Mar 1, 1983 - the use of CT in the diagnosis and management of patients with head and neck tumors will be presented. Material and Methods. This report.
Jo
Computed
tomography
Carlos
M.D.*t
R. Martinez,
Bob
z
W.
Gayler,
of the neck
M.D.*
#{149}m
Haskins 0.
Stanley
t. A
vOrth
Kashima,
M.D.
S. Siegelman,
M.D.*
Ae
Computed choice”
tomography for the evaluation
interpretation cross
has
ofsuch
sectional
become ofneck
images,
anatomy
“the masses.
is a detailed
imaging
modality
Here,
of
to facilitate
exposition
the
of the normal
of the neck.
THIS EXHIBIT, A SELECTION OF THE GENERAL RADIOLOGY PANEL, WAS DISPLAYED AT THE 67Th SCIENTIFIC ASSEMBLY AND ANNUAL MEFI’INC OF THE RADIOLOGICAL SOCIETY OF NORTH AMERICA, NOVEMBER 15-20, 1981, CHICAGO, ILLINOIS.
Introduction Computed and uation
airway
tomography, detail,
of patients with communication
neck
This *
From
the
Russell
H.
as depicted the thoracic
Morgan
Department of Radiology and Radiological Science, The Johns Hopkins Medical Institutions, Baltimore, Maryland. t Presently, Radiological Services, Tampa General Hospital, Davis Islands, Tampa, Florida. From the Department of Laryngology and Otology, The Johns Hopkins Medical Institutions, Baltimore, Maryland. Address
reprints
requests
to Carlos
R. Martinez,
M.D., Radiological vices, Tampa General Hospital, Islands, Tampa, Florida 33606.
Volume
3, Number
1
March
SerDavis
1983
with
has rapidly
its unique
become
capacity
the imaging
for displaying
soft
tissue
of choice
in the eval-
sectional
anatomy
of the neck
masses. reviews
by CT using fifteen inlet. The capabilities
the normal
cross
reference levels and limitations
extending from of this technique
and interesting cases that illustrate the use of CT in the diagnosis of patients with head and neck tumors will be presented.
Material This report is derived of head and neck tumors. 500) unit. The examinations
bone,
modality
and
the mastoid tip to will be discussed, and
management
Methods
from the study of 140 patients referred Scans were obtained with a high resolution were carried out in the supine position
for evaluation (AS&E Pfizer with the neck
slightly hyperextended and during quiet breathing. The scanning plane was parallel to the infraorbitomeatal line. In most instances 10 mm sections were obtained at 10 mm intervals using a 10 second exposure, 20 mA, and 120 kVp. In specific instances, such as the evaluation of the larynx and trachea or the examination of an uncooperative patient, a shorter (5 second) scanning time and higher (50) mA setting
RadioGraphics
9
CT
of the
were used. pharyngeal, tumors,
For the laryngeal
5 mm
iodinated
contrast
were
We infusion
found the of a 30%
material
to
infused
be
of neck
approximately infusion rate
at the
rate
if a 19 gauge
of
structures,
an
with
a short
neck.
additional
in order to improve the reducing artifacts. Scans at of the thoracic inlet are frecompromised by beam
larities
This
in the
outline
of the
from
dental
Motion
fillings
artifacts
lowing patient tongue.
by two successive scans the area of interest. We utilized a few technical
“tricks” image by the level quently
This alirregu-
my,
the
of 25 cc of a 60% contrast mawas injected, followed imme-
diately through
H.U.) level. of minor
problem can be partially solved by using a “swimmer’s” position and increasing the tube current. Artifacts
was of
were used. Whenever there need for greater enhancement vascular
et al.
that might be obscured tissue settings were used.
nee-
dle
bolus terial
patient
and a low (-200 lows visualization
the humeral true in an
can be avoided
obtaining open mouth views slight changes in the scanning
20 cc per minute. This was usually achieved
difficulty
hardening artifacts from heads. This is particularly obese
hundred cc were given first scan; an additional
cc were
without
of small
obtained
in the CT evaluation
masses. One prior to the 200
examination or other
sections
at 5 mm intervals. rapid intravenous helpful
Martinez
neck
partially
tip
of
should
be
at different
levels. Soft photographed
window window Bone
viewed
window
the
to
level
of approximately
structures
400
H.U.)
and widths
structures
to
not scans
at each
level.
visualized
on the
ref-
are included
in the
line
because and
of
their
constant
demonstrable
clinical
relationship
anatomical
land-
marks.
a
In general,
40 lowing
are best studied
to simplify
the
fol-
structures
that
are
discussion,
bilaterally symmetrical anatomic relationships scribed in terms of the
with a wide window (1000 or more if an expanded scale is available). The airway should be viewed with a very wide window (1000 H.U. or more)
one side
Upper
Nasopharynx
! Lower
Nasopharynx
..per
Alveolar Cavity
Ridge
Angles
Border
of
1Valleculae Hyoid
Body
only.
Palate
Submandibular
-
-
Carotid
-
Sup.
Glands Horns
of
Hyoid
Bifurcations
Aryepiglottic
-
Cartilages
jVocal
Soft
-
Epiglottis
Notch
Arytenoid
neck
Hypopharynx
-
Thyroid
of the
and their will be destructures of
Uvula
-
Mandibular ;Free
thoracic depicts
drawings have been derived each scan; some anatomical
importance
Oral
to the diagram
of the
drawings
and
of the nasophar-
Line from erence
tissues are best viewed at a relatively wide
(250
level
some
structures
studied
H.U.
extruded
at the
ynx and extending inlet. This reference
by swal-
soft
To represent the normal anato15 scans have been selected, be-
ginning
can be avoided by asking the to bite gently with the lips on
Scans and and
produced
by
or by plane.
airway
if only
-
Folds
Laryngeal
Vestibule
Cords
Subglottis 1Cricoid
Ring
‘Upper
Trachea
First
Ribs
ISTRUCTU
Figure
10
-
Laryngotrachea
-
-
Lower
Thyroid Thyroid
Isthmus Gland
RES
1
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
et al.
CT
LEVEL
1-UPPER
of the
neck
NASOPHARYNX
Figures
2A & 2B
section demonstrates the relationship of the nasopharynx to the prevertebral and pharyngeal muscuIature and to the anterior arch of C 1. It also demonstrates the torus tubarius at the opening of the eustachian tube. The nasopharyngeal air shadow may be asymmetrical because of the asymmetric distribution of lymphoid tissue. The deep soft tissue planes in the parapharyngeal space should be This
symmetrical,
however.
The
close
re-
lationship of the nasopharynx to the carotid sheath clarifies the basis for the from
Figure
complex disease
syndromes in this region.
that
arise
2A
Antrum nt.
Carotid
.
Mandibular Condyle
Facial N.
Mastoid
Jugular
nt. Carotid
Cranial
x, xi, xii nt.
Volume
Torus
Odontoid Post.
Styloid
Figure
V.
A. Eustachjan
ix
Tip
Jugular
Arch
Cranial
Cl
Nerves
V.
2B
3, Number
1
March
1983
RadioGraphics
11
CT
of the
Martinez
neck
LEVEL
Figures
2-LOWER
et al.
NASOPHARYNX
3A & 3B
Here, the infratemporal fossa is well seen. It is limited laterally, by the mandibular ramus and the parotid gland; and anteriorly, by the posterolateral wall of the maxillary antrum. The external carotid artery proximal to the origin of the internal maxillary artery is surrounded by parotid gland tissue at this level. A zone of low attenuation tissue (fat) is normally present between the pharyngeal musculature and the pterygoid muscles. These zones are bilaterally symmetrical.
Figure
3A
Mandibular
Retromandibula Facial Parotid
Figure
12
Glan
3B
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
et al.
CT of the neck
LEVEL
3-UPPER
ALVEOLAR
RIDGE-SOVr
PALATE
Figures
Figure
4A & 4B
The oral cavity and the isthmus of the pharynx are seen in this section. The midportion of the parotid gland is demonstrated. In adults, the parotid gland is usually of relatively low attenuation (less than surrounding muscles and vascular structures) because of variable amounts of fatty infiltration of the parenchyma. The retromandibular vein is commonly visualized just posterior to the mandibular ramus. The main trunk of the facial nerve, although not visualized on the CT image, lies just lateral to the retromandibular vein.
4A
Soft
Palate
Cavity Antrum
Oropharynx
Masseter Pharyngeal
Constrictor
Int. Carotid
M.
M.
A.
Retromandibular
(Post. Carotid
A..
Post. Auricular
V.
Ext.
Sternocleidomastoid
Figure
Volume
Facial
V.
V.)
M.
4B
3, Number
1
March
1983
RadioGraphics
13
CT
of the
neck
Martinez
LEVEL
Figures
4-ORAL
CAVITY-UVULA
5A & 5B
The tip of the uvula appears here as a punctate structure in the middle of the oropharynx. It is surrounded by palatine tonsils and the oropharyngeal musculature (pharyngeal constrictor, palatoglossus and palatopharyngeus muscles). The posterior belly of the digastric muscle is an important anatomical landmark. It lies lateral to the carotid sheath and the external carotid artery. The retromandibular vein becomes the external jugular vein after exiting from the parotid gland.
Figure
5A
)ular
Figure
Ramus
Carotid
A.
:Jugular
V.
I
14
et al.
5B
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
et al.
CT of the neck
LEVEL
5-MANDIBULAR
ANGLE-SUBMANDIBULAR
GLAND
Figures
Figure
6A & 6B
The oropharynx, the base of the tongue, and the upper portion of the submandibular gland are well visualized at this level. The internal and external carotid arteries and the jugular veins are in close proximity to the oropharynx. The most inferior portion of the parotid gland is separated from the adjacent submandibular gland by the stylomandibular ligament. The stylohyoid and digastric muscles separate the structures of the carotid sheath from the submandibular gland. The attenuation of the submandibular gland is usually greater than that of the parotid gland.
6A
haryngeal Constrictor
M.
Carotid A. us N.
V.
Figure
Volume
6B
3, Number
1
March
1983
RadioGraphics
15
CT
of the
LEVEL
Figures
Martinez
neck
6-FREE
BORDER
OF
EPIGLOUIS-SUPERIOR
HORN
OF
et al.
HYOID
7A & 7B
This section demonstrates the relationship of the submandibular gland to the base of the tongue and to the free border of the epiglottis. The superior horn of the hyoid is adjacent to the internal and external carotid arteries. The suprahyoid group of muscles (stylohyoid, mylohyoid, and geniohyoid) is visualized as a group in this section.
Figure
7A
Epiglottis Mandible Submandibular
Gland
and
.Sternoclejdomastoid
Int. Carotid
A.
nt. Jugular
Vertebral
Figure
16
V.
Semispinalis Capitis Levator Scapulae
Semispinalis
M.
and Mm.
Body C3
7B
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
et al.
CT
LEVEL
8A & 8B
The valleculae, epiglottis and median glossoepiglottic fold are seen at this level. The asymmetry of the valleculae in Figure 8A is accounted for by secretions on the right side. The vallecular spaces are best seen if scans are obtained while the tongue is protruding. The fat layer deep to the sternocleidomastoid muscle is regularly seen irrespective of the body habitus of the patient. Muscle definition is dependent on intermuscular fat rather than on muscle size. The hyoid bone is a useful reference structure.
8A
Hypoglossal
N’
mt. Carotid
,8
Int.
onstrictor
Jugular
?idomastoid
Figure
Volume
neck
7-VALLECULAE-HYPOPHARYNX
Figures
Figure
of the
M.
M.
8B
3, Number
1
March
1983
RadioGraphics
17
CT
of the
Martinez
neck
LEVEL
Figures
8-HYOID
BODY-CAROTID
et al.
BIFURCATION
9A & 9B
The pre-epiglottic space is well demonstrated because of its low (fat) attenuation. A portion of the aryepiglottic fold is seen laterally. The carotid artery bifurcates at this level in most individuals, usually at the level of the fourth or fifth cervical vertebral body. Note the relationship of the internal jugular vein to the carotid bifurcation.
Figure
9A
Sternocleidon
Figure
18
9B
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
CT
et al.
LEVEL
9-THYROID
NOTCH-ARYEPIGLOTHC
neck
FOLDS
Figures
Figure
of the
1OA & lOB
The alae of the thyroid cartilage are seen at the level of the thyroid notch in this section. The pattern and extent of ossification of the thyroid cartilage is variable, but usually symmetrical. On each side, the aryepiglottic fold separates the laryngeal vestibule from the pyriform sinus. The common carotid artery and the jugular vein lie under the sternocleidomastoid muscle posterolateral to the thyroid lamina.
1OA
Thyroid Aryepiglottic
Ext. Jugular
Fold
V.
C5
Levator Semispinalis
Figure
Volume
Capitis
M.
lOB
3, Number
1
March
1983
RadioGraphics
19
CT
Martinez
of the neck
LEVEL
Figures
hA
lO-ARYTENOID
CARTILAGES-LARYNGEAL
et al.
VESTIBULES
& 11B
Here the upper portions of the arytenoid cartilages are present posteroinferior to the aryepiglottic folds. The corniculate cartilages are very seldom calcified and cannot be identified within the aryepiglottic folds. Visualization of the pyriform sinuses may be improved by phonation (EE-E) or by a modified Valsalva maneuver during the scanning period.
Figure
11A
al Constrictor
Neural Ext.
Foramen
Jugular’
Figure
20
M.
llB
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
et al.
CT of the neck
LEVEL
11-VOCAL
CORDS
Figures
Figure
12A & l2B
The level of the true vocal cords is identified by the close apposition of the anterior commissure to the inner surface of the thyroid cartilages, as well as by the presence of the vocal process of the arytenoid cartilage. The uppermost portion of the cricoid ring is seen at this level forming the posterior boundary of the glottic space.
12A
Anterior
Arytenoid
Int. Jugular
Commissure
Cartilage
V.
Middle and Post. Scalene Mm.
Vertebral
Figure
Volume
12B
3, Number
1
March
1983
RadioGraphics
21
CT
of the
Martinez
neck
LEVEL
Figures
et al.
12-SUBGLOTFIS
13A & 13B
Here the mucosa of the subglottis is closely applied to the cricoid ring and thyroid cartilage. The cervical
esophagus
is posterior
to the poste-
nor lamina of the cricoid. Note the relationship of the cricoid lamina to the inferior cornu of the thyroid cartilage. In children and young adults, the carotid arteries and jugular veins may be difficult to separate from the adjacent muscles unless a rapid infusion of contrast material is employed during the examination. Normal lymph nodes usually measure less than 5 mm in diameter.
Figure
Horn Thyroid
l3A
Cartilage
Cartilage .Cricoid lnt. Jugular
Cartilage
V. Vagus N.
.
Deep
Figure
22
Longus
Vertebral
Colli
M.
Body
C7
13B
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
CT of the neck
et al.
LEVEL
Figure
Middle
13-CRICOID
RING-LARYNGOTRACHEA
Figures 14A & 14B The cricoid ring surrounds the airway. The upper pole of the thyroid gland is readily identified because of its high attenuation which results from the vascularity and iodine content of the gland. The common carotid artery is usually found posterior to the thyroid.
14A
anc,
l Cervical
V.
Post. ScalenE
tor Scapulae
Figure
Volume
l4B
3, Number
1
March
1983
RadioGraphics
23
CT
Martinez
of the neck
LEVEL
14-UPPER
Figuresl5A&15B The thyroid isthmus is seen anterior to the trachea at this level. The Carotid artery lies posterior to the thyroid gland while the jugular vein is more laterally placed between the anterior scalene and the sternocleidomastoid muscles. The jugular veins are frequently asymmetrical, the right being larger in most subjects.
Figure
TRACHEA-THYROID
ISTHMUS
15A
Vertebral Body
Figure
24
et al.
Ti
l5B
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
CT
et al.
LEVEL
Figure
15-FIRST
RIB-LOWER
THYROID
of the
neck
GLAND
Figures 16A & l6B This section, just above the thoracic inlet, is at the level of the first rib. Individual tracheal rings are visible in older individuals if they have become calcified. The esophagus is commonly just to the left of the midline at this level. The lower cervical nerves may be seen directed inferolaterally between the anterior scalene and the middle and posterior scalene muscle group. The anterior scalenes may be prominent in patients with chronic obstructive pulmonary disease and should not be mistaken for masses or
16A
adenopathy.
Vertebral
Figure
Volume
Body
Ti
l6B
3, Number
1
March
1983
RadioGraphics
25
CT
of the
neck
Martinez
Case
history thyroid. because
This 35 year of papillary
old man had carcinoma
et al.
One
a past of the
He consulted a physician of a right parapharyngeal
mass.
Figure 17 A 2.5 cm partially cystic mass (arrowheads) space displaces the styloid process (arrow)
DIAGNOSIS Metastatic of the
26
thyroid
papillary gland.
carcinoma
in the right anteriorly
parapharyngeal and laterally.
Figure 18 Section obtained 2 cm caudad. The lateral pharyngeal wall is distorted and the right submandibular gland is displaced anteriorly. The relationship of the cystic mass to the carotid artery and jugular vein is demonstrated (arrow).
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
CT
et al.
Case
of the
neck
Two
This palpable region.
68 year masses
old in the
man right
had
two
parotid
1%
Figure 19 This sialogram showing traparotid mass lesion
displacement (arrowheads).
of the ducts
suggests
a single
Figure 20 Two sharply defined masses (arrowheads) are present in the right otid. Note the clear visualization of the posterior facial vein within normal parotid tissue between the two masses. The study was formed during the infusion of a contrast medium.
Volume
3, Number
1
March
1983
RadioGraphics
in-
parthe per-
DIAGNOSIS Adenopathy-Hodgkin’s
dis-
ease.
27
CT
Martinez
of the neck
Case
This mitted glottic
53
year
old
man
was
Three
ad-
for the evaluation of a supralesion. An asymptomatic left
parotid mass examination.
was
noted
on physical
Figure 21 A laryngogram shows of the valleculae.
a thickened
epiglottis
Figure 22 This scan shows a thickened epiglottis, infiltration of the pre-epiglottic space
28
et al.
RadioGraphics
(arrowheads)
obliteration (arrow).
March
and distortion
of the valleculae
1983
Volume
and
3, Number
1
Martinez
et al.
CT of the neck
.
Figure
23
In this perficial
sialogram, ductal displacement lobe suggests an intraparotid
Figure
24
This
scan
Moderate density
Volume
shows
a sharply
fatty of both
3, Number
infiltration parotid
1
March
defined
of the
in the mass.
mass
within
parenchyma
lower
the
portion
left
accounts
of the
parotid
for
su-
DIAGNOSIS
gland.
the
low left
glands.
1983
RadioGraphics
Carcinoma of the epiglottis parotid Warthin’s tumor.
and
29
CT
of the neck
Martinez
Case This slowly
26
enlarging
year
old left
neck
man
had
Four
a
mass.
Figure 25 A cystic mass is seen between submandibular gland (arrow). to the floor of the mouth.
Left (ranula).
30
DIAGNOSIS submandibular
et al.
Figure 26 At this level, gland
cyst
portion
gland
of the
the hyoid mass.
the mylohyoid muscle and deformed left The anterior portion of the mass extends
is seen to be displaced
Note
the
lateral
displacement
to the right of the
by the lower submandibular
(arrow).
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
et al.
CT
Case
of the neck
Five
This
49 year
subglottic
old
carcinoma
treated
with
radiotherapy
woman
with
had
been
five
years
earlier. At this time, she had wheezing and a palpable lesion of the left lobe of the
Figure 27 In this scan, a soft tissue mass (arrowheads) partially obliterates subglottic airway. Note the well defined soft tissue plane between cricoid and the mass in the left lobe of the thyroid (arrows).
thyroid.
the the
Figure 28 Pathology Specimen. Laryngectomy and thyroidectomy were performed after partial laser excision of the subglottic mass. The residual lesion of the left subglottis (arrowheads) and the lesion of the left lobe of the thyroid (arrows) are demonstrated.
DIAGNOSIS Recurrent carcinoma.
subglottic Colloid
cyst
squamous of the
thy-
roid.
Volume
3, Number
1
March
1983
RadioGraphics
31
CT
Martinez
of the neck
Case
This lump
39 year
in the
old
woman
had
et al.
Six
a
throat.
Figure 29 A lateral radiograph of the soft tissues of the neck shows a smooth mass (arrowheads) in the base of the tongue displacing the epiglottis posteriorly.
Figure 30 In this CT scan (without contrast agent), there is a high uation) mass’ (arrowheads) in the base of the tongue. of this lesion is the same as that of the normal thyroid high because of its iodine content. The superior horns rows) are seen in either side of the mass. ‘ ‘
DIAGNOSIS Lingual
32
thyroid.
‘
RadioGraphics
March
1983
density (attenThe attenuation tissue, which is of the hyoid (ar-
Volume
3, Number
1
Martinez
et al.
CT
Case
of the
neck
Seven
This two year
76 year history
old
woman
of progressive
had
a
airway
obstruction.
Figure 31 A CT scan at ‘Level 8’ shows a partially from the inner lamina of the cricoid. cartilage appears intact. ‘
‘
calcified subglottic The outer lamina
mass arising of the cricoid
Figure 32 A follow up study after an interval of 4 months and after partial laser excision of the tumor shows unequivocal decrease in the size of the lesion which coincided with clinical improvement.
Volume
3, Number
1
March
1983
RadioGraphics
DIAGNOSIS Chondrosarcoma
of the
larynx.
33
CT
of the
Martinez
neck
Case
This enlarging
48
year
goiter
old and
man
had
Eight
an
stridor.
Figure 33 A lateral xeroradiograph demonstrates with erosion of the cricoid ring (arrow) airway.
DIAGNOSIS
Carcinoma of the thyroid transmural subglottic extension.
34
et al.
with
a large neck mass (arrowheads) and narrowing of the subglottic
Figure 34 This CT scan shows a large mass (arrowheads) of the thyroid, erosion of the cricoid ring transmural extension.
RadioGraphics
March
arising from posteriorly
1983
the right (arrow)
Volume
lobe and
3, Number
1
Martinez
et al.
CT
Case
of the
neck
Nine
This
29
year
slowly enlarging had previously a glomus
old
man
had
a
left neck mass. He been operated on for
tympanicum.
Figure 35 A sharply defined enhancing mass (arrowheads) under the sternocleidomastoid muscle displaces the left submandibular gland anteriorly. The carotid bifurcation is usually located at the level of the hyoid horns.
I r
DIAGNOSIS Figure
36
In this
left
common
at the carotid imal internal
Volume
3, Number
carotid
bifurcation. and external
1
March
angiogram,
Multiple carotid
1983
a highly
vascular
mass
small feeders arising from arteries are demonstrated.
RadioGraphics
is seen
Carotid caroticum).
body
tumor
(glomus
the prox-
35
CT
of the
neck
Martinez
Case
This pable
34 year
masses
old
man
in the upper
had and
et al.
Ten
pallower
neck.
Figure 37 An oblique view of the neural foramen (arrow)
cervical spine on the left.
shows
enlargement
of the
C2-3
Figure 38 A small, well defined, lobulated mass (arrowheads) is seen anterior to the scalene muscles in this CT scan. It minimally displaces the left carotid artery and the left jugular vein. Note the asymmetry of the jugular veins with a very large right jugular vein, a normal variant.
36
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
et al.
CT
of the
neck
Figure 39 In this CT scan, a large lobulated parapharyngeal mass is seen (arrowheads). The internal carotid artery is displaced (white arrow) and there is distortion of the lateral pharyngeal wall on the left. The C2-3 neural foramen (black arrow) on the left is enlarged, corresponding to the radiographic finding.
DIAGNOSIS Neurofibromatosis.
Volume
3, Number
1
March
1983
RadioGraphics
37
CT
of the
Martinez
neck
Case
This
plained
62
year
old
man
et al.
Eleven
com-
of hoarseness.
Figure 40 A CT section at the level of the vocal cords demonstrates of the margin of the enlarged left vocal cord (arrowheads).
excellent
Figure Normal
definition
41 subglottic
irregularity Note the
of the laryngeal cartilages.
region
5 mm
below
the vocal
cords.
DIAGNOSIS
Squamous vocal cord.
38
carcinoma
of the left
RadioGraphics
March
1983
Volume
3, Number
1
Martinez
et al.
CT of the neck
Case
Twelve
This
50 year
in the posterior
Figure 42 A sharply defined mass tween the semispinalis muscle.
with very capitis
low (fat) muscle
attenuation and the
old man
had a mass
neck.
is visualized besplenius capitis
DIAGNOSIS Lipoma.
Volume
3, Number
1
March
1983
RadioGraphics
39
CT
of the neck
Conclusions 1. Computed tomography is helpful in the evaluation of neck masses. Specifically, it is capable of documenting tumor size, location and relationship to adjacent structures; it can demonstrate routes of tumor spread and provide clues supporting a specific diagnosis. 2. Thorough knowledge of the normal cross sectional anatomy of the neck and meticulous tomographic technique are mandatory. The examination should be planned on the basis of the clinical presentation. 3. Intravenous contrast material given as a rapid infusion during the examination provides the best enhancement of the vessels, and thereby improves recognition of key vascular structures.
4. The exact location and extent of tumors in the infratemporal fossa and parapharyngeal space is best evaluated by CT. The detection of parapharyngeal tumors depends more on asymmetry, and distortion of deep soft tissue compartments than on asymmetry of the airway. CT does not provide a histologic diagnosis or permit differentiation between benign and malignant processes. An inflammatory process may mimic tumor infiltration. 5. CT is very useful in the evaluation of parotid tumors and will probably replace conventional sialography for the assessment of tumor pathology of the parotid. Sialography, however, remains the procedure of choice for the evaluation of inflammatory diseases of the salivary glands. 6. CT is extremely valuable for the evaluation and staging of laryngeal carcinoma. It is the best imaging modality for the evaluation of cartilage erosion and tumor extension into the pre-epiglottic, paraglottic and subglottic spaces. 7. Current limitations of CT of the larynx are: (a) motion artifacts, (b) lack of dynamic information, (c) inability to differentiate edema from tumor infiltration and (d) lack of adequate
40
Martinez
characterization of mucosal surfaces. 8. CT is most helpful in the detection of metastatic adenopathy, especially in obese patients. Reactive nodes, however, cannot be differentiated from metastatic nodes Normal lymph nodes usually measure fewer than 5 mm in diameter and reactive nodes usually measure fewer than 15 mm in diameter. Large nodes with central necrosis usually indicate metastatic involvement. 9. The role of CT in the evaluation of thyroid nodules is limited because of the accuracy of nuclear medicine and ultrasound techniques. CT, however, is helpful in defining the extent of paratracheal and thyroid masses by defining the extent of tracheal cornpression and transmural airway invasion.
Additional
133:145-149.
8. Sons PM, ShugarJMA. Combined CT sialogram. Radiology 1980; 135: 387-390. 9. Som PM, Shugar JMA, Train JS et al. Manifestations of parotid gland enlargernent: Radiographic, pathologic and clinical correlations Part I-The autoimmune pseudosialectasis. Part Il-The diseases of Mikulicz’ syndrome. Radiology 1981; 141:415426. 10. Stove DN, Mancuso AA, Rice D et al. Parotid CT sialography. 1981; 138:393-397.
Radiology
11. Mancuso AA, Hanafee WN. Cornputed tomography of the head and neck. Williams & Wilkins Baltimore/London:
1982.
Readings
1. Carter BL, Karmody CS, Blickman JR, et al. Computed tomography and sialography Part I-Normal anatomy Part Il-Pathology. J Comput Assist Tornogr 1981; 5:42-53. 2. Doubleday LC, Jing BS, Wallace S. Computed tomography of the infratemporal fossa. Radiology 1981; 138:619-624.
included here that previously appeared in Martinez BW, et al. COmputed tomography of the neck. Ann Otol Rhinol Laryngol 1982; 91:Supplement 99 are reproduced with permission. Figtres
CR. Kashima H, Gayler
acknowledge the cooperation of ow colleagues in the Departments of Otolaryngology and Radiolo. gy and the expert assistance of the technical staff. We appredate the typing of Ms. Agnes Bridges and Ms. Rose We gratefully
3. Larsson 5, Mancuso AA, Hoover L et al. Differentiation of pyriform sinus cancer from supraglottic laryngeal cancer by CT. Radiology 1981; 141:427-432. 4. Mancuso AA, nafee
et al.
WN.
Calcaterra
Computed
of the larynx.
TC,
Walker.
The
photoaphy
of Mr. Henri Hessels is
much ap-
preoated.
Ha-
tomography
Rad Clin N Am 1978;
XVI:195-208.
5. Mancuso AA, Bohman L, Hanafee WN et al. Computed tomography of the nasopharynx: Normal and vanants
of
normal.
Radiology
1980;
137:113-121. 6. Mancuso AA, Macen D, Rice D et al. CT. of cervical lymph node cancer. AJR
1981; 136:381-385.
7. Miller
EM,
computed ation
Normal D. The role of tomography in the evalu-
of neck
masses.
Radiology
1979;
RadioGraphics
March
1983
Volume
3, Number
1
