so without further ado I'm going to end
up with the imaging of sinusitis so what
is a sinusitis sinusitis is an
inflammation of the sinuses in the nasal
cavity it's diagnosed it's a clinical
diagnosis it's based on four weeks of
cloudy or colored drainage from the nose
with congestion or pain in the face it
involves one out of eight adults in the
US with about 30 million diagnoses per
year and the direct cost of imaging is
believe it is 11 billion dollars 11
billion with the BEA dollars and it's
the fifth most common diagnosis
responsible for antibiotic therapy so I
know I always you know argue with my
wife is when I started getting pretty
bad sinuses I try to get her to write me
a prescription and she refuses she's a
pediatrician so then if I call up my ENT
colleagues I'll get my prescription for
a z-pack or something like that I know
it's not the right thing to get but at
least it takes care of things so from
from an Anatomy standpoint don't you can
go over the ostomy unit right okay so
from an Anatomy standpoint it's I think
it's important I think can you see can
you see the red pen right there anybody
see that right so in anatomy standpoint
everyone has heard about the ostia male
unit or the ostia male complex so what
I'm gonna do is I'm just gonna go over
this and you know it's late in the day
I'm getting a little tired and sometimes
I don't know what comes out of my mouth
when I get tired Joe can tell
you that sometimes I don't know what
comes out sometimes but you know I'm
Hindu right so you know if I'm a good
person I'll come back as somebody good
but if I'm bad I could come back as
something bad right if I do a bad job
and the worst thing that you can do is
come back as an ant in someone's
maxillary sinus imagine that right so if
I'm an ant and I come back in someone's
maxillary sinus I've got to figure out
how to get out of there right and
essentially in order to get out of the
maxillary sinus I've got to walk around
and try to get out well if I walk down
here into the inferior portion of the
maxillary sinus this has a specific name
to it this is the alveolar recessed of
the maxillary sinus and there's no way
out right if I walk up this way I try to
get out then I'm at another recess of
the maxillary sinus and that's the
zygomatic recess of the maxillary sinus
if I walk up to the roof of this there's
no one there in fact once I walk to the
roof of the maxillary sinus this is now
contiguous with the inferior the the
inferior wall of the orbit but then if I
continue walking lo and behold I can
find a way out and that way out is
referred to as the primary ostium of the
maxillary sinus so if I'm as I now I
found a pathway so now I'm exiting
through the primary ostium of the
maxillary sinuses and now I'm
essentially in a cave right here a
little channel if you will and the name
of that channel as I'm escaping the
maxillary sinus is referred to as the
ethmoidal
infundibulum so when I look at this area
here this little space right here is the
ethmoidal infundibulum now in order for me
to continue my journey on the ethmoidal
infundibulum you know I have to walk on
something right and what I'm walking on
is this bone right here and this bone is
referred to as what anybody that's the
that's the uncinate process so the
channel the air channel that I'm trying
to escape is the ethmoidal infundibulum
but the bone that I'm actually walking
on this little slope right here is
called the uncinate process now you know
I've spent a lot of time walking in this
maxillary sinus trying to get out and I
get all the way up to the top of this
I'm walking through the ethmoid
infundibulum I'm on the uncinate process
and oh my gosh I get to this cliff right
here and the area where my pointer is
right now runs anterior to the posterior
and it's referred to as the hiatus
semilunaris that's the hiatus
semilunaris and then I found my escape
all I have to do is jump off the
uncinate process and I land in the
middle meatus so this is the middle
turbinate and this is the middle meatus
so what I've diagram for you is the
ostial male unit or the Ostial male complex
and it's comprised of the primary ostomy
the maxillary sinus yet ethmoidal
infundibulum
the uncinate process the hiatus
semilunaris the middle meatus and then
the middle terminate so when someone
undergoes functional endoscopic
sinus surgery this is what they're
trying to open because what I've
outlined for you by trying to escape the
maxillary sinus is a normal sinus
drainage of the maxillary sinus and so
when someone performs functional
endoscopic sinus surgery what the
surgeons do is they go in and they
resect part of the ethmoid sinuses the
middle turbinate they take out the
uncinate process and essentially what
they're doing now is expanding the
opening between the medial portion of
the maxillary sinus and the nasal cavity
to permit greater egress of all the junk
that builds up into our sinuses into the
nasal cavity so that's the purpose of
functional endoscopic sinus surgery so
is that does that make sense to everyone
okay all right so what are the imaging
recommendations well first of all
radiographic imaging of the paranasal
sinuses is unnecessary in patients who
have already met clinical diagnostic
criteria and these are actually the
recommendations from the AAOHNSF
criteria that are that are on the web
it's still recent the recent updates and
imaging is indicated in patients with
either potential complications of
sinusitis or when considering an
alternative diagnosis just like the
tumors that Doug talked about and
certainly as we have evolved the ACR has
stated that plain films of the sinuses
are inaccurate and should be replaced by
CT so it's not just us there's a
radiologist this is the the best
practices now and it's general consensus
that MR is greater than CT for
intracranial complications now one thing
I just want to emphasize to the
residents and the fellows and I guess
you know the staff that are here too is
that the diagnosis of sinusitis is a
clinical diagnosis in the clinical
diagnosis like I mentioned before was
based on four weeks of cloudy or colored
discharge from the nose in congestion
and the reason why I emphasize that is
that you know I decided to become a head
neck radiologist by second day of my
residency so my the second day of my
residency I wanted to go into head and
neck right and so I was on the
neuroradiology rotation and somebody
sort of pointed out the skull base ram
and I said this is really cool this this
is what I
want to do like you know this is great
so the next time I was on the
neuroradiology rotation I'd already
decided I wanted to go to head neck
right and I thought to myself I know
these sinuses these ethmoid sinuses so I
was on the ICU rotation neuroradiology
and I thought you know I'm a pretty
smart guy right so because I know I can
see the ethmoid sinuses and I see a
bunch of junk in them in all these
intubated patients I started saying no
evident no change in the ventricular
size shape and configuration number two
findings consistent with ethmoid
sinusitis in all of the patients in the
ICU right so about two weeks into the
rotation my division chief comes up to
me and says hey how's it going I said
fine he said can I talk to you I said oh
he's gonna say what a great job I'm
doing I used to it comes to me I kind of
puts his arm around me and said hey you
know you may want to stop saying ethmoid
sinusitis I said why he said because all
the ents residents are kind of pissed off
right now because they're all getting
consulted on every report and what
you're saying ethmoid sinusitis so from
that point on I learned remember good
judgment comes from experience and
experience comes from bad judgment so
from that point on I realized you know
sinusitis is a clinical diagnosis and
really our job is to define the extent
of disease and if there is a clinical
diagnosis of sinusitis we can comment on
the findings that can support that so at
this talk I'll talk a little bit about
cysts and polyps we've already talked
about the anatomy I'll just reiterate
that later talk a little bit about
mucocoels fungal diseases and then
we'll end with a little bit of radiation
dose awareness now Doug already talked a
little bit about cysts vs polyps I'll
just add just a couple caveats
so the sinuses are lined by mucosa and
within the mucosa themselves are mucous
retention cysts and serous retention
cysts so the true definition of a cyst
is the obstruction of one of these
glands and if there is an obstruction of
a mucous retention of a mucin assist
it's a mucous retention cyst if there is
obstruction of a serous cyst it becomes
a serous retention cyst but the bottom
line is they look all
same so this is a CT scan here we can
see this smooth margin lesion that has
low attenuation it looks fluid and this
is a t2-weighted mr and we can see that
it contains fluid so this is a classic
cyst not much to be taught here right
well what's a polyp a polyp is
something different a polyp is
infiltration of eosinophils into the sub
mucosal layer of the sinus mucosal
lining so whereas a cyst was an
obstruction of the cyst with in the
mucosa itself a polyp is infiltration in
the sub mucosal layer and this is
typically seen in patients that have
allergies infections aspirin
intologence cystic fibrosis is pretty
common in motile cilia and other
vasomotor impairments and this is what a
polyp looks like now we typically don't
do mr especially give contrast to
evaluate for polyps we usually do CTs
but this is a contrast-enhanced
t1-weighted image with fat suppression
and I can think I can convince you with
the leap of faith this little white line
here is enhancement of the mucosa
but everything below the mucosa in the
sub mucosal layer is a polyp
so that's the true polyp and when this
is taken out this is what it looks like
so this is all this polyploid junk
that's been resected in the sub mucosal
layer so this is the true definition of
what a polyp is now from a practical
standpoint when I did my fellowship I
would discuss with my old mentor I'd
say well you know do I say cysts or do I
say polyps is it a cyst or is it at a polyp
and it's there's a pendulum that goes
back and forth the way that I was taught
25 years ago and I have not varied from
this is that I refer to this as
polyploid mucosal thickening because
some people will say well this sort of
looks rounded so it's gotta be a cyst
but in actuality this could easily be a
polyp and Doug showed some very nice
cases of antrochoanal polyps and I'll
show a case too but the point is is that
just on non-contrast CT alone the
standard sign of C T's that we do we
just can't tell so I use the term
polyploid mucosal thickening and then
I'll just
talk about the extent of disease now I
will specifically comment on extent of
disease whether or not there's an air
fluid level whether or not there's bone
erosion multiple diseases specifically
as I mentioned before comment on the
integrity of the primary ostium of the
maxillary sinus that's all in the report
but to actually try to make a histologic
diagnosis without the secondary findings
of bone erosion or as we'll see some of
the other findings we'll talk about in
some of the more complex inflammatory
diseases we just stay away from that now
I think we can all make the diagnosis
you heard Doug talk there's a lesion
here that's extending through the
primary ostium of the maxillary sinus
and extending into the nasal cavity so
this is a type of polyp and anybody want
to guess what type of polyp this is yeah
it's an antrochoanal polyp so going
through the antrum of the maxillary
sinus into through the choana so this
is the antrochoanal polyp that we just
we just talked about alright what about
quote unquote sinusitis now we talked
already about the drainage pathway so in
the maxillary sinus we talked about
those pathways in the sphenoid sinus it
has a pathway to it's a sphenoid with
moidal recessed but in general when we
talk about as cute sinusitis the
pathogenesis of acute sinusitis arises
from and I'll just going to point this
out in the maxillary sinus the most
common area is if you have obstruction
of the primary ostium of the maxillary
sinus if you have obstruction this
results in a reduction in the amount of
oxygen in the maxillary sinus and now it
just starts to create this ugly stew
because this reduction and the oxygen
tension results in an inflammation of
the sinuses and unfortunately it becomes
a cauldron in which various bacteria can
begin to grow and this is the
pathogenesis of acute sinusitis and this
is what we can see so clinically like I
said before huge sinusitis is a clinical
diagnosis so what do we say on imaging
when we see something like this and when
we see something
yes well one thing that I've learned
over time is that this patient was
performed in the coronal plane so if you
see someone performed in the coronal
plane we have to realize that this is an
air fluid level and we've evolved in
that back in the days when when I was
growing up we would do our sinuses in
the coronal plane so we'd have to look
at that air fluid level remember now
oftentimes we'll do axial images and
reconstruct in the coronal plane so in
that case the air fluid level is not
going to look like this rather it's
going to look like this and when we do
our coronal reformats
it's not going to look like a typical
air fluid level so you have to be aware
in the plane in which you're imaging and
as a result realize the fluid is going
to be more dependent so this is an air
fluid level so we can say in a patient
that has clinical signs of acute
sinusitis we can see that there's an air
fluid level which is consistent with the
clinical diagnosis of acute sinusitis
similarly on this mr we can see this air
fluid level now I know there are some
people that have talked about performing
especially with the radiation dose
issues that have been brought about the
last five years it's again it's always a
pendulum some people have said maybe do
a very quick t2-weighted image to look
for just a quick t2 image just to look
for air fluid levels and the extent of
disease we tend not to do that I don't
Doug have you done that at all yeah doesn't
either so in general we still are doing
CT in order to look for those air fluid
levels now here's some disease here
involving the frontal sinus we can see
there's complete opacification of the
frontal sinus and you know sometimes
there's certain areas that you have to
increase your what's the right word you
have to turn up the gain you have to be
very concerned about focal disease in
specific areas and and I'm going to
point some of those out and one of those
is the frontal sinus so patients with
frontal sinus disease do present with
headaches and typically if you see
something like this you can say well
okay it's frontal sinus disease he
probably has headaches we're done but I
will caution you that if you're not if
you're not
vigilant and that disease is not treated
you can go on to develop this type of
disease so here we see an abscess that's
involving both the outer and the inner
table of the frontal bone deeply we can
see a subperiosteal abscess and an
empyema and then in the soft tissues we
can see a little abscess right here and
this has a certain name to it and again
for those of you that like to look at
the origins of names anybody we know
what this is called yeah this is a Potts
puffy tumor now I've done look it up I
don't know if this is the same pots that
develop potts disease I think it is yeah
so this is this in fact is Potts puffy
tumor so when you look at this on the
sagittal images we can see this abscess
right here involving the soft tissues of
the of the scalp and on the sagittal
images we can see this area right here
there's our subdural empyema and then on
this agile t1-weighted images we can see
all of this dural enhancement consistent
with the severe meningitis so this is
the result of acute frontal acute
sinusitis involving the frontal sinus
that's untreated if this continues to
grow on you can develop a osteomyelitis
involving the frontal bone so this is
just frank bony osteomyelitis if it's
untreated it can go on to develop a
large subdural empyema and if you have a
large subdural empyema what is the
structure that's located right here so
this is the falx but what runs directly
along the falx this your superior
sagittal sinus so you have to be aware
of this and if you have a patient that
has subdural empyema you always have to
look at the superior sagittal sinus
because in this case we can see t1
shortening right here and this is
superior sagittal sinus thrombosis and
if that is not picked up and
appropriately treated this is the MRV
demonstrating the absence of flow in the
superior sagittal sinus and then on the
axial images this is a large venous
infarct involving the posterior aspect
of the left cerebral hemisphere so this
is a venous in far to superior sagittal
sinus thrombosis
well how do you work up superior
sagittal sinus thrombosis and I think
it's evolved over time there are
different opinions on this and my own
feeling is that if we have a patient
that's really sick like this we want to
get them in and out of our radiology
department as quick as we can and get
the study that's going to be most
diagnostically reproducible so we tend
to do a lot of CTV so in this case
here's a CTV in a patient that has
superior sagittal sinus thrombosis and
we can see absence of flow and I know
there are a lot of people don't say well
what about MRV why not do MRV MRV is
is good that the benefits of doing an MRV
is that you can do the
diffusion-weighted imaging to look for
the infarct
and i think it's certainly in in
pregnant patients MRV is is good
because you can avoid giving the
contrast but I think in general for the
average person that comes in that's not
pregnant that's not actively lactating
that's not breastfeeding then I think
doing a CTV is a very quick and easy
study to do unless your neurologist
specifically want to look at the
diffusion to look for a potential venous
infarct so I think if they do have focal
seizures that could be cortical
cortically based then you may want to do
an MR to look for the diffusion
abnormality but in general I certainly
like to do the CTV and this
is the example on the sagittal image and
the proper terminology for this is what
anybody know what this is called here
it's called the Delta it's called a a
delta sign and the reason it's called a
delta sign is because there's no flow
involving the superior sagittal sinus
and all the vena structures it's getting
into the vein right here so this is
actually the leaves of the dura that
formed the superior sagittal sinus so
instead of the flow occurring within the
lumen it's redirected into the walls of
this of the superior sagittal sinus
now what about chronic sinus disease
well we can make the diagnosis of
chronic sinus disease and what we look
for obviously is evidence of reactive
hyperostosis so on the right hand side
normal normal aeration of the sinuses we
can see a very very thin bone
here but on the left hand side we can
see diffusely thickened of walls of the
sinus involving both the anterior and
posterior walls of the maxillary sinus
and we can see that we can clearly say
that this is disease is not acute but
it's chronic and sometimes we are asked
is this acute or chronic and this is the
finding that tells us that this disease
has been around for a while now if we
have really chronic disease it can go on
to form this disease entity which is a
mucocoele
now the mucocoele by definition is the
following it's complete obstruction of a
sinus that also expands the sinus so the
mucocoele is a form if you will of
chronic sinusitis now the typical mucocoele is well-defined it completely
opacifies the sinus and on MR on the
non-contrast t1-weighted images we can
see that there's high t1 signal and this
is due to the protein content now mucocoele
if it expands the sinus again can be
like a water balloon but because you
have all this intrinsic protein when you
look at the CT scan it can sometimes
give you a pretty ominous appearance so
this was a pathologically proven mucocoele
but notice how it's eroded through
the frontal sinus and it also contains
high attenuation within the process
itself so this is a mucocoele so
occasionally they can give you a bit of
a confusing appearance just because of
the protein content another example this
is a mucocoele here complete
opacification of the frontal sinus I
think I can easily convince you there's
an expansion of the sinus with filling
thinning of the anterior and posterior
walls of the sinuses this is another
mucocoele that's involving the
anterior and posterior and excuse me
that middle and posterior ethmoid air
cells and the sphenoid sinus this just
emphasized the fact of another mucocoele
involved in the sphenoid sinus and
look at it on t2 it's very dark so
that's why sometimes I'm a little bit
leery about commenting on the sinuses
when I do a brain MR because I've seen
brain MRs when you look at the ethmoid
sinuses they look completely completely
aerated but in actuality you can come
back
and they're completely opacified
because if there is chronic disease this
de phasing from the ferromagnetic
accumulation of various heavy metals can
give you the signal loss so that's why
I'm a little bit leery just to comment
on the sinuses just purely on
t2-weighted images and this was a post
traumatic mucocoele this was given by
Bill Nemzek many years ago this was a
guy who was messing around and his wife
walked in and found him with somebody
else and got a pickaxe and went out his
brain so unfortunately there's a bunch
of traumatic mucocoele you know
fortunately with all this frontal lobe
atrophy he didn't remember a thing oh
wow you guys are terrible okay all right
it's just just awful all right so anyway
he did develop post traumatic-- are getting it
all right yeah okay but he did develop
these post traumatic mucocoeles
involving the frontal sinus now one of
the areas that you have to watch out for
are the pyomucocoeles so remember I
mentioned to you about their certain areas
where you have to have heightened
scrutiny and one of those areas is the
frontal sinus if it's completely
opacified but the other area is a
sphenoid sinus because if you have a
sphenoid sinus that becomes infected
realize all the structures that are
located adjacent to the sphenoid sinus
so posterior that sphenoid sinus is that
directly opposition to the pre pontine
sister and the CSF laterally the
sphenoid sinus is directly adjacent to
the cavernous sinus so we have to be
careful because in this case this was a
pyomucocoele and on the coronal images
this was a very subtle subdural empyema
and this patient ended up having
cavernous sinus thrombosis which I'll
talk about in just a little while and
this is complications of sinus disease
so on the right hand side here well here
we have a normal appearance of necklace
cave and we can see that there's this
diffuse inflammatory process that's
extending into the cavernous sinus and
we can see marked narrowing of the carotid
artery within the cavernous sinus and
this is all due to phlegmon and another
example here this is example of a
cavernous carotid aneurysm
in a patient that end up having an
inflammatory process that weakened the
wall of the carotid artery developing
this large carotid artery aneurysm on
one side and on the opposite side it
actually occluded the carotid artery you
now like I mentioned before good
judgment comes from experience and
experience comes from bad judgment and
why do all bad things happen Friday
afternoon you ever you ever noticed that
right so this is true this was back when
I was at U of M I was the ER I was
on the ER rotation and we'd end at 6:00 I'd
just gone through a whole bunch of
studies I was getting tired and it was
literally the last case and the history
came in sinus disease I got another
sinus disease right so have you ever
dictated something and then have this
feeling of impending doom you ever done that
you know that you know in the good old
days when we had transcription you know
we could dictate something and then
actually think about it and then when
the report came back we could actually
you know be like a pathologist and you
know think about it look things up and
then sign it off right now now once we
give that dictation and we hit Send it's
gone right yeah you may have a couple of
minutes to hit the ups button do you
guys have an oops button on your voice
recognition so you may be able to pull
it back but I sort of dictating this out
and I thought well here's just some
you know there's a little bit of disease
involving the sinuses here there's not
too much going on and but something
didn't smell right and so when I went
back and looked at it I saw all of this
reticulation in the retrobulbar fat so I
called up the emergency room and I said
and there's some dilatation here
involving this vein so I called up the
emergency room and I said is there
anything going on with this patient with
sinusitis and they said oh yeah I'm like
oh great what else he said it's a sixth
nerve palsy oh great all right a sixth
nerve palsy so let me go back and look
at it then you know you picked up the
dilatation of the superior ophthalmic vein
the reticulation of the fat and any time
that you have a patient with sinus
disease and you have a cranial nerve
palsy you've got to take a real hard
look to make sure he doesn't have this
disease he or she doesn't have this
disease entity so this disease entity we
diagnosed based on in this case in a CT
venogram
so here we can see opacification of both
transverse sinuses but when we look in
this area here we see opacification the
carotid artery but what's not opacifying
here the cavernous sinus so this is
cavernous sinus thrombosis and this is
one of those cases that you know I'm
back when I was a when I was a resident
and I was gonna do my fellowship you
know I kept calling up the person I was
gonna work with Tony said hey I want to
I want to write a paper I want to write
a paper and this was before the days of
email and texting right imagine what
that would be like there was email and
texting I'd be emailing and texting them
every day but this was we had phones
right so I'd call him up and so he
finally threw me a bone and he said I
got to get this guy off my case right so
he gave me six cases of cavernous sinus
thrombosis to write up and you know for
the residents in the audience whether
you're ENT or radiology I'm sure that
you know sometimes you say well I don't
want to do this research stuff it's kind
of boring even if it's a case support
there's nothing out of it and one thing
I'll tell you is that if you ever do
write a paper you've become an expert in
that subject matter and it's amazing
that will stay with you for the rest of
your life so the thing about cavernous
sinus thrombosis it was an old saying it
says you only see what you look for and
you only diagnose what you know and when
we looked at those six cases of
cavernous sinus thrombosis all six of
those patients either died or had
significant neurological deficits and
the real scary thing about it is that
they were actually initially on the
imaging study but they were missed so to
think about cavernous sinus thrombosis
just remember anytime that you have a
patient with cranial nerve palsy with
sinus disease you have to think of that
diagnosis and this was one of the cases
at my old place and it still kind of
haunts me but this came in in the middle
of night and I thought you know you
can't fault the residents or the ER this
is that disease involving what is
isolated disease involving the sphenoid
sinus and when you look at the brain CT
this was a kid you typically don't have
this dilatation here involving the
temporal horns and unfortunately this
child was dead 12 hours later and I
think what the kid had was probably
developed an empyema and cavern
sinus thrombosis and died from this so
you know nothing unfortunately couldn't
do much the the the ER wasn't expecting
that but the patient did have cranial
nerve palsy so when you see this and
especially when you see dilatation of
the horns like this you know have a
really low threshold about working these
kids up so yeah you may do an
inappropriate imaging study but on the
other hand you do have the problem you
you do avoid the risk of having this
type of really significant severe
outcome and this is just a bone
algorithm see all this disease involving
that sphenoid sinus so you have to be
very cautious about that well the next
thing that I'll talk about its fungal
sinusitis and again when we talk about
the value of radiology in 2016 um one of
the things I think we can really make a
difference is to be able to educate our
referring physicians on fungal sinusitis
because when I asked our my colleagues
in internal medicine and others about
fungal sinusitis most people say well
all fungal sinusitis is invasive disease
it's the mucormycosis it's the invasive
aspergillosis well that's not
necessarily the case there's actually
different types of fungal sinusitis and
we as radiologists can actually help
triage those patients so the first type
is this and this is the allergic
rhinitis or the hayfever and these
findings are nonspecific you know it's
just like we looked at before Doug made
a funny comment is that you know how do
patients with tumors present they
present with sinus disease right who has
runny nose well we all may have tumors
right yeah it's the same thing with
allergic rhinitis you know it's pretty
ubiquitous the symptoms are they're
pretty nonspecific so there's no imaging
criteria that tell us that this is
allergic rhinitis but one point I want
to make is that look at the types of
bugs that can cause allergic rhinitis
it's aspergillosis and it's also mucor
but the key thing is is that these
are non-invasive types of aspergillosis
and non-invasive types of mucor but
these are all types of fungal sinusitis
the second type of fungal sinusitis is a
mycetoma and
again it's typically formed by
aspergillus and in a normal host the
Aspergillus is non-invasive and it
cannot actively penetrate the membranes
because it has no keratolytic
properties in a normal host so again
this is a type of fungal sinusitis and
this is what we typically see so here's
your characteristic fungus ball that's
floating in a chronically diseased sinus
so here's your typical mycetoma
typically well defined it's high
attenuation and high attenuation is felt
to be due to some type of concentration
of heavy metals whether it's iodine or
whether it's manganese or whether it's
any type of heavy metal that's what's
felt to give the high attenuation within
the mycetoma the third type of fungal
sinusitis is this and this is allergic
fungal sinusitis and this is a disease
that we can diagnose as a radiologist
now the ENT surgeons I assume you know
about this disease entity because this
is separate from the invasive fungal
sinusitis but when you look at it it can
look pretty bad but this is a spot
diagnosis that we can make so when you
look at something like this the key to
making this diagnosis is that all three
of these patients underwent a
non-contrast CT so non-contrast CT and
what we see here is a pretty aggressile
disease that's involving multiple
sinuses and contains high attenuation so
if you see something like this involving
multiple sinuses high attenuation
expansion of the walls can actually
extend intracranially but we did not
give contrast there's really only one
thing this can be and this is allergic
fungal sinusitis and again I you know
I've never done a functional endoscopic
sinus surgery but what's been written in
the literature and what my antiques
colleagues tell me it's almost like
toothpaste when you go into a peanut
butter you go in there and you slowly
resect it it's very peanut buttery
consistency and so the surgeons go in
they try to take out as much as they can
and then the patients are put on some
type of low dose steroids if I'm correct
and they actually have
very good prognosis and this was a case
when I was at UNC many years ago this
was a 14 year old kid that was
transferred into UNC
after a renal transplant and this was
red on the outside as a rhabdomyosarcoma
so not only did the kid have a kidney
transplant but now they have a
rhabdomyosarcoma well we looked at this
no contrast was given and we just made
the diagnosis of allergic fungal
sinusitis now what are the other things
that tell us this is not a
rhabdomyosarcoma well first of all we
talked about the internal attenuation
but then look at the bone you see the
bone right here with something this big
if this was a rhabdomyosarcoma there
really should be very aggressive bone
destruction but in actuality the bone is
expanded it looks like it's regressive
remodels so we have involvement of
multiple sinuses there's high
attenuation on the non-contrast CT and
the final finding is that this bone is
more expanded as opposed to aggressively
destroyed just one other point here this
is an MR if you looked at this we can
say Wow looks pretty normal but on the
other hand when we perform a CT scan we
can see that what we thought were
aerated sinuses especially in the
sphenoid sinuses was chock-full of
disease and that disease again was high
attenuation due to the allergic fungal
sinusitis well this is the bad one this
is the invasive fungal sinusitis and
this is mucormycosis and invasive
aspergillosis and the first stage of
this disease you really can't tell you
know we can be here all day and look for
an abnormality but this looks like any
type of polypoid mucosal thickening that
we talked about before but on the other
hand this finding was described about 20
years ago I should say 15 years ago and
these are the earliest findings of
invasive fungal sinusitis so really to
add our value and I'm going to show a
few case of invasive fungal sinusitis in
order for us to really make a difference
the take-home is that we have to be
familiar with the early findings of
invasive fungal sinusitis so if you have
someone at high risk the areas that you
need to look for are the soft tissues
anterior to the wall of the maxillary sinus this is called the canine
fossa and then the area posterior we've
talked about this already the
pterygopalatine fossa and the pterygomaxillary fissure so look at the fat on
the left hand side you see how there's
nice crisp fat these are the superficial
muscles of facial expression and postierily we can see the fat involving the
pterygomaxillary fissure but notice
how the bone looks like it's intact but
you see all this grayness right here
that's actually extension of this
disease through the bone through these
emissary veins and into the soft tissues
if you can catch the disease at this
point you can really really make a
difference another example here subtle
finding but this is located right in the
pterygopalatine fossa so if you have
someone that's immunocompromised that's
had any type of kidney transplant that's
a uncontrolled diabetic these are the
patients at highest risk and these are
the areas that you really need to
concentrate on just compare the fat on
the right side with that on the left
another example here who sees where the
abnormality is is the abnormality on the
left side or the right side first of all
right side good on the right side is the
abnormality at A B or C you got it A B
or C it's a little bit more subtle here
but this is where the real abnormality
is here that's where you can make a
difference because this was invasive
fungal sinusitis another example here
invasive fungal sinusitis is extending
out into the soft tissues of the cheek
and again look back here see all this
disease here involving the
pterygomaxillary fissure that's where you make
a difference so in this particular case
this is more advanced right I think
everyone can make this diagnosis could
this be a tumor absolutely but if I tell
you the patient was status post a kidney
transplant and we can make that and he's
very sick we can make the diagnosis of
invasive fungal sinusitis so here's an
example here disease here involved in
the pterygomaxillary fissure
wasn't picked up wasn't treated the
patient came back and then developed all
of this erosion involved the anterior
and posterior wall of the maxillary
sinus then the disease extended
superiorly into
at pterygomaxillary
fissure in the pterygopalantine fossa
once it gets into this area I get one
sorry one more example here here's this
disease involving the canine fossa later
on the same patient everything is eroded
and now we start developing this disease
in the masticator space one more example
invasive fungal sinusitis extending back
into the nasal cavity erosion into the
sphenoid sinus erosion of the posterior
wall the maxillary sinus into the
pterygopalantine fossa this disease
that once that get there can extend
laterally to involve the masticator
space as the seen here and here's a
coronal image involving the masticator
space but it's also extending superiorly
to involve the floor of the orbit and
also involve the muscle once this
disease gets up into the inferior
portion of the orbit it can extend into
the cavernous sinus and in this case we
can see abnormal enhancement involving
the medial portion of the right temporal
lobe and a different patient this went
on to form an intracranial brain abscess
involving the temporal lobe now this was
a patient that still haunts me still
haunts me because this is again when I
was at UNC this was a patient that was
status post I think it was I think it
was a kidney transplant and we actually
saw this diagnosis and we made the
diagnosis of invasive fungal sinusitis
so here we can see the enhancement of
the sinus and if you look closely we see
this enhanced with the mucosa but look
at the brain this patient ended up
having a cerebritis that were result of
the invasive fungal sinusitis I remember
talking with the neurosurgeon I tried to
convince him to go back in and
potentially resect that portion of the
brain but they opted not to and
fortunately this was the the autopsy
this patient end up dying of this
disease and here we can see the Burling
in here of the frontal lobe this is just
all eaten away brain from the cerebritis
the other thing too is invasive fungal
sinusitis can be angiophilic once it
gets into the cavernous sinus it can
jump on the carotid artery it can
compress the carotid artery and this
patient developed a huge MCA infarct
from the invasive fungal sinusitis as it
literally just constricted the carotid
artery
so that's why I emphasize in this
specific disease it's important to
diagnose it early if we can diagnose it
early and know the early signs we can
make a difference but to be honest with
you once it's already spread out into
the soft tissues of the face to be you
really can't do much it becomes very
very difficult the last thing that I'll
talk about very briefly is radiation
dose awareness now and I know I'm
preaching the choir on this is I would
of how many of you in the audience
actually look at the dose the DLP report
from your sinuses got one right start
looking at that okay because you know
the thing that you don't want to happen
is have radiology end up on the New York
Times and every 7 years ago every seven
or eight years now dose awareness is
there and we went through this massive
thing when it was shown that David
Brenner came out with the articles and
says that CT radiation dose can cause
cancer and I think it's a little bit
debatable cumulative dose and so on and
so forth but I think what it did do it
increase our awareness to actually look
at the amount of dose that we're giving
so I would encourage you is that when
you're looking at your CT of the sinuses
take a look at the DLP the dose length
product now it's statute in the state of
Michigan that each CT that we do has to
have this dose link product recorded and
sent to the pack so it is part of the
patient record if you're from California
this DLP actually goes in your report in
Michigan it's not in our report but it
is on the images so I would encourage
you to look at this and the best
practice now I would say it varies a
little bit but certainly anything over
500 right now for a DLP is way way too
high so our DLP s here at MSU are
probably around a hundred to 200 so
really that's where it should be in fact
you can even get it down lower than that
especially if you have some of the MBIR
things we use Acer here but if you
have some of the MBIR type dose
reduction you can get it down to 80 or
90 the challenge is is that it
a little bit grainy but the take-home
message is to start to look at these dose
length products because if you're not
looking at it eventually someone else
will and I would say I don't know Doug
what do you think it should be the sweet
spot our sweet spots between about 200
to 300 is that what you all are that's
right so I think that's the area where
we should be alright so in summary we
talked about cysts versus polyps sinusitises mucucoeles remember the fungal
sinuses it's hayfever mycetoma
allergic fungal sinusitis which is a
diagnosis we can make and also invasive
fungal sinusitis and look at the
radiation dose awareness
