Temporal Bone Trauma

Temporal Bone Trauma Overview

We are going to switch gears in a big way
and hit up the temporal bone for
the next four lectures.
And I'm gonna start with temporal bone trauma.
I'm gonna use it as an opportunity to just review
CT temporal bone anatomy.
We will talk about how we detect fractures,
what makes us suspicious of fractures are there,
we'll talk about the various ways
of classifying fractures,
and then we'll wrap up with associated injuries
and the various complications that occur in the setting
of temporal bone trauma.

CT Temporal Bone Anatomy Review

When I look at temporal bone scans
and when I teach trainees, I try to find,
we're bombarded with so much imaging now,
there's so many series
that we get on a PACS station,
and some of these exams, especially
with thin sections, there's so many images.
So I find it's useful to find a few stereotypic levels
and concentrate on those.
And then you can kind of look for them
and make sure
that the major anatomic structures are intact.
So, in the axial plane, I've sort
of identified a stereotypic superior, middle
and inferior axial image to focus on.
And the same thing in the coronal plane,
anterior, middle, and posterior.
So I wanna use those as a way to
review the anatomy.

Axial Plane Anatomy

So this is a stereotypic axial top image.
And it has the most recognizable temporal bone
structure that everybody knows.
And that's the ice cream cone of the malleus
and incus within the epitympanum of the middle ear cavity.
When you look posterior to that,
you typically see a triangular shaped
airspace, which is the mastoid antrum.
It's essentially the dominant air cell within the
mastoid cavity.
And it connects to the middle ear cavity through
an airway not demonstrated on here called the aditus ad antrum.
At antrum, you see a portion of the intratympanic
and epitympanic facial nerve canal.
And I'll review that separately on its own.
And other structures you'll see in the inner ear are
portions of the cochlea and the vestibule.
You will see the oval window, which I think is
better evaluated a little bit more inferiorly.
And then in the coronal plane, moving to a
middle axial image, approximately middle,
you can see the malleus neck.
The malleus is the most anterior ossicle.
So ossicular structures
that you see more anteriorly are likely
to be part of the malleus.
You see sort of a conglomerate shadow of the long
and lenticular processes, portions
of the distal incus in this plane.
The incus is better seen on the coronal plane.
And then you should be able
to see on your imaging as a routine.
The stapes really to this level at this point.
I use that as a kind of hallmark of whether my scans are
of reasonable quality or not.
I think in the when I trained,
we all sort of hallucinated that.
They're like, oh, there's the anterior crus, here's a posterior crus.
And I was like, oh, yeah, yeah, whatever you say.
But now I think with our multi detector scanners
and very thin images, we can expect to see the stapes well,
and it's a very recognizable structure, anterior
and posterior crus, the capitulum
and the footplate, which sits on the oval window.

Now at the bottom of your axial images,
you should expect to see two parallel lines.
Again, the more anterior one represents a portion
of the malleus, it's the more anterior ossicle.
And then posteriorly, again, you're gonna see kind
of a conglomerate shadow of distal portions of the incus,
and you should be able to see both
of those structures pretty reliably.
Now you're seeing the round window niche as in one
of the posterior air spaces along the posterior wall.
Lateral to that you see the sinus tympani.
This is really a structure only important in
that it's a place where disease can hide
and is relatively inaccessible to the
surgical examination.
And then lateral to that,
you see the descending facial nerve canal.
And again, we'll review the facial nerve canal separately.
Here again, within the inner ear,
I think we have a nice view of the basal turn of the
cochlea with the middle and apical turns anterolateral to it.

Coronal Plane Anatomy

Now switching to the coronal plane,
a fairly stereotypic anterior slice.
And again, our anterior ossicle is gonna be the malleus.
And you're seeing the head, neck
and the manubrium.
You can make out a very thin
normal appearing tympanic membrane.
You don't need to see all of the tympanic membrane.
If it is abnormal and perforated likely it will be thickened.
You'll be able to see that. You see the scutum.
And then between those structures, you see Prussak space,
not particularly important for trauma,
but just a recognizable anatomic landmark,
also called the lateral epitympanic recess.
And then you see the two Cs, the
carotid canal inferiorly and the cochlea anteriorly.
And that's a little mnemonic to remember that if you see
the cochlea on a coronal image
and you see a vascular channel beneath it, that's going
to be the carotid canal, not the jugular.

Now you use the roof
and the floor, the external auditory canal
to divide the middle ear cavity into its various compartments.
And grossly any portion of the middle ear cavity
that is superior to a line parallel to the roof
of the external canal is in the epitympanum.
And that contains ossicles and air.
The hypotympanum is between those two lines.
And then the small
and relatively unimportant hypotympanum is inferior
to a line drawn parallel to the floor
of the external auditory canal.

Now, if you look at a approximately midsection in the
coronal plane, again,
some fairly stereotypic structures, it's easy
to find the lateral semicircular canal
'cause it juts out into the middle ear cavity.
And as you look inferiorly, you can see the intra-
and epitympanic segment of the facial nerve.
You can always find that inferior
to the lateral semicircular canal.
And then even more inferiorly have a really nice view
of the oval window,
and that's where the stapes footplate sits
and where sound is transmitted from the ossicular chain
to the inner ear structures.
Here we also can see the internal auditory canal.
And that's something that should be on your checklist
of things that you look at when you examine these studies.
The tegmen is the roof of the epitympanum cavity, the tegmen
and mastoid, the roof of the mastoid cavity.
And these are important structures to assess in the setting
of trauma because defects in these related to fracture
can create a communication
between the intracranial compartment and the mastoid cavity.

Another coronal mid slice with windowing
to emphasize the ossicular chain shows you the very stereotypic
check mark, the long process of the incus
and the lenticular process of the incus.
And these again, form a check mark,
and it's a good thing to look for.
I think it's an easy thing to find.
And you can again see the oval window,
facial nerve canal,
and the lateral semicircular canal. On these slices, just
to remind us the chain of events,
the tympanic membrane vibrates, that vibrates the
malleus, the incus and the stapes.
And this is that check mark structure that we're seeing
so nicely on the coronal scan.

A posterior slice in the coronal plane.
I think that's where I really learned how
to understand this anatomy
and sort of triangulate in multiple planes
because those posterior recesses that we saw previously,
the sinus tympani,
and the facial recess, the round window niche,
are all displayed on this coronal slice,
but you kind of have to look for them.
So the more medial one is that round window niche.
And then as you move progressively laterally,
you see the sinus tympani.
And then the second genu of the facial nerve canal,
and the facial nerve is going to descend in this plane.
And then lateral to that is the facial recess.
So those three airspaces,
you can usually routinely find those on a coronal scan.
This is the styloid process.
And again, the descending facial nerve canal will
exit the cranium in that location.

Facial Nerve Anatomy

So we'll now quickly review the facial nerve on an axial plane.
The facial nerve will come in through the IAC,
make its first genu at the level of the geniculate ganglion,
and then dive posterosuperiorly along the medial surface
of the tympanic cavity.
It then hits its second genu.
And you're seeing the sinus tympani again,
medial to it.
And this would be the level of the second genu.
And then that where it makes it second dive.
In this case, it dives inferiorly,
and you will see it on consecutive axial images
as a kind of soft tissue density.
It can be sometimes confused
with an opacified mastoid.
But when you do see it in sequential images, you'll realize
that it is in fact the descending facial nerve canal.
And of course, that's easier to see on the coronal scan.
So that's the basic course of the facial nerve.

Detecting Temporal Bone Fractures

So let's move to temporal bone trauma.
There are clues that
a temporal bone fracture might be there.
I mean, we'd all like to believe that we examine every
structure and incredible detail on every scan.
But sometimes we have to rely on clues to
prompt us to make a special survey of the structure.
So obviously both intracranial blood
and particularly blood that is around the mastoid
as well as extracranial blood.
So a scalp hematoma that's over either the occiput
or the lateral part of the skull are clues
that there may have been direct trauma to this region.
And we need to be very vigilant about looking
for a temporal bone fracture.
And of course, the presence of air where air doesn't belong
is always a good clue that there has
to have been some way that that air was introduced.
And again, this can be intracranial air,
typically in the middle fossa or the posterior fossa,
or it can be extracranial air related to a fracture
of mastoid air cell in a subgaleal location.

Distinguishing True Fractures from Pseudo-Fractures

One of the challenges I think
for temporal bone trauma is distinguishing true fractures
from pseudo fractures.
There's so many just normal developmental lines in
and around the temporal bone that many
of these are easily confused with fractures.
And these can be sutures, fissures, or canals.
So let's look at some examples.
This is a bone window from a head CT,
and that's often what will prompt these exams.
You know, the patient has had significant trauma,
they have a head CT,
and somebody notices that there is one of these clues, air
where it doesn't belong or blood in a suspicious location.
So our astute resident
he did see the air trapped in the
nasopharyngeal recesses,
but also noted these two air bubbles over there,
which are really too lateral to be part of any portion
of the aerodigestive tract.
And you can see it is in approximately
to the styloid process.
And here you see the mastoid tip as well.
So the patient went on to have a temporal bone CT,
and that did demonstrate that the patient had a
longitudinal temporal bone fracture. In another patient.
Two areas of air, both intracranial
and extracranial air, so air in the middle fossa
and then extracranial air, similar in location to the
scan I just showed you.
The temporal bone has abnormal soft tissue density within it, of course,
not specific, but in the setting of trauma needs
to make you think about the possibility
of this represents hemotympanum.
And then this patient went on to have a temporal bone study
with a complex fracture in here.
You can see those intracranial air bubbles
and then an associated intracranial hemorrhage again.
Both clues at that fracture existed.

Now this is an interesting case.
This is another case read on call by the residents,
you know, just bone windows from a head CT
and the resident was astute enough, again,
to pick up the fact that there was a pneumolabyrinth.
So there was an abnormal focus of air within the cochlea.
And I think if you look at a lot of head CTs
and bone windows, you will notice
that sometimes you get a spurious appearance of air.
It's a beam hardening type of artifact,
but in this case, it did turn out to be real.
Now, that of course, is air in the wrong place
and a clue that a fracture might be
present, but actually it
Doesn't mean that a fracture is necessarily present.
And we'll revisit this case a little bit later
and discuss how that might happen.

So again so many lines in
around the temporal bone, it's can be very difficult
to differentiate between some of these and fractures.
Obviously, looking for corticated surfaces is very helpful.
And if of course you are an expert on the various fissures and canals
and sutures that occur around there,
and you can recognize them
for what they are, that's great.
But luckily for us, these structures are
almost invariably symmetric.
So you can use just looking at the other side.
The other side is your friend to help distinguish normal structures
from those that are abnormal.
This singular canal,
which transmits the posterior ampullary nerve
to the posterior semicircular canal, is one
of the most frequently called I think, fractures by people who are
somewhat inexperienced with looking at these cases.
It's obviously hard to see a corticated surface,
especially since this is going
through the very dense otic capsule bone.
And in fact the astute resident
who did pick up this pneumolabyrinth called the singular canal fracture
and failed to notice that the same line
existed on the other side.
And in fact, this patient did not have a fracture.
And again, we will revisit this case one more time.

Temporal Bone Fracture Classifications

So let's talk about temporal bone fracture classifications.
I think everybody's familiar with the traditional
transverse versus longitudinal versus mixed or complex,
and these are very useful
and they're very anatomically descriptive.
I think if you say there is a longitudinal fracture through the temporal bone,
the clinician or whoever reads it,
will have a starting idea of
where the fracture is oriented.
And I think it is very useful.
However, it turns out that there are other ways
of describing fractures that are more clinically relevant.
So in particular, if you describe the fracture as either
violating or sparing the otic capsule you have
you have performed a classification scheme of significant clinical relevance.
So in patients who have otic capsule violating fractures,
there's a fivefold increase in facial nerve injury.
There's a 25 fold increase in sensorineural hearing loss,
and an eightfold increase in the incidence of CSF leak.
So that's a very useful fracture classification scheme.
So what I would suggest, and the way I do it is I
give two classifications.
You're not limited to saying this is a horizontal or longitudinal fracture
or otic capsule sparing or violating.
I'll say this is a longitudinal fracture
that is otic capsule sparing.
And I've used both classification schemes,
I've given them a nice anatomic descriptor of
what the fracture looks like,
and I've also given them some information
of clinical relevance,
the features otic capsule sparing and violating.
I don't think that's really taken off.
You'll see it occasionally in the literature.
But I think the otic capsule is probably the more
the more used one of those terminology.

Longitudinal Fractures

So working with that anatomic description,
most fractures turn out to be longitudinal.
This occurs when there is a lateral blow
and often is associated with a fracture
of the squamous portion of the temporal bone,
and the portion of that contributes to the calvarium.
These typically do spare the otic capsule, so
that's a good thing. In these patients, the incidence
of conductive hearing loss exceeds sensorineural hearing
loss, which makes sense
because the otic capsule again, is spared.
But other structures are at risk.
So the tympanic membrane clearly that is
often involved in longitudinal fractures.
The ossicular chain, the facial nerve canal,
the carotid canal,
and the roof of the epitympanum cavity,
the tegmen tympani are all at risk.
And remember that the TMJ lives right underneath
and can be involved in these fractures.
And these patients can present with trismus as a sign of possible temporal bone fracture.

So here's a pretty classic longitudinal fracture.
It's oriented along the long axis of the temporal bone.
You can see it going through the temporal squama
through the mastoid cavity through the middle ear
and then actually heading towards the
carotid canal over here.
And then the attic region, the region
of the first genu of the facial nerve is at risk in this particular fracture.

Transverse Fractures

Less frequent are transverse fractures about 20%,
and these occur from an occipital impact.
So somebody falls off a ladder
and smacks the back of their head.
And the way I like to think about it is it kind
of shears the petrous apex off from
the rest of the temporal bone.
So in these patients, there's a much lower incidence of tympanic membrane rupture
because these fractures don't ever really go out
through those lateral structures.
However, facial nerve injury is very common.
There are several points that the facial nerve can be
injured, although the geniculate ganglion remains the area
that is the most susceptible.
It's just an area of weakness along the anterior margin
of the temporal bone, because the bone, as you see,
is not intact in that location.
In these patients, it is more common
to have sensorineural hearing loss than
a conductive hearing loss.
And that can be through fractures
of the otic capsule.
So through the labyrinthine structures,
a cochlea vestibule
or through the internal auditory canal,
as is demonstrated in this image.

So here's a patient with a transverse fracture.
The patient has some pneumolabyrinth.
You can see some abnormal air bubbles in the
patient's vestibule.
And here is this fracture.
It's kind of shearing off the petrous apex.
Again, I think it's kind of a useful construct.
And it is potentially hitting the facial
nerve in probably its intratympanic course.

Mixed or Complex Fractures

Many of these fractures cannot be neatly
compartmentalized. In those cases you can call them mixed
or oblique or complex.
This particular fracture looks like it wanted
to be a longitudinal fracture, but then changes mind
and dove posteriorly to become a transverse fracture.
And in those cases, I just try to be descriptive,
you know, I'll say it goes out to the cortex follows along axis through the mastoid air cells
and the sympanic cavity, and then changes its course.
And in this case it goes actually across the internal
auditory canal and the basal turn of the cochlea.
So this is a longitudinal mixed otic capsule violating fracture.

Associated Injuries and Complications

So important structures
to look at when you are mapping fractures
and when you are reporting fractures really have to do
with things of functional importance.
So the otic capsule, obviously,
of significant functional importance in terms
of hearing facial nerve canal facial paralysis is a very
devastating complication of facial nerve fracture.
The internal auditory canal ossicles, again, the tegmen,
the roof of these epitympanic cavities.
Any place where the mastoid abuts the intracranial
compartment is an important area to scrutinize
because of the incidence potentially of CSF leak
or the opposite complication extension
of mastoid contents into the intracranial compartments
potentially causing infection,
and then of course, the carotid canal.
So let's look at what these complications are
and why they're particularly
important structures to look at.

Facial Nerve Injury

So facial nerve injury again
is a potentially devastating complication.
It occurs more frequently in transverse fractures.
About half of patients
with transverse fractures will have facial nerve injury,
but it does occur in a significant percentage of people
with the more common longitudinal fractures.
Again, it's most common in the geniculate region
because that area is an area of developmental dehiscence
of the temporal bone, of allowing that geniculate ganglion.
And then the greater superficial petrosal nerve,
which comes off of that ganglion
and heads towards the region of the cavernous sinus.
That canal is just a natural area of dehiscence there.
Now, first nerve injury occurs along a spectrum.
Obviously the most devastating one would be complete transection,
although that can be repaired with grafts.
The prognosis is relatively poor.
And then sometimes it can really just be contused,
stretched and concussed and function will recover.
So because of that, most
of these are treated conservatively.
And then if nerve degeneration is demonstrated on studies, then the patient may be taken to the
OR for either a decompression or grafting.

So here's an example of a transverse fracture through the
facial nerve canal.
This is actually a chronic fracture.
You can see that the margins are well sort of corticated,
they're widened.
There is no hemotympanum, there's no swelling.
So this is not a new fracture.
And here you can see the facial nerve canal drawn out.
And this fracture potentially hits the facial nerve either in the fundus
of the IAC or at the geniculate ganglion.
So several potential sites of facial nerve injury.
And this patient did have facial paralysis following
trauma. In another patient.
Again, a transverse fracture.
The fracture again, you can see is going through the
labyrinth, but if we draw out the facial nerve canal, you can see
that this likely hits the fracture in its proximal intra-
and epitympanic segment, or at the level of the geniculate ganglion.

Hearing Loss

So hearing loss is obviously an important complication.
Conductive hearing loss is extremely common in the acute
setting, but most commonly represents just hemotympanum.
So if your ear is filled with blood,
you don't have normal transmission of the sound
through the ossicular chain.
And you won't hear that well.
And but that should obviously resolve.
If conductive hearing loss persists
after the hemotympanum clears up, then you really need
to look very carefully for ossicular injuries.
Most ossicular injuries represent dislocations
and they are dislocations at the incudostapedial joint,
incudomalleolar joint, and these stapediovestibular joints.
So the incus being the largest and most complex,
and the middle ossicle is the most susceptible
to dislocations from its adjacent ossicles.
These are very hard to see.
I will show you an example,
but I think with as we improve our scanning techniques
and our spatial resolution, we're able to see more
and more of these. Ossicular fractures do occur,
although they are less common and most frequently do involve the incus.

And this just showing you the appearance of hemotympanum.
So one of the more common ones,
and probably the easiest
to recognize is the dislocation between the incus
and the malleus.
So on the normal side, we have the normal appearance of the
ice cream cone, the malleus head sitting on the body
and short process of the incus.
And on the abnormal side, you can see the clue of hemotympanum.
And then if you look very carefully,
there's just very subtle offset,
and it can often be extremely subtle.
There's a little bit of widening of the joint relative
to the other side, and the malleus head is laterally offset,
and I think you can appreciate
that on the coronal image as well.
So the ice cream has fallen off
and everybody's pretty sad.
This patient actually did recover good hearing. The dislocation between the stapes and the vestibule.
So essentially what we're talking about is the stapes foot
plate is offset off of the oval window.
That's a tough diagnosis to make.
As Doug says, you gotta be pretty full of coffee
to make that diagnosis, I think,
and you gotta have a technically near perfect scan.
But this patient did have a prospectively diagnosed
SVJ, so stapediovestibular joint dislocation.
And here you can see the,
or you can imagine that, you can see the stapes anterior
and posterior crus.
This is the level of the oval window.
Here's the normal side, and the anterior
and posterior crus are sitting well set on the level of the oval window.
And that is really the finding that you're looking for.
So here I've sort of indicated
where the oval window is,
and you can see that the stapes is posteriorly dislocated
relative to that level of the oval window.
Here's again, the oval window on the contralateral side
with the stapes normally located.
And just to show you on a better image in a patient
who was able to cooperate for a better scan,
the stapes anterior
and posterior crus should really be located perfectly in the middle of the oval window.
And that is you know, the kind of subtle finding
that if you make it, I think it's really great.
This patient had the bonus
of having an additional fracture of the incus at the level of the junction of the long
and lenticular processes.

Some of these dislocations are easy diagnoses to make.
So normal ice cream cone on the left
and a completely disorganized joint with offset
of the head from the body of the incus.
This is just the same patient on the coronal scan
showing you the short process
of the incus really abutting the scutum.
So completely dislocated.

Sensorineural Hearing Loss

Sensorineural hearing loss occurs in a significant
percentage of patients with temporal bone trauma.
Again, it is more frequent in those transverse fractures
which go through the otic capsule
and go through the internal auditory canals.
There's a variety of causes ranging from
again, an injury to the otic capsule,
the cochlea vestibule, the IAC, but also to the brainstem.
And in patients with severe head trauma that can occur.
The other entity that can give you sensorineural hearing
loss is perilymph fistula.
We'll get to that in a minute.
You can actually have a concussion that may result in intralabyrinthine
hemorrhage which even in the absence of a fracture.
So you can have blood within your labyrinth,
membranous labyrinth, and that can lead
to secondary labyrinthitis ossificans
and longstanding hearing loss from that.
Remember, labyrinthitis ossificans is the endpoint
of a variety of bad stimuli, infection,
and blood being one of them.
Certainly a fracture, as in this case,
that goes demonstrably through the structures
of the otic capsule through the
labyrinth is at high risk.
And this patient did develop abnormal calcification in the basal turn
of their cochlea labyrinthitis ossificans,
a long-term sequela.

Vertigo and Perilymph Fistula

Vertigo happens in about 50% of patients
with significant head trauma.
And it's one of those concussion
sort of findings as well.
Again, a spectrum of causes ranging from brainstem injury
to labyrinthine concussion to Meniere syndrome, which can
occur following trauma as well.
And again, perilymph fistula. So let's talk about perilymph fistula.
This occurs when there is an abnormal communication
between the membranous labyrinth either at
because of rupture at the oval or round window
and the middle ear cavity.
So essentially you have a fistula with which
leakage of perilymph into the middle ear cavity.
These patients are clinically difficult to diagnose.
It's a odd sort of composite of syndromes
of symptoms.
And it can be a difficult clinical diagnosis,
but often they have vertigo, fluctuating sensorineural
hearing loss, tinnitus
and headache, all very non-specific symptoms.
You really have to work hard to put them together.
Radiographically it's even harder.
All you need what you may see in its entirety is just fluid at the level of the oval
or round window in a patient with pneumolabyrinth.
I'm not suggesting that anybody should suspect this
diagnosis unless there is an additional strong
clue like pneumolabyrinth.

So going back to that first case that I showed you
where the resident astutely picked up the pneumolabyrinth,
mistakenly called a singular canal fracture.
Here is an axial image from the temporal bone study,
again confirming the pneumolabyrinth.
And then the patient was ultimately noted
to have fluid at the level of the oval window.
You can see again, see the pneumolabyrinth.
And this was a surgically proven perilymph fistula.
So the clue was the pneumolabyrinth.
And then the secondary finding was the
fluid at the oval window.
If everybody can put everything together,
you may be able to suspect this,
and obviously it needs to be proven surgically.

CSF Leak

CSF leak in meningitis occurs in almost half
of patients with significant temporal bone trauma.
Again, typically secondary to fracture of the tegmen.
So that interface between the intracranial compartment
and the mastoid and more frequent longitudinal fractures.
So obviously seeing fluid density on a CT study in the
middle ear cavity is very nonspecific.
It can be an effusion, it can be hemotympanum way more frequently than it is a CSF leak.
But in some cases there will be a CSF leak.
Most of these will luckily close spontaneously,
but a small percentage
of them will need to be repaired.
And these patients can have the delayed complication
of meningitis from that abnormal communication
between the middle ear and the mastoid cavity
and the intracranial compartment.

So here's an example of a tegmen fracture.
Nothing better than seeing air in the wrong place
to prove to you that
there is an abnormal communication, right?
They had to get there some way.

Brain and Vascular Injury

And finally, brain and vascular injury.
Remember that these patients have had significant enough
trauma to fracture their temporal bone.
So about a third of them will have significant brain
or vascular injury.
Subarachnoid hemorrhage, subdural epidurals, contusions,
and DAI carotid canal fractures.
When I was training,
we were doing conventional angiography
on all of these patients.
I think we've calmed down a little bit
about this entity.
Patients probably should have a vascular study,
but a CTA is probably good enough to rule out the sort
of intimal injuries that
and maybe pseudo aneurysms that can occur in the setting
of this kind of trauma.
Again, the presence of air
where it doesn't belong is a great clue.
So here's a fracture through the carotid canal
with air within the carotid canal, proving that
that fracture actually happened.

So here's a patient with air in the wrong place,
subgaleal air, and a big hematoma was on, went on to
have a documented longitudinal temporal bone fracture.
And then on his head CT note the small contrecoup injury.
So remember to assess very carefully the intracranial
structures opposite from where the trauma occurred.

Summary

So in summary, make sure
that your scans are technically appropriate.
You should really see the stapes, look at the right
and left temporal bone separately.
Look at small field of view studies, optimize things.
'cause these are really hard, I think, to look at.
Look at the right
and left side to try to avoid the pitfall
of all these pseudo fractures.
And then have an internal sort of checklist
for the most important structures
that are potentially injured in the setting of trauma.
Otic capsule, facial nerve canal, carotid.
And then don't forget
to look at your soft tissue windows
for the significant intracranial
injuries that can occur.
So thanks for your attention.