we're gonna go over the various spaces
of the head and neck and again I'm gonna
make this incredibly simple because you
know part of the challenge about head
neck imaging it's it's really all boils
down to Anatomy and and as you know part
of the the department here at MSU we're
also in charge of anatomy for both
medical schools I think there's some
nice synergy there because I know when I
was in medical school we learned very
little head and neck and then as
radiologists we have this daunting
experience to not only understand the
anatomy but understand its appearance on
various types of cross-sectional imaging
so not only CT NMR but when I started
out it was mostly just in the axial
plane and now you throw in sagittal
planes and coronal planes it just makes
everything a little bit more complicated
so, so much of what we do is anatomy so
in my talk I'm really going to be
focused on the anatomy the head and neck and
we're gonna go over the various spaces
of the head neck so we're gonna go over
all these spaces and hopefully by the
end of the next 40 minutes or so if
you're not really familiar with the head
neck Anatomy and the spaces I hope that
you'll be able to translate this in your
practice in fact you'll be so excited on
Monday you're gonna steal all the head
and neck cases from your partners right
that's what we that's what we hope will
happen okay so we'll go and first start
off with the first base which is the
masticator space so pure and simply the
masticator space are the muscles of
mastication there are different
components of the masticator space but
when we think about the masticator space
we really have to primarily concentrate
on the muscles of mastication so when i
fibers to contour the masticator space
what i would end up doing is taking this
little pointer like I am right here
coming around and making a little dip
right here coming across coming over and
then coming back around so we look at
the masticator space the primary
component of the masticator space are
the muscles of mastication which are the
lateral pterygoid muscle the the
temporalis muscle just medial to the
coronoid process and the masseter muscle
which is located here now just inferior
to the lateral pterygoid muscle is
another
so right here which is the medial
pterygoid muscle so you can see the
pterygoid muscles are one on top of the
other but the largest component of the
masticator space by far and away are the
muscles of mastication the second
largest come the second biggest
component of the masticator space are
the bones here now these bones are
essentially all attached to them to the
mandible so I just contoured the
coronoid process and here's the condyle
of the mandible now when I was doing my
contour there was a little area right
here that I went around and that's the
third division of the fifth cranial
nerve so the primary components of the
masticator space are going to be muscle
bone and nerve and if you can understand
those three components of the masticator
space this will give you a foundation of
the various pathologies that will arise
in the masticator space so if we see
something like this here is a large mass
involving the left masticator space we
know that the primary component of the
masticator space is muscle so when we
see something that's large the most
likely diagnosis is going to be a
sarcoma in this case this happened to be
a synovial cells sarcoma now how do we
know it's in the masticator space well
pure and simply what I do is I try to
put my finger or my pointer in the
middle of that space and then I take it
over on the opposite side and try to
find the center on the opposite side we
can also look in this area here here's
the pair of pharyngeal space that we'll
talk about later notice how this is
intact and you can see how the pair of
pharyngeal space is displaced medially
so by demonstrating that this mass is in
the masticator space and it's separate
from the pair of pharyngeal space then
we can accurately localize the
mass to the masticator space another
example here here's a mass of primarily
involved in the masticator space we can
see this is bleeding over a little bit
in the pair pharyngeal space and it's
encasing the carotid artery we'll talk
about that a little bit later but again
you can see primarily this is arising in
the masticator space and again this was
another form of sarcoma this is another
masticator space mass and now we get
into those crazy jaw lesions so here's a
large osteoma that's arising from the
condyle of the mandible and here is an
expanse eye lesion involving the ramus
of the man
and this happened to be anybody want to
take a guess it starts with an a
ameloblastoma exactly right those are
some of those crazy jaw lesions but
again in a way the pathology is not
important in this talk the main thing is
to properly identify that the pathology
that we're seeing is in the masticator
space and then we can come up with an
appropriate differential diagnosis in
this case this was a mass that was
involving the masticator space but it
very nicely demonstrates that you can
see this muscle right here which is a
lateral pterygoid muscle which is
displaced laterally and we can see if
it's displaced laterally then the mass
has to be arising just medial to the
pterygoid muscle so here's a pterygoid
muscle here there is this structure
right here which is oval shape that's
actually v3 so in this particular case
the lateral displacement of the
pterygoid muscle laterally suggests that
this may be arising from the third
division of the fifth cranial nerve and
then when we look at the coronal images
we can see this mass extending
superiorly through foramen ovale which
confirms the fact that we're looking at
a schwannoma arising from the third
division of the fifth cranial nerve so
that's the masticator space remember the
three primary components are muscle bone
and nerve and if we can properly
identify it then we can come up with a
solid differential diagnosis the next
space is the visceral space and you know
the great thing or the bad thing about
head neck radiology is that we take the
same piece of anatomy and we just give
it different names so for instance the
actual name of the fossa here that I'm
contouring I use the term visceral fossa
because this was the original term given
in the classic articles on the spaces of
the neck space of the head neck written
in 1937 by green-skinned Hollyoaks so I
tend not to change the names but having
said that as we have involved this
fashion now has different names to it
some people will call it the fringo
mucosal fascia some people will call it
you know you know whatever there there
numerous names to it but I just call it
the visceral fossa and if you call this
the visceral fossa then the next space
is very very easy to identify because
the name
this space is the visceral space so how
do you identify the visceral space well
what you do is you look in someone's
mouth so if you look in someone's mouth
and you do endoscopy in direct or
indirect endoscopy everything that you
can see in that patients mouth is in the
visceral space so sometimes this space
is referred to as a per Ingo mucosal
space so because it's in the pharynx and
it contains mucosa it's called the
fringo mucosal space but again I tend to
use the term visceral space now the
visceral space about dumps are here's
another example here of the visceral
facha and everything that's enclosed
here is in the visceral space so these
are just some examples of visceral space
masses and again what do you think the
most common malignancy is going to be
involved to involve the visceral space
squamous cell carcinoma yeah number one
two and three but in general when we see
masses that are involving the pharynx or
the visceral space the most likely
malignancy is going to be squamous cell
carcinoma but on the other hand one of
the lessons that I learned many years
ago and my fellowship is that if you see
a mass that's involving the visceral
space you don't need to give a huge
differential diagnosis because sometimes
as radiologists we get a lot of joy
saying well I can name 10 things that
this could be in actuality when
something's in the visceral space the
ENT surgeons can look directly at this
mass and do a biopsy and they can tell
you the diagnosis what we really need to
be able to do is provide information
that they cannot see on their clinical
examination so to reiterate this point
yes this could be squamous cell
carcinoma but this was actually a
metastatic adeno carcinoma there's no
way we can make that diagnosis but what
we need to be able to say that the mass
is in the visceral space comment on
potential spread patterns look for deep
extension that really is the job of the
the head neck radiologist now this is
another and I'm not going to say
necessary and abnormality but it's one
of those potential pitfalls that we see
so we see this mass here involving the
visceral space it looks pretty large
right and if I told you that this was a
child well this is just an
normal finding this is just adenoidal
hypertrophy in a kid and these are just
retro pharyngeal lymph nodes that are
slightly enlarged remember kids can have
enlarged retro pharyngeal lymph nodes
but if you see something like this in a
child you know realize that it's
probably not in the majority of cases an
aggressive nasopharyngeal carcinoma or a
rhabdomyosarcoma it just tends to be
adenoidal hypertrophy the other thing
that tells us it's not malignant is that
something this big eventually should
creep through laterally through the
visceral space to involve the adjacent
muscles and the adjacent fat and in this
case everything is confined to the
visceral space so this was just
adenoidal hypertrophy in a child and I
think we can all make the diagnosis here
here's a cystic mass that's located
between both longest coleye muscles in
the pharyngeal Bursa anybody want to
shout this out starts with a t torn wall
assists exactly right
so why does this make a difference it
makes a difference because we can see
that this torn wall cyst is anteriorly
displacing the overlying mucosa so this
is a sub mucosal mass that's causing
some mass effect so our ENT surgeons may
see this sub mucosal mass but they may
not be sure what the exact etiology is
so we can say that there's a sub mucosal
mass it's cystic and we can confirm the
diagnosis that this is not honest rather
that this is just a torn wall cyst okay
so the next space that we'll talk about
is the retro pharyngeal space now you
know it's pretty simple that this space
it's we just talked about the visceral
space so the other name for the visceral
space is essentially the pharynx so what
do you call the space that's located
behind the pharynx well that's why it's
called the retro pharyngeal space so if
we look here here's the visceral fossa
that we just talked about which encloses
the visceral space now there's another
facial layer this dotted line right here
which is referred to as the pre vertebral fascia again this name has
evolved over time I think some people
now call it parry vertebral fascia it's
essentially the same thing but the
original name given to this is the pre
vertebral fascia so that's the
terminology that I use so in essentially
in a general practice I think if you can
say the
there's air here that's located behind
the pharynx and that's located between
the visceral facha and the pre vertebral
fascia and you can say that this is a
retro pharyngeal space and to be honest
with you I think you're doing just fine
but for the aficionados out there if we
look more closely at the anatomy behind
the visceral fascia but anterior to the
pre vertebral fascia there's a dashed
line right here which represents a very
thin partial layer that starts with an A
anybody want to shout it out
Alar fascia exactly right so that's the
Alar fascia so the true retro pharyngeal
space is located between the visceral
space and the Alar fascia so these lymph
nodes right here are located in the
retro pharyngeal space and the space
that's located between the Alar fascia and
the pre vertebral fascia is another small
space anybody know the name of that
starts with a D at the danger space
exactly right so in there actually are
two components if you will in this
area so that most anterior one is a
retro pharyngeal space and the posterior
one is a danger space now this space the
true retro pharyngeal space extends down
into the mediastinum and terminates
somewhere between t2 and t6 but the
danger space extends all the way through
the mediastinum through the kerr of the
diaphragm and is continuous with the
retroperitoneum and the way the spaces
were first diagnosed actually or
identified where these French anatomist
that were doing these dissections and
trying to figure out in the late 1790s
why patients that had infections in the
head and neck that end up dying of abscesses
involved in the chest or the abdomen and
this was the answer and that was the
original individuals that first looked
at the spaces and identified the spaces
so the spaces were not created to
torture boards on their own your
residents on your boards believe it or
not it's hard to believe but in
actuality they were first identified to
figure out why patients that had
infections in their head and neck could
somehow die of these terrible
diseases so what are some pathology
that can
involve the retro pharyngeal space well
this was an interesting thing we always
have to be aware of this on the
patient's right hand side there's a
carotid there's a jugular vein
here's the jugular vein and this is a
carotid artery that's wandering into the
retro pharyngeal space now why is this
important because this patient was pre
operatin selected me the surgeon thought
that the patient may have a wandering
carotid artery so before they did the
tonsillectomy they did the CT scan to
look for the location of the carotid
artery and lo and behold there is the
carotid artery in the visceral space
this is another example of a pathology
involving the retro pharyngeal space
this is a classic metastatic retro
pharyngeal lymph node I think we'll talk
about this later when we talk about
lymph nodes but here's the carotid
artery here's the jugular vein and there
is a retro pharyngeal lymph node just
lateral to the carotid artery and this
is a not a true retro pharyngeal abscess
this is actually a separation or liquid
liquification or liquefaction of a retro
pharyngeal lymph node so when I started
out years ago we would always call these
retro pharyngeal space abscesses but
when you see something that's this
rounded just medial to the carotid
artery that's lateralized like this that
doesn't cross the midline in a patient
that has infection this the true
diagnosis is separative retro pharyngeal
lymph node and the reason that's
important is that now these patients if
we see this radiologically the patients
can be successfully treated with
broad-spectrum antibiotics this is a
true retro pharyngeal space abscess as I
mentioned before the retro pharyngeal
space ends between t2 and t6 and in this
particular case we can see the abscess
here in the retro pharyngeal space and
when we look down in the mediastinum we
can see that there's actually a
medias tinnitus and immediate
Steindl abscess and the way the
infection gets from this area into the
mediastinum is through direct extension
of the conduit of the retro pharyngeal
space okay now let's move on to the next
space which is a pre vertebral space now
oftentimes when I give this talk I'll
ask the residents I'll say how many of
you have ever seen a pre vertebral space
mass and nobody raises their hands and
it's always fascinating to me and then I
said how many of you have ever looked at
a spine see to your mr then everybody
raises their hand so the point being is
that the pre vertebral space encompasses
the longest coleye muscle and
essentially the vertebral body so when
we look at the anatomy of the pre
vertebral space what this really
encompasses are the vertebral bodies
including the clivus C 1 C 2 C 3 and C 4
we also look at the various longest
coleye muscles and we also have the
vessels that run laterally to the
vertebral bodies and those are the
vertebral arteries so the thing about
head and neck is that if you think of
this as a pre vertebral space mass then
everyone says oh I got head and neck stuff I
hate it you know I never see that stuff
whatever but on the other hand if we
just pivot that and we say that have you
ever seen something in the spine then
all of a sudden you can come up with a
very robust differential diagnosis so
this is just a couple of examples of pre
vertebral space masses this is a true
retro pharyngeal space abscess and we
can see that's extending posterior lis
and it's extending between c1 and c2 and
if we look closer we can see that this
pre vertebral abscess is extending all
the way into the spinal canal resulting
in a epidural abscess this on the other
hand is one of the classic findings of a
pre vertebral space mass and again if I
was i put on my neuroradiology a hat I'm
just gonna say a cervical spine mass but
here we can see relative preservation of
the cervical spine in a patient let's
just say they came from India or South
America what do you think the
differential would be here
TB exactly right so this is tuberculosis
with pots otherwise known as pots
disease now here is one of those if you
will head neck masses that's kind of
unique to the head neck so if I tell you
here there's this aggressive mass that's
arising at the top of the vertebral body
located just below the clivus it
enhances with contrast but on
t2-weighted images it's high
signal indicating that it's a little bit
more mucoid containing and anybody want
to take a guess at what this diagnosis
is chordoma exactly right perfect so this
is one of the unique things but realize
when we are when we are talking about
pre vertebral space masses you know yes
we we sometimes think of chordoma but
in your practice the most common pre
vertebral space mass is going to be a
disc bulge a disk herniation some type
of degenerative disc disease metastasis
myeloma the stuff that you normally
think about when you're looking at the
cervical spine so when you think of the
pre vertebral space lesions those should
be at the top of your differential
diagnosis it shouldn't be the rare birds
like chordoma and this is just one
other example here this was turned out
to be a plexiform neurofibroma involving
the clivus
but it the diagnosis is not important
what's really important that you
identify that on the right-hand side of
this patient there's normal signal
involved in the clivus and this lesion
is completely replacing the clivus so
the key thing is isolating these lesions
into the pre vertebral space because
once you identify in the pre vertebral
space then you can come up with your
differential diagnosis another example
here if I told you that this patient was
involved in trauma this is a pre
vertical space mass if I told you there
was trauma they presented with acute
vertigo what do you think the diagnosis
is going to be here
dissection exactly right involving the
vertebral artery notice the narrow
caliber on the left side
compared to the right side alright so
the next one is really easy right so
well let's review a little bit right
masticator state right muscles of
mastication bone muscle and nerve right
this role space anytime that you look in
someone's mouth everything that you see
is in the visceral space the retro
pharyngeal space is that space that's
located just behind the pharynx the pre
vertebral space in other more common
terms is the cervical spine and
everything that surrounds a cervical
spine and this one's really hard right
the next space is just pure and simply
the parotid space so everywhere that you
see the parotid gland you'll see the
parotid space so if I had to contour the parotid gland this is where I
would be contouring the parotid gland
here again just to review what space is
located here masticator space good
what's the potential space that's
located here potential space yeah retro
pharyngeal space danger space that's
fine then what's space of my contouring
right here free vertebral space exactly
right so when we look at the parotid
space again I'm gonna contour the
parotid space on the opposite side it's
everyone knows where the product land is
but what we always have to be aware of
the parotid gland is there's a certain
nerve that's associated with the product
land what nerve is that the facial nerve
so here's a page that underwent a
superficial parotid ectomy and we can
see the various branches beautifully
laid out in the prada and in the facial
nerve and the facial nerve separates the
product gland into a superficial and a
deep lobe so how do we identify the
location of the facial nerve well what
we do is we look at the retro mandibular
vein which is located right here and the
facial nerve is located just lateral to
it there so there's our facial nerve so
the facial nerve separates the parotid
gland into a superficial lobe and a deep
lobe and on the right hand side there is
the facial nerve and you can see it's in
a plane and the superficial lobe has
been removed and everything deep to the
branches of the facial nerve are located
in the deep lobe of the product land so
what are some pathologies that involve
the parotid gland well here's a
pathology involves a parotid gland here
we have multiple lesions that are
located in the tail of the parotid gland
they're bilateral and they're multiple
and so what do you think the most common
diagnosis is going to be here
that's exactly right it's a Wharton's
tumor so you know what's a Wharton's
tumor and why are worth ins tumors
typically in the tail of the product
land multiple and often times bilateral
and the reason is is that the other name
for Wharton's tumors it's called cystadenoma lymphomatosum so what does
that mean in English because that's a
Latin term just remember that the
parotid gland has has multiple lymph
nodes and those lymph nodes can be at
the pre traigo region
it can be a around the capsule the
parotid gland they can be along the
facial nerve or the tail of the product
land so lymph nodes can be multiple in
fact they are multiple in the product
gland and their bilateral so cystadenoma lymphomatosum indicates that
the Wharton's tumors arise from some
embryonic remnant of lymphoid tissue and
the lymphoid tissue in the parotid gland
tends to be in these lymph nodes so
that's why Wharton's tumors can be
multiple and bilateral and have a
propensity to arise in the tail of a
parotid gland so I know I've got a
couple of fellows out there we've seen a
couple of probable cases of Wharton's
tumors and that's why when we see
something in that region that's why we
suggest the diagnosis of a Wharton's
tumor now this was a diagnosis that we
used to make twenty years ago when I was
a fella if I told you that this patient
was HIV positive then what's the what's
the diagnosis that we see here anybody I
remember 20 years ago everybody would
get this diagnosis yeah Lymphoepithelial cysts
exactly right these are Lymphoepithelial cysts so back when I was a
resident a fellow this was in the AIDs 
era and a lot of patients would come in
with the triad of head neck findings
with HIV and they were the presence of
Limbo epithelial cysts all of these
multi shaadi lymph nodes and then
prominence of the adenoidal tissue
involving waldeyer ring we don't see
this as much anymore I think fortunately
we've got a much better handle on AIDS
and there's been tremendous success with
with triple therapy but if you do see
multiple cysts like this these are
lymphoma Theo leo cysts
now often times when I show it to this
generation of residents they'll say well
it's multiple Wharton's tumors because
if you read the books they say Wharton's
tumors have cysts
well the cysts in the Wharton's tumors
aren't big balloons like this like big
water balloons you can have little focal
cystic areas and more consumers but
rarely have I seen Wharton's tumors that
have been this cystic so when I see
cysts that are t his big then I started
thinking of lymphoepithelioma and
one of the main things when we look at
head neck imaging is as I mentioned
before the real value that we have is
not only to identify
that there's a mass there and
potentially look for if you will more
malignant findings but really trying to
determine whether it's involving the
superficial lobe or the deep lobe because
the superficial prodded ectomy the
surgeons do not have to go deep to the
facial nerve or as if we say the tumors
involve in the deep lobe of the parotid
then the surgeons have to either dissect
or potentially sacrifice the facial
nerve in order to remove the full extent
of the tumor so this is just an example
of lesions in this case involving the
superficial lobe so here's the amass
involving the superficial lobe of the
parotid gland here's a retro mandibular
vein so our facial nerve is about of the
tip of the arrow but in this particular
case we can see this mass is deep to the
retro mandibular vein deep to the facial
nerve and extends deeply to involve the
pair of pharyngeal space so if you will
this is where again we earn our value
because we can then help direct the
surgical management because if we do say
the mass is involved in the deep lobe
then these patients have to undergo a
total parotidectomy or if it was
isolated just to the superficial lobe
then they can just undergo a superficial
parotidectomy here's another example
of where we earn our value in head neck
here's an aggressive lesion involving
the right parotid gland now if you look
at the parotid gland these tumors can
grow deeply and extend between the
styloid process and the mastoid bone in
the stylo mastoid foramen and with the
leap of faith' if you look right at my
arrow there's a dot right there that's
actually the facial nerve in the stylo
mastoid foramen so anytime that we have
tumors involving the parotid gland these
tumors then can extend deeply to the
skull base and because the facial nerve
is located in the parotid gland we can
we should be performing MRs to
determine whether or not there's
retrograde perineural extension along
the facial nerve now the fact of the
matter is is that nine times out of ten
the surgeons are going to know whether
or not the patients have a malignancy of
the product land why because the facial
nerve is already out so our job is not
necessary to give again a litany of a
large di- a large differential
diagnosis what we need to be able to
tell our
virgins is whether or not there's
retrograde perineural extension because
if there's no perineural extension then
the surgeons could potentially just do a
total product to me but if there is
retrograde perineural spread along the
descending portion of the facial nerve
then these patients would either have to
have their mastoid drilled out to remove
the facial nerve or if it's very
extensive then they would just
potentially be treated with non-surgical
organ preservation therapy so really
that's the value of imaging you know
we're now we're in the value era of
radiology so we have to emphasize the
value that we provide to these patients
so the next area is pure and simply the
para pharyngeal space so let's go ahead
and review right repetition is good
right so what space am i looking at here
vascular space which space is here what
space is located right here yeah retro
pharyngeal space what space is located
here pre vertebral space perfect what
space is located here broad space
exactly right
now we're gonna look at the space that's
next to the pharynx so what do you call
the space that's next to the pharynx
hair fair and isn't head and neck easy
right if you want something really hard
do mammography or something like that
right - mammo I have no idea what that
is right cc's I don't I have no clue so
anyway yeah the pair of pharyngeal space
is located just adjacent to the to the
pharynx and you know to be honest with
it there's not a lot of pathology that
arises in the pair of pharyngeal space
but I'll tell you just a couple of
things to remember the most common
pathology to involve the pair pharyngeal
space is this pathology here on your
left hand side and this is deep spread
of squamous cell carcinoma see the how
this tumor is extending deeply into the
pair of pharyngeal space so that's the
most common tumor to involve the pair of
pharyngeal space but the most common
tumor to arise within the pair of
pharyngeal space is this pathology here
and this is a pleomorphic adenoma so the
minor salivary gland tumors are the most
common pathology to arise in the pair of
pharyngeal space so I'll just toss the
like I'm not the smartest tool in the
shed it takes me a long time to get
things I never did understand what a
minor salivary gland tumor was because I
would think you know what is a minor
salivary gland tumor well what a minor
salivary gland tumor is is that you take
the same constituent histology that
comprises a major salivary gland which
is the parotid gland of the
submandibular gland and then you place
that in an area where it shouldn't be so
if I take this type of salivary tissue
and put it in the pair of pharyngeal
space and then you have tumors that
arise from that same tissue so the same
tumors that can arise in the parotid
gland can now arise in the pair of
pharyngeal space that's why we call it a
minor salivary gland tumor so the fact
of the matter is these are the same
types of tumors that occur in the major
salivary glands it's just that these
tumors are not there now arising outside
of the major salivary gland so that's
why it's called minor salivary gland
tumors and the most common as you know
the benign ones are warth ins tumors and
pleomorphic adenoma pleomorphic adenoma
and the malignant ones are adenoid
cystic and Mucoepidermoid carcinoma
so in this particular case the most
common tumors to arise in the pair
pharyngeal space are going to be minor
salivary gland tumors another example
here this is another pathology involving
the Paris pharyngeal space and again I
want to emphasize that in this case the
pathology is not important I know if
anyone can guess this is a benign lesion
that cystic and has a fluid fluid level
anybody want to take a guess it benign
lesion anybody lymph angioma yeah
exactly lymphatic malformation cystic
hygroma exactly right but the key thing
here is how do we know that this is
involving the pair of pharyngeal space
well the reason is is that if we look at
the carotid artery here the carotid
artery is displaced in inferiorly excuse
me let me say that again if the carotid
artery is displaced in fearly that we
know it's in the pair of pharyngeal
space and here we can see the carotid
artery is has been displaced in fearly
so that tells us that the pair of
ngo space we'll see later what happens
if the carotid artery is displaced
anteriorly because anterior displacement
of the carotid artery tells us it's in a
different space and we're in a
completely different differential
diagnosis and so the next space is this
space that involves the carotid artery
so let's go through our spaces again so
what space do we just talk about right
here what space is located here here
pharyngeal space the space that we're
going to look right now is the carotid
space this space was the masticator
space this space was the parotid space
this space was the visceral space and
back here is the retro pharyngeal space
right so we're putting the pieces of the
jigsaw puzzle together right all of a
sudden that's all it's all starting to
make sense so what are the components of
the carotid space
well the carotid space contains the
carotid artery the jugular vein cranial
nerves nine through twelve and also the
various lymph nodes so again you you
know essentially all those components an
artery of vein lymph nodes and the
nerves arise everywhere else in the body
but again once we get to the head/neck
it starts you know head neck is really
hard right but take these anatomic
structures and give it the same
differential diagnosis you would in
other parts of the body so for instance
here's a carotid space mass right so
what's what's the diagnosis where
there's very large carotid space mass
that's what an aneurysm right here's
another carotid space mass this patient
had a prior history of a central line so
we can see the jugular vein the carotid
artery the carotid artery and what's
this from bosephus of the jugular vein
exactly right again a carotid space mass
here's another carotid space mass or
carotid space abnormality so here's the
carotid artery here's the carotid artery
the patient had trauma so what is this
right here a dissection exactly right
dissection involving the carotid artery
the previous dissection I showed
involved the vertebral artery this was
involving the carotid artery and on this
gradient echo image here you can see the
very very narrow lumen of the carotid
artery and there's
men hemoglobin now this is the classic
carotid space mass and I'll spend a
little bit of time on this because the
most important area in this region the
identifier the indicator is the carotid
artery so here's our carotid artery here
and anatomy anatomy anatomy if we can
understand the anatomy then we will be
able to properly identify the space in
which the mass is located and once we
identify this space and we'll be able to
come up with a differential diagnosis so
I mentioned before if the carotid artery
is displaced in fearly what space is it
in here pharyngeal space if the carotid
artery is displaced medially than what
spaces are then carotid space right
if the carotid artery is displaced
laterally then there's going to be a
mass pushing here so what spaces could
that mass be a retro pharyngeal space or
pre vertebral space and if the carotid
artery is displaced anteriorly than what
space is the mass in carotid right
there's a pre vertebral is going to
shift the carotid artery to the right
hand side because a pre vertebral space
is going to be in here so in this
particular case we can see that the
carotid artery is displaced anteriorly
so what space is it's mass in carotid
artery in this particular case across
already displaced anteriorly so what
space is this mass in same thing right
so internally what's the difference
between this area in this area what do
we see what do we see here
internally that we don't see on this
side what are these guys right here
somebody said it flow voids right
vessels right so both of these are
carotid space masses on this one on the
right hand side their flow voids and on
the left hand side there no flow void so
what do you think the diagnosis is here
what's that kar-- but well a Glomus
turmeric yeah some type of glomus I'll
go over the various types of glomus
tumors and what do you think the
diagnosis is here benign lesion
Schwannoma exactly a neurogenic tumor
so the classic once you get into this
area in the carotid space if you see a
benignly a very bland lesion no flow
voids that's in the carotid space then
you think of schwannoma you see a
similar-sized Leeson with multiple flow
boards then you think of Glomus tumors
now why is that important
because if we're the radiologists say
that this is a Glomus tumor then the
patients are undergoing some type of
vascular imaging whether it's CTA in
this day and age and the old days we
used to go straight to angio but if we
tell the surgeons that this is a
schwannoma and they're gonna go to
surgery right so on the other hand if we
tell the surgeon that this is a
schwannoma and what's going to happen
they're gonna be pissed right right
they're gonna be pissed cuz they're
gonna go in and they're going to be
scooping out buckets of blood right so
that's why it's very important because
this is a clinically blind area it's
deep to the tonsil it's deep to the
mandible it's deep to the parotid gland
it's in a clinically blind area so again
when we talk about the value of imaging
this is what we really provide so here's
an example again a carotid space mass
notice how there's no flow voids this is
a schwannoma and just to prove it we did
this just happened to be there we go
there's the MRA you can see there's no
flow of flow voids in this at all this
on the other hand a CTA we can see a
diffusely densely enhancing lesion
involved in the carotid space this is a
again a Glomus tumor and we'll go over
the different types of Glomus tumors and
on MR here we can see the carotid artery
displaced anteriorly multiple flow voids
within it again this is a
oklahoma's tumor so if we have a Glomus
tumor that arises between the carotid
arteries and separates the internal and
the external carotid arteries this is a
carotid body tumor and this is the same
two patient just after embolization you
can see that the carotid artery are
separated the intra on the external
carotid arteries are separated so this
is a carotid body tumor this on the
other hand you can see that the intro
and the external carotid arteries are
pushed together so when the internal and
the external carotid arteries are pushed
together that means the mass has to
extrinsic so this is what's referred to
as a Glomus Magali tumour and these
arise from the nodos ganglion if you
have the same tumor that then arises
from the skull base then this arises
from the superior cervical ganglion and
this is what's referred to as a Glomus
jugular
so the globus tumors are the same
pathology but it's just given the
different names based on the location so
a Glomus tumor at the carotid body is a
carotid body tumor a Glomus tumor in the
neck that compresses the intro and the
external carotid arteries that is a
Glomus vague alley tumor the Glomus
tumor that arises from the jugular
foramen
that's the Glomus regulary and to
complete it what do you call a Glomus
tumor that arises in the middle ear
cavity that's a glomus tympanicum tumor well the last two spaces
again are pretty straightforward in
order to understand the last two spaces
I'm how many people in the audience
majored in the classics nobody it's
terrible how many
we're biochemistry or science majors how
many didn't go to college but end up
going to med school because okay all
right hey you the person that raised
your hand you're the same person that
came in you just came in for the free
food right and instead right okay yeah I
thought so right so again as I mentioned
before the thing about head and neck is
that we take the same piece of anatomy
and then we change names mentioned as I
said before and we do the same things
when we talk about this next area
because we're now going to talk about
the sublingual space and pure and simply
the sublingual space is the space
located below the tongue so linguae is
Latin for tongue so that space that's
located below the tongue is in the
sublingual space so what forms the
sublingual space well the roof of the
sublingual space is formed by the tongue
the lateral rim of the sublingual space
is formed by the mandible the rim or the
wall of the sublingual space is formed
by this muscle right here which anybody
want to take a guess with that muscle is
mylohyoid muscle and then the base of
the sublingual space is formed by this
phone right here which is what everybody
knows that right
it's the hyoid bone we'll talk about
that later but essentially the way I
look at it is that if you look if this
is the anatomic images here's the here's
the top of the tongue here's the
mandible here's the mylohyoid muscle and
here's the hyoid bone so to me it looks
like a teacup so essentially the rim of
the teacup is formed by the mandible the
wall of a teacup is formed by the
mylohyoid muscle the base the teacup is
formed by the hyoid bone so everything
within that teacup is essentially within
the sublingual space but the here's
where the challenge comes in so these
muscles that run from the mandible all
the way back to the tongue base are
referred to as the genial glassess
muscle the Wai glasses well glasses is
actually Greek for tongue so even when
we talk about the sublingual space we
flip our roots so linguae is Latin and
glasses is Greek so the muscles
are based on the Greek roots but the
space itself is based on them on the
Latin roots so what are some pathologies
that involve the sublingual space well
the most common tumor that we see is
going to be squamous cell carcinoma so
here's a schematic illustration and on
the right hand side here's a t1-weighted
image with contrast demonstrating a
squamous cell carcinoma now these are
very nonspecific this could be squamous
cell carcinoma this could be any type of
malignant minor salivary gland tumor so
for us we can't really say much about
the specific histology so we really do
leave it up for the surgeons to biopsy
it and the pathologist to come back and
give us the diagnosis but 9 times out of
10 the pathology is going to be squamous
cell carcinoma this on the other hand if
I told you the patient had a fever what
are we going to say that this is
sublingual space abscess and here's the
rotten tooth so here we can see the
rotten tooth we can see the sclerosis
back when I was a resident we used to
call this sclerosing osteomyelitis now
the classic thing that was always
described for the head neck was
actinomycosis I think this was just a
bacterial
sublingual space abscess but if you're
taking your boards or whatever and they
say well what's a what's a pathology
involving the mandible that can result
in the chronic osteomyelitis the the
diagnosis tends to be actino-
actinomycosis and this is a mass that's
involving a cystic mass anteriorly and
midline this is an epidermoid if this
same lesion was in the tongue base than
this then this would be a thyroglossal
duct cyst in this case we have a cystic
lesion involving the lateral aspect of
the sublingual space this is a ranula
so ranula here epidermoid here and if
there was a cystic mass involved in the
tongue base then that would be a
thyroglossal duct cyst
now ranulas can involve the sublingual
space and they can eventually extend
down below the the mylohyoid muscles so
if we say that this bilateral ranula is
contained as it is here by the mylohyoid
muscle and this is what's referred to as
a simple ranula and the surgeons can
go in through an intraoral approach and
marsupial eyes the ranula so it's
pure and simply it's a pretty easy
procedure but as we'll see later if the
randula is extend deep to the mylohyoid
muscle and we can identify that on
imaging and all of a sudden it changes
how the surgical approach to these
lesions and the last space that we'll
talk about is the submandibular space
now this is very easy right so what do
you call the space that's located below
the mandible now real quickly if I still
have a couple of minutes left I'm gonna
ask you again real quick what space am i
looking at right here masticator space
perfect what space am i looking at right
here
sublingual space exactly right so when
you look at the submandibular space it's
all of this space here that's located
below the mandible and below the
mylohyoid muscle so what are the
components of the submandibular space by
far in a way the largest component the
submandibular space are going to be the
lymph nodes so the lymph nodes are
located in submandibular space these are
what's referred to as the level one or
the group one
the second most common thing that you'll
see is pathology involving the
submandibular gland so remember the
submandibular gland is located in the
submandibular space however the duct of
the submandibular gland which is
referred to as Wharton's duct extends
superiorly and runs along the mylohyoid
muscle and eventually runs in the sub
lingual space so this is an example of
enlargement of the submandibular gland
here we can see dilatation of the
submandibular duct or Wharton's duct and
the reason why this is obstructed is due
to what what's this right here anybody
it's a little stone it's a little sigh
ala litt so this is what's referred to
as an obstructive sigh Latin itis and
the cause for the obstruction is the
stone that's located in the sub lingual
space so remember that communication of
the submandibular gland with eventually
where the submandibular duct extends out
into the frenulum and another example
here this was a tough case here we have
enlargement of the left submandibular
gland down this was a case that came a
few years ago this floor of mouth CT is
the exact same patient that's associated
with this so this is a little bit subtle
but you can make the diagnosis if you
know where to look so here's a
submandibular gland here's a genial
ocess muscles here we can see en-
enhancement of the lingual arteries
here's the normal sublingual space
notice the fat here notice how the fats
obliterated on the left hand side and
the frenulum is located right at the tip
my pointer so the reason this patient
had obstruction of the submandibular
gland is because this squamous cell
carcinoma was actually occluding the
submandibular duct as it was coursing
through the sublingual space okay so
anytime the bottom line is any time that
you have obstruction of the
submandibular gland you have to take a
very close look at the sublingual space
to make sure there's no stone or to make
sure there's no aggressive lesion that's
causing the obstruction of the gland and
the last thing that we'll talk about is
here is another ranula right a little
cystic lesion and involving the lateral
aspect of the sublingual space and look
how this ranula is now extending into
the submandibular space remember I told
you before and head and neck we take the
same piece of anatomy or the same
process and give her different names
well this type of ranula that
extends deep to the mylohyoid muscle has
three names to it and that's why people
get confused anybody remember the three
names to this diving is one plunging is
two and if it's simple then you have
complex so the three names for this type
of ranula that extend below the
mylohyoid muscle are diving plunging or
a complex ranula but it is important
because if you say that the ranula is
extending below the mylohyoid muscle and
the surgeons cannot do an intraoral
approach but rather they have to do a
cervical approach so again this type of
free surgical planning is again based on
what we say on imaging so in summary
what I've tried to do over the last 45
minutes is give you a simplified
approach to the space of the head and neck
remember the masticator space muscles of
mastication visceral space as the day
goes on and you start to yawn remember
everything that you can see in someone's
yawn is the visceral space the retro
pharyngeal space is just behind the
pharynx the pre vertebral space is the
spine parotid space is self-explanatory
the para pharyngeal space is just next
to the pharynx if a carotid space
contains the carotid artery the
sublingual space is below the tongue and
then that's space below the mandible is
a submandibular space so thank you very
much for your attention
