Interactive Transcript
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Hello and welcome to Noon
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Conference hosted by MRI Online.
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In response to the changes happening around
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the world right now and the shutting down of
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in-person events, we have decided to provide free
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Noon Conferences to all radiologists worldwide.
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Today we are joined by Dr. Rony Kampalath.
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Dr. Kampalath is an abdominal imager at the University
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of California, Irvine Medical Center where
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he has worked for two and a half years.
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His professional interests include
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oncologic imaging, as well as
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resident and medical student education.
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A reminder that there will be a Q and A
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session at the end of the lecture.
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So please use the Q and A feature to ask
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your question and questions, and we will get
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to as many as we can before our time is up.
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That being said, thank you all
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for joining us today. Dr. Kampalath,
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I will let you take it from here.
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Okay, great.
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Um, I'm Dr. Rony Kampalath. I'm an Associate Professor at
0:57
the University of California, Irvine.
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Today we're gonna talk about,
1:00
uh, abdominal and pelvic trauma.
1:03
Um.
1:04
So the way I structured this talk, um,
1:06
I'm gonna mainly gonna talk about CT in,
1:09
uh, trauma of the abdomen and pelvis.
1:11
Uh, I'm gonna start out by talking with
1:13
blunt abdominal trauma, which is what
1:15
most of what we see at, uh, UC Irvine.
1:17
Uh, and talk a bit about solid organ injury,
1:20
uh, bowel injury, and then patterns of injury.
1:22
And then I'm gonna finish up with
1:24
a bit about penetrating trauma.
1:27
Um, so a little bit, uh, about CT for trauma.
1:30
CT, um, as you may or may not know, is really
1:32
our workhorse for the evaluation of patients
1:34
with, um, uh, abdominal pelvic trauma.
1:37
Uh, and that's because it's
1:39
a really good study, right?
1:40
It has a very high negative predictive
1:42
value for, uh, significant injury.
1:44
Um, it's, uh, very useful to rule out
1:47
significant injury, uh, in the ER setting.
1:50
Uh, the clinical examination is very unreliable
1:52
because patients are frequently intoxicated,
1:55
have distracting injury, which, uh, prevents
1:57
a good physical or clinical examination.
2:00
Um, historically speaking, uh, penetrating
2:03
trauma has been treated surgically with
2:05
surgical exploration for all patients.
2:07
Uh, but increasingly now over the past few decades,
2:10
um, penetrating trauma has also been evaluated
2:13
initially with, uh, CT of the abdomen and pelvis.
2:17
At our institution, our, uh, protocol is just
2:20
to do a, uh, venous phase examination about 70
2:22
seconds after the, uh, administration of contrast.
2:25
That's not universal.
2:27
Uh, a lot of, uh, institutions will also do an
2:30
arterial phase examination at 25 to 30 seconds,
2:33
um, especially if there's a, um, high energy
2:36
mechanism of injury, uh, with, uh, displaced
2:40
pelvic fractures to look for a vascular injury.
2:43
Uh, some people have also, or some
2:44
authors have also advocated for the use
2:46
of a delayed phase three to five minutes after the
2:48
administration of contrast, predominantly to evaluate
2:51
the, um, the, uh, bladder and collecting systems.
2:55
Uh, typically we do not use oral
2:56
contrast because it delays evaluation.
2:59
Uh, oral contrast can sometimes be
3:01
helpful to identify bowel injury.
3:03
Uh, but, uh, we don't use it
3:04
on the initial examination.
3:06
If there is concern for bowel injury, uh, you can do
3:09
a repeat examination with oral contrast afterwards.
3:13
Um, so this is a nice image that I took
3:15
from the website, uh, Radiology Assistant.
3:18
Um, and, uh, I like this image because it kind of
3:20
shows you this poor individual with sort of every
3:24
pattern of injury that you can see or that you
3:26
should look for on a CT of the abdomen pelvis, right?
3:29
Um, in terms of solid organ injury, uh, you can
3:32
look for contusions, which is just sort of a
3:35
ill-defined area of low attenuation within an organ.
3:38
Lacerations tend to present as, uh, branching or
3:42
linear hypoattenuating structures within an organ.
3:45
Uh, intraparenchymal hemorrhage, uh, hemoperitoneum,
3:49
pneumoperitoneum are all things you should
3:51
be looking for as well as active bleeding.
3:53
Devascularization.
3:55
This kind of gives you an overview for the
3:56
things you should be, uh, keeping an eye
3:58
out for when you evaluate a CT after trauma.
4:03
Uh, one thing I want, uh, everyone to understand
4:06
about, uh, trauma is over the past few decades, uh,
4:09
there has really been a trend towards non-operative
4:11
management, uh, in blunt abdominal trauma.
4:14
And this has been facilitated by the use of CT.
4:17
Um, and because of that, today about 80%
4:19
of liver injuries, 50% of splenic injuries,
4:22
and almost all renal injuries are managed,
4:24
uh, conservatively or non-operatively.
4:28
So let's start with, uh, splenic injury.
4:30
Uh, the spleen is the most commonly injured organ.
4:34
Um, most, uh, splenic injury
4:36
can be managed non-operatively.
4:40
So let's start with a case.
4:43
Let me move this.
4:46
So this is a, uh, 26-year-old, uh, male who
4:49
fell off a horse, um, uh, and came into our
4:52
ER, uh, for a blunt abdominal trauma obviously.
4:55
So I'll give you a second to look at this.
4:57
What are the pertinent observations, things you
4:59
have to include in your, uh, radiology report?
5:01
I.
5:05
So obviously here in the spleen, in the
5:07
left upper quadrant, there's a, a, a
5:09
linear hypoattenuating area in the spleen,
5:11
which, uh, look looks like a laceration.
5:14
Um, and also, uh, there's this right along
5:18
the, uh, along the, um, uh, periphery of the
5:21
spleen, there's, uh, free intraperitoneal
5:23
fluid and it's hyperdense fluid.
5:24
So there's a, a small to moderate hemoperitoneum here.
5:29
So here you would say, um, there's a splenic
5:31
laceration, uh, as well as a hemoperitoneum.
5:35
Um, right.
5:36
So we'll keep that in mind as we go to our next case.
5:42
So this is a patient, she's a 36-year-old
5:44
lady who was in a, uh, motor vehicle accident.
5:46
She also has a splenic injury.
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I'll give you a second to look at the images, um, and
5:51
to figure out what the pertinent observations are.
5:56
So, like we said, um, the, um, uh, the abnormal
6:00
area, the area of injury is the spleen, right?
6:04
Um, so this looks a bit different
6:08
from the prior examination.
6:10
So what is the finding?
6:13
How does it affect management?
6:15
So I wanna, what I wanna draw your attention
6:17
to is, like on the previous examination,
6:19
there's this hypoattenuating area.
6:21
In the spleen, there's a small hemoperitoneum,
6:24
but also something that was on, that's on this
6:26
exam, which wasn't on the prior examination, was
6:28
the presence of active contrast extravasation.
6:31
So, active contrast extravasation is gonna be an
6:33
area of, uh, contrast blush within the, uh, splenic
6:37
parenchyma that's almost as bright as the blood pool.
6:39
Uh, so this is an, uh, this is evidence of
6:42
um, active, um, intraparenchymal hemorrhage,
6:44
and this, um, uh, predicts a high failure
6:47
rate for non-operative management.
6:49
So these patients often need some sort of
6:51
intervention, whether it's, um, um, embolization
6:55
or, um, laparotomy, uh, for management.
6:58
And so it's very important when you
6:59
describe splenic, um, injury, not only to
7:02
mention the, um, type of injury, but the
7:05
presence or absence of active extravasation.
7:09
Here is, um, the, um, AAST Splenic Injury
7:13
Scale, which you may be familiar with.
7:16
Uh, this is the most recent, uh, revision in 2018.
7:20
Um, and that's important because the most
7:23
recent revision, uh, mentions splenic, uh,
7:26
um, active extravasation in the spleen.
7:28
So for example, here in grade four, any injury, um,
7:32
in the presence of splenic vascular injury or active
7:34
bleeding, confined within the splenic capsule is
7:36
considered a grade four, uh, grade four injury.
7:39
So previous, um, uh, editions of the AAST, uh,
7:43
Splenic Injury Scale did not include a reference
7:46
to active bleeding, and as such, they weren't,
7:48
they were criticized for not being very good
7:50
at, at predicting the need for, um, surgery.
7:56
Um, so, so make sure if you're using the A
7:58
AST, uh, scale to grade your injury, uh, to
8:00
make sure that you use the most recent, uh,
8:02
revision, 'cause it does include reference to a
8:05
splenic vascular injury with active bleeding.
8:07
Note that active bleeding, confined within the
8:09
splenic capsule is a grade
8:12
four injury, whereas active bleeding beyond the
8:15
spleen into the peritoneum is a grade five injury.
8:18
So our take-home points are, um, most splenic
8:21
injury can be managed non-operatively.
8:24
Uh, and look out for active extravasation.
8:26
Make sure to comment, uh, on whether if there is
8:29
active extravasation, whether that extravasation
8:31
is confined within the splenic parenchyma, or
8:34
whether there's bleeding into the peritoneum.
8:38
Okay, moving onward to liver injury.
8:40
Um, the liver is the, actually the second
8:42
most commonly injured organ after the spleen,
8:44
but it has a higher mortality than splenic
8:46
injury and is in fact the most common cause
8:48
of death after, uh, blunt abdominal trauma.
8:51
The most frequently injured part of the
8:53
liver is the posterior right hepatic lobe.
8:57
So let me give you a case.
8:58
This is a patient who, um, was in a car accident.
9:06
So here's the, um, um, abnormal,
9:09
the abnormal area, right?
9:10
Um, and I'll give you a second to look at that.
9:12
Take a look at what the pertinent observations are.
9:21
So what do you see here?
9:22
You see in the right posterior hepatic lobe,
9:24
there's sort of this large ill-defined area of
9:27
hypoattenuation in the, uh, right hepatic lobe.
9:30
Probably going to be, um, an intraparenchymal
9:32
hematoma, a contusion and intraparenchymal hematoma.
9:35
The other important observations to make are, um.
9:40
So what are the, uh, important associated, uh,
9:42
observations here where the yellow arrow is?
9:44
You see a small focus of what looks like active
9:46
extravasation or a small pseudoaneurysm.
9:49
Uh, so that's important to mention in your report.
9:51
And then the other important finding is
9:53
that there's a hemoperitoneum, right?
9:56
Um, so these are things that you
9:57
have to include in your report.
9:59
Um.
10:05
So let's move on to the next case.
10:06
This is another patient who
10:07
was, um, in a, um, car accident.
10:11
This patient also has a, uh, hepatic hematoma, right?
10:14
There's a crescentic hematoma, uh,
10:17
along the periphery of the liver.
10:20
Um, and note how this hematoma is a bit
10:23
different from the one we saw in the prior case.
10:25
Um, liver hematomas after blunt
10:27
trauma come in two flavors, right?
10:29
There's the intraparenchymal hematoma, uh,
10:31
which, uh, looks like that last case where it's
10:33
intraparenchymal, it's ill-defined, whereas
10:36
subcapsular hematomas like this one look like,
10:39
uh, areas which cause mass effect on the liver
10:42
parenchyma.
10:43
In this case, there's probably both a
10:45
subcapsular and an intraparenchymal hematoma.
10:47
You can see, uh, here on the right, on the right
10:50
side, there's, uh, there's, uh, blood within the
10:54
liver parenchyma and along the, uh, liver capsule.
10:58
The other important finding to mention is
10:59
that there's active extravasation, and this
11:02
active extravasation, as opposed to the last
11:04
case, isn't confined to the liver parenchyma.
11:06
There's, in fact, bleeding into the
11:08
peritoneum with a, a small hemoperitoneum.
11:11
So these are all important findings to
11:12
mention, and this patient will likely require
11:14
some sort of, um, uh, intervention, either
11:17
in the IR suite or in the operating room.
11:22
This is the 2018 revision of
11:24
the AAST Liver Injury Scale.
11:26
Uh, this one also incorporates
11:28
vascular injury with active bleeding.
11:31
Um, so in grade three you'll see vascular injury
11:33
with active bleeding contained within the liver
11:35
parenchyma. Uh, grade four injury, uh,
11:38
includes vascular injury with active bleeding,
11:41
breaching the liver parenchyma into the
11:42
peritoneum like we saw in the most recent case.
11:48
Excuse me.
11:51
Right.
11:51
So liver injury, um, historically it's been
11:54
managed operatively, but with the help of CT,
11:56
we can, uh, risk stratify patients who can be
11:58
managed conservatively without a trip to the OR.
12:01
Uh, and patients will need more, uh, aggressive care.
12:05
Uh, delayed complications of,
12:07
uh, liver injury do occur.
12:09
And that's a nice segment to this next case.
12:11
So this case, uh.
12:13
Um, this, uh, in this case, this is a patient
12:16
who was in a, a motor vehicle collision, uh,
12:19
presented with abdominal pain, and we did a CT
12:21
one month after the, uh, motor vehicle collision.
12:26
Uh, so here's the area of interest, right?
12:28
There's a, um, uh, collection, uh,
12:31
and that's not the gallbladder.
12:32
You can see on the coronal image it's a
12:34
little too low, uh, to be the gallbladder.
12:37
Um, so what is this?
12:41
What's your differential
12:42
diagnosis for this collection?
12:44
And if you think you know what
12:45
it is, how do you prove it?
12:46
One month after an MVC, you have a peri-
12:48
hepatic collection. Note also on this
12:51
image there's, um, you know, there's
12:52
evidence of, uh, liver parenchymal injury.
12:55
I.
13:00
So this is, of course, a, uh, a biloma.
13:02
So bile leak is a not uncommon, uh,
13:05
delayed complication after liver injury.
13:07
Um, and then, uh, you can, uh, you
13:10
can prove that it's, if you've.
13:11
Fact that there's a biloma, you can prove it
13:13
by either doing a nuclear medicine hepatobiliary
13:16
scan, uh, so-called HIDA scan, or a, um, MRI of the
13:20
abdomen with hepatobiliary phase contrast or Eovist.
13:23
Um, and if you see, um, opacification
13:26
or, um, uh, of the, uh, collection, then
13:29
you know that it communicates with the
13:30
bile system and is in fact a biloma.
13:32
Uh, once you've identified a biloma, you're not done.
13:35
Uh, remember that bile can erode the
13:37
vessels and form a pseudoaneurysm.
13:39
And for that reason, there's a high correlation
13:41
between bile injuries and pseudoaneurysms.
13:44
So every time you see a biloma, make sure to
13:45
look carefully for evidence of vascular injury.
13:49
Um, other things on your, um, other sort of
13:51
presentations for delayed complication after liver
13:54
injury include, uh, biliary stricture, uh, vascular
13:58
complications like pseudoaneurysm like we mentioned.
14:01
And then abscesses.
14:02
Abscesses can look like bilomas,
14:04
but abscesses are less common.
14:08
Okay, great.
14:09
Moving away from the liver, this is
14:11
another patient who was in a motor vehicle.
14:13
Actually.
14:13
This patient was, uh, struck by a car.
14:15
This was a pedestrian struck by a car.
14:18
The, um, abnormality, I'll give
14:20
you a second to look at the images.
14:24
So here you see, um, a linear hypoattenuating,
14:27
uh, thing in the right kidney, and then there's
14:30
a small amount of, uh, perinephric fluid.
14:32
So this is a, uh, uh, renal laceration.
14:38
So my question to you is, what are the
14:40
important pertinent negatives to mention while
14:42
describing a renal laceration?
14:47
Um, so the important pertinent negatives
14:50
are size of the laceration, of course, and
14:52
then involvement of the collecting system.
14:55
Remember, the vast majority of renal
14:56
injuries can be managed non-operatively.
14:59
Um, um, the therapeutic interventions
15:04
like surgery or, um, IR intervention are
15:07
usually reserved for patients who have
15:09
vascular injury or, uh, injury which involves
15:11
the collecting system with or without urinoma.
15:16
Moving onward.
15:18
Here's a case of another type of renal injury.
15:20
You can see that, um, this differs
15:23
from the prior case, right?
15:24
Um, here we have the, uh, right kidney is injured.
15:28
You have a crescentic collection along the
15:30
periphery of the kidney, and it looks like
15:32
there's mass effect on the renal parenchyma.
15:34
And this is a typical appearance of a
15:35
subcapsular hematoma of the right kidney.
15:38
Um, one of the things I want to caution you, uh,
15:41
about and one of the pitfalls in evaluating for
15:44
subcapsular hematoma: just make sure that you
15:46
don't get tripped up by, um, motion artifact.
15:49
Motion artifact can look often very, um, very
15:53
deceptively similar to a subcapsular hematoma,
15:56
not only of the kidney, but of the liver as well.
15:58
Uh, one of the ways you can differentiate a true
16:01
subcapsular hematoma from just motion artifact
16:03
is look at all the other structures in the—
16:05
Structures in the abdomen.
16:06
If everything else seems to be moving, then
16:08
what you're dealing with is likely not a
16:10
subcapsular hematoma, but just motion artifact.
16:15
Okay, great.
16:16
Moving onward, take a look at this case.
16:18
This is another case of a, um, a car accident, and
16:21
the abnormality is here in the, uh, right kidney.
16:34
So my questions to you about this injury
16:37
are, um, is this a renal contusion?
16:41
And if it is not—if it is not a renal
16:44
contusion (I kind of gave away the answer there),
16:45
but if it is not a renal con—
16:46
uh, contusion, why or why not?
16:48
How do you—how can you distinguish
16:49
what this is from a contusion?
16:54
So like a contusion.
16:55
Um, this is a, um, um, hypoattenuating
17:00
area in the upper pole of the right kidney.
17:02
Uh, it is different from a contusion though, in
17:04
that it's very sharply demarcated and it's very,
17:07
wedge-shaped along the periphery of the kidney, right?
17:10
This isn't a contusion.
17:11
This is, in fact, a segmental infarction of the kidney.
17:13
This patient needed to be taken to the, um,
17:16
the IR suite, um, uh, for, um, intervention.
17:20
You can see they've, um, they've, um, the ca— the
17:23
catheter is in the renal artery, and there's abrupt
17:25
cutoff of the, uh, right upper pole segmental
17:28
artery, uh, consistent with an infarction.
17:34
Moving on to other, uh, renal injuries.
17:37
This is a patient with, uh,
17:38
who was also in a car accident.
17:40
Take a look at these images and, um,
17:42
try to, um, figure out what you think.
17:52
So here are the abnormalities
17:53
in the right kidney, right?
17:54
So you see this is a delayed phase image.
17:56
You have opacification of the calyces in the
17:58
collecting system, and you also have what
18:01
appears to be extravasation of urine, uh, at
18:03
the level of the right ureteropelvic junction.
18:06
Um, you have, uh, urine, it kind of, um, extravasates
18:09
into the, uh, right lateral conal space and into the
18:11
extraperitoneal, uh, spaces of the anterior abdomen.
18:14
So this is a ureteropelvic junction
18:16
injury, uh, due to blunt trauma.
18:19
Uh, so UPJ injuries can be caused by
18:21
both penetrating injury or blunt trauma,
18:24
uh, due to sudden, uh, deceleration.
18:26
Uh, if there is, um, uh, injury due to blunt
18:30
trauma, it's usually at the UPJ because of
18:33
sudden deceleration and tension on the renal
18:35
pedicle, uh, causing, um, causing rupture.
18:39
Um.
18:40
Uh, so you often see a urinoma.
18:42
Typically you don't see hematoma.
18:45
Uh, and these UPJ injuries can,
18:47
uh, can come in two flavors.
18:48
They can either be an avulsion or a laceration, um,
18:51
a laceration, uh, maybe like this case where you
18:54
see extravasation of urine, but you see, um, um.
18:58
Opacification of the more distal ureter, uh, whereas
19:01
complete avulsion, uh, the, uh, UPJ is completely
19:05
dissociated from the more distal ureter, and you
19:07
won't see any opacification of the more distal ureter.
19:12
Great.
19:13
Moving onward.
19:16
What do you think of this, uh, case?
19:18
This is a case after, uh,
19:19
blunt abdominal trauma again.
19:24
So here it's, uh, it's pretty clear, right?
19:26
You see a non-enhancement of the
19:28
left kidney corresponding to a, uh,
19:31
injury to the left vascular pedicle.
19:33
This patient had to be taken to the, uh,
19:35
um, uh, interventional radiology suite.
19:37
Um, these were the results.
19:39
You can see there's sort of this linear.
19:40
Filling defect in the left renal artery.
19:42
This was thought to represent a,
19:44
uh, left renal artery dissection.
19:46
You can see there's delayed
19:47
enhancement of the left kidney.
19:49
This patient ended up being stented for repair, so
19:53
vascular injuries to the, um, um, the renal pedicle
19:57
can come in, uh, a couple of different varieties.
20:00
Uh, you can see dissection like in this case.
20:02
You can also see pseudoaneurysms and
20:04
even AV fistulas after blunt trauma.
20:06
So keep an eye out for, uh,
20:07
those types of vascular injuries.
20:11
Uh, so in the most recent revision of
20:12
the AAST Renal Injury Scale, there's a
20:15
lot of emphasis given to vascular injury.
20:17
Um, so make sure to look for vascular
20:20
injury and then comment on whether it's
20:21
confined within the pararenal fascia.
20:24
Um, uh, whether there's vascular injury
20:27
to a segmental renal artery or vein, or
20:29
whether there's a segmental infarction.
20:31
Um, uh, like we saw in that, uh, last case.
20:35
Um.
20:36
Uh, mention whether there is associated active
20:39
bleeding, um, uh, if there is an infarction.
20:41
And then in the most severe, uh, renal
20:44
injuries, there'll be avulsions of the renal
20:45
hilum, devascularization, devascularization
20:48
of the entire kidney due to a hilar injury.
20:51
Uh, and that's, uh, similar to what
20:52
we saw in the most recent case.
20:56
Um, again, um, um, the therapeutic
20:59
interventions, either endovascular,
21:01
urologic, or surgical, are reserved for,
21:04
uh, disruptions of the collecting system.
21:06
Um, so if you do have a laceration of the
21:08
kidney, make sure to, uh, look for whether
21:11
it involves the collecting system, uh,
21:13
and whether there's urinary extravasation.
21:19
Okay, so renal injury isn't as common
21:21
as splenic or, uh, liver trauma.
21:23
It occurs in about three to 10% of abdominal trauma.
21:26
Um, 80, uh, 80 to 90% of renal injuries are actually
21:30
seen in blunt trauma as opposed to penetrating trauma.
21:33
Uh, one useful clinical sign is that hematuria is
21:36
often present in patients with renal trauma, so that
21:39
you should maintain a high index of suspicion if the
21:40
patient has, uh, hematuria on initial evaluation.
21:46
Again, CT has been very helpful.
21:48
It's facilitated a move towards
21:49
conservative management.
21:50
Um, about 98% of renal injuries
21:53
can be managed non-operatively now.
21:55
Um, so, um, if there is concern for delayed
21:59
for a collecting system injury, uh, you can
22:01
consider, uh, repeat, uh, scanning with delayed
22:04
images to evaluate for urinary extravasation.
22:09
Okay, moving onward.
22:11
So here's a, um, CT cystogram.
22:14
I'll take—give you a second
22:15
to, uh, look at the images.
22:20
And then this, um, this additional
22:22
image, which I'm showing you.
22:28
So what type of bladder injury
22:29
is this, and how is this managed?
22:33
So, um, so this is a case of—this,
22:36
like we said, this is a CT cystogram.
22:38
You can see there's an obvious
22:39
abnormality, uh, anterior to the bladder.
22:41
There's all this contrast extravasation
22:43
in the anterior space of Retzius, and there's
22:46
extravasation of contrast into the, uh,
22:48
soft tissues of the right inguinal region.
22:50
The reason I showed you this,
22:51
uh, more superior image is to establish that
22:54
there's no contrast leaking into the peritoneum.
22:57
Um, there's no—you don't see any
22:59
contrast outlining the bowel loops.
23:02
So, uh, this is an example of an
23:04
extraperitoneal bladder rupture.
23:07
Um, there's a sign associated with
23:09
this if you like radiologic eponyms.
23:11
Someone thought that
23:12
this contrast extravasation into the
23:13
space of Retzius looks like a molar tooth.
23:15
And so this is called the molar tooth sign.
23:18
Uh, remember that extraperitoneal bladder injuries
23:20
can be usually managed, uh, non-operatively,
23:23
whereas, uh, rupture of, um, the bladder into the
23:26
peritoneum usually requires, uh, surgical repair.
23:32
Um, the chance of bladder rupture—so bladder
23:35
rupture is highly associated with pelvic fractures.
23:37
It used to be thought that the, uh, fracture fragments
23:40
themselves stabbed the bladder and caused the
23:43
bladder injury, but that's not necessarily the case.
23:45
Um, and remember that you can't do the
23:48
cystogram at the same time as the initial CT,
23:50
because the findings will confound one another.
23:52
Um, so you have to do the CT cystogram at a later
23:55
point if there's high suspicion for bladder injury.
23:58
Um, the way we do it at our institution—we
24:00
drain the bladder via an indwelling Foley.
24:02
Uh, we give contrast solution: 50 ccs of IV
24:05
contrast material in normal saline, and then
24:08
we instill about 350 to 400 ccs of contrast.
24:10
And then we do a CT of the pelvis.
24:14
And this is, uh, you know, as you
24:16
may know, very good for bladder rupture.
24:18
It's got about 100%,
24:20
uh, uh, and 99% sensitivity and
24:22
specificity for extraperitoneal rupture.
24:25
Uh, and over 90% sensitivity and
24:27
specificity for intraperitoneal rupture.
24:32
Okay, moving onward.
24:34
This is another case.
24:35
This is a 22-year-old male
24:36
with blunt abdominal trauma.
24:38
This is kind of a tough case.
24:39
I'll give you a few minutes—or a few
24:40
seconds, rather—to, um, look for the findings.
24:48
If I told you that the patient had an
24:50
elevated lipase, um, see if that would
24:53
help you to determine the findings.
25:01
So here are the findings right here.
25:02
You see this kind of ill-defined area of
25:05
hypoattenuation between the pancreatic
25:07
parenchyma and the splenic vein.
25:09
That's a small amount of fluid.
25:10
You also see it on the sagittal view.
25:13
So this is a pancreatic injury.
25:15
Um, and you know, like you can see here, it
25:17
can be very subtle, the pancreatic injury.
25:19
So it's a relatively uncommon injury.
25:21
Uh, it's only got about a 1.1%
25:24
incidence in penetrating trauma, and
25:26
less than 1% incidence in blunt trauma.
25:31
Um, one helpful, uh, tip is that
25:35
pancreatic injury is rarely an isolated injury.
25:38
Um, so if you do see, um, a severe mechanism
25:41
of injury with lots of solid organ injuries,
25:43
uh, look carefully for pancreatic injury.
25:47
Most of the, um, um, most of the blunt injury to
25:51
the pancreas occurs in the, um, pancreatic body.
25:54
Uh, look for a rising amylase and lipase.
25:57
Um.
25:58
And look for peripancreatic inflammatory changes.
26:01
Um, and in this case, sometimes pancreatic injury—
26:04
the only sign will be a little bit of subtle
26:06
fluid between the splenic vein and pancreas.
26:08
Uh, maintain a high-end index of suspicion,
26:10
especially if there's a lipase, uh, that's elevated.
26:13
I. And pancreatic injury can present as,
26:17
uh, contusions, which are non-linear, hypo
26:20
attenuating areas, lacerations, which
26:22
are linear, hypoattenuating regions.
26:24
Uh, and then make sure to look for
26:26
integrity of the pancreatic duct.
26:27
It's very important, um, for the surgeons
26:30
to know whether the pancreatic duct is,
26:32
um, involved by the pancreatic injury.
26:35
This is the AAST Pancreatic Injury Scale.
26:38
Uh, one thing I wanna call your attention
26:40
to is if there is a laceration or
26:42
parenchymal injury to the pancreas.
26:44
Make sure to tell the surgeons where it is,
26:47
um, if it is proximal to the superior
26:49
mesenteric vein via, uh, or, uh, distal to the, uh,
26:53
superior mesenteric vein.
26:55
Um, so, uh, that can affect surgical management.
26:58
So grade one, pancreatic
26:59
injury is usually non-surgical.
27:01
Grade two is variable.
27:03
Grades three, four, and five are
27:04
typically surgically managed.
27:09
Okay, let's look at this case.
27:11
This is another patient, blunt abdominal trauma.
27:17
What is the name of this sign here?
27:27
So this is of course the dependent viscera sign.
27:29
I don't know if you've heard of this, but what
27:30
you can see here is all the abdominal viscera
27:33
are lying, uh, against the, uh, thoracic
27:36
wall, and there's no diaphragm in between
27:38
the, um, viscera and the abdominal wall.
27:41
Uh, this is a, uh—
27:42
specific, fairly specific
27:44
sign of diaphragmatic injury.
27:45
And if you look at the coronal, you can
27:47
see there's a diaphragmatic injury with
27:48
herniation of the intra-abdominal contents.
27:52
So in diaphragmatic injury, uh, in blunt trauma, it's
27:56
due to a sudden increase in intra-abdominal pressure.
27:58
Uh, you'll see a diaphragmatic discontinuity
28:01
with herniation of intra-abdominal
28:03
contents like we did in this, this case.
28:06
Um, as you might imagine, our sensitivity for
28:08
diaphragmatic injuries on the right side is lower,
28:11
because the liver has kind of a protective effect.
28:13
Um, we're better at finding diaphragmatic injuries
28:16
on the left than we are on the right.
28:20
Moving onward.
28:24
After blunt abdominal trauma, what is your
28:26
differential diagnosis for this finding?
28:31
So the finding of course, is, uh, pneumoperitoneum
28:34
right after blunt abdominal trauma.
28:35
What do you think this, uh, could represent and does
28:39
it change, uh, does it change your differential?
28:41
If I show you this image, which is
28:43
of the same patient at the same time?
28:47
So this is a case of pneumoperitoneum, and
28:48
usually when you see pneumoperitoneum after
28:51
blunt abdominal trauma, you think of, uh, bowel
28:53
injury and perforation with pneumoperitoneum.
28:56
That's not, uh, that may be true,
28:58
but it's not always the case.
28:59
And there's—you have to remember, there's
29:00
a differential for pneumoperitoneum.
29:02
Um, if the patient underwent a peritoneal
29:04
lavage or had traumatic Foley placement,
29:07
um, that can also cause pneumoperitoneum.
29:09
Uh, but a common reason that we see in our
29:11
patients is translocation from the thorax.
29:13
If the patient had extensive thoracic injuries
29:16
with a, uh, pneumothorax or pneumomediastinum,
29:19
that air can, uh, translocate into the
29:21
abdomen causing a pneumoperitoneum, which is
29:24
unrelated to the presence of bowel injury.
29:27
If there is concern for bowel injury, one
29:30
thing you can do is, uh, give the patient
29:31
oral contrast and then, uh, re-scan.
29:37
Okay, next case.
29:39
Uh, so this is a young patient, uh,
29:41
again after a blunt abdominal trauma.
29:43
Um, the patient had no solid organ
29:45
injury, no obvious bowel injury.
29:47
What he did have was, uh, this finding here,
29:50
uh, what I'm pointing to is a small amount
29:53
of, uh, free, free fluid in the pelvis.
29:58
So in the absence of other, um, you
30:00
know, abdo—intra-abdominal, uh, findings,
30:02
what do you think this finding means?
30:04
Uh, and is it pathologic?
30:09
Well, in the 1990s, a lot of studies
30:10
suggested that, uh, free fluid in the
30:12
pelvis indicated occult bowel injury.
30:15
Uh, we see free—especially in a male patient, right?
30:17
We see free fluid in, uh, in reproductive female
30:20
reproductive-age female patients all the time.
30:22
Uh, what's less clear is what—
30:24
or what was less clear is what to do with a small
30:27
amount of isolated free fluid in a male patient.
30:30
Um, so like I said, in the 1990s, it was thought
30:32
that this suggested occult bowel injury.
30:35
Um, as our CT technology improved, we started
30:37
seeing, uh, small amounts of incidental free
30:40
fluid in lots more patients who otherwise had—
30:42
no evidence of injury.
30:44
And so more recent studies have suggested that
30:46
a small amount of fluid is actually okay, even
30:48
in a male patient, especially because these
30:50
patients get a lot of hydration after trauma.
30:53
Uh, I like to, um, direct
30:55
my residents to this paper.
30:56
This was published in Radiology in 2010.
30:59
They looked retrospectively—patients
31:02
with blunt abdominal trauma—uh, trying
31:04
to answer the question of whether a small
31:07
amount of fluid in the pelvis was okay.
31:09
Um, and what they found is:
31:11
if there is a very small amount of simple free
31:14
fluid deep in the pelvis, which is to say, um,
31:17
below the third sacral vertebral body, and,
31:20
um, if the fluid is simple in attenuation,
31:22
meaning not hyperdense free fluid, then it's
31:25
likely not a sign of bowel or mesenteric injury,
31:28
and you can safely, um, ignore it basically.
31:33
So small bowel injury can be very tricky
31:35
to see on the initial abdominal pelvic CT.
31:38
Uh, the problem is that the specific
31:39
findings are very, uh, insensitive, and the
31:42
sensitive findings are very non-specific.
31:45
Um, so the sort of spectrum of findings includes
31:48
focal bowel wall thickening, which is sensitive,
31:50
but not specific; contrast extravasation, focal bowel
31:54
wall discontinuity are two signs that are, uh, very
31:57
specific but not sensitive.
31:59
And then you can also see mesentery
32:00
stranding or intraloop fluid.
32:02
Um, if you see, uh, mesentery stranding and,
32:05
uh, focal bowel wall thickening in combination,
32:08
that's strongly suggestive of a bowel injury.
32:10
So the combination of
32:12
those two findings can be very helpful.
32:15
Um, so bowel injury—about 5% of patients
32:18
with blunt abdominal trauma—the small bowel is
32:20
the most commonly injured, uh, followed by the
32:22
colon and then followed then by the stomach.
32:28
Here's a special type of, um, bowel injury.
32:31
Um.
32:33
I'll give you a second to look at it.
32:35
Here you see, uh, thickening of the duodenal wall.
32:39
Um, this ended up being a, um, an, uh,
32:41
intramural hematoma of the duodenum.
32:44
Um, so, um, duodenal injuries can, uh, either, um, uh—
32:48
uh, present as, uh, intramural hematomas or
32:51
lacerations with extravasation of contrast.
32:54
And for that reason, the surgeons asked us to do
32:56
this, um, fluoroscopic examination where you can
32:59
see there's, um, um, abnormality of the mucosa
33:02
in the second portion of the duodenum related
33:04
to a hematoma, but no extravasation of contrast.
33:06
So this was safely managed, uh, conservatively.
33:10
Um, make sure to keep an eye out for duodenal injury.
33:13
It's not very common, but if it is
33:15
present, it has a significant mortality.
33:17
Um, we're not, uh, that great
33:19
at identifying duodenal injury.
33:21
There was one study which showed, uh, um,
33:23
accuracy of 57% for duodenal injury, and like
33:26
we said, hematomas—intramural hematomas—
33:29
of the duodenum are treated conservatively.
33:31
Lacerations with extravasation of
33:33
contrast are treated with urgent surgery.
33:39
Um, yeah.
33:42
This case I just wanted to show and tell.
33:43
This is just an example of, um, intra-abdominal
33:46
aortic injury due to blunt trauma.
33:48
Here's a dissection roughly at the aortic hiatus.
33:51
Um, and I just wanted to, um, mention to you,
33:54
so if you do have injury to the aorta due to
33:57
blunt trauma, it's usually in the thorax, right?
34:00
Blunt injuries to the abdominal
34:01
IVC and aorta are uncommon.
34:04
There's a 20-to-1 ratio: thoracic
34:06
to abdominal injury after
34:07
blunt trauma.
34:08
Um, oftentimes—so, uh, while, uh, blunt
34:11
injuries to the IVC and aorta are uncommon,
34:14
retroperitoneal hemorrhage is actually quite common.
34:17
And often what you see is kind of this
34:18
whole mess in the retroperitoneum.
34:20
You've got hemorrhage, you've got stranding.
34:22
It's unclear what's bleeding
34:23
or where it's coming from.
34:25
Uh, and this is often the case, right?
34:27
You see a retroperitoneal hemorrhage,
34:29
it's not clear where it's coming from.
34:31
Um, and so the radiologist—
34:32
um, one advice that I give is to
34:34
focus on the location, the source,
34:36
and the stability of the bleeding.
34:38
Um, look for evidence of active extravasation,
34:41
like we probably have in this case.
34:42
Um, and then, um, look for, um, and then describe
34:46
in your report where the bleed is located.
34:49
Uh, if you've read any operative reports
34:51
with, uh, retroperitoneal injury, you'll
34:53
see that the surgeons will describe, uh, will
34:55
divide the retroperitoneum surgically into
34:57
three, um, sections.
34:59
Zone one is the central retroperitoneum,
35:01
uh, consisting mainly of the
35:03
aorta, celiac axis, and so forth.
35:05
Zone two is the lateral retroperitoneum,
35:08
the renal arteries, and um, uh, veins.
35:11
And zone three is the pelvic retroperitoneum.
35:16
Okay, so we've spent the past few minutes
35:17
discussing, um, uh, organ by organ, um, uh,
35:21
the various injuries in abdominal trauma.
35:24
This is where I want to give you, um, I want
35:26
to encourage you to take a more holistic
35:28
approach, um, uh, evaluate the CT in total, um,
35:32
because abdominal-pelvic, uh, blunt trauma
35:35
frequently, uh, gives you
35:37
specific patterns of injury.
35:39
So think about where the trauma or where the force
35:42
is coming from. If it's coming from the right, um,
35:44
anterior, you think about right hepatic lobe, right
35:47
kidney, right adrenal injuries, diaphragmatic
35:50
injuries, pancreatic head injuries, and so forth.
35:52
These are often associated.
35:54
So if you see one, keep an eye
35:55
out for the other injuries.
35:57
If the injury is coming, um, anteriorly,
36:00
think about injuries to the left hepatic lobe,
36:02
pancreatic body, aorta, transverse colon, and so forth.
36:07
If it's coming from the left, think about
36:09
spleen injury, left kidney injury, diaphragmatic
36:12
injury, and pancreatic tail injury.
36:14
If it's coming from the posterior side, left or right,
36:17
think about flank contusions, lower rib fractures,
36:20
transverse process fractures, and T and L spine fractures.
36:23
The reason I'm telling you this is
36:24
because, like I said, these injuries can
36:26
be commonly associated, and especially
36:28
retroperitoneal injuries can be very subtle.
36:30
So if you're not looking for them carefully
36:32
based on what the mechanism of injury is,
36:35
uh, you may miss them.
36:36
Uh, so remember the words of, uh, Wayne Gretzky, who
36:39
was once asked to, uh, describe why he was so great.
36:43
He said, I don't skate to where the puck is.
36:45
I skate to where the puck is going to be.
36:47
What does this mean for radiology?
36:49
Remember to be proactive, not reactive.
36:52
Think about the mechanism of disease and look
36:54
for the findings that you expect to be there.
36:57
For example, look at this Chance fracture.
36:59
So this is a flexion-distraction injury, um, at the
37:02
thoracolumbar junction involving the posterior elements.
37:05
Um, the fulcrum is anterior to the spine, so if you
37:08
just identify this Chance fracture, you haven't,
37:11
uh, finished your job, especially in pediatric
37:14
patients, because of the mechanism of injury.
37:16
This is highly associated with pancreas,
37:18
small bowel, and mesenteric injury,
37:20
which can be very subtle. So may,
37:22
uh, keep an eye out for these injuries.
37:25
So I'm running a bit short on time.
37:26
I'm gonna talk a little bit
37:27
about, uh, penetrating trauma.
37:29
Um, these have traditionally been
37:31
managed surgically, uh, but more and more
37:33
we're using, uh, CT for, um, evaluation
37:37
of patients who've been stabbed or shot.
37:39
Um, CT has—
37:40
excellent sensitivity for excluding surgically
37:42
important injury and is cost-effective.
37:45
Prevents a lot of people from
37:46
undergoing, uh, unnecessary laparotomy.
37:49
Um, blunt trauma versus penetrating trauma—
37:51
there's a few differences when you evaluate the CTs.
37:54
Uh, in blunt trauma like we described, um,
37:57
there's a combination of injuries which cluster
37:59
based on mechanism, whereas in penetrating
38:01
trauma, the injury is determined solely
38:03
by the path of the knife or the bullet.
38:05
Um, in penetrating trauma—or rather, in blunt trauma—
38:08
there are well-protected organs like the, uh, aorta or
38:11
the pancreas, uh, which are only rarely, uh, injured.
38:15
Whereas in penetrating trauma, the wound
38:17
trajectory is kind of indiscriminate.
38:19
There are more pancreatic, rectal, and IVC injuries
38:22
in penetrating trauma rather than blunt trauma.
38:26
Also keep an eye out for small diaphragmatic
38:28
injuries, uh, which can be quite subtle but
38:31
can be potentially catastrophic if missed.
38:33
Um, gunshot wounds, um, as you might imagine,
38:36
cause more severe injuries than, uh, stab wounds.
38:39
Uh, they cause internal wounds
38:41
in about 90, 90% of patients. Uh, one-half
38:43
to two-thirds of stable patients with gunshot
38:46
wounds, uh, will require surgical repair.
38:50
Um.
38:52
On the other hand, stab wounds—about 50 to
38:53
75% of them enter the peritoneum, and about 50
38:57
to 75% of those will require surgical repair.
39:00
Um, the one mantra I want you to internalize
39:02
when looking for, uh, penetrating
39:04
trauma is that trajectory is everything.
39:07
Uh, so figure out what the wound track is.
39:09
Your wound track is depicted by tissue, tissue
39:11
destruction. Clues to the wound track, um, uh, include
39:16
gas, hematoma, bone fragments, or bullet fragments.
39:20
Um, that can—
39:20
kind of help you figure out where the
39:22
knife or the bullet, uh, uh, passed.
39:26
Uh, entrance wounds are usually
39:28
smaller than exit wounds.
39:29
Uh, also bullets when they hit bone kind
39:32
of cause a snowstorm pattern, which, um,
39:35
increase conically as they, uh, move forward.
39:37
Uh, so that can help you, uh, determine
39:40
whether, uh, what the wound track is.
39:42
Um, sometimes finding the
39:44
wound track can be very tricky.
39:46
Stab wounds, especially in the paraspinous
39:48
muscles, can be very, uh, subtle.
39:50
Uh, sometimes foci of subcutaneous gas can be helpful.
39:53
Um, although the subcutaneous gas can migrate
39:56
along soft tissue planes and, uh, kind of mislead
39:59
you, uh, remember not to just draw a straight
40:02
line between the entry and the exit wound.
40:04
Uh, bullets can wobble and bounce off bones,
40:07
um, and then differences in the phase of
40:09
respiration between the time the patient was shot
40:12
and the time of the scan can cause, uh, sort of, uh,
40:15
ambiguity in what the, um, what the bullet track was.
40:18
Uh, remember, patients can, uh, have old bullet
40:21
fragments in their abdomen, so those can mislead you.
40:23
And then bullet fragments can sometimes hitch a
40:25
ride via the GI tract or the vessels and end up in,
40:29
uh, positions that they, uh, weren't originally.
40:34
So peritoneal violation is one of the
40:36
important questions you have to answer,
40:38
uh, after, uh, penetrating trauma.
40:40
Um, pneumoperitoneum is very specific for
40:43
peritoneal violation after, um, penetrating
40:45
trauma, but it's only seen in 35% of patients.
40:49
Um, a more, um, common finding is free fluid
40:53
after, uh, peritoneal violation, which is
40:55
actually seen in about 85% of patients.
41:00
Okay, this is a patient who was, uh, in his
41:02
hotel room, lying in his bed when he got shot.
41:05
Um, I've drawn arrows to where the entrance
41:07
wound is and where the exit wound is.
41:09
You can see an obvious, um, uh, kidney injury here.
41:13
Uh, if you look carefully, you
41:14
can see a defect in the diaphragm.
41:15
This patient had a focal diaphragmatic injury and,
41:18
um, that's clear because of the, uh, the wound tract.
41:21
Interestingly, the wound, uh, the, the trajectory
41:23
goes through the stomach, but we don't see
41:25
any perigastric fluid collections or wall
41:28
thickening. Um, uh, but this patient
41:31
actually did have, uh, through and through
41:33
full-thickness, uh, stomach injury.
41:35
So if you do see a trajectory through
41:37
a hollow viscus, uh, that's, uh, very,
41:40
very suggestive for hollow viscus injury.
41:44
You can say with a high degree of confidence
41:45
if there is a trajectory through bowel,
41:47
that the bowel is in fact injured.
41:49
Uh, sometimes if you see—if you get lucky
41:51
and see contrast extravasation, that's
41:53
very specific, but it's not often seen.
41:55
Indirect signs of hollow viscus injury include mural
41:59
thickening, mesenteric hematoma, or mesenteric fluid.
42:03
Um, uh, this is just a nice image I took
42:06
from this, uh, Radiology article in 2015.
42:08
They used a, um, uh, curved planar reformat to
42:12
figure out the exact trajectory of the bowel.
42:14
If you have a—or rather the bullet—if you
42:17
have access to this at your institution, you
42:18
can really figure out very nicely what the
42:21
trajectory is and what organs may be injured.
42:24
Colonic injury is a special type of, uh, bowel injury.
42:28
Um, if you have a trajectory through the
42:29
colon, uh, you should suggest colon injury.
42:32
Other findings that you may see are fecal collections,
42:35
or pericolonic stranding, and contrast extravasation.
42:38
Um, if you've given rectal contrast, I—
42:43
So penetrating pelvic injury
42:45
is kind of a special situation.
42:47
Um, and it's special because
42:49
the surgeons may miss them.
42:51
Uh, the injuries in the pelvis are
42:52
often extraperitoneal, and they're
42:54
difficult to surgically explore.
42:56
Um, so it's important if there is penetrating—
42:59
um, trauma through the pelvis to mention any pelvic
43:01
injuries. In particular, rectal and ureteral injuries
43:04
can be easily missed on, uh, surgical exploration.
43:07
So make sure to comment if these
43:09
structures, um, are, uh, along the, uh,
43:12
tract, uh, or the trajectory of injury.
43:17
Very good.
43:18
Uh, and so that's more or less all I have.
43:20
So in summary, remember there's been a
43:22
trend over the past few decades towards
43:24
non-operative management, both in blunt
43:26
and penetrating trauma in abdominal trauma.
43:28
Our real workhorse is CT, which is
43:31
used to rule out significant injury.
43:33
Uh, identify patients who require
43:34
surgical or IR management.
43:36
And then CT is increasingly used for penetrating
43:38
trauma to identify peritoneal violation and look
43:41
for patients who may need immediate surgery.
43:45
Uh, remember then blunt trauma, look for
43:47
combinations of injury which cluster based
43:49
on mechanism. Uh, in penetrating trauma,
43:52
on the other hand, trajectory is everything.
43:54
And in ambiguous cases, especially
43:56
if there's suspected bowel injury,
43:58
follow-up studies can be very helpful.
44:02
And that's all I have.
44:03
Thank you very much.
44:05
Alright.
44:05
It does look like we have a few questions
44:08
from the audience in the Q and A feature.
44:15
Yeah.
44:15
So how did you—how do you differentiate
44:17
active extravasation from pseudoaneurysm?
44:19
That can be very difficult, and sometimes, you
44:22
know, at our, uh, institution, we just do a 72-second
44:25
portal venous phase, so we end up dictating,
44:28
um, pseudoaneurysm versus active extravasation.
44:31
If you're at an institution where
44:32
they do delayed phase images,
44:34
uh, a pseudoaneurysm would—expect you'd expect a
44:37
pseudoaneurysm to remain a small round ball of, um,
44:40
um, increased attenuation, whereas extravasation would
44:44
be expected to sort of diffuse into the parenchyma and
44:47
become less well-defined on more delayed, uh, images.
44:51
Um, okay.
44:53
Very good.
44:54
So the two questions on why we use, uh, portal
44:57
venous phase, uh, or venous phase is enough.
44:59
Yeah, that's a good question.
45:01
Like I said, a lot of, um, authors do
45:03
advocate, um, arterial phase images or delayed
45:06
phase images in our, uh, in polytrauma.
45:08
Uh, our experience has been that, um—
45:13
uh, that, um, uh, most of our studies are negative,
45:17
uh, and, um, most of our patients are young.
45:20
Uh, we're trying to balance the, um, uh,
45:23
the need to reduce radiation dose, uh,
45:25
and catch as many injuries as possible.
45:27
Um, we found that, um, um, for the—for
45:31
our patients as a whole, venous phase
45:33
images are, um, what we've gone with.
45:38
Uh, would you see a small intraparenchymal
45:42
pseudoaneurysm in liver on portal venous phase?
45:45
Yeah, you can certainly see it.
45:47
The images that I showed you were, um, uh, the
45:50
image I showed you was a small pseudoaneurysm,
45:52
and we did see it on portal venous phase.
45:54
I take your point that, um, it may be more visible
45:57
on arterial phase, but again, we, uh, uh, we've found
46:01
that we can see enough of them on portal venous phase.
46:03
Um.
46:06
Um, okay.
46:08
What is your intake on whole-body CT?
46:10
Uh, I'm not sure I understand that question.
46:12
Uh, is the question how many CTs we get?
46:19
We can, um, we can move to the next question.
46:22
Um, in AAST, do the gradings need to
46:24
meet all the sub-bullets or at least one?
46:26
It's just one. Uh, it doesn't need to meet all
46:28
the sub-bullets to make a particular grade.
46:32
Uh, can—do you use dual
46:34
energy for virtual enhancement?
46:36
That's a good question, which, um, we are, um,
46:39
uh, we haven't been using dual energy so far.
46:43
Um, I, uh, think some people do use virtual
46:45
enhancement, but I can't, uh, answer that question.
46:50
Uh, my thought about whole-body CT
46:52
and its indications. So people use the
46:54
term whole-body CT, um, differently.
46:57
Um, I think that you mean by
46:58
whole-body, head to—head to pelvis?
47:02
Is that—is that true?
47:04
Um, so I think that, um—
47:09
I think that CT, um, you know, when we, uh, when
47:13
we read cases in the ER, a lot of our studies are
47:16
negative and, um, I don't think that's a bad thing.
47:19
I think it's a good thing.
47:20
Uh, I think that CT has been shown to be
47:22
cost-effective in pre, uh, preventing,
47:25
um, um, unnecessary laparotomies.
47:28
And although I'm not a neuroradiologist.
47:30
Um, I'm sure the, um, the—it would be—you see
47:33
something similar with head and neck injuries.
47:35
Um, so, uh, I think, uh, CT is very
47:39
sensitive for, uh, important injuries.
47:42
I think, uh, you—I think it's generally
47:44
shown to be a good thing to have a low threshold
47:46
to, uh, to do a whole-body CT, especially if
47:49
the, uh, mechanism of injury, uh, supports it.
47:55
Okay.
47:55
What protocol do you use for
47:56
trauma scan with contrast?
47:58
So, uh, like I said, we do use, um, so, um.
48:03
Uh, let me think.
48:04
So we use, uh—so our abdominal pelvic
48:07
CTs are done in the portal venous phase
48:09
with, um, about a, um, 60 to 72-second delay.
48:12
Um, the lungs are actually scanned first,
48:16
so we do an earlier phase for the—for the chest.
48:19
Um, that's, uh, going to be, um, more of like
48:21
a, um, CTA protocol that we use for our chest.
48:28
Uh, in a patient with BA or history of allergy,
48:32
is it all right to administer contrast in?
48:36
Um, I think, uh, you know, I think it is.
48:40
I think that, um, uh.
48:44
Well, you know, you have to really
48:46
weigh the risks and, and the benefits.
48:48
Uh, certainly in severe mechanism of trauma,
48:52
I think it's, uh, totally okay to administer
48:55
a contrast and then, uh, deal with any
48:57
complications as they occur. In patients
49:00
with relatively minor mechanism of trauma,
49:02
there, you really have to sort of risk the, um,
49:04
um, weigh the risks and the benefits, especially
49:07
if there's, um, evidence that the patient
49:10
has a very severe, uh, anaphylactic-type
49:12
reaction to contrast.
49:18
Okay, great.
49:19
I think that might be it for the questions.
49:21
So as we bring this to a close, I want to thank
49:24
Dr. Kampalath for this lecture and thanks all of
49:26
you for participating in our noon conference.
49:29
A reminder that this conference will be
49:31
available on demand on MRIonline.com in
49:34
addition to all previous noon conferences.
49:36
Be sure to join us again on Monday
49:38
for a replay lecture from Dr. Nolan
49:41
Chu on Neuroradiology Horror Stories.
49:45
You can register for that at MRIonline.com and follow
49:49
us on social media at the MRI Online for updates
49:52
and reminders on upcoming noon conferences.
49:55
Thanks again and have a great day.
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