CEUS in Paediatric Blunt Abdominal Trauma - HD

Abdominal Trauma in Pediatrics

Paul told you we're gonna speak about abdominal trauma in pediatrics.

You heard a little bit about it before when Miko had this talk, but we'll go a little bit more in depth on the topic.

To kick off this topic, it's important once again to remind ourselves of the damage of radiation exposure.

And this is more so important in children and know how many of you in the audience are actually pediatric radiologists, or how many of you do pediatrics.

But all of you will certainly know about the damage of radiation exposure.

And an abdominal CT involves quite a big amount of radiation and the risk of developing a radiation induced cancer is higher.

The younger the patient you're radiating is.

And as you can see, it increases from one in a thousand when you are only 15 years of age to 2.5 in a thousand when you're 1-year-old.

And there are many studies out there.

This is one of the most important ones from 2012 from the Lancet that do reiterate the need for awareness of the risks related to radiation exposure.

Risks of CT and Modality of Choice

Having said all of that, CT still remains the modality of choice to image children in the setting of trauma.

And the reason is that it is the gold standard technique in case of the hemodynamically stable patient who has undergone a high energy multi-trauma, and that means that the patient needs a rapid triage, which will eventually allow a reduced morbidity and mortality.

So you can't really get away with performing a CT nor those cases.

However, as we all know, CT comes with many disadvantages, and these are more important in children.

The patient needs to be cooperative, and this may mean sedation when the patient is a child, you need to inject the iodinated contrast and again carries radiation exposure risks.

Limitations of Other Modalities

So what about other modalities to image trauma in children?

When you look at FAST scan and ultrasound?

Well, none of these two techniques.

The bottom line is that none of these two are good enough to image children in trauma.

For many reasons, FAST scan has got good sensitivity, generally speaking for hemoperitoneum, for detecting free fluid, but it's very operator dependent and cannot diagnose organ injury.

Moreover, one third of traumatic lesions may present without a hemoperitoneum at all, so you may well miss those lesions in patients without a hemoperitoneum.

And also the way a FAST was developed, it was mainly to address trauma in the setting of adult trauma.

So the way we use it may not be as applicable in children as it is in adults to influence management decisions.

At the same time, even in the most experienced hands, a normal baseline ultrasound, again, is not good enough to detect organ injuries, because very often these are isoechoic compared to the rest of the normal parenchyma.

Shift to Conservative Management

So more and more in the last years, we have moved towards a conservative management of the trauma patients, and this is more so in the pediatric population.

This is more real and important.

That means that we need to know which kind of injury we are dealing with to be able to make a sensible decision regarding the management and follow up.

At the same time, we want to do this keeping the radiation exposure to a minimal.

So there is a need there for an imaging modality that would be superior to baseline ultrasound, but at the same time would act as a filter for those patients who don't really need a CT at presentation.

Introduction to CEUS

So that's where CEUS come into the picture.

And even though there aren't official guidelines out there, the ABS has made some recommendation for the use of CEUS in the context of trauma, and it recommends it's used in case of minor or localized injuries or low energy injuries.

The classic situation is a child who's playing in the playground and it falls from one of the toys.

But also sometimes it can be useful to delineate lesions that are uncertain on the CT and also importantly, we can use it in the follow ups.

And obviously it comes with all the advantages of traditional baseline ultrasound and is also cost effective compared to CT.

It is indeed the first choice for imaging children in trauma in many European centers.

And when you look at the literature, the performance values are indeed very good.

And that's because it can really give an accurate definition of all the lesions, and especially because of the purely intravascular nature of CEUS.

It can also allow you to detect the tiny, subtle vascular alterations.

In other words, you can depict importantly active bleeding when assessing a traumatic lesion.

And therefore it can guide you towards conservative management versus surgery.

As I said, there are many papers out there to help you and to support you in the use of CEUS in the context of trauma.

Literature Support for CEUS

This was one of the first series back in 2008.

They published this patient.

This is an Italian group that looked at 27 children.

And the bottom line of this paper was that definitely CEUS, as you heard before, is superior to normal baseline ultrasound in the depiction of organ injury.

And they also conclude that CEUS is almost as accurate as CT in the evaluation of these patients.

And this is a more recent paper.

And from 2015, again, another Italian group, I think there is a bias there when I mention all these Italian papers.

And they looked at 73 children, and again, CEUS in this case identified all the 67 lesions present in these children.

So compared to the gold standard it performed, it had a hundred percent of sensibility and sensitivity and accuracy.

And also importantly in this paper, they outlined the fact that CEUS identified important prognostic factors such as parenchymal active bleeding, and the vascularization of the organ involved.

And they've come up with the flow chart that's quite helpful.

And they've now moved fully to image children presenting with trauma with CEUS first as first line examination.

And then if that's negative, the patient can be discharged.

And if it's positive, then they perform a CT scan, and in all cases the patient gets followed up with CEUS.

So that's quite useful to have in mind.

Practical Performance of CEUS

Very briefly, I'm just gonna mention how we perform in practical terms CEUS in the context of trauma, we always have the dual screen and we inject the bolus of contrast, the doses in children.

If you try and find a recommended dose in the literature, you're probably be disappointed because there aren't really any particular guidelines in terms of doses in children.

What we tend to do is we measure it according to the size of the patient.

So we start off for small children, we will give 0.6 milliliters, and we go all the way up to 2.4 in teenagers and adolescents, adult sized teenagers.

We always have the timer around.

We record a cine loop to go back and look at it, and we also save static images.

Common Injuries: Splenic Trauma

So we're just gonna go with an overview of the most common injuries encountered in children.

You heard Miko this morning talking about splenic trauma.

That's where it obviously it's really useful, especially in children because this is the most commonly injured organ in children.

You have to remind yourself that you are looking initially at the arterial phase where you've got this zebra pattern of enhancement, which mustn't be mistaken obviously for laceration.

But then you've got plenty of time in the late phase to look at the lacerations or hematomas, and you can get all sorts of injuries from simple laceration to the shattered spleen.

So here are a few examples.

This is a small girl, a 7-year-old girl who fell.

You can tell from the probably from the B mode that there is an area of a hyperechoic area here, which may well represent the injury.

But when you inject contrast, it is like day and night, you know that that's the extent of your injury and you can delineate it really accurately.

Back in the day we used to perform CT as a follow-up of these patients, and you can see we don't routinely perform these anymore because we've seen that CEUS is indeed good enough and you can see that the pictures match perfectly.

Again, this is another patient.

Sadly, we've got quite a few of these stabbing incidents here in Camberwell.

And this is a 17-year-old boy who was stabbed.

If you look at the B mode picture of the spleen, you can't really tell much.

There isn't much to say in terms of is this organ injured, but you will see that as soon as you inject contrast following the initial arterial phase, you can start delineating the multiple sites of entry of the knife.

And the multiple injuries are delineated very clearly with CEUS.

And again, this was the CT snapshot showing one of these injuries.

And you can see how there isn't really any need to perform a CT in these cases when you've got such clear pictures with CEUS.

This is another splenic injury.

Obviously in this case, you may argue that you can tell straight away that this spleen is injured, but sometimes the problem may be that you don't know how much of this tissue is still viable, and that's what the surgeons ultimately need to know.

So when you inject some contrast you will see that very soon you realize that there is very little parenchyma left enhancing.

The vast majority of the organ is non perfused.

And this was almost completely devascularized spleen.

This is a shatter spleen.

And the patient subsequently also had a CT, but that only confirmed the findings that were already seen on CEUS, and he just underwent a total splenectomy.

Liver Trauma

Onto the liver again, following the spleen, the liver is the second most common injured organ in children, and more often than not, it's the posterior segments of the right lobe that will be affected by the injury.

And that's just for anatomical reasons.

They're the most fixed bit of the liver.

And you look for laceration, again, as non perfusing linear or branching hyperechoic areas.

And then you can get, as I said before, all sorts of injuries including hematomas.

And you can, you may or may not have a hemoperitoneum in case the laceration extends to the capsule.

So on to a few images.

Again, this is a handlebar injury.

You again, on the B mode, not much to tell the color Doppler doesn't really help much, but this is obviously this is just a grade one tiny injury.

But the reason why I always show this video is because it really gives you an idea of the exquisite detail that you can get with CEUS when you can pick up this tiny linear grade one laceration really clearly.

And once you've done this, the patient can go home and doesn't need to be kept in the hospital.

This is yet another example of a stabbing, and again, this is just to show you how you can very easily demarcate your area of injury compared to the normal parenchyma.

And you can see how within this injury, very easily you can see that there is no enhancement whatsoever, and you would be able to pick up an active bleeding if that was the case, this is again the CT showing the corresponding picture.

And this is again matching perfectly your CEUS picture.

You can get, as I said, all sort of other injuries including subcapsular hematomas, compressing the underlying parenchyma or intraparenchymal hematomas.

Renal Trauma

And again, these are very beautifully demonstrated in terms of renal trauma.

The things that you need to be aware of here is that we tend to inject a little bit less contrast because of the avid cortical enhancement on the arterial phase that may then obscure underlying injuries of the parenchyma.

And another thing that's really important to remember, which all of you know, is that CEUS does not get excreted through the collecting system, so you will not be able to pick up injuries to the collecting system.

So these are the only caveats to be aware of.

And these are a few examples, again, tiny injury just to show you how you can easily demonstrate even the smallest laceration, which couldn't be visible at all on the B mode ultrasound,

and this is we have all sorts of varieties of injuries related to gangs and things like that.

So we will go from stabbing to gunshot wounds, unfortunately, and this is an example of a laceration through the lower pole of the kidney.

And again, you can demonstrate it really easily.

This is a sad case of a very small boy who was playing in his father's gym apparently at home, and then really had a dumbbell fall in his abdomen.

He came in, he had the baseline ultrasound that didn't really show much, went on to have a CT angiogram, and you can see how there is nearly complete lack of enhancement of the left kidney here.

And the left renal artery appears truncated.

Now, the question was, how are we gonna manage this patient?

Is this kidney salvageable at all?

So what we did was we injected him a little bit of contrast and literally within a few seconds, this is the cine loop, and you can see that it's 10 seconds on from injection right away.

You can give the clinicians their diagnosis.

The cortex is not enhancing at all in this kidney.

This is a case of acute cortical necrosis.

I was gonna show you as well the MRI pictures of this child.

And as you can see, the anatomical detail of MRI is pretty much the same as the one as US.

So you can go ahead and confidently save the child and a procedure such as an MR, which involves another contrast injection and very often sedation or GA, another

Pancreatic Trauma

less commonly seen, but we see quite a few here because we are a referring center and you need to be aware of these as well, is the pancreatic trauma.

The only thing I would say here is yes, you can see it quite neatly with CEUS again, but the problem is that very often pancreatic traumas are indeed associated with duodenal injuries.

And in that case, I would recommend you not to stick with CEUS only.

Most of the times you will not get away without doing a CT in these patients.

And again, you can get different types of injuries depending on the mechanism of injury.

And here is a couple of examples here you can see the laceration really nicely and also a few weeks down the line, you may be able to detect them.

Obviously you will see the development of a pseudocyst really easily on CEUS, but then on normal baseline ultrasound.

But then after injecting contrast, you can see that the pancreatic duct was completely truncated.

And that's what's feeding, so to speak, the pseudocyst.

And you can demonstrate that is really easy.

Adrenal Trauma

Very briefly on adrenal trauma, because again, it's quite rare and it almost never occurs in isolation is normally part of a multiorgan trauma.

You can get hematomas that will present as a rounded enlargement or displacement of the gland.

And when it's quite helpful, but perhaps this applies more on the adults, is to differentiate traumas with incidental adrenal lesions.

And again, you will see that with a little bit of contrast, you can delineate the adrenal gland and the non-injured part will have a normal configuration and enhancing normally, whereas the hematoma will be completely non enhancing and perhaps displacing the intact adrenal gland, like in this case.

Follow-up with CEUS

Another area where we have and we actually started using CEUS in was for follow ups of traumas.

And we've seen that it's indeed really helpful.

Our pediatric surgeons are completely on board with this, and they always ask us to follow up their patients with CEUS instead of other modalities.

So we normally perform a CEUS on day five of the liver lesion and on day seven of the splenic lesion.

And this is just basically to avoid repeated radiation exposure.

These are a couple of examples.

This is a liver laceration at presentation and two weeks later the fracture is starting to heal.

And eventually the patient can be discharged.

The reason why we do follow up this patient is because of a feared complication, which is the development of a pseudoaneurysm.

This is a small boy who came to our attention six days following initial trauma.

And you can see how after injecting contrast, you can delineate this large splenic pseudoaneurysm with the feeding vessel.

And it's important to detect these probably in the spleen less so than in the liver, but because we would follow them up historically, these used to be always implications that this is not the case anymore.

At least in our center, we try and have a conservative approach of watch and wait.

So that's why CEUS can be really helpful to follow these patients up serially until self resolution of the pseudoaneurysm.

I'm saying this is more important in liver because obviously, as you all know, those are pseudoaneurysms that are very often surrounded by biliary leakage.

And that's what causes the increased likelihood of bleeding.

And therefore in those cases, we would go ahead and embolize the pseudoaneurysm, as in this case where this girl who was kicked by a horse developed this large pseudoaneurysm, then embolization.

And again, this is another quite useful application because following embolization, you may well want to know whether the embolization was completely successful, and that's when you can inject a little bit of contrast, which will show complete, like in this case, embolization of the pseudoaneurysm with perhaps a little bit of hyperemia in the surrounding region.

Conclusion

So in conclusion, we've seen in our practice that CEUS is a very safe modality to image children that present with a history of trauma.

The performance values are, as we've seen in the literature, are really good, really close to those of CT.

We now use CEUS instead of CT for all follow ups of pediatric patients.

And we have indeed started using it as a first line examination for all those children who come in with minor injuries with low mechanisms of injury.

And that really has saved us a lot of radiation exposure in this such vulnerable population.

Thank you very much.