic shape and position, the
arytenoid cartilage can help localize the
ventricle on axial scanning.

• The imaging appearance of these cartilages depends
on whether or not they are ossified.
• The epiglottis and the vocal process of arytenoids are
fibrocartilages that do not ossify.
• Nonossified cartilages have soft tissue attenuation on
CT and intermediate signal intensity on T1-weighted
(T1W) and T2-weighted (T2W) images.
• The thyroid, cricoid and arytenoid are hyaline cartilages
that show progressive ossification with age.
• On CT, the ossified cartilages have hyperattenuating
inner and outer margins with low attenuation of the
medullary cavity.
• On MRI, the ossified cortical margins are of low signal
and the fat-filled medullary cavity is of high signal on
T1W and T2W images.

Laryngeal Soft Tissues
• The soft-tissue structures can be separated into the
major functional intrinsic structures of the larynx and
the surrounding deep laryngeal spaces.
• The intrinsic structures consist of the epiglottis, true
vocal cords, false vocal cords, and the aryepiglottic
folds.
• The deep laryngeal spaces consist of those areas that
cannot be evaluated by clinical examination or even
laryngography because they lie beneath the mucosal
surface. These spaces consist of the preepiglottic space
and the paralaryngeal spaces as well as the space deep
to the cricothyroid membrane.

• The inner mucosal surface of the
larynx, or endolarynx, is the
working part of the organ.
• Two prominent parallel folds
stretch from front to back along
the lateral aspect of each side of
the airway
• These are the true and false vocal
cords or folds, and they are in the
horizontal plane.
• The true cord (the glottis) is the
key functional component in the
generation of voice and has a fine
edge at the medial margin. The
thyroarytenoid muscle makes up
the bulk of the true cord.
• The more superiorly placed false
vocal fold has a more blunted
medial edge.

• Laryngeal Ventricular
Complex (LVC)
• This is the key
component in organizing
the larynx into the
supraglottis, glottis and
subglottis.
• It comprises the false
cords, true cords and
intervening laryngeal
ventricle.
• The LVC is best identified
on coronal images; the
ventricle itself is seen as
a small air-filled
outpouching between
the false and true cords.

• The three parallel structures-the true cord, the false cord,
and the ventricle organize the larynx 'into three regions:
the supraglottis, the glottis, and the subglottis.
• The true cord is the glottis. The glottic region of the larynx
extends from the upper surface of the true cord to a line
somewhat arbitrarily chosen as being 1 cm below the level
of the ventricle.
• The subglottic region is between this arbitrary line and the
inferior edge of the cricoid cartilage, the lower margin of
the larynx.
• There is no defined mucosal structure representing the
exact boundary or separation of the glottic and subglottic
regions.
• The supraglottic region is the part of the larynx that is
above the ventricle. This region includes the false cords, the
epiglottis, and the AE folds.

• Above the false cord the mucosa sweeps
upward and outward to the aryepiglottic (AE)
folds, which are mucosal folds extending
from epiglottis to arytenoid cartilage.
• Inferiorly, the mucosa covering of the true
cord sweeps outward into the subglottic
area, eventually merging smoothly with the
mucosa of the trachea.

Anterior and Posterior Commissure
• The anterior commissure is the
midline anterior meeting point of the
true vocal cords.
• It comprises of the anterior cord, the
anterior junction of the two vocal
cords, the thyroid cartilage and the
Broyle’s ligament, a fibrous structure
connecting the vocal ligaments to the
cartilage. There is no perichondrium
at that point, so the fibers extend
directly from the vocal ligament into
the cartilage.
• The posterior commissure is the
mucosal surface on the anterior
surface of the cricoid cartilage
between the arytenoid cartilages.
• Both the commissures are seen very
well on the axial images
The thyroarytenoid muscle forms the
bulk of the true vocal cords (block
arrows) at this level. Note the
anterior commissure (elbow arrow)
and
the posterior commissure (curved
arrow)

The Paraglottic Space (PLS)
• The PGS is located deep to the mucosal
surfaces of the true and false cords and
bound laterally by the thyroid and
cricoid cartilages and is best seen on
axial CT and MR sections through the
supraglottis, where it is entirely
composed of fat.
• At the level of the supraglottic larynx,
the paraglottic space is filled mostly with
fat. Below the ventricle, the
thyroarytenoid muscle fills the
paraglottic region.
• It extends caudally upto the
undersurface of the true vocal cords.
The entire extent is clearly
demonstrated on coronal images .
• The PGS is continuous with the
extralaryngeal soft tissues between the
thyroid and cricoid cartilages
antero-laterally; an important pathway
for extralaryngeal tumor spread.

Pre-Epiglottic Space (PES)
• The pre-epiglottic space (PES) is a
fat-filled space, rich in
lymphatics.
• It is bound superiorly by the
hyoepiglottic ligament, anteriorly
by the thyrohyoid membrane,
inferiorly by the thyroepiglottic
ligament and posteriorly by the
epiglottis.
• The PES and PGS communicate
with each other superiorly.
Sagittal images are best suited to
delineate the entire extent of the
PES

MR imaging, larynx. Preepiglottic space (P) is hyperintense secondary to fat.

Imaging Considerations
• CT
– CT has the advantage of fast imaging speed.
– The scan is faster and thus allows the entire larynx to be
covered in a single breathhold.
– The thinner-slice thickness allows multiplanar reformatted
images comparable in quality to direct imaging.
– Motion artifact is a significant problem in imaging of the
larynx. CT scanning tries to avoid the problem by its use of
fast imaging. The spiral acquisition may cover the larynx in
10 to 20 seconds. The examination can be performed
during slow, shallow respiration, or the scan can be done
with the breath held.

• The patient is in the supine position, and he is
instructed to resist swallowing or coughing.
• Axial slices are obtained from the base of the
skull to the trachea with a scan orientation
parallel to the true vocal cords.
• Iodinated contrast material (total dose, 35–40 g
iodine) is given intravenously.
• Images are obtained during quiet breathing
rather than during apnea because the abducted
position of the true vocal cords facilitates
evaluation of the anterior and posterior
commissures

• At present, magnetic resonance imaging (MRI) is
better at differentiating various soft tissues
compared with CT. MRI may allow better analysis
of potential cartilage invasion or improved
definition of the tumor muscle interface.
• An additional examination for better assessment
of the tumor in laryngeal ventricle, anterior
commisure and aryepiglottic folds may be done
with e-phonation

• MRI
– A high field MRI scanner using a dedicated neck coil is
preferred.
– A combination of multiplanar noncontrast T1-weighted,
T2-weighted and T2-weighted fat saturation images with
postcontrast T1 fat-suppressed images are routinely used.
– The entire examination takes about 30 minutes, and the
patient is asked to refrain from coughing and swallowing
during the acquisition.
– The choice of imaging modality is subject to the availability
of the CT or MR scanner and the expertise in
interpretation of the scans, as also the ability of the
patient to tolerate an MR examination.
– In most institutions, CT is the preferred imaging method
for evaluating laryngeal SCC and MRI is used as a
complementary problem-solving tool when CT does not
provide all the information prior to therapy.

Carcinoma Larynx
• Cancers of the larynx constitute about 25% of
all head and neck malignancies.
• They commonly present in adults between 50
and 70 years and show a strong male
predominance
• Tobacco smoking and alcohol consumption are
important risk factors for laryngeal SCC.

• Clinical examination followed by endoscopy is
always the first step in T staging of laryngeal SCC.
• CT and MRI are performed to define the
submucosal extent and deeper margins of the
tumor.
• Small and superficial mucosal tumors may not be
appreciated at CT or MRI and hence, it is
mandatory that an endoscopy is done prior to
any imaging study.
• Integration of cross-sectional imaging with
endoscopy findings significantly improves the
accuracy of T staging.

Tumor Origin and Characteristic Patterns of
Spread (T staging)
• Supraglottic SCC
– Approximately 30% of all laryngeal cancers arise in the
supraglottis.
– They often present in advanced stages, because
symptoms (hoarseness, due to vocal cord
involvement) do not occur until late.
– Due to the rich lymphatic network of the supraglottis,
nodal disease (levelII and III) is a frequent finding in
these patients.
– Supraglottic SCC may arise in the anterior
compartment (epiglottis) or the postero-lateral
compartment (aryepiglottic fold and false cords).

Supraglottic SCC – epiglottis. Axial contrast CT
image shows a lobulated enhancing epiglottic
mass filling the preepiglottic space (black
asterisk)
Supraglottic SCC – epiglottis. Axial
contrast CT image in another
patient shows the epiglottic mass
(arrowheads) filling the right
vallecula (white asterisk). Enlarged
necrotic deep cervical node level
II on the right side (elbow arrow)

Supraglottic SCC – aryepiglottic fold. A right
aryepiglottic fold mass (thin white arrows) is seen
invading into preepiglottic (white
asterisk) and right paraglottic space (black
asterisk) and narrowing the right piriform sinus
(curved white arrow). Note sclerosis of thyroid
lamina (thin black arrow) with extralaryngeal
tumor (white curved elbow arrows)

• Glottic SCCs represent about 65% of all laryngeal
cancers.
• Hoarseness of voice due to vocal cord involvement is
the primary presenting symptom in these patients.
• Metastatic nodal disease is rare in glottic carcinomas
due to the sparse lymphatic drainage of the glottis.
• Glottic SCCs commonly arise from the anterior half of
the vocal cord and spread into the anterior
commissure.
• Anterior commissural disease is seen on CT or MRI as
soft tissue thickening of more than 1-2 mm. The
accuracy of CT in predicting anterior commissure
involvement is about 75%.

Glottic SCC. Axial contrast CT image shows a
glottis mass in the left true cord reaching the
anterior commissure (black asterisk).
Mild thickening of posterior commissure is
noted (thick black arrow) with sclerosis of left
arytenoid and left lamina of thyroid cartilage
Advanced glottic SCC. Axial
contrast CT image at a
caudal level shows the mass (thin
white arrows) with disease in the
posterior commissure (curved
black arrow) and cricoid erosion
(thick black arrow)

• While vocal cord mobility is best assessed at endoscopy, disease in
the cricoarytenoid joint and interarytenoid region have been
described as imaging correlates for vocal cord fixation
Advanced glottic SCC. Axial contrast CT image
shows aleft vocal cord mass (thin white
arrows) reaching anterior commissure
(asterisk). Note the sclerosis of left thyroid
lamina and left cricoarytenoid
joint (thin black arrows)

• Subglottic SCC
• These cancers are rare, accounting for only 5%
of all laryngeal cancers, clinically silent and
present late in the course of the disease and
have a poor prognosis with a 5-year survival
rate of 40%.
• Lymph node metastases are common and
affect the pre and paratracheal nodes. Hence,
the neck CT should be extended to include the
superior mediastinum in patients with primary
subglottic cancer.

Advanced subglottic SCC. Axial CT image
through the subglottis in another patient
shows a circumferential subglottic mass
with destruction of the cricoid and the thyroid
cartilages (curved black elbow arrows) and
extralaryngeal spread of tumor (thin white
arrows)

• Transglottic SCC
• Laryngeal SCC encroaching on both, the glottis
and supraglottis, with or without subglottic
component and when the site of origin is
unclear, is termed as transglottic tumor.

Large transglottic SCC. Coronal CT shows the
entire
extent of transglottic mass spreading along
the right paraglottic space
(thin arrows).

Cartilage invasion
• MRI has a high sensitivity (89%-95%) but lower
specificity (74%-84%) as compared to CT for the
detection of cartilage invasion.
• Nonossified cartilages(epiglottis) have soft tissue
attenuation on CT and intermediate signal
intensity on T1-weighted (T1W) and T2-weighted
(T2W) images.
• On MRI, the ossified cortical margins(thyroid,
cricoid, arytenoid) are of low signal and the
fat-filled medullary cavity is of high signal on T1W
and T2W images.

• Presence of tumor
invasion can be readily
identified on the
T1-weighted images if
the cartilage is ossified .
• Tumor is seen as
abnormal soft tissue
intensity within the
bright signal of the
medullary fat of the
cartilage.
Cartilage invasion on MRI. T1 axial image
shows a large
mass destroying left thyroid lamina with
extralaryngeal spread encasing
left carotid artery (curved arrow). See the
normal ossified right thyroid
lamina (thick arrow

• High intracartilaginous
signal on fat-suppressed
T2 weighted and
cartilaginous
enhancement on
postcontrast
fat-suppressedT1-weigh
ted sequences have
been the accepted
criteria for positive
identification of
neoplastic cartilaginous
invasion.
Cartilage invasion on MRI. T2 axial image
shows the large
mass with cartilage destruction. The
intracartilage signal is similar to
the adjacent mass

• However, peritumoral inflammation may mimic
neoplastic invasion if these criteria are used, especially
in the thyroid cartilage, thereby leading to false
positive assessments.
• Recently, Becker, et al, reported that in assessing
neoplastic infiltration of laryngeal cartilage at MR
imaging, the T2-weighted and gadolinium-enhanced
T1-weighted signal intensity should be compared with
the signal intensity of the adjacent tumor on the
corresponding sequences.
• If the cartilage displays higher signal intensity than
tumor, a diagnosis of peritumoral inflammation within
the cartilage is suggested; if, however, the cartilage
displays a similar signal intensity to tumor, neoplastic
cartilage invasion is suggested

T1-weighted MR image obtained at supraglottic level shows left-sided laryngeal tumor (T) with
intermediate to low signal intensity. Adjacent anterior right and left thyroid lamina also
show an area of intermediate to low signal intensity (arrows). (b) T2-weighted fast spin-
echoMRimage obtained at same level as a shows that the tumor (T) has intermediately high
signal intensity, whereas adjacent thyroid cartilage (arrows) has similar signal intensity.

T1-weightedMRimage obtained after intravenous
administration of contrast material shows enhancement of
the tumor mass (T) and similar enhancement of the
adjacent thyroid lamina (arrows). This suggests—
according to the old and the newMRimaging criteria—that
the thyroid cartilage is invaded by tumor anteriorly.
Corresponding axial slice from surgical
specimen at
same level confirms that anterior thyroid
cartilage is invaded by tumor (long arrows).

(a) T1-weighted spin-echoMRimage obtained at glottic level shows left-sided piriform
sinus tumor (T) with intermediate to low signal intensity. Adjacent left thyroid lamina
(arrow) shows similar intermediate to low signal intensity. (b) T2-weighted fast spin-
echoMRimage obtained at same level as a shows that the tumor (T) has moderately
high signal intensity, while the adjacent thyroid lamina (arrow) has much higher signal
intensity than the soft-tissue component of the tumor itself.

(c) T1-weighted spin-echoMRimage obtained after intravenous administration of contrast material shows
enhancement of the tumor mass (T) and stronger enhancement of the thyroid lamina (arrow) relative to
the adjacent tumor mass. According to the old diagnosticMRimaging criteria,
neoplastic invasion of the thyroid cartilage should be suspected . According to the new criteria, the most
likely diagnosis is inflammation of the thyroid cartilage without neoplastic invasion because the signal
intensity on b is higher than that of the adjacent tumor and the enhancement of the thyroid cartilage is
stronger than the tumor enhancement.
Corresponding axial slice from surgical specimen at same
level shows
that the left thyroid lamina is not invaded by tumor
(arrow). The tumor (T) arises from the lateral wall of the
left piriform sinus. Black dotslateral tumor borders

• The CT criteria for reporting cartilage invasion
include sclerosis, erosion, lysis and the
presence of extralaryngeal tumor.

Post-Treatment Evaluation
• Surveillance is especially crucial in the first 2-3 years because
two-thirds of local recurrence and nodal metastases occur in this
period.
• PET-CT has superior diagnostic accuracy in detecting tumor
recurrence.
• A baseline pretreatment FDG PET CT has been recommended to
use for comparison at subsequent post-treatment follow-up in
patients with laryngeal SCC.
• A decreased FDG activity in the early phase of combined
chemoradiation is associated with greater tumor response, survival
and local control.
• A pretreatment SUV(standardised uptake value) less than 9 in the
primary tumor has been found to be predictive of a lower rate of
local recurrence and improved disease free survival compared with
a primary tumor SUV of 9 or more

• While endoscopy remains the preferred
method to diagnose mucosal recurrences,
imaging contributes to the detection of deep
recurrence.
• Recurrence following surgery is generally
reported on CT, when focal areas of nodularity
or soft tissue are noted in the surgical bed.
• Radiation for laryngeal SCC is followed by
significant edema, thickening and abnormal
enhancement in the laryngeal tissues.

Laryngeal cyst
•Laryngeal cysts originate from the minor salivary glands
within the mucosa of the larynx.
•They occur in any part of larynx, but are more frequent
on supraglottic locations, such as epiglottis and vallecula.
•On CT, cysts demonstrate a low attenuation values (0-20
HU) and they show no enhancement after injection of
contrast material.
•On MR, the cysts display a high signal intensity on
T2weighted images and variable signal intensities on TI-
weighted images owing to the variable protein content.

LARYNGOCELE
• It refers to a dilatation of the laryngeal
ventricular saccule.
• Laryngocoeles are usually acquired rather
than congenital.
• Laryngoceles may contain air or fluid. In the
latter case they are also referred to as saccular
cyst or laryngeal mucocele.

• Risk factors
• Raised intralaryngeal pressure secondary
to excessive cough
• playing woodwind/brass instruments
• Lesion Obstructing the laryngeal
saccule(laryngeal appendix) where it opens
into the laryngeal ventricle., e.g. tumour
– The finding of a laryngocoele should prompt a
search for an underlying laryngeal carcinoma
obstructing the orifice of the laryngeal ventricle

• Classification
• Three laryngocoele subtypes are described
– internal: the dilated ventricular saccule is confined
to the paralaryngeal space (~40%)
– external: the saccule herniates through the
thyrohyoid membrane, and the superficial portion
is dilated (~25%)
– mixed: with dilated internal and external
components (~45%)

• CT
• Typically seen as a well defined, air or fluid density lesion
related to the paraglottic space, which has continuity with
the laryngeal ventricle.

Infection of laryngomucocele may occur which results in laryngopyocele formation.
On CT it appears as Fluid density lesion with thick enhancing walls

ACUTE
LARYNGOTRACHEOBRONCHITIS(Croup)
• It is due to viral infection of the upper airway
by parainfluenza virus or respiratory syncytial
virus (RSV).
• It is commonly seen between 6 months to 3
years with peak at 18 months.
• It is the most common cause of upper
respiratory distress in infants and young
children.

Radiographic features
• Plain film
• The typical radiographic
findings:
– steeple sign: seen on AP
radiographs of the neck
or chest and neck
demonstrates uniform
narrowing of the
subglottic airway due to
mucosal edema; also
referred to as a wine
bottle sign

• A corresponding
lateral x-ray would
show narrowing of
the subglottic trachea
and ballooning of the
hypopharynx, due to
the patient's attempt
at decreasing airway
resistance.
• Epiglottis appears
normal which helps in
differentiating
epiglottitis.

Epiglottitis
• Epiglottitis is a medical emergency caused by
inflammation of the epiglottis and aryepiglottic folds.
• It is a life threatening condition which can lead to acute
airway obstruction.
• The commonest age of presentation is in children of 3
to 6 years. It is exceedingly rare in the adult population.
• Epiglottitis is almost always caused by infection
Haemophilus influenzae type B (HIB). However, with
the increasing availability of the HIB vaccine, the
incidence of epiglottitis has changed.

Radiographic features
• Plain Film
• Lateral radiograph
demonstrates
thickening and
enlargement of
epiglottis and
aryepiglottic folds due
to edema which is
called thumb sign .
• Hypopharynx may be
over-distended.

• CT
• CT is only rarely obtained, and usually when the diagnosis is
unclear. Indeed, placing the child in the supine position can
actually precipitate respiratory arrest. If a scan is obtained,
marked oedema and thickening of epiglottis and
aryepiglottic folds may be seen with narrowing of the
airway.
• The entire supraglottic larynx, tongue base, and tonsils
often are edematous, and a phlegmonous collection may
be seen within the adjacent soft tissues.
• CT may be used to assess the extent of disease and
possible complications such as necrotizing epiglottitis and
epiglottic or deep neck abscess.

Acute epiglottitis caused by a gas-forming organism. Axial (a) and sagittal (b)
contrast-enhanced CT images show the epiglottis, which is enlarged and contains
multiple foci of air (arrow in b).

VOCAL CORD PALSY
• Vocal cord paralysis (VCP) can be caused by any
process that interferes with the normal function
of the vagal nerves or recurrent laryngeal nerve.
• It is important to recognise the imaging findings
of VCP and know the course of the vagal and
recurrent laryngeal nerves, imaging evaluation of
these nerves and thereby the possible sites for
pathology, the imaging characteristics and
imaging mimics of VCP.

• The vocal cords play a crucial role in phonation. The
muscles that are responsible for vocal cord movement
are mainly innervated by the recurrent laryngeal
nerves. The recurrent laryngeal nerves are branches of
the vagal nerves.
• Vocal cord paralysis (VCP) can therefore be caused by
any lesion along the course of the vagal nerves above
the branching of the recurrent laryngeal nerves or of
the recurrent laryngeal nerves itself.
• An offending lesion located in the brainstem or the
skull base usually results in multiple cranial nerve
deficits because at this level the vagal nerve is
intimately related to other cranial nerves.
• Pathology involving the recurrent laryngeal nerves
and/or the extracranial vagal nerves frequently results
in isolated laryngeal symptoms. VCP most frequently
affects one side but can be bilateral.

• Iatrogenic injury by mediastinal and neck
surgery is the most important cause of VCP.
• Bilateral VCP was more often caused by
thyroid surgery, while unilateral VCP was more
often caused by other surgery, like carotid
endarterectomy, anterior approaches to the
cervical spine, and heart or great vessel
surgery.
• Idiopathic and malignancy are second and
third common causes of VCP.

• The movement of the vocal cords is controlled
by the intrinsic laryngeal muscles. All intrinsic
laryngeal muscles except the cricothyroid
muscle are innervated by the recurrent
laryngeal nerves, which are branches of the
vagal nerves.
• The cricothyroid is supplied by superior
laryngeal nerve, the paralysis of which is rare.

Imaging strategy
• Brainstem and skull base.
• Bilateral VCP is indicative of a central cause in the
medulla oblongata. Acute onset of symptoms also
points toward a central cause.
• The area of the medullary nuclei of the vagal
nerve can best be evaluated with magnetic
resonance imaging(MRI).
• If multiple cranial nerves are involved, the jugular
foramen should be scrutinised.

• Extracranial vagal
nerves and recurrent
laryngeal nerves
• To depict pathology
in the course of the
extracranial vagal
nerves and the
recurrent laryngeal
nerves, a contrast-
enhanced computed
tomography (CT)
from the midbrain to
the aortic arch
including the AP
window is preferred.

• The CT should be acquired during quiet
breathing, in order to bring the vocal cords to
an abducted position.
• Axial reconstructions should always be
obtained parallel to the true vocal cords for
optimal diagnostic accuracy.

• During quiet respiration the cords are in a relaxed, abducted state.
• Breath-holding brings the cords together in an adducted midline
position.

Imaging characteristics of VCP
• The most specific findings of unilateral VCP are
– (1) widening of the laryngeal ventricle(passive
result of atrophy of the ipsilateral cord).

–(2) medial deviation and thickening of the
aryepiglottic fold
–(3) dilatation of the piriform sinus.
• The changes in the aryepiglottic fold and the
piriform sinus are a result of paralysis of the
posterior cricoarytenoid muscle. This muscle is
the only muscle that abducts the vocal cords.
Atrophy of this muscle and the inability to
abduct the cord results in anteromedial
rotation of the arytenoid, medial deviation of
the aryepiglottic fold, and (passive) dilatation of
the piriform sinus.

Bilateral VCP. a Axial CT reformat
showing bilateral medial
deviation and thickening of the
aryepiglottic fold (arrows) and bilateral
dilatation of the piriform sinuses (*). b
Coronal CT reformat showing
bilateral widening of the laryngeal
ventricles (arrows)

• In addition to these
imaging findings,
several other less
specific supportive
signs have been
described in the
literature.
• On coronal
reformats, the
atrophied cord can
have a pointed
appearance due to
reduced bulk.

• On axial images, the
subglottic area on the
affected side can
appear full due to
sagging of the
paralysed cord.
• Also the paralysed cord
often has a
paramedian position
due to the inability to
abduct

Mimics of VCP
• To avoid misdiagnosis, first of
all, the axial CT reformats
have to be angulated parallel
to the true vocal cords with
both crycoarytenoid joints
within the same plane.
• Tilted axial reformats may
lead to subglottic air
projecting anterior to the
angulated normal vocal cord.
This imaging appearance may
mimic a widened laryngeal
ventricle and thereby VCP.

• Second, malignant
infiltration or fibrosis
of the vocal cord can
result in
immobilisation or
thickening, mimicking
a paramedian
position of the cord.
• Laryngoscopy helps
in differentiating
focal lesions of the
vocal cord from VCP.
Small squamous cell carcinoma of the left
vocal cord (*) mimicking the
paramedian position seen in VCP

• Third, traumatic injury to the arytenoid
cartilage with medial dislocation may mimic
VCP.
• This dislocation can be either the result of
direct blunt trauma to the larynx or
intubation. Especially after intubation the
differentiation between traumatic dislocation
and paralysis can be difficult since intubation
can cause both.
• In addition, intubation can result in fibrosis of
the vocal cord, which can also mimic VCP.

CT scan obtained following traumatic
intubation shows arytenoid cartilage
dislocation mimicking right VCP. The right
arytenoid cartilage (arrow) lies anterior to the
cricoid cartilage, slightly below the expected
level of the true vocal cords.

• A confusing imaging finding, which the
radiologist should be aware of, can be seen
on 18Ffluorodeoxyglucose positron emission
tomography (FDG-PET) exams of patients
with VCP.
• In such cases, the PET may show increased
metabolism in the unaffected vocal cord due
to compensatory hypertrophy.
• This finding mimics malignancy on the
unaffected side.

FDG-PET findings in VCP. a Non-contrast CT image showing medial deviation and
thickening of the left aryepiglottic fold (*) indicative of left VCP. b Fused PET-CTshowing
FDG uptake in the right vocal cord (arrow) due to compensatory hypertrophy. This
should not be confused with disease. Note the paramedian position of the left true
vocal cord (T)

Hemangioma Larynx
• Laryngeal hemangiomas have been subdivided into
two groups: the infantile type and the adult type.
• Infantile Hemangioma is the most common benign
tumor of the head and neck in infants, constituting
about 1.6% of all congenital laryngeal anomalies.
• Although present at birth, hemangiomas of the airway
usually become symptomatic between 1 and 6 months
of age, when their rapid growth causes increasing
obstruction of the airway
• Clinically, hemangiomas present with sudden onset of
acute respiratory difficulty that varies in severity.

• The location of the hemangioma along the
airway is variable. Hemangiomas can be
present in the supraglottic area, subglottic
region, trachea, and in the mainstem
bronchus.
• In each of these locations, the hemangioma
has the potential complication of causing
significant, sometimes life-threatening airway
obstruction.

• At CT, hemangiomas enhance strongly after
administration of contrast material, and
phleboliths are pathognomonic for the
cavernous type.
• At MR imaging, hemangiomas have very high
signal intensity on T2-weighted images and
enhance strongly after administration of
gadolinium chelates, which allows a correct
diagnosis in most cases.

Unenhanced axial CT image shows
supraglottic hemangioma (arrow).
B, Contrast-enhanced axial image
(B) show soft-tissue mass in right
aryepiglottic fold (arrows) with
marked enhancement
after contrast administration.

LARYNGEAL TUBERCULOSIS
• Laryngeal tuberculosis is a rare form of extrapulmonary
tuberculosis (TB). It was considered in the preantibiotic
era to be the most common disease of the larynx,
affecting 35--83% of patients with tuberculosis.
• It is usually a complication of pulmonary TB, and most
patients with laryngeal TB have coexisting active
pulmonary TB, sputum-positive rate being 90-95%.
• Currently its incidence is estimated to be less than 1%
of all TB cases.Due to its vague clinical presentation
and because of a lack of clinical suspicion, laryngeal TB
is frequently confused with entities like laryngeal
carcinoma and chronic laryngitis.

• The radiological appearance of laryngeal TB
depends on the stage of the disease.
• In the acute phase, the lesions are of
exudative nature and have a diffuse
distribution within the larynx.
• On CT scan, patients with acute TB laryngitis
show bilateral diffuse thickening of the vocal
cords, epiglottis, and paralaryngeal spaces,
whereas those with chronic TB laryngitis show
focal or asymmetric thickening or a mass.

Axial contrast-enhanced CT scans. At the
supraglottic level (A) there is soft tissue
thickening and enhancement of both
aryepiglottic folds and pyriform sinuses , with
an enlarged left deep cervical group lymph
node (black arrow) the paralaryngeal soft
tissues bilaterally (arrows). At the level of the
glottis (C) there is soft tissue
thickening that extends to the anterior
commissure (arrow)

• The most important differential diagnosis to be
considered in acute and chronic TB larynx is laryngeal
carcinoma – diffuse circumglottic in the former and
localized in the latter.
• Imaging features that favor a diagnosis of TB laryngitis
over laryngeal carcinoma include a bilateral diffuse
pattern of involvement ; thickening of the free edge of
the epiglottis; intact laryngeal architecture (i.e., no
sclerosis or destruction of the cartilages); lack of
subglottic or hypopharyngeal extension; and focal low-
attenuation areas in the lesion, which are probably
indicative of caseation necrosis

• Ultrasound has a relatively good view of the different
structures of the larynx (and even, pharynx), allowing an
excellent assessment of cervical soft tissue remaining.
• A possible exception to this rule involves access to older
men, where the thyroid cartilage morphology and
calcification may impede an easy access of the larynx from
an echographic point of view.
• In these cases, a side or lateral access of the vocal cords
allows a better assessment of them.
• The use of color or power Doppler allows the detection of
vascularization and movement of both focal lesions and
functionality of the vocal cords.
High-resolution ultrasound of the
larynx

• VOCAL NODULES
• Vocal nodules are located
between the anterior and
middle third of the vocal
cords and are usually
bilateral.
• Often occur in individuals
who abuse of the voice
(singers, teachers).
• Valsalva maneuver
(adduction of the vocal
cords) may help for
identifying them

VOCAL CORD POLYP
• It is the most common benign neoplasm and
occurs mainly in men aged 30 to 40 years.
• This is usually unilateral nodular lesions in the
free edge of the vocal cord.
• They usually have a larger size than nodules,
so they are more accessible by ultrasound

Vocal cord polyp. A) CT showing a small exophytic lesion in the middle third of
left vocal cord (arrows). B) B- mode ultrasound correlation demonstrating a
hyperechoic nodular lesion in the same location observed in CT (B).

Vocal cord polyp. A) Axial CT section showing a small exophytic lesion in the
anterior third of left vocal cord (arrow). B) Angle and calcification of the thyroid cartilage
does not allow a proper assessment of the vocal cords. C) A lateral access allows
the identification of a hyperechoic nodular lesion corresponding to the vocal cord polyp
identified in CT scan

Vocal cord palsy
• Ultrasound, particularly if there is good
ultrasound access, allows a dynamic
assessment of the vocal cords movement.
• It is possible to identify an alteration in the
mobility of vocal cords, with quite breathing,
as with the Valsalva maneuver and phonation

Left vocal cord paralysis in a patient with a history of breast cancer. Axial Bmode
ultrasound at the level of vocal cords showing positional asymmetry. Absence of left
vocal cord mobility is demostrated in dynamic evaluation, which is located in paramedian
position (recurrent nerve injury).

Right vocal cord paralysis after thyroidectomy.
A y B) Axial B-mode ultrasound
at the level of vocal cords in time sequence
showing the setting of right vocal cord and
normal mobility of the left. C) In this case,
color Doppler assessment objective absence
of Doppler signal in paralyzed cord.

Laryngoceles
• Ultrasonography laryngoceles are identified as
nodular structures with aerodigestive walls

Right laryngocele. A) CT scan in an elderly patient with a suggestive image of
right external laryngocele with air content (arrow). B) Corresponding ultrasound
image, medial to the great cervical vessels with well defined wall layers (aerodigestive)
(arrow).

MALIGNANT TUMOURS
• On ultrasound laryngeal tumors shows as
hypoechoic lesions with relatively well-defined
edges and presenting hypervascularity at color
Doppler study.

Hypopharyngeal carcinoma. A) Axial contrast-enhanced CT. Lobulated mass
affecting the right pyriform sinus, lateral wall of the hypopharynx with involvement of
soft tissue lateral to the thyroid cartilage (arrow). B) Color Doppler ultrasound showing
hypervascularity and identifying the soft-tissue perilaryngeal involment more clearly than
CT (arrow).

Imaging and pathology of larynx (2)

Imaging and pathology of larynx (2)

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Imaging and pathology of larynx (2)