Pediatric Chest Ultrasound - SD

Introduction to Pediatric Chest Ultrasound

Hi, I am Brian Coley from Cincinnati Children's Hospital Medical Center in Cincinnati, Ohio.
And today I'll talk to you about pediatric chest ultrasound.

In talking about the pediatric chest, we're going to look at several different areas, the plural spaces,
the lungs themselves, the chest wall,
mediastinum and diaphragm.

Approaching the Pediatric Chest Scan

And when you first approach scanning the pediatric chest,
remember to be creative with your acoustic windows.
There are many ways you can get access into the pediatric
chest from a supraclavicular
or super sternal approach, you can go parasternal,
or even in young children right through the sternum.

Looking at the lung itself, you can go subxiphoid,
through the liver subdiaphragmatic,
and even using the heart itself as an acoustic.

So a lot of people are not used to looking at the chest.
This is not something
that radiologists have traditionally done,
but this is something that our friends in point
of care ultrasound and the emergency departments have
really embraced and learned a lot from.

And so this is a very old quote from Thomas Morgan Roach,
who is a pediatrician that wrote the first textbook
on pediatric imaging.
And like anything, you have to know what normal looks like
before you can figure out what abnormal is.

And if you're just getting started,
I would recommend this paper by Lichtenstein.
There are several reviews out there
that talks about the artifacts in normal findings
that you can see with lung ultrasound as well as some
of the common disease processes.
If you look at some of these, you'll also get
a sense of the jargon
and common terminology that's coming
to be used when discussing chest ultrasound findings.

Indications for Chest Ultrasound: Pleural Space

So the most common indication
for using chest ultrasound right now is to look
for the pleural space.
And traditionally we've looked for pleural effusions
and things of that sort, but it's also become
more common to use it to look for pneumothorax
and abnormal air collections.

Normal Lung Findings

You have to realize in the normal lung,
you have normal lung interface of the echogenic pleura,
and then these multiple reverberations down
below it called a lines.
Also in real time, you'll see the lung moving back
and forth, and I'll show you a clip of that in a second.

M mode is actually nicely useful in chest ultrasound.
In this case, you get what's been referred to
as a seashore sign
with the static chest wall forming waves coming up against
the sandy shore, which is the motion of the lung,
giving this pattern in this M mode picture.

Pneumothorax Detection

Now when you have a pneumothorax, you'll get loss
of this normal lung sliding
and you'll get loss of the normal A lines.
So in m mode ultrasound, you will have a normal appearing
seashore sign.
And then where this p is indicated,
that's sometimes referred to as the lung point sign
beyond which you no longer get the normal sliding indicative
of a pneumothorax.

Now my friend Alyssa, who now works in Washington DC gave me
this clip from her fellowship.
And you can see normal lung sliding here at the
upper aspect of the image.
And then just below this last rib here, you can see
that there's no lung sliding.
You lose some of the normal markings indicative
of a pneumothorax.

Ultrasound in Respiratory Distress

Now a lot of us are familiar
with using ultrasound in this kind of case.
Here we have a child in respiratory distress.
They've been intubated. It's a newborn
with an umbilical venous catheter.
There's clearly an opacified left chest
and shift to the mediastinum,
but really radiography can't tell us what's going on in
that left hemothorax.
But with ultrasound it becomes very, very clear.
You've got consolidated lung,
you've got a very large pleural effusion
with actual aversion to hemi diaphragm.
And this case you can see the spleen below the diaphragm.

Pleural Effusions: Varieties and Guidance

Now effusions come in different varieties.
A lot of them are very simple, so they're very an coic.
And as you scan through, you can see consolidated lung
moving freely within that fluid.
Simple effusions may have some debris,
some echogenic debris,
and you can't tell whether this is going to be empyema
or pus in a monic effusion
or if it's going to be hemorrhages in chest trauma.

And as things get more complex,
you may start seeing septations develop,
but early on, these septations will be thin
and wavy, especially in early monic effusions.
And as time goes on,
these septations may thicken become more solid
and restrictive to the underlying lung and fluid.
And then ultimately you can get a very organized empyemia
with a solid pleural peel
like ultrasound elsewhere in the body.

It is terrific for guiding procedures
and making sure they're performed safely
and that you are accessing the target you want
and not hitting anything you don't want to.

So in this particular case
with a fairly large simple effusion
and consolidated lung,
you can see the thoracentesis needle just coming in gliding
right over the spleen.
And here we've aspirated most of the fluid
and you can see the underlying lung becoming rear rerated and expanding.

Lung Parenchyma: Consolidation and Abscess

So in looking at the lung parenchyma itself,
we're gonna talk about consolidation
and when it continues on into abscess,
we'll talk a little bit about interstitial disease
and though not quite so common in children,
a little bit about masses as well.

So in consolidated lung,
you can often find these linear branching echogenicity.
And these are air broncho Grahams.
And this is the equivalent
of the chest radiographic finding on air Broncho Graham.
And this is just air that you're seeing against a background
of consolidated non aerated lung.

So there's a fair amount written about air bronchos
and trying to make the distinction between static
and dynamic air bronchos.

So in these static air bronchos
that is the air within the bronchi does not move.
It's felt that this represents atelectasis more
likely than pneumonia.
And hopefully you can appreciate in these couple
of clips dynamic air bronchos
where you actually have the little bubbles of air move
as the lung moves.

And so what this indicates is that there's gonna be air
and fluid within the bronchi.
And while not a perfect sign,
in this situation,
it's more likely that the air bronchos
and consolidation represents pneumonia
and infection rather than just simple atelectasis.

Now this is not a foolproof sign, even though some
of the literature suggests it has a very high sensitivity
and specificity, but it's still something to look out for
and something to take into consideration of the rest
of the clinical findings.

The lung can get very dense
and this has been referred to as HEPA in this particular
image of a consolidated right lower lobe
against the diaphragm.
You can see that the lung is consolidated with a bronchos
and it looks similar to the liver
that's immediately under underneath
with the branching echogenic structures representing
portal triads.

As consolidation increases
or as ischemia may happen in the lung,
you can start getting more heterogeneity
as you can see in this particular case.
And if it goes on with a poor insufficient treatment,
you can actually get a necrotizing pneumonia.
Here you can see multiple hypo coic lesions within
the consolidated lung.
These are probably areas of incipient necrosis in children.
There seems to be tremendous ability
to recover from this kind of infection.
But sometimes as in this case it'll go on
to form an actual abscess.
Here's actually air within the abscess cavity.
And again, if it's up against the pleural space,
ultrasound can be a terrific method to guide aspiration and
or drainage of these collections.

Abnormal Air Collections in the Lung

Now, something else you may not think ultrasound would be
good for, but it's actually to identify
abnormal air collections within the lung as well.

So this is a very sick child who had a pneumatic seal
of unclear etiology.
You can see that there's consolidation of most
of the left lung as well as a lot of body wall edema,
and they could not get this child off the ventilator.
So we were asked to try to drain this in the ICU
in the hopes that this would allow re expansion of the lung
and improvement in respiratory status.

And so this can be sort of a daunting
task if you're not used to it.
And when you first put the transducer down,
you just see this sort of image, which I think is very hard
to interpret as to what's going on in the left chest.
But as you gradually move inferiorly where you know,
this hemato seal is all of a sudden you see a very specific,
very different structure that corresponds to the hemal
and that allowed placement
of needle at the patient's bedside and a drainage catheter.
And within 48 hours, you can see
that there is marked improvement in
that chest body wall edema is down
and the patient's been able to be extubated.

Interstitial Disease Evaluation

Now a very interesting area in chest ultrasound is the
evaluation of interstitial disease.
Again, in radiology we're generally used to thinking
that air and its interfaces just get in the way,
but you can actually get a lot
of information from the artifacts
that you get from interstitial disease
and what it does to the ultrasound beam.

So I want to call your attention to these very
bright linear stripes emanating from the diaphragm here.
These are called lung rockets or B lines.
And a clip again provided by my friend Alyssa
shows you multiple B lines here at the lung surface.
Notice how these go all the way to the bottom of the image.
They obliterate the A lines
and are indicative of interstitial lung disease.

Now it's in kids. It's really hard to say
what this disease might be.
In adult literature you can read about B three
and B seven lines indicating lines
that are either three millimeters apart
or seven millimeters apart.
And people claiming you can discern interstitial fibrosis
or emphysema from interstitial disease such
as volume overload.
And that may happen in children.
I just don't think there's enough experience,
but it's also uncertain as
to whether these measurements really apply in the pediatric
chest or at what ages they may or may not apply.

So I think we'll stay tuned on that
and see what we can get from it.
But certainly I think there's enough value
that you can diagnose interstitial disease in kids just from
the lung rockets alone.

So here's a child who's intubated,
clearly has both interstitial and alveolar disease
and on ultrasound done for other reasons.
You can see some peripheral areas
of consolidation here on the transverse image.
You can see some discreet lung rockets,
but I also want you to look at
just the abnormal interface.
And these are really confluent B lines.
And when you have very severe disease,
you just get this abnormal echogenicity.
You don't see normal A lines.
And this is again indicative
of very severe interstitial disease.
This is the kind of thing you can see in newborns
with severe respiratory distress syndrome,
or hylan membrane disease.
And there's some reasonable literature from Europe
that suggests you can actually predict outcomes in severity
with the basis of lung ultrasound, just another child
who is being scanned for other reasons.
Here's the spleen in the left upper quadrant,
and you can see innumerable lung rockets
or beelines in the lower part of the image.
This is almost confluent
and just the corresponding chest radiograph again confirms
that there's interstitial disease.

So the cases I've shown you
before were in kids who we knew they had lung disease.
So you might ask yourself, well, this didn't really
add anything to the examination
showing lung rockets.
But here's a child came to the emergency room
and had acute renal failure
and we were performing an ultrasound to evaluate the kidneys
to try to figure out why.
And in this image you can see the liver
and you can see an abnormally echogenic kidney.
There is no hydro nephrosis.
The child ended up having
acute post streptococcal glomerulonephritis.
But look at the edge of the image.
You can see there are a whole bunch
of little lung rockets and that's not normal.
And as we talked to the clinicians, they said, well,
the child is a little bit short of breath,
and the subsequent chest x-ray shows some severe
interstitial lung disease
and en large cardiac silhouette indicative
of volume overload because of the acute renal failure.

Chest Wall Evaluation

Another very useful area
of chest ultrasound in kids is looking at
the chest wall itself.
In general, most of the time we're looking at masses,
occasionally infections,
and occasionally looking at fractures.
Abnormal ribbons are very common.
These are painless bumps
that sometimes cause great distress.
In this case, here is a normal hypo coic cartilaginous
ribbon, and here's a bifid rib, a smaller ribbon right there
in children who have painless lumps of their thorax.
These are almost never anything serious,
and I believe that all of them should be approached
with ultrasound first.

Here's a case in point.
This is a teenage girl who had a small chest bump,
had two cts, which failed to diagnose it.
Here in retrospect is actually,
is actually the abnormal bump.
You can see it has a similar density
as the underlying muscle, sort of non-specific soft tissue.
There's nothing inflammatory around it.
And when finally they came to ultrasound, which
of course you can actually palpate
and scan the bump itself in this transverse image
with the sternum and the center, you can see
that it's just abnormal
or rather an anomalous little accessory slip of muscle,
which is not that uncommon, completely unremarkable
and benign that the child did not need the radiation
or the expensive two CT scans for this painless slump.

So again, they should all be evaluated
with ultrasound first.

Here's another case of a hemangioma, a pretty
common chest wall abnormality.
These are variably echogenic, depending on their stage
of involution, generally fairly well circumscribed.
This particular case was moderately hyperemic.
Here's another one, A slightly larger lesion within the
intermuscular portions of the chest wall.
Again, fairly hyperemic.
This child got a CT scan just because of its size,
but again, this just shows a typical hemangioma
with contrast enhancement.
These are benign lesions
and typically will involute
as the child grows older than the age of two or three years.

Painful Chest Wall Masses

Painful chest wall masses are a little bit different.
This was a child who had pain and fever.
And as you scan here
to get you oriented in this transverse image,
this is on the bottom right, this is the rib,
and it is surrounded
by this abnormal fluid collection at real time.
This did demonstrate swirling and mobility.
There's hyperemia in the surrounding soft tissues.
The child again had pain and fever.
There was an aspiration and we got pus.
The child went on to an MRI to look for other sites
of disease and actually this child had
disseminated foci of infection.
But on the chest wall, you can see pockets of fluid
with surrounding enhancement on this post contrast T one weighted images
as well as indentation of the liver.
And this ended up being methicillin resistant staph aureus.

This child, teenager came into the emergency department
with fever and shortness of breath
and was sent to us in interventional radiology
to place a chest tube for presumed monic effusion
and
or empyemia.
We got the patient on the table
and the first thing we did is we looked with ultrasound.
And lo and behold, this was not just a simple effusion was
a very large mass.
We changed our approach
and did a biopsy followed by a chest tube
to drain the pleural effusion.
The child did subsequently go and get a CT for staging.
You can see this large primitive neuro dermal tumor
or aspen's tumor arising from the rib along the chest wall.
And if you go back to the chest x-ray,
you can actually see some subtle changes
on those plain films.

So again, not everything that comes to you
as a monic effusion
or simple fluid will turn out to be that way.
But quite honestly, ultrasound is completely sufficient
for diagnosis and initial patient management.

Rib Fractures

It's usually not vital to diagnose a rib fracture.
Usually the things of concern
or make sure there's no pneumothorax
or underlying hemothorax.
But it is often to comfort patients
and reinforce a diagnosis
to actually show them that there's a fracture.
And in this case, it's very easy to pick up.
As you scan over the tender portion of the rib,
you'll see a very obvious break in the underlying cortex,
often a little associated hematoma
or subperiosteal collection.
And so this can be very valuable as well
and is a fairly quick screening tool.

Mediastinum Evaluation

Most of the time the mediastinum is evaluated with CT or mr.
But I think especially in younger kids,
ultrasound is often a very reasonable first line choice.

So in this child who has an abnormal contour
of the superior right mediastinum, we were asked
to do a chest ct,
but we said, look, can we really do an ultrasound first?
I think we can get you the answer.
And in this case, we very quickly saw a soft tissue mass
right behind the sternum, which is hypoechoic here
because it's all cartilage.
And this is a very typical appearance of a thymus.
It sort of has a dot dash appearance.
It is soft and conforms to the chest wall
and very quickly and
very easily without any radiation, without any sedation.
You can assure everybody, clinicians and parents alike.
This is a normal finding,
just a slightly anomalous looking thymus.

Similarly, this child on this frontal radiograph has
what appears to be an enlarged cardiac silhouette.
But if you come and do the ultrasound examination,
again, you can see this fairly large thymus,
which is just a normal variant
with this typical dot dash pattern.
Filling the chest and the heart is actually normal size.
There is no abnormal mass and again, no radiation.
Very quickly you can determine that this is normal.

Thymus, Another thymus here,
okay, it looks like it might be a right upper lobe collapse,
but again, with ultrasound you can see it's a very typical
thymic pattern with these little dots
and dashes conforming to the anterior chest wall
and without any mass effect.

This child's clearly had multiple thoracic interventions,
has an unusual rounded contour in the right side
of the mediastinum.
There was some concern.
Could this represent a pseudo aneurysm from the
patient's prior procedures?
Again, ultrasound clearly shows the normal dot dash pattern
of thymic tissue
and that there is nothing to be concerned about.

Occasionally children may present
with bulging masses at the base of their neck.
And again, real time ultrasound here can show a thymic
tissue herniating up into the chest,
or sorry, into the base of the neck.
This is a normal finding and only needs reassurance
and no other therapy.

And occasionally you can't actually find
other diseases.
So this is a mediastinal teratoma solid
and cystic mass within the thorax.
And in this case with ultrasound on the left,
an MRI at the right, there's a lymphatic malformation
behind the heart that surrounds the aorta and esophagus.

Diaphragm Evaluation

Another very good use of ultrasound is
to evaluate the diaphragm to look for normal function
to evaluate for hernias, orations, and in the acute
or ICU setting to look for diaphragmatic paralysis.

So in this particular clip you can see normal
and symmetric movement of the hemi diaphragms.
You can also see quite a few lung rockets here coming off
the base of the right chest.

So this is not exactly a mystery diagnosis.
This is a diaphragmatic hernia, a little unusual in
that it's on the right side,
but looking with ultrasound, which is occasionally useful
to tell the surgeon what the size of the defect might be,
you can see normal diaphragm here with the arrows,
hypo coic muscle.
And then where the arrow is, you can see a break.
And then herniation of abdominal contents into the chest
cavity, even ations can be evaluated occasionally.
This is useful to help the surgeons know whether there needs
to be a plication, to see if there's any movement at all
or if it's actually a hernia.
Just with a little liver in the chest.
And again, at ultrasound you can clearly see just an ation
or a thinning part of the diaphragm
with a protrusion liver up into the thorax.

You know, on this clip you can see portions
of the diaphragm down below that are working,
but an area where the ation is,
where there's no contraction of the diaphragm.
And if they go and placate this,
the child might have better lung excursion
and better exercise tolerance.

Here's a child post-op who has a very elevated
hemi diaphragm.
Given the shape of that,
you would be concerned about diaphragmatic paralysis
and it's very easy to go up at the bedside
with ultrasound of the patient.
Off the ventilator, you can see normal motion
of the left hemi diaphragm and no motion
or perhaps even paradoxical motion
of the right hemi diaphragm.
And again, notice the lung rockets indicative
of basilar lung disease.

Conclusion

So in some chest ultrasound is not a tool that's used
with great frequency by radiologists,
but has been embraced
and really promulgated by emergency
and critical care physicians.
And I think it's got great benefit
and great utility in pediatrics.
It's still being discovered.
But already I found a lot of use for it in my practice
and I think it's gonna be a real game
changer for a lot of people.

Be creative with the acoustic windows.
The pediatric chest has a lot more ways to get in
to the thorax because of un ossified cartilages.
Because of thymus,
because of the smaller size,
you can even go para sternal from behind.
It provides unique information,
information you can't get from other sources
and it can often obviate the need for CT in many cases.

So I recommend giving it a try.
I think you'll find it useful in your practice.
Thanks for your time.