Liver Abscesses and Collections - HD

Introduction

Good afternoon.
My name's Tim ef.
I'm one of the radiology fellow here at Kings.
And today I'll be talking not just about liver abscesses,
but also expanding into endo cavitary use
of contrast ultrasound.

To give you a brief layout of
what I'll speak about today, I'll give you a very brief
introduction to liver abscesses and the bits of the history.
I'll then talk about the use
of contrast ultrasound intravenously with liver abscesses
and then go on to a variety of endo cavitary uses.

Liver Abscesses Overview

As we know, liver abscesses are a well known pathology.
They've been around for a very long time.
As bleep being slightly uncommon
with a higher prevalence in Asia,
there has have been a roughly stable prevalence,
although there's been a matter of improved detection,
improved mortality following increase in technology.
Typically they come as genic abscesses.
The vast majority, although eBIC
and fungal abscesses also exist.
And as we've alluded to earlier, there are a wide variety
of causes including local
or distant infection trauma, which we see a fair amount
of hair, biliary abs iatrogenic
or even cryptogenic in origin.

And I won't go into too much detail on this slide at the
moment, but there are a range of ways of imaging.
Typically ultrasound
or CT are the most commonly used on ultrasound.
It presents as we've heard a number of times,
a focal liver lesion, which on gray scale ultrasound may be
difficult to really define much further.
But typically a hypo coic mass with irregular edges
and you may possibly see septations on ct.
You see the peripheral rim enhancement that's quite typical
along with a a fluid density center,
possibly irregular edges and septations again.

Contrast Ultrasound for Liver Abscesses

Why do we actually need contrast ultrasound?
It's adding to a differential diagnosis.
It's taking out that one step further to characterize it
and to be really give us an idea of how
to guide management in that instance.
Also, for liver abs,
the critical thing is temporal resolution.
So you must also monitor the size
and the excellent spatial resolution
of contrast Ultrasound allows us to do that.
Another option is to guide intervention, which I'll come on
to speak slightly more about in due course.

Here we have an example, our patient
with right upper quadrant pain
and fever, a very typical presentation
and we have a, a focal liver lesion.
But again, how much further can we really take it on Here we
have a hydrogenous lesion, a hypo coex central region.
There's still a number, a fair way
to go to characterize that.
And as we've heard about from uh, our previous speakers,
the FSO guidelines are in place
and mention to us how we can do that
and indicate that there's a a great number of uses
for characterization.

And this is our helpful cheat sheet which
fits on any ultrasound table.
And if we highlight the area that says abscesses, we can see
that what's described is arterial peripheral enhancement
that may remain hyper enhancing in the portal phase
and may be hypo enhancing in the, the late phase.
That may also be enhancing septi.
However, what's critical is there's no central
enhancement to the fluid component.
And if we look into that in slightly more detail, that's
because of the expansion
and emerging of chronic inflammatory cells
around the edge resulting in hyperemia
and that can give us a hyper enhancing rim.
There may also secondarily be defective venous perfusion due
to this and due to the extent of the edema
which may result in our hypo
enhancing rim in the late phase.
Furthermore, there is also surrounding mass effects
and surrounding abnormality
of the vessels which can cause us
to have hyper enhancing seg
sub-segments or segments of liver.

These are our, our typical images of our liver tra
of our liver abscess patient, which we've seen earlier.
You can see that there's arterial early arterial rim
enhancements and I hope you can appreciate
centrally within these.
There's no enhancement in the early phase
and again, that persists in the late phase
with very similar appearance in this case,
there's no washout.
You can also see these small areas within the fluid
components representing septi.
But liver abscesses have a a gradation.
They don't simply appear outta nothing.
They progress from inflammatory regions to micro abscesses
to a collection of a single cavity to widespread.

Pseudo Tumors and Inflammatory Regions

So the first area to look at is, uh, pseudo tumors,
an inflammatory region with no defined pus components.
And this is important to recognize
'cause it's known as a great mimic.
It can have a variety of contrast in appearances.
In particular, it may mimic malignancy
and can be very difficult to distinguish, particularly
as it may have early portal phase washouts.
And here's an example of just an ex of
how it can look in a different context.
This is a patient with a gallbladder empyema,
which ruptured causing an adjacent liver abscess.
However, you can also see nodular areas
of very defined washout in the central image in the middle.
And again, contextually we know that this was, uh,
this was a liver, liver abscess in inflammatory regions,
but in isolation you could easily
mistake that for a malignancy.

Endocavitary Uses of Contrast Ultrasound

So this is where I'll diverge slightly
and just suggest to you,
is this the only way we can use contrast ultrasound
to look at liver abscess?
No, there's also the possibility
of endo cavitary ultrasound.
And to go into that in more detail, we've always thought
of ultrasound contrast as a truly intravascular agent.
I'm going to encourage you to think of it
as a truly intraluminal agent.
As a, as an off-label application, normally we,
we dilute a, uh, ultrasound contrast in,
so the circulating volume eight liters.
However, I'm, I'm yet to see an eight liter liver abscess.
So I, I believe you have to use a much smaller dosage.
So we typically use 0.1 mls in 50 mls of normal saline
and deliver that through the drains.
But why do we do this? What's the actual benefit of it?
We want to a, confirm the drain position,
which can be quite difficult sometimes.
B, we also want to define the internal aspects
of the collection itself, particularly
as there may be distant at distant parts of the collection,
which may not appear linked at first.
Is there a communication between the two?
Can we also guide drainage?
Do we need to put a second drain in?

Liver Abscess with Drain

And if we go back to our patients, again,
we can see the liver abscess and the intravenous contrast.
We can also then see the appearances of the contrast
after it's injected through the indwelling drain.
And yes, you can see a very clear definition
of the size of the edges.
You can also see on the far picture
that there's communication between distant aspects.
So again, we don't necessarily need
to put a second drain into drainage.
We know that they are connected.

Other Collections: Intraabdominal and Renal

Is that the only endo cavitary use we can use? No.
Again, there's, there's a number
of other places it can be used.
We can think of any collection with the same,
the same uh, thought process.
It can be used in an intraabdominal collection of any sort.
What about other places? What about
the renal collecting system?
What about with nephros grams and indwelling nephrostomy?
What do we want to do with that?
We want to confirm that it's placed correctly.
We also want to confirm there's drainage
through the collecting system
and identify the presence of strictures or complications.
All three of those things, contrast
ultrasound is able to do.
In addition it's got the benefit of being radiation free.

Nephrostomy Case

So we'll go through this case.
Now this is a, a patient with bilateral nephrostomy.
Clearly on the left side you can see
that there's drainage along the collecting system.
There are two fibroids in the pelvis
but there is no no contrast within the bladder.
We've got the counterpart endochondral ultrasound again
delivered through the nephrostomy tube.
You can see excellent ification of the caly.
You can see that there's the ureter clearly
defined along its length.
And then because you've got excellent spatial resolution
and you've got dynamic imaging, you can see
that typical ureteric jet
with individual microbubbles filling the bladder.

Intracystic Contrast Ultrasound for Reflux

Are there further uses we've already had?
Uh, uh, initially we had alluded to the use
of intra cycle contrast ultrasound.
Professor Dar in the United States has pioneered this
and he's shown that it's not only safe
but it's also as effective
as a traditional tating cyst urethrogram in children to look
for icteric reflux.
And you can see from the images,
you can see definitive filling of the bladder reflux
through the dilated ureter
and up into the collecting system.
And 94% of the time the grade of reflux with either the same
or the contrast enhanced ultrasound was shown
to be more sensitive again due to that ability
to pick up individual bubbles.

Biliary System

So where else? What about the biliary system?
Well we have a, this was a patient, a pediatric patient
with a HEPA ostomy, had a biliary drain in situ you.
And we wanted to confirm the position.
We can inject contrast through the DR tube
and again, confirm that we've got filling of the rule loop.
We've got no leaks, we've got no fistula.
We've confirmed the patency and the placement.
Other studies, although there are very few in the
literature, have taken this one step further
and have actually gone to the extent of saying
that we can identify strictures
and the degree whether they're complete
or incomplete at the time of percutaneous cholangiogram.
We've also had one of my colleagues, Dr.
Eshi, has done a a study which shows that
there is a indwelling per biliary drain, which
although you see a ification of the biliary system,
you also start to see hepatic parenchymal ification.
And we go back to the idea of a truly intraluminal agent.
We shouldn't get that unless we think that there's some sort
of vascular fistula.
And that was in fact confirmed at angiography as well.
So we've got that, that potential to know
that we are in a defined space
and that we know that shouldn't extravasate art of it.

Gastrostomy Case

This was another patient who had a
gastrostomy tube in inside you.
She came complaining of pain
and the team were very concerned
that the gastrostomy was misplaced.
She was unable to move on to our fluoroscopy bed
and so we couldn't perform the procedure.
So what alternatives do we have?
Well, we can do an ultrasound
and we can see a small collection surrounding the
gastrostomy tube, but how do we know if it's leaking or not?
We need a dynamic mode of imaging.
We inject some contrast through
and we can see very clear ification of the gastrostomy,
which easily see you can easily see
filling of the stomach as well.
We can also see definitively there's no filling
of the collections surrounding the tube.
So we know that we're safe on the subject
of oral contrast.

Oral Contrast

There is very little evidence at present.
However, we know
that the micro bulbs are stable within the stomach
and this is an example of a, of someone's distal esophagus.
You can see along its length
to get the fundus of the stomach as well.
Although there stu have been studies using hydro sonography
and intravenous contrast to look at the bowel wall.
Very little has been done for ingested contrast,
however, a number of uses have been postulated
including the identification of peristaltic anomalies,
definition of strictures,
and also to look for gastroesophageal reflux.

Lines and Tubes: Portacath Case

What are the lines and tubes are there?
That's essentially what we're thinking now.
So this is a patient with a porter calf.
They had point tenderness, so we scanned along the length
of the porter calf and we saw the line looked entirely
normal until you came to the distal tip.
So there's a small fluid collection in the per ular region,
but again, there's not much you can tell without taking this
patient's fluoroscopy.
So we injected through the port cath
and you can see a ification of the entire line length.
You can also see at the images at the bottom rupture
of the line, again the truly intraluminal agents
on the very far image.
You can see that there is then
opacification surrounding the line tip.
However, when next to the internal jugular vein
where the line should be placed
and there's no opacification there, that tells us
that it's misplaced and explains the presence of a rupture.

Sterosalpingograms

Studies have also been done to look at stero sa picograms
and this has been done to either confirm tubal patency
or in fact the absence
of tubal patency following laparoscopic sterilization.
And there's found to be a very high concordance rates 94
to a hundred percent with traditional stero sa picograms.
But again, we've got the benefit of being bedside
and radiation free.

Interventional Use

I'll leave you with, uh, with one, one more slide about this
and this alludes to what professor said about Dr.
Wang's lecture later on about interventional use.
Here's an example of a ultrasound contrast filled needle
entering a collecting system
during a nephrostomy of a dilated system.
And you can actually appreciate the bubbles moving back up
the needle indicating correct placement.
And I can assure you as you, as you, uh,
await his talk later, it's much
more impressive in the videos.

Conclusion

So there are a wide range of places
where we can use endo cavitary contrast ultrasound.
We've mentioned liver abscess as a route
to describing a bit more.
There is very little evidence at present,
but it does appear to be safe certainly
in anecdote use of it.
But why use it?
Well for localization
and determination of positions of drains is a fantastic use.
But also you've got that ability to dynamically image.
You've got that ability to detect individual microbubbles
with excellent spatial resolution
and that can be even be beyond the resolution
of conventional fluoroscopic imaging bedside.
You can perform it in patients who are in IUs who are unwell
or simply unable to move to a bed.
And you've got that aspect of avoiding radiation,
particularly important as we've seen
with intra cycle contrast ultrasound.
However, it is a case by case basis
and it is used to answer specific questions.
That doesn't necessarily mean there's a one size fits all.
It doesn't mean there won't be,
but at the moment, the the main uses are thinking about
where you can use it to prove with dynamic imaging, prove
with high degree of accuracy
that something is appropriately cited.

And so I'd leave you with advice to, to be adventurous
and consider the use of endo cavitary contrast
ultrasound in your practice.
Thank you.