so what I'll go ahead and do is end with
the brachial plexus and how many people
love the brachial plexus right yeah
that's why you're still here and half
the audience left because you love the
brachial plexus right well the brachial
plexus for those of you that are
here I can assure you by the end of this
I will make a bet with any amount of
money you will understand the brachial
plexus in 40 minutes you will be able to
identify the anatomy you trust me on
this one yes in that residents the back
row you trust me on this one yeah all
right all right and the way I'm going to
tell you is that next time you look at a
cervical spine CT or or neck mr just
ignore the accessory organs just look at
these structures and you will always see
the brachial plexus promise you
so the brachial plexus arises from the
anterior divisions of c5 through t1 now
there are some variations in innervation
some people say goes from c4 through c8
it's called a prefix plexus and
sometimes c6 to t2 posts for the fixed
but really for the purposes of this talk
just remember the brachial plexus goes
from c5 through t1 this is the classic
anatomy that we learned in medical
school we always learned that radiology
techs drink cold cold beer right and
that's the roots trunks divisions cords
and branches so if you could remember
that your radiology techs drink cold
beer you'll always remember the roots
the trunks the divisions the courts and
branches that's the mnemonic that I
remember and often times as I meant the
reading room I'll just remember that
I'll say what radiology techs drink
and if beer is too offensive you can say
beverages okay
now let's go ahead and with the standard
anatomy that we learned in medical
school so this is the route so this is
c5 and c6 and if you're following at
home just look at the schematic
illustration over here but c5 and c6
combine to form this upper trunk then c7
continues by itself to form the middle
trunk and then c8 and t1 combined to
form the lower trunk so you've got your
upper your middle and your lower trunks
then the trunks divides and so you have
the anterior divisions and the posterior
divisions and these divisions eventually
go on to form the cords now the cords
are given their name by the relationship
with
subclavian / axillary artery so if
you're purists and you read the anatomy
textbooks it's the axillary artery for
me I just say subclavian artery so the
posterior cord lateral cord or medial
cord is that relationship with the
axillary / subclavian artery so that's
the anatomy that we all learned in
medical school
remember the 10% of us that went to
medical school maybe that 10% left and
the 90% that didn't go were still in the
room but that's the anatomy that we
learned in medical school
now the surgeons have their own
relationship or their own anatomic
classification with the brachial plexus
and they refer to it as the
supraclavicular plexus the retro
clavicular plexus and the infra
clavicular plexus so when we look at the
supraclavicular plexus this essentially
are the roots some small spinal nerves
and the trunks the retro clavicular
plexus are the divisions and the infra
clavicular plexus of the cord so
remember radiology techs drink cold
beverages okay
just in case anyone found it offensive that's a surgical
Anatomy now what I say is then the
Radiological anatomy now the
Radiological anatomy can be easily found
if you remember three pieces of anatomy
just three pieces and since the crowd
has thinned out at the last lecture of
the day it's been a long intense day I'm
going to preach the choir and I'm going
to emphasize this over and over again
because if you remember these three
pieces of anatomy you'll always find the
brachial plexus
so the supraclavicular plexus remember
this area right here the roots and the
trunks is located between the anterior
and the middle scalene artery so here's
the anterior scalene excuse me the
muscle and here is the middle scaling so
Scalinious anterior scalinious medias
and posterior are combined and
within the plane of these muscles are
the roots and the trunks of the brachial
plexus so here's an anatomic this is
from the anatomic visible human project
on your left and a non-contrast t1 on
your right so if we look at that you
just have to identify where the anterior
scalene is so let's work our
way centrally and work our way peripherally
here's our trachea here's our
esophagus here's a thyroid gland carotid
artery as we come out here is the
anterior scalene here's a longest coleye
muscle here's the middle scalene so
where is the brachial plexus at a B or C
B, you see how it's right there once you
know the anterior in the middle scalene
it just jumps out at you now let's look
at the non-contrast axial t1-weighted
image so anterior scaling middle scaling
everybody see the brachial plexus right
there standard standard those those are
the two muscles for the supraclavicular
brachial plexus so anytime you again
ignore the vertebral bodies and the cord
next time you look at the cervical spine
mr Ct start looking at the brachial
plexus and I can guarantee if you do
this for the next five days and just
look at two or three brachial plexuses on those this will be embedded in
your memory for time in memoriam now
what about the other parts the plexus
the retro and the infra clavicular
plexus can also be easily seen because
remember what was a relation how were
the cords named the cords were named by
what by their relationship to the
subclavian / axillary artery so if you
find the subclavian or the axillary
artery then just adjacent to it you're
going to find the cords of the brachial
plexus it's that simple so again on the
visible human project here is the
subclavian artery and there are the
cords of the brachial plexus
similarly there it is on the right side
you see them laying right there and then
on this non-contrast coronal t1-weighted
image here is a subclavian artery and
just like pieces of linguini and
spaghetti there are the cords of budding
the brachial plexus so one of the things
when I first learned the brachial plexus
or I should say when I first did learn
the brachial plexus as a resident and
bless my attendings heart great folks
and they were trying to teach me the
brachial plexus and they first said here
it's on the sagittal Anatomy it's always
on the sagittal anatomy I didn't even
know the axial anatomy that well and now
I have to transfer to the sagittal
anatomy once you understand the
axial anatomy mean you know the anterior
scalene middle scaling the subclavian
artery then I think the sagittal image
makes more sense so here's a sagittal
images here's anterior
here's posterior so this muscle right
here is what coming down that's the
anterior scalene what structure is this
right here
subclavian artery and just adjacent to it
are the cords of the brachial plexus
everybody see that yeah what's this guy
right here
yeah jugular vein and this is what the
clavicle right it's always scary to me
back remember well gosh when I was in
medical school they used to have us try
to put central lines and in the VA
patients remember those days and when
put them in reverse out valve put him in
reverse Trendelenburg and would have them
da a valsalva and they would so it's
easy with the central line just poke it
behind the clavicle and I'm so glad I
didn't know what the hell I was doing I
didn't know exactly where the lung was
what's relation to the subclavian vein
because it's easy to drop a lung right
sometimes it's better what you don't
know instead of what you know so what
are some symptoms that go with brachial
plexopathy well a brachial plexopathy is
defined as supraclavicular and shoulder
pain it's worsened by palpation of show
a little movement and occasionally it
can be associated with a palpable
abnormality now sometimes you can
localize it and if you have a brachial
plexopathy associated with a paralyzed
diaphragm that typically means involving
the phrenic nerve so that indicates
something in the upper plexus whereas as
will see the Horner's syndrome goes from
c7 through t1 and that indicates
something in the lower plexus there are
various causes for brachial plexopathy
but being the first one that we'll talk
about is traumatic course causes a
brachial plexus me I think there was
someone that was talking to earlier
about when to perform imaging and
brachial plexopathy so hopefully I can
answer that question brachial plexopathy can
be due to vehicular injury or a birth
injury in fact up north
snowmobile injuries would count as a
vehicular injury right so what are some
birth trauma things well the most common
cause of brachial plexopathy is the Erb's
Palsy so how many people have recently
delivered a baby it's been a while right
so the Erbs palsy is a shoulder dystocia
that's caused by an injury to c5 or c6
so what does this shoulder dystocia mean
so those of you who remember delivering
a baby right the
the head comes through the vaginal vault
and the shoulder gets stuck so you're
trying to gently pull yank or whatever
or encourage the head to come first
until I haven't delivered a baby in a
while and then this shoulder gets caught
so you have this out it's stretching
motion one day I'm going to give myself a
erb's palsy by doing this but this
stretching is what causes a c5 or c6
injury and this results an abduction
internal rotation the forearm pronation
as is seen on the illustration here
a klumpke's palsy the klumpke's policy
is due to shoulder stretching and it's
typically due to involvement of c7
through t1 now what do the patients also
have if there is an injury to c7 through
t1 they have what syndrome then the
Horner's syndrome exactly right because
that's where the cross innovation comes
in now what happens in a kumpke's
palsy well this is and again in the
days of yore when when Giants walked
when we would do a vaginal delivery when
the baby was breech right so the bum
would come out and but this time the
stretching was this way so the tail
would come out in the stretching with
this one but we don't see Klumpke's
palsies very often now due to from birth
right because now what happens if the
kids in breech they have a cesarean
section so this one anyway is almost
more for historical perspective you can
still see a klumpke's in some type of
injury a vehicular injury or something
else but not necessarily due to a birth
injury what about a total plexus injury
well this is the vehicular trauma
there's complete arm paralysis the
sensory symptoms are gone and there's no
reflexes so how do you work it out so I
have to admit I went under an evolution
here because when I was a resident we
were shifting from CT to MR and we would
do a lot of CT myelogram as a resident
again this was back this was years ago
like a 88 to 92 and so towards the end
of my training we were doing all MR and
when I was at UNC my first faculty
position we were doing all MR but then
when I joined you U of M in 2001 we had
some pretty senior neurosurgeons and
they all want to do CT myelography
so I went from doing MR back to CT
myelography and you know I kind of groused
a little bit
you have to do an LP and so on and so
forth but you know one thing about CT
myelogram you really get beautiful
images of the ventral in the dorsal
roots so if the intent is is to evaluate
the roots to determine whether there's
an avulsion CT myelography is actually a pretty elegant study in
fact here on the right hand side you can
see the ventral in the dorsal roots but
on the left hand side you can see that
the roots are gone and there's your
pseudomeningocele and if I recall
correctly there's another one see the
ventral the dorsal roots are intact on
the right side there's no roots on the
left hand side and look at that pseudomeningocele on the left hand side so CT
myelography is really a lovely way if you still wish to do it in order to look at the exiting
roots from the spinal cord
well you can this is a page that had a
shoulder dystocia this was a kid a
newborn and instead of doing MR they
asked us to do a CT myelogram and again
and you've got the newborn kid got to be
six weeks old or something can't move
their arm and there you are doing an LP
it's a little bit daunting you have to
remember there's not much room in the
spinal canal but on the other hand
there's no degenerative disc disease and
a six six week old either so actually
accessing the CSF this is pretty easy so
it doesn't take long to do you just want
to use just a little bit of contrast but
again the images are pretty excellent
excuse me
very elegant and order to look at these
various pseudomeningocele well with MR
certainly with 3t and the various
channel coils you can get a very good
view of the cord itself the central gray matter there's your ventral
and your dorsal nerve roots so certainly
now with the regular t2s or you can do
some again elegant imaging with the
heavily t2-weighted images you can get
beautiful evaluation of the exiting
nerve roots as well one thing I'll
caution you is that you know we're all
under pressure to do more with less
right cut sequences cut sequences cut
sequences and you know we need to
perform best practices we need to get
standardization we need to customize we
don't need to do I think in this day and
age the full menu on the routine
patients but having said that we have to
be cautious that we don't cut too much
because this was a patient that had a
left-sided shoulder dystocia
and you may not be able to see it on the
t1s but you always have to make sure
that as you're optimizing your sequence
you have some type of t2 sequence or a
gradient echo sequence as a scene here
because certainly the pseudomeningocele
is easy to see on the gradient echo
images than the t1-weighted image if you
do have a chronic dislocation or a
disruption you can have retrograde
wallerian degeneration and this patient had
a chronic brachial plexopathy and
eventually this migrated to involve the
left hemming cord and here we can see
the atrophy of the left hemming cord so
this was a patient both these patients
had total plexus avulsions and the issue
is is first of all what do they look
like and when do you do your imaging
study I personally don't think you need
to do your imaging study right away
because you have to let some of the
swelling resolve and the patients have
to be stable etc it's not they're not
going to fix it immediately but realize
when you're looking at total plexus
avulsions you tend to think that the
brachial plexus is like the linguini
right in which you what you would think
you would see is you take the linguini
and you stretch and you break it you're
gonna have the little things flapping in
the breeze but that's not the case in
fact the brachial plexus is surrounded
by a very thick intense and durable
perineum so if you have a total plexus
avulsion because of this thick fibrous
perinerium you're not gonna have the
things flapping in the breeze rather
what you'll end up having is this
diffused _______ along the
course of the brachial plexus so if you
see this hemorrhage or see this soft
tissue that's extending along the course
of the brachial plexus
that's the imaging findings that we see
in a total plexus of avulsion
similarly this was a patient that had
another total plexus avulsion this is
a stir image notice a normal appearance
on the right side and again all of this
is edema extending along the course of
the brachial plexus following a severe
injury and this was the Radiological
correlate to this patient that had a
clinically diagnosed total plexus
avulsion well what about other
Radiology's about vascular compressions
so
this patient presented with the
right-sided brachial plexopathy and this
patient has we used to say North
Carolina had lead poisoning you know
what this is right there there's a
bullet right there they got shot got shot
developed an aneurysm and all of a
sudden developed a right-sided brachial
plexopathy so what's the cause of the
break brachial plexopathy it's the
aneurysm that's compressing on what the
brachial plexus why is that the case
because where did the cords the brachial
plexus run it run right along the
subclavian the axillary artery so Matt
Mauro at the time who's now chair at UNC
was my colleague at that time just went
in there and put a stent in and
collapsed the aneurysm and the patient's
symptoms resolved how about this case
you know the I love the head and neck
surgeons are all terrific they they tend
to see a mass and the first thing to do
is well we need to make sure it's not a
tumor so we end up sampling it right so
you see this mass involving the right
supraclavicular area and something's not
right here it's a non-contrast
t1-weighted images so is there something
here on the phone that says to hold on
for a second let's let's take a look
because it could be something else
anything about the signal here what's
that
yeah it's increased signal so then when
you look at the sagittal images what's
what's the cause of the increased signal
what is this right here
yep that's the blood and this is
actually a little jet because there's a
subclavian artery and this little jet
right here is actually the the flow
caused by blood flowing into a
pseudoaneurysm and this was actually the
sudo capsule of the pseudoaneurysm so
you know if you do see something in the
base the neck always try to and we all
know this but just make sure you
understand the full relationship of that
mass associated with the artery because
if you're not careful you could
potentially get beat by a little
pseudoaneurysm there well what about
neoplastic things you know you figured
out now I'm a pretty simplistic person
I'm not very complex and I like to break
down these concepts and the
things that we can follow so I just
break my tumors into nerve sheath and
non nerve sheath tumors and let's talk
about the benign ones you know the most
common
primary nerve sheath tumors in
neurofibroma
about two-thirds are solitary about a
third or associated with
neurofibromatosis type 1 and the key
thing here is that neurofibromas are
unincapsulated so if I showed a histologic
specimen of a nerve so there's a Schwann
cells surrounding the nerve but the
nerve itself comprised of little
neurofibrals it's almost like in the
days before wireless communication the
way that we would run cables connecting
the transatlantic you have these cables
coming through had this thick protective
layer as they ran in the bottom of the
ocean think of that protective layer of
Schwann cells and each individual cable
running through tells you how old I am
right each individual cable running
through is the neurofibroma
so a neurofibroma is an is enlargement
of each one of those individual neural
fibers that's actually with that's in
case within the Schwann cells so this is
what we mean by unencapsulated these are not
encapsulated so the surgeons have a hard
time resecting these especially in
the larger nerves on CT they tend to be
iso to hypo intense with muscle they can
have the bone remodeling if they're
extending into a neural firamina and on
MR there Iso intends to t1 they enhance
and there is some t2 signal so this is
an illustrative case this patient has a
mass involved in the neck right so let's
take a look at the top left image we see
this mass involved in left neck we're
all experts now right so we see this
mass and we'll say aha so what's our
differential now diagnosis for that mass
you could go through the litany right
all sorts of stuff a lymph node to
direct metastasis a leiomyosarcoma
rhabdomyosarcoma etc but now what are
the principles that we talked about
before what were the three piece of
anatomy that we had to have and we
remember them what were the two muscles and
anterior scalene middle scalene what was
the vessel subclavian artery so what we
do now is we come over here we draw a
line down the middle right draw a line
down the middle and we can compare one
side to the other so this is pre
contrast and this is post contrast so we
have to engage ourselves and to figure
out where the scalene muscles are so if
we look at this image on the bottom
left this is what muscle located here
and here's what muscles back here middle
and so where's the brachial plexus gonna
be it's gonna be right in here right now
look at the opposite side
what muscle is here and which way is it
displaced yeah exactly where's what
muscle is here and where is this
displaced so where does this mass have
to be arising from it has to be arising
from the plane between the anterior in
the middle scalene muscles see how the
anatomy helps you out and then when we
go to the contrast-enhanced t1-weighted
image again there's the anterior scalene
there's the middle scalene and now we
can see the two round enhancing little
balls right here between the two planes
so that tells you you're dealing with
some type of nerve sheath tumor could it
be a schwannoma neurofibroma
absolutely but you're dealing with
something that's arising from the
brachial plexus and this image here a
little bit a little bit higher you can
see the mass extending into the neural
foramen another example here you look at
this and I would bet earlier you would
say these look like lymph nodes all
these things right here look like lymph
nodes but again go to your Anatomy this
is a complex here don't knee jerk these
things understand the anatomy and when
you understand the anatomy what you see
is that the anterior scalene muscle is
being displaced anteriorly middle
scalene is being displaced posteriorly
and because this is arising between the
plane of these muscles it's got to be
something arising from the brachial
plexus and in this particular case it's
at neurofibroma and in fact this patient
at nf1 and here you can see the
sausage-shaped dilatations of the
nerve roots these are all individual
nerve roots leaving the spine and one of
the most dramatic cases that I've seen
of plexiform neurofibromas involving c5
c6 c7 t1 well schwannomas look they look
exactly like neurofibromas there's
really nothing different to it but they
are encapsulated so remember those
transatlantic cables that I was talking
about that sheath surrounding the
transatlantic cable is a pretty good
analogy to a Schwann cell so these for
schwannoma so these are encapsulated
lesions and what the surgeons have told
me is they can go in and they're on the
surface they're not involve all
the internal neural fibrals and then the
surgeons can go in they kind of if you
will pop out they're very very easy
through to resect because they're
eccentric exact same slide I showed for
neurofibromas they are essentially
indistinguishable but here's an example
of a schwannoma so you look at this and
say well there's a mass there's a
mass on the right side but again you
have to break it down I'm going to draw
my line down the middle again compare
one side to the other here's the
anterior scalene here's the middle
scalene and there is a brachial plexus
there on the left side now in this side
you have to look and when you look real
closely there's your anterior scalene
here the middle scalene is back here and
this mass is heading right into the
neural foramen so there is indicative
that whatever this mass is it's
involving the brachial plexus and in
this case it had it happen to be
schwannomas another example here on your
left hand side just a nice example here
there's your anterior scalene being
displaced anteriorly the middle scalene
posteriorly there's your brachial plexus
and one more case here t2-weighted image
your anterior scalene is draped over
middle scalene draped posteriorly and
there's your schwannoma has high signal
on t2 so there's an old saying mark
twain one time said good judgment comes
from experience and experience comes
from bad judgment anybody ever heard
that anybody in the room have experience
beside me yeah unfortunately I have a
lot of experience right so this was a
case that's but I was at UNC that was
read three times twice by me I think
read normal on CT just and it was a neck
mass based the right neck every time
this surgeon pressed on they could feel
a little nodule but we just couldn't see
it on CT I looked I looked and
couldn't see it if anybody sees it there
but hopefully no one sits there
hopefully no one's gonna say mukherji its
there are you moron it's easy to see now
do you see it right it's right it's
right there so there's the anterior
scalene middle scalene if we go back in
the retrospective scope it's right there
but it certainly does tell you that the
continuity of the small
lesions are easier seen on mr than CT
and this turned out to be a little
schwannoma now what about neuro
fibrosarcomasarcomas you know we don't see
too many of these the other name for
this is now sometimes use malignant
peripheral nerve sheath tumor so you
know when I was growing up we called it
neurofibromasarcomas but I think certainly a
name has transitioned most patients with
nf1 don't get radiation therapy anymore
but historically if you read the
textbooks it was viewed as a delayed
complication there is an example of a
neuro fibrosarcoma yeah again let's it's
it's not necessarily that what I want I
want you to be able to say this is
involving the brachial plexus because if
you see something like this the first
thing that you're going to give is a big
differential diagnosis for a neck mass
but the key thing here is how do we what
tips us off that we're probably dealing
with some type of aggressive mass that's
involving the nerve so we can include in
our differential and again the main
thing now is to look for this vessel
right here which is what subclavian
right now it's a subclavian eventually
the axillary artery and when we see that
we can see that the artery is being
displaced inferiorly and with the leap of
faith this mass looks like it's more
longitudinal and sausage-shaped
and extending along the expected course
of the brachial plexus and this is the
contrast-enhanced t1-weighted image
again here is the artery on the right
side and here is the artery here on the
left side so again that tells us that
it's directly adjacent to the brachial
plexus so we have to consider a
malignant tumor involving the brachial
plexus in our differential diagnosis
another example here on the sagittal
image there is the artery remember the
cords live right along the artery and we
can see this tumor involving the cords
and when we look a little bit more
approximately there's a linear
enhancement then we look at the spine
this tumor actually extended proximately
all the way through the neural foramen
in fact here is a target sign of a
normal neuro foramen with the little
nerve in the center how about benign
lesions involving the brachial plexus we
can all make the diagnosis here it's a
lymphatic malformation undergone various
iterations when I grew up it used to be
called a cystic
hygroma then I think we had micro
cystic macro cystic and mixed if I
recall the the various types and on this
axial t1-weighted images here we can see
the artery being displaced anteriorly by
this mass so cystic hygroma is high
signal on t2 low signal on t1 and see
how the subclavian artery is displaced
anteriorly that tells us that the mass
has to be involving the brachial plexus
and this was a mixed vascular
malformation again I just show it
because pretty complex I won't we don't
have talked on vascular malformations
this year but just to say that you can
say that the plexus is involved because
the proximity to the subclavian artery
here's a lipoma involving the
supraclavicular fossa here's a
subclavian artery there's a brachial
plexus this is a non-contrast
t1-weighted image and after fat
suppression you can see that the high
signal is completely suppressed against
the key thing is how do we know that
it's involving a involving the plexus
because of this proximity to the
subclavian artery and this was an
interesting case this was a 16 year old
kid I'll never forget this a 16 year old
kid and we used to have tumor boards
every morning at UNC and it's 7:00 a.m.
so it all show up at 7:00 a.m. and I
remember the head of ent comes up they
says how you doing I said hello dr.
so-and-so
I said hey hows it going he said good good I got this
kid here
he's a wimp what do you mean as a wimp
every time I try to biopsy hes saying he
screams bloody murder he said it's just
a mass I said what do you mean well
here take a look at these films and then
if you look carefully where is this mass
actually arising from so what is the
structure right here
it's mastoids here anterior scalene and the posterior scalenes here
so when he was actually doing his biopsy
I think he kept missing the mass but he
did he did hit the brachial plexus so I
didn't tell him that and I said I don't
know I guess your right so the kids a
whimp and oh by the way so anyway he this
this kid ended up going for embolization
of this this was a little kid here again
with the capillary capillary hemangioma
or
should say hemangioma at birth and just
to show here we can make these diagnosis
and see the brachial plexus on CT we
just have to tease out the anatomy so
here's the subclavian vein here's a
subclavian artery and right behind the
subclavian artery is the brachial plexus
everybody see that here and right behind
it all of this extension this is a huge
hemangioma huge hemangioma but again
something this complex you know
literally what I do I see see something
like this I take a deep breath and I
said let me tease out the anatomy and
just step through the anatomy because if
you try to pattern recognize that it's
not going to happen
well there are a variety of nerve sheath
non nerve sheath tumors too the most
common that can involve the brachial
plexus are Pancoast tumors and
certainly the axial images are very
beneficial so here's a schematic
illustration from neder demonstrating
this Pancoast tumor involving superior
sulcus so that's why we would call it a
superior sulcus tumor so this expected
spread patterns and the illustrations is
that the superior sulcus tumors extend
into the supraclavicular fossa and then
begin to encase the various components
of the brachial plexus which is what
we're seeing here so here's the Pancoast
tumor going through the lung apex and
extending into the super clavicular
fossa and engulfing the components of
the brachial plexus here is this normal
sagittal image on your left subclavian
artery excuse me subclavian vein
subclavian artery there are the cords of
the brachial plexus this is the venous
confluence here's the subclavian artery
and notice how this tumor has grown
through the lung apex there's one of the
cords of the brachial plexus there's
another one and it's involving another
cord of the brachial plexus so my point
is the sagittal images I think are
helpful but yeah I think you really need
to learn the the axial and the coronal
anatomy as well you know for metastasis
again when I was programmed as a
resident I someone showed me a mass like
this and I would go through a huge
differential diagnosis right
it could be metastasis it could be blah
blah blah in real-life situation you
already know what the answer is
you know the
we'll tell you what their primary tumor
is but our real job is someone comes in
and they've have a tumor and they've
been treated the issue is is there are
there metastases present and is their
involvement specifically of the brachial
plexus so you'll see this huge thing
you're like well the answer yeah
probably so it's so big right
probably so right but in actuality how
could we be a little bit more erudite in
our diagnosis and our assessment so yeah
you've got a pretty good sense here you
were starting to make out the anterior
middle scalene but what's the finding
here that tells you that this has to be
the brachial plexopathy
unequivocally due to the metastasis what
is being encased here
what's that see that yeah there's your
trigger remember we talked about the
carotid arteries being an indicator of
what spaces masses were in the
subclavian arteries our trigger to
determine whether or not that plexus
involved in this particular case we have
this huge mass here there is a
subclavian artery we know the plexus is
on it so it's got to be involved with it
another example here metastasis is again
too all right so let's let's go through
our thing where is the you see it now
now it's easy right now your eye goes to
it
trachea-thyroid carotid artery there's a
big mass is the mass involving the
plexus well there is a scalene there's
the middle scalene the brachial plexus
is heading here and guess what right
same thing here anterior scalene middle
scalene there's the plane and there's a
tumor extending medially to involve the
brachial plexopathy so in this
particular case again by knowing the
anatomy we can say that the brachial
plexus is involved one more example here
this was actually due to leukemia
leukemic infiltrate anterior scalene
middle scalene there all of this is
involved in the expected course of the
brachial plexus in fact this is
extending medially to go through the
neural foramen
what about inflammatory process let's
get to the real-life situations it can
be due to post radiation or
idiopathic or familial one of the
challenges that we'll get is that if
someone comes in they've had lung cancer
or they've had breast cancer and they've
been treated with high-dose radiation
therapy
the patients may develop that brachial
plexopathy but it's unclear to the
referring physicians as to whether it's
due to metastasis or whether it's due to
radiation associated brachial plexopathy
now we used to do a fair amount of MR 20 years ago for this and then the
utilization of MR for brachial plexopathy
started to decline and the reason was
what what modality we did we start
looking at it was more PET CT right
patients were sent for PET CT but
surprisingly enough I've seen more and
more MR is now being done to look to
see determine of whether there's a
radiation associated brachial plexopathy
and as dr. saw mentioned I have learned
after many years of work with radiation
oncologists I never used the term
radiation induced anything right there's
no such thing as a radiation induced
sarcoma right my radiation oncologists
always say well it could be radiation
associated but it's not radiation
induced so I'm very clear to use
radiation associated brachial plexopathy but then the issue is how do
we is there something here that tells us
that this is radiation associated
brachial plexopathy and it's not a tumor
and so what I'm about to tell you is
really more of an art than a science
because not every one of the cases that
I've seen that I've made the diagnosis
on has gone for biopsy and confirmation
but on the other hand they have had
follow-ups so could there be small
little micro tumors and they're sure but
having said that what I look for that
suggests I'm looking at a radiation
associated brachial plexopathy is if I
see the brachial plexus and it looks
like someone took Elmer's glue anybody
at the Vintage where we used Elmer's
glue before Elmer's glue and glued the
brachial plexus together and it looks
like a glued sausage-shaped linear
structure if I see something like that
then the patient otherwise has no
evidence of disease anywhere else and
you go back and you look at the ports
and this part of the plexus was included
in the ports then for me I'm very
comfortable suggesting a diagnosis of a
radiation associated brachial plexopathy
if the referring
want to go in there in biopsy you know
have at it but this is what I end up
looking for another example radiation
associated brachial plexopathy again look
let's look at that normal anatomy
because it's so important on the right
hand side anterior scalene middle
scalene and look at the normal
appearance of the brachial plexus pretty
well distinct right
no enhance now look at the involved sign
anterior scalene middle scalene and
look at the brachial plexus it looks
thickened enhanced and swollen similar
to this side here we go subclavian
artery there is a brachial plexus and
here we can see thickening of the
various components of the plexus with a
little bit more enhancement and one more
case radiation associated brachial
plexopathy compare to this side we
could almost see a striated appearance
to the cords of the brachial plexus as
you can see intermediate fat
intermediate fat but look at this side
see the sausage shape appearance on the
non-contrast t1 we give contrast that
diffusely enhances and here's a stir
image see just the diffusive increased
signal again along the cord so I don't
know if take the same drugs I do but to
me it looks like those things are all
glued together so that's why I would
suggest that these are the findings
associated with radiation induced
plexopathy the other thing that we can see
is that if patients have had
chemotherapy they'll sometimes develop a
mononeuropathy or polyneuropathy that's
extending down the arm so in these
particular cases make sure you look at
the spinal canal because in this case
this was diffuse enhancement and this
patient was treated with vincristine
which we know has a higher likelihood of
a neuropathy and here we can see
enhancement of in this case the dorsal
nerve root and compare that to the
appearance of the other nerve roots as
well too so remember the roots are a
part of the brachial plexus so we always
have to remember to look centrally we
could have also idiopathic brachial
plexopathy so here's an example again I
would say earlier you would say well
these are a bunch of lymph nodes right
involved in the neck but when you see
something like this just go through your
litany the anterior scalene middle
scalene because these things are in the
plane of the brachial plexus it's got to
be involving the nerves right so in this
case this is an
idiopathic brachial plexopathy and one other
one too here we see diffuse enhancement
and thickening this patient ever had
radiation therapy but in but instead
this patient had idiopathic plexopathy
probably one of the chronic idiopathic
inflammatory neuropathies involved with
the brachial plexus here we can see
diffuse enlargement of the cords of the
plexus and this is something I'm not a
musculoskeletal guy and I have to admit
I always try to avoid talking about this
disease but this is parsonage Turner so
I in general being a head neck guy I try
not to go more peripherally than about
half the lung apex but on the other hand
I have to realize that the brachial
plexus does supply some musculature
peripherally and one of the things that
I probably have missed cases of
parsonage Turner I will readily but
that's my quote-unquote experience right
so parsonage Turner we have to remember
when someone has a brachial plexopathy
parsonage turner clinically is the acute
onset of brachial plexopathy it's
typically felt to be virally induced and
the two most common muscles that are
involved are the deltoid and the
infraspinatus if there any
musculoskeletal radiologist here please
collect me if I'm wrong but it is do I
have it right I think those are two
muscles I don't see cannot cure for
heart oh here so but there's anybody
else correct me if I'm wrong but here we
can see on the coronal image in this
case enhancement of this muscle and I
believe that's the infraspinatus if I'm
not if I'm correct the deltoid should be
a little bit more peripheral and in this
case in another case again diffuse
enhancement of this transversely
oriented I should say in the axial plane
we can see and I believe that's the
infraspinatus as well so essentially
what we are seeing is a in a way not
necessary as a way to think of it it's
felt to be virally induced it inflames
the muscles and now we're seeing
essentially a Myositis due to the
muscles that are at the end of an
involved nerve
so that's parsonage Turner and actually
when you look peripherally in this case
we can see enhancement of multiple
nerves and roots compared to the rest of
the spine the last thing that we'll talk
about is pain management
pain localization so if you do perform
CT scans there we can do interventions
involving the brachial plexus and we
sort of borrow this from our
anesthesiologist because some of the
local ways that they can do pine box is
called the inner scaling approach where
the anesthesiologist will palpate the
neck they can feel the anterior the
middle scalene muscle they can put the
needle between the two muscles and do a
nerve block we can essentially do the
same thing by CT so for instance this is
how we do this there is the anterior
scalene middle scalene we can place our
needle right between those two muscles
we can inject in this case a little
lidocaine and with contrast that we can
see the flow of this and this patient
actually had a c6 modern neuropathy and
the surgeons didn't want to go in and do
a frame Anatomy until they were
convinced that yes indeed this was the
exact level so we just put one or two
cc's actually two or three cc's of a
mixture of lidocaine and contrast and
the patient's pain resolved so that was
felt to be a positive tests and the
surgeons went in and did a frame Anatomy
you can also do it for neurolytic
therapy as well too so you know we do
neurolytic therapy the some of you may
be doing for pancreatic cancers like a
celiac plexus block well we can do the
same thing for a brachial plexus block
we just have to be a little bit careful
so now we're all experts here's a
subclavian artery and you can see the
brachial plexus isn't it jumping out at
you right now now on the left hand side
you can see the subclavian artery and
how do we know this mass is involving
the brachial plexus because the mass is
completely encasing the subclavian
artery I hope it's not too dark there
it's a little darker slide but it's
encasing the subclavian artery so what
do we do in this case we place the tip
of the needle between the anterior and
the middle scalene muscle and we
injected a phenol mixed with lidocaine
and we carefully watch this obviously
one be very careful because it's a
non-reversible sclerosing agent so we
wanted to make sure nothing trickled
through the neural foramen at all but in
this particular case the patient was
requiring very very high doses of
morphine it made it a very difficult
lifestyle but afterwards and this was a
palliative case we were able to reduce
the amount of more
being the patient was given and made the
patient more comfortable so it's more
palliative in nature but the point is
you can perform these aggressive
procedures if you understand the anatomy
the anatomy of the anatomy anatomy is
key so in summary what I've tried to do
over the last 45 minutes let's talk
about the anatomy of the brachial plexus
and here's your mantra so tomorrow when
you go to church and you're in the pews
you just repeat and here's scaling
middle scalene subclavian artery that's
your that's your roadmap and you will
always find the break of plexus I would
encourage you for the next week or so
five spines just look at the anterior
scalene middle scalene subclavian artery
and you'll always be able to find the
brachial plexus and then we talk about
trauma and neoplasms inflammation pain
management so thank you for attention I
want to thank all of you all for
supporting the course we hope you had a
good time I read every single evaluation
so in your comments and we use what you
say this year to help plan our course
for next year so thank you very much for
your attention and safe travels
