Chest Ultrasound - SD

Introduction

Marilyn J. Siegel.

I am from the Mallinckrodt Institute of Radiology,
which is in Washington University School of Medicine in St.
Louis, Missouri. And the topic
that I'll be discussing will be chest sonography.

We're gonna discuss chest ultrasound
and the objectives will be to discuss the technique
of chest sonography, describe normal anatomy,
and then review the imaging features
of common chest lesions.

Technique of Chest Sonography

Let's start with the technique.

If you're doing chest sonography, you want
to use a small footprint sector transducer
because it's best to inate the ribs
and above the sternal notch.

A linear array transducer is best for chest wall lesions.

To look at the peripheral lung
and pleura for near field structures,
you should use a higher resolution transducer 7.5 to 10.

And for deeper structures such as long or mediastinum
or larger patients, five megahertz will suffice.

There are a number of acoustic windows
and you've got to know these to do successful chest
sonography, the supraclavicular window is labeled number one
above the clavicles.

Sternal is two above the sternum,
we can use a parasternal window denoted by three.
That can be done on the right or left side.

Four shows the transsternal window
going through the sternum.
This is particularly advantageous in the neonate.

Five indicates an intercostal approach.
Who can be used at any age to look at the pleura
and peripheral lung.

Six is below the xiphoid process
and seven is subdiaphragmatic.

Eight is a posterior paraspinal approach.

Why do we wanna use these? What's the rationale?

The supraclavicular great for looking at lung apex.

Sup sternal gives you a wonderful view
of the upper mediastinum and great vessels.

The parasternal, which can be right
or left, is an excellent way of looking at thymus ascend
aorta and the right pulmonary artery transsternal the sternum.

You can use this in the neonatal infant.
Easy way to look at the mediastinum and the thymus.

Intercostal works at all ages.
We can look at the pleural space
and peripheral lung, the subxiphoid
below the xiphoid process
and the subdiaphragmatic below the diaphragm.

It's the best way to look at the lower lung
and pleural space as well as the diaphragm.

And then along the spine, paraspinal approach, good
for posterior masses.

We know how to do this.

Normal Anatomy

Let's look at some normal anatomy.

One of the things structures that you should see in infants
and neonates, in fact in the first few years
of life, is the thymus.

It is a soft tissue structure.

It has a quadrilateral or rectangular shape.

Smooth convex are straight margins.

The arrowheads point to that
and the characteristic finding of normal thymus
and the clue to the diagnosis
are these regular linear echogenic densities throughout.

Let me, let's skip ahead.

Let's go back to this,
these linear irregular densities throughout the thymus.

And here you see the quadrilateral shape.

Thymus changes with respiration
and it lives in front of the vessels.

And this is the superior vena cava.

Another normal thymus transsternal approach and a neonate.

We put the transducer over the sternum.

Here's the cartilage.

We can see the thymus denoted by the caliber marks.

It's quadrilateral rectangular.

It's got these fine linear echo densities
and it lives in front of the vessels,
the superior vena cava and aorta.

If you put color, you see flow in the vessels
behind the thymus and some flow in the thymus.

Let's look at normal ple and parenchyma.

Other normal findings.

The pleural lung interface is hypercoic.

It is this white line that we see,
this echogenic white line anterior to the white line.

We can see the normal hypoechoic black cartilage in front of
that muscle and soft tissue.

Behind the pleural lung interface, we have aerated lung,
which is echogenic,
but not as bright as the pleural lung interface.

And very typical of aerated lung or reverberation artifacts.

Deep to the near field, deep to the pleural lung interface.

These are these white linear lines we see
and this is a blown up image of that.

You can see these echogenic lines,
they're very regular intervals.

And in between we see air filled lung,

another normal structure, the diaphragm, it is a smooth,
slightly undulating echogenic line.

This is normal liver with hepatic veins.

This is the diaphragm, this is the transverse view.

And on the opposite side,
the long view the echogenic diaphragm
here is liver and kidney.

And on the other side is aerated lung.

And finally we should see vessels.

That's another normal finding.

So you can see these through a suprasternal approach.

Anteriorly, we have some thymus
and behind that superior vena cava and the aorta.

Now you should understand the
technique and normal anatomy.

Imaging Features of Common Chest Lesions

And let's look at imaging features
of some common chest lesions.

Indications for Chest Sonography

What are the indications for chest sonography?

Number one, and perhaps the most common is evaluation
of pleural effusion, the character
and extent of the effusion.

Another indication is looking at a peripheral opacity
on the chest x-ray.

The question is, is it parenchymal or pleural disease?

A third indication is the abnormal mediastinal contour,
particularly in neonates and infants.

Is it thymus or a mass?

Fourth indication, we use it for congenital lung anomalies,
particularly sequestration.

And the final indication is
evaluating an abnormal diaphragm.

Pleural Effusion

Let's start with pleural effusion.

Most effusions are monic
and related to an infected lung.

The important question, the decision that needs
to be made, is this a simple serous effusion
or is this a complex purulent fluid?

Simple effusions appear anechoic
and change shape with respirations.

The complex purulent fluid are echogenic.

And why is it important?

Because simple or anechoic fluid is usually a minimal
to aspiration.

In fact, that's all you may need.

And conservative management,
a thoracostomy tube may be placed for drainage,
but you don't need to give additional fibrotic therapy.

Complex effusions impas are not a contraindication
to percutaneous drainage,
but their presence often suggests
that a catheter may be needed
or the catheter may stay in place for a longer time than
that associated with a simple fluid.

In addition, complex
or purine effusions may need fibrotic therapy.

This is a simple effusion transverse view,
the fluid's anechoic.

Here's the echogenic diaphragm in the kidney.

And if you add color, you see color flow in the fluid.

A sign that it's mobile, simple fluid.

This should respond to either putting a needle in
and aspirating the fluid.

Perhaps a catheter is needed,
but you don't need to give additional therapy.

Here's another one. Here's simple fluid. It's anechoic.

You can see it around this collapsed atelectatic lung.

It's beneath the lung. It's on top of the diaphragm.

Here's the liver. This is a catheter that's being placed.

You see the tip of it, the catheter is advanced,
the fluid collapses completely.

And now you can see some aerated lung
beneath the catheter.

On the other hand, these are complex effusions.

This is a lot of puss in it. Here is a fluid with echoes.

Adjacent to it is some consolidated lung, long axis view.

Here is showing the diaphragm
echoes in the fluid consolidation or pneumonia.

A couple more effusions.

This has got a lot of septation in it.

Next to it is pneumonic or consolidated lung
and long axis showing septated effusions.

Why do you need to recognize this?

Because these effusions will need a catheter in place
for a longer time than a simple effusion
and they may need additional fibrotic therapy.

Evaluation of Opacity in Hemithorax

A second indication for ultrasound is evaluation
of opacity hemithorax.

The question is you wanna separate
an effusion from atelectasis or consolidation.

We know what fluid looks like.

What does atelectasis and consolidation look like?

They will transmit sound unlike normal lungs.

So they'll be echogenic.

Other findings in consolidation, you can see bronchi,
they can be air or fluid filled.

As a rule, you won't see much color flow in consolidated lung
and with atelectasis, you probably won't see bronchi,
but you will see flow because perfusion is maintained.

A couple of examples of bronchograms. Long axis view.

Here's fluid. Here's the diaphragm.

And this echogenic area is pneumonia.

Consolidated lung.

The linear black areas are fluid-filled bronchi.

Here is another one, fluid around the lung,
the lungs echogenic and the bright linear areas.

Air bronchograms air within bronchi, bronchi and echogenic.

Lung means consolidation or pneumonia. Here's another one.

Transverse view is the diaphragm liver.

This echogenic area which is slightly hyperechoic, liver
fluid filled structures, tubular structures, pneumonia,

and this is atelectasis.

Here's the diaphragm liver, long axis view
and echogenic area.

And now you see vessels in it.

The vessels are crowded together, no bronchi atelectasis.

Abnormal Mediastinal Contour

Third indication for ultrasound.

Abnormal mediastinum, particularly in a neonatal infant.

Is it thymus or is it a mass?

Now most of us don't do sonography routinely for evaluation
of the mediastinum, but the neonate it can be useful
and provide a diagnosis.

Here's the question, do you suspect an
abnormal mediastinum?

Is it thymus or is it a mass? This is a neonate.

Has a cough, gets a chest x-ray, so called double density.

In the right upper hemithorax, we see two shadows,
ultrasound's great.

You can do a parasternal
or transsternal approach through that.

Here we are. Here's a structure
that's echogenic, has linear echoes throughout it.

This is normal thymus. There's no mass effect.

You can see the vessels behind it, typical of the thymus.

What about this one? Another neonate with a cough.

Double density, two shadows. So let's do ultrasound.

We can use parasternal transsternal
and in this case long axis view.

Here's some cartilage. It's a cystic mass.

It's a cystic mass in the mediastinum.

This turned out to be a bronchogenic cyst.

How about this patient? There's a mass
or at least increased density in the left upper chest.

Trachea is deviated to the right.

This almost looks like pneumonia.

Maybe this is pneumonia or is it a mass ultrasound's done?

This is a large mass filling.

Most of the chest, there's some very bright echoes.

They're not scattered homogeneously
through the structure.

This is not thymus.

These bright echoes represent calcifications.

This is neuroblastoma. It's a solid mass.

It has mass effect.

And the CT shows this posterior mediastinal mass.

One more. This patient had a mass around the lower spine.

Here's the heart transverse view. Here's the heart.

We can use it as a window.

The spine's back here
and in front of the spine there's the aorta
and it's surrounded by a complex mass that has some fluid
and some echoes.

So this is a complex multilocular mass. MR is done.

It's filled with fluid.

This is the mass surrounding the aorta.

This is typical of lymphangioma ultrasound's.

A great way to look at masses and neonates
and separate masses from thymus.

Congenital Lung Anomalies

The fourth indication for ultrasound congenital anomalies.

Now most of the time CT and MR are done,
but ultrasound can have a role in pulmonary sequestration,
particularly in neonates and infants.

What's pulmonary sequestration?

It's a mass of lung that has no normal connection
to the airway or pulmonary artery.

There are two types.

Extralobar has its own pleural coverage.

This is normal lung. That's the extralobar sequestration.

It's shiny because it is pleura.

It drains to systemic veins.

Usually the azygos vein, it's supplied
by an artery off the aorta.

Intralobar sequestration does not have a separate pleura.

It often becomes infected.

You can't separate it from the remaining lung.

It has arterial supply also from a branch from the aorta,
but it drains to pulmonary veins.

What's it look like? An ultrasound gray scale?

It's echogenic, it's a mass.

If it's above the diaphragm, it's probably intralobar.

If it's below it's extralobar.

Does it really make a difference if
you separate the two types?

No. But you can do it
and sometimes it's helpful to the surgeon,
but the major job for the sonographer is
to identify the sequestration.

Doppler ultrasound will confirm there's an abnormal
artery off the aorta.

We're not as good at looking at the draining
vein with ultrasound.

We need CT or MR for that.

Here's an infant with recurrent pneumonias
and density on the chest x-ray in the lower left hemithorax,
recurrent pneumonias, we think
of sequestration ultrasound's done.

Here is the diaphragm, that white line above the diaphragm,
above the diaphragm, there's an echogenic mass with a vessel
in it sequestration to confirm it, put color on.

Here we have the aorta
and you can see this feeding artery going to the area
of the sequestration, the arteries in red.

In fact, in this case we can see a little
bit of the vein in blue.

How about this one? This is a newborn
who had a mass in utero seen
around the diaphragm on the left and on the chest.

There's a little tinting here.

That's the mass ultrasound's done. Long axis.

Here's the spine back here.

Here's the kidney and there's a mass in front
of the kidney or on top of it.

Put color on. Here's the aorta vessel going to the mass
pulse Doppler shows arterial flow vessel.

That's an artery coming off the aorta sequestration.

And the CT shows that same vessel coming off the aorta
and the sequestration.

And one more. Another neonate with an in-utero mass.

Long axis view of the spine. Part of the heart here.

Here's this mass below the diaphragm.

This is the area of the diaphragm.

Here's the spleen, the mass you put color on,
you see flow in the aorta
and a feeding vessel going
to this echogenic mass sequestration.

Abnormal Diaphragm

The final indication for ultrasound would be evaluation
of the abnormal diaphragm.

And the question is, is it a hernia?

Is it eventration or paralysis? Hernias.

Most of these in children are so-called Bochdalek hernias.

These live more commonly in the posterolateral chest
on the left side.

Morgagni or anterior herniations.

They like the right side,
although either of these hernias can occur
on the right or left side.

What do you see on ultrasound?

You see interruption of the normal linear
diaphragmatic echoes and abdominal contents in the chest.

This is a neonate on day one
with respiratory distress.

And we see increased
density in the left lower chest
with a few lucencies thought to be bowel.

So an ultrasound's done
because a hernia is suspected long axis view.

This is the back of the chest and these echogenic areas
and they moved at ultrasound,
bowel bowel going into the chest.

Here's some aerated lung in front of the bowel Bochdalek hernia.

Here's another newborn with respiratory distress.

And the right hemithorax is nearly totally opacified.

It's displacing the heart
and the mediastinum to the left little lucency.

Maybe it's bowel, maybe it's lung ultrasound's done.

Sagittal view. Here's the back.

Here's the front. Here is the
liver in the abdomen.

This is the area of the diaphragm, which we don't see.

This is liver going into the chest and lung in front of it.

This is a Bochdalek hernia. How about this patient?

An infant about a month of age, comes in with a cough,
has a bulge on the chest.

X-ray here in the area of the right hemidiaphragm
lateral view show some increased opacity behind the sternum.

Is this a hernia or is this an eventration?

Sagittal ultrasound.

And this is a case that George Taylor nicely loaned me.

Sagittal ultrasound, anterior part of the chest.

Here's part of the diaphragm. It's interrupted.

You see the liver? This is in the abdomen.

Here's the diaphragm. This anything below.

This is in the abdomen.

We don't see part of the diaphragm here.

The liver goes into the chest, it goes anteriorly.

This is lung behind it.

This is an anterior hernia, a Morgagni hernia.

What about this infant has a bulge in the left.

Hemidiaphragm hernia
or eventration do ultrasound.

You see the diaphragm? It's intact.

You can follow it all the way up. There's a bulge in it.

This is an eventration. An eventration is a weak or thin diaphragm.

And ultrasound instead of the normal straight diaphragm,
you see a bulge beneath the bulge.

You see liver on the right and spleen on the left.

And the final diaphragmatic abnormality is paralysis.

So this patient is having some respiratory difficulty.

The chest showed the hemidiaphragms at different levels,
transverse view.

Here's one diaphragm.

Here's another diaphragm, right,
hemidiaphragm left hemidiaphragm liver going across.

Here's the spine, the aorta diaphragms.

The hemidiaphragms at similar levels. Expiration.

The right is back here.

The left hemidiaphragm has moved anteriorly.

This is paralyzed. The right's paralyzed. It's not moving.

The left is moving. So diaphragmatic paralysis.

Summary

In summary, I think ultrasound's a great way
to image the chest.

What I've tried to show you are the techniques
of doing this normal anatomy.

You have to understand that.

And then some of the common indications,
ultrasound has a role
and then neonate, particularly in looking for masses
and separating them from the thymus at all ages.

It can be used to look at pleural effusions
and consolidation, the diaphragm
and some other abnormalities such as the vascular
abnormalities or even sometimes cartilaginous abnormalities.

And at that point I'll stop
and thank you for your attention.