Pediatric Hollow Viscus Imaging - HD

Introduction to Ultrasound of the Pediatric Hollow Viscus

Hi, I am Brian Coley from Cincinnati Children's Hospital Medical Center in Cincinnati, Ohio.

And I'll be talking about ultrasound of the pediatric hollow viscus.

Today we're gonna talk a little bit about imaging of the pediatric hollow viscus, and I'll talk some about children with vomiting, Crohn’s, inflammatory disease, necrotizing enterocolitis and obstruction.

Not too much about masses, although ultrasound is still very useful for that.

Now, if you haven't done a lot of bowel ultrasound, it's really important that you familiarize yourself with what you're looking at.

And this wisdom from Thomas Morgan Rotch of 1910 really speaks to us in any sort of branch of imaging that before you can decide what's abnormal, you really do have to understand what normal looks like.

And there are lots of resources online and certainly on SonoWorld's website about looking at bowel sonography, understanding the different layers of the bowel wall from serosa to superficial mucosa.

So it's important to familiarize yourself with some of the anatomy as you're getting started.

Necrotizing Enterocolitis

So, necrotizing enterocolitis is an ischemic injury to bowel, and it most commonly affects preterm infants, but can affect any child who has hypoxia.

Congenital heart disease may have hyperosmolar feeds, is under stress or has sepsis, so it's a very common condition that neonates can be life threatening.

Radiology or radiography is the typical thing that we monitor these children with.

And when the bowel gets sick, it stiffens and unwinds, and you get these dilated stacked fixed loops.

As the ischemic process goes on, you may get pneumatosis intestinalis, and that's air in the bowel wall.

You may get portal vein gas overlying the liver, and if the ischemic injury goes on long enough, you'll actually get perforation and free intraperitoneal air.

And what's really becoming clear is that ultrasound is an incredibly sensitive way to look at the bowel and probably is much more sensitive than plain radiography, particularly in a gasless abdomen of trying to find out what's happening in these sick children.

So this is ultrasound in a child with necrotizing enterocolitis.

You can see that there is some fairly simple looking fluid around, but you can see that there are areas of abnormal bright echogenic mucosa, probably related to ischemia and hemorrhage within the small bowel.

In another child with a similar looking markedly abnormal hyper echoic mucosa, there is abnormal turbid fluid.

This is the bladder throughout the abdomen as we put on color Doppler, there was certainly perfusion within the mesentery.

It was less clear. There was good perfusion within the bowel wall itself.

And as we scanned around further, we were actually able to show the discontinuity in this portion of the small bowel with spillage of the enteric contents out into the abdominal cavity.

So if you wanna get started with this, I think this is one of the best papers to look at, by doctors Faingold and Daneman from the Hospital for Sick Children in Toronto.

And they did a very nice radiologic pathologic study looking at what happens to NEC.

And in their scheme, which has been borne out in my experience and lots of other experiences, you start off with a normal bowel with normal little amounts of color Doppler flow.

You then get thickening and hyperemia as time goes on, the thickening persists, but the hyperemia starts to wane and then the bowel starts to thin, and that's when it really gets concerning for perforation.

So the bowel starts to thin the color flow diminishes until you have these sort of barely perceptible walls.

And this is the point where a perforation often occurs.

So this is another example from their paper showing these abnormal thickened hyperemic loops.

But then right in the middle, you have this loop with some pneumatosis intestinalis little dots of air within the wall, no hyperemia.

So again, you might think this is being worse.

And at surgery, yes, this child had segmental areas of basically infarcted bowel corresponding to the abnormal ultrasound.

On plain radiograph. Pneumatosis intestinalis, when it's florid, like this is easy to see.

You can see both linear, presumably serosal gas as well as bubbly, presumably mucosal gas within this very sick bowel.

And you can see similar things at ultrasound as well.

So here's some little dots within the bowel wall.

Here's some more confluent air within the bowel wall, really giving you posterior shadowing.

And this takes a little practice to get comfortable with, but I think the learning curve is fairly short.

And you'll find that you can start picking up things much more sensitively than you can on plain radiographs.

Similarly, portal vein gas, when it gets to be this much, you can actually see it on plain radiographs as these branching lucencies over the liver.

This is that same child we just looked at.

We know that there's pneumatosis in the bowel wall.

And if you have any concerns about that or whether there could be portal venous gas, put a cursor accompanying the entire width of the portal vein.

And as little bubbles go by, you'll see these little artifacts, and you'll be able to hear them if you turn the volume up as each little bubble goes by.

And in this particular case, you look more broadly throughout the liver, and there are certainly lots of areas of linear pneumatosis.

Just remember that every little bit of air does not necessarily mean sick bowel.

If you have a child who's got an umbilical venous catheter, may be low lying.

If there are any bubbles in whatever they're injecting, you'll also have a similar appearance.

And we'll get similar artifacts on your pulse Doppler examination.

As necrotizing enterocolitis goes on, you can have perforation.

This is a relatively subtle sign in this plain radiograph.

Here's a little bit of abnormal air as well.

A crossfire lateral view will show you that yes, there is certainly abnormal free air here.

There is a pretty good body of literature that suggests that ultrasound is also very good for free air.

I don't think most radiologists are that comfortable with it, but it's something I encourage you to try.

Particularly looking over the liver, you may see little bubbles of free air that may be very difficult to detect otherwise on examination.

After perforation, you can often get abscesses as well.

This was in the peritoneal cavity.

There was swelling and erythema right over this.

We aspirate and got purulent material.

Occasionally you can also get infections within other organs.

This is a very small child after NEC had tremendous hepatomegaly and elevated liver function tests, and we looked in his liver.

We saw this very large ugly collection that we drained and got purulent material, and the child did markedly better after that.

Bowel Obstruction

Bowel obstruction is an area that isn't used where ultrasound isn't used quite as much.

Plain radiography is still a dominant role, but there are certainly ultrasound findings to be aware of.

And occasionally ultrasound can help make the diagnosis or augment the diagnoses that are made with other methodologies.

Duodenal Atresia

Duodenal atresia is a classic plain film diagnosis.

Really doesn't need much help from ultrasound.

Typical double bubble sign, dilated stomach, dilated duodenal bulb gasless remainder of the abdomen.

But here's a child who had abnormal prenatal studies, and certainly has an odd gas pattern, but also has this abnormal echogenic rim, calcified mass in the periphery.

And as we ultrasounded him, we could see here's this contained meconium pseudocyst.

Here's the child's enema examination as a microcolon.

And this child had multiple small areas with perforation.

And this meconium pseudocyst, this seven day old preterm had no stool, had copious or gastric aspirate.

And it was a little unclear what was going on with this child.

The gas pattern wasn't terribly abnormal, but certainly there were some peculiar densities overlying the liver.

As we went with ultrasound, we could see that there are multiple little punctate echogenicity around the liver, all sides of it.

Here's the enema examination showing a small colon filled with meconium, more of the same, and perforation actually in this child with small areas of calcification in the peritoneal cavity.

Meconium Ileus

This child's another term newborn with vomiting distension and failure to pass meconium.

As we look here, we see multiple abnormal, very thickened looking bowel loops with this complex material within it.

Here is the enema examination showing a microcolon, very tiny, tiny colon, probably some reflux into some meconium filled ileum.

And this is a case of meconium ileus in a child with cystic fibrosis.

And it's been written about.

Here's another case which shows this sort of soap bubble appearance, if you will.

It's been written that ultrasound showing these abnormal thickened loops with this sort of thick inspissated material can actually be a very sensitive indicator for this disease.

Inguinal Hernias

Inguinal hernias are the most common cause of neonatal bowel obstruction after the fourth day of life.

They're much more common in boys than girls, and they're much more common on the right.

And certainly if you have something like this where you have enlarged bowel folds and actually gas within the scrotum, it's not a mysterious diagnosis, but most aren't always that clear.

Ultrasound is terrific way to look for hernias in this particular child.

You can see the internal ring. Here's a loop of bowel.

Here's the hernia sac with abdominal contents.

Doppler is very important to help decide whether these could be strangulated.

In this particular case, the hernia was incarcerated, meaning it couldn't be reduced.

But if you look at the amount of color flow in the intraabdominal loops versus the amount of color flow within the herniated portion, you can see it's much less indicating that there's vascular compromise and incarceration.

The Vomiting Infant

So let's talk a little bit about the vomiting infant, medical causes.

The most common is gastroesophageal reflux.

You can have gastroenteritis and various formula allergies.

Usually imagers are called when we're concerned about a surgical cause.

In which case we're really considering hypertrophic pyloric stenosis, which should have nonbilious vomiting, or whether it's malrotation and midgut volvulus, in which case there's bilious vomiting.

Hypertrophic Pyloric Stenosis

So hypertrophic pyloric stenosis is hypertrophy with the muscular channel leading out of the stomach.

It happens between the ages of zero and three months.

These children typically present with nonbilious projectile vomiting.

If it's been going on long enough, they can have dehydration and weight loss.

You may see hyperperistalsis along the abdominal wall, like in this child.

And while very few people feel for it anymore, you can actually sometimes feel the palpable olive.

That is the hypertrophied pyloric muscle.

Ultrasound is absolutely the methodology of choice for the diagnosis.

You typically use a high frequency, linear or curvilinear transducer, warm gel, and scan the right upper quadrant somewhere between the supine position, right lateral decubitus position.

To best visualize the pylorus, you've gotta have some fluid in the antrum.

As we go on, you have to distinguish the antrum from the pyloric channel itself.

There's lots of different measurements that are given out there.

Most people use a pyloric muscle thickness of three millimeters, as well as elongation of the pylorus of 16 millimeters.

The pyloric wall muscle thickness is the most reliable in my experience.

Surgeons still want to know what the length of the channel is, not so much for deciding whether the child has pyloric stenosis or not, but if they're going to do a laparoscopic pyloromyotomy, they want to know how long to make their incision, so as to get complete relief from obstruction and not to get a mucosal perforation.

So here's a normal looking pylorus, okay?

I don't even measure them when they look like this normal antral bowel wall.

Normal pylorus, normal duodenal bulb.

As a bonus, please pay attention.

Here's the superior mesenteric artery, always surrounded by a little collar of echogenic fat and superior mesenteric vein, showing a normal relationship, indicating pretty reliably that this child also has normal intestinal rotation at real time.

When you watch, you can see fluid easily go through the pyloric channel here into the duodenal bulb.

Always a nice thing to be able to demonstrate.

And when it's thickened, it's usually very, very obvious.

So here is a elongated thickened pyloric channel.

Okay, certainly much greater than three millimeters.

There is mucosal hypertrophy centrally, again, a normal superior mesenteric artery, superior mesenteric vein looked at in another particular case.

Here's a very thickened pyloric channel.

This is about four and a half millimeters.

There is protrusion of pyloric mucosa back into the stomach, so-called nipple sign or Tet sign.

This is the upper GI equivalent of a mushroom cap sign where you have the muscular channel pooching into the duodenal bulb.

And then if you look at the transverse section again, to get your muscle thickness, you can often see multiple channels here.

Again, this is can be seen on upper GI as sort of the double pyloric channel sign.

So what are some pitfalls?

Typically, pyloric stenosis is a fairly straightforward examination.

But if you don't have any fluid in the antrum, you can't tell what's antrum and what's pylorus.

Similarly, if you have too much fluid in the stomach, that can push the pylorus away posteriorly, and I'll show you some tricks for that.

And then there's pyloric spasm where the pylorus doesn't open normally, and you'll have a long channel, but typically not a thick channel.

So here's a case of a vomiting child, and we're already starting to measure because we think this is abnormal.

Now, this doesn't really look abnormal, but clearly we're starting to measure the pyloric channel length.

There's only a little bit of fluid in the antrum, but this, I like to roll the child up a little bit.

Things start to look fairly normal, and then lo and behold, everything just dumps right through.

And this is a completely normal child.

So you need to have some fluid in that antrum to make sure you know where the margins of your pylorus are.

So if you've done upper GI in children, you know, if you fill their stomach too much, the pylorus gets pushed away, posteriorly.

This is clearly abnormal, but it's not a very nice picture.

Here's an older case where the stomach's very full.

This certainly looks like an abnormal pylorus, but it's hard to get a good image of it.

So if they truly have pyloric stenosis, you can wait for them to vomit again to empty their stomach.

You can put an NG tube down, which personally I wouldn't bother with.

And one thing I learned some from some of my friends at Boston is that you can turn them and look at them prone.

So you can lay them on their stomach and look through the back, here's the kidney, and actually get a very nice view of the pyloric channel posteriorly.

So that can sometimes help you out.

Again, pyloric spasm is when this pyloric channel you can watch for many, many minutes and it just won't open.

You know, it certainly isn't normal.

There's no fluid going through, but there's no muscular thickness there at all.

And for these, you just have to be patient.

You have to be willing to walk away and give it a little time.

And eventually, almost all these cases, eventually this will open up.

You can see that yes, there is no muscular hypertrophy, there is no real elongation of the pyloric channel.

There's a normal duodenal bulb.

And this child has pyloric spasm, not pyloric stenosis.

Just a couple of surgical pictures from the literature.

When you do them open, this is what that olive looks like, that hypertrophy muscle.

This is the longitudinal muscle splitting incision, come down to the mucosa and diagrammatically, this is what it looks like.

So you're not really fixing the pyloric stenosis, but you are relieving the obstruction of this muscle.

This will eventually scar over.

It's always a problem with child who have had pyloromyotomy come back with vomiting.

Your ultrasound examination won't be a whole lot of use because the pyloric muscle is going to look abnormal for several months after the fact.

And there's been some nice work by Dr. Marta Schulman from Vanderbilt about that.

If you're interested in learning more.

Intestinal Rotation and Malrotation

Intestinal rotation in utero is the process by which the small and large bowel herniate out into the amniotic cavity and then return back into the child's abdomen, forming sort of the normal pattern when there are abnormalities, it's referred to as malrotation.

These children have anomalies of rotation and fixation, an abnormal duodenojejunal junction in a short mesentery.

And the reason that that's important is that if you have a short mesentery, your bowel can twist upon itself, get vascular compromise, and actually completely infarct.

Midgut volvulus typically happens in the first week of life, although certainly can happen in older children and teenagers.

These kids are typically very ill.

They have bilious emesis, abdominal distension, bloody stool, and are quite ill due to varying degrees of intestinal ischemia.

Traditionally, this has been a diagnosis for upper GI with the classic sort of corkscrew, twisting of the bowel right here.

But there are things that you can do with ultrasound to help you out.

So, as we talked about already, the SMA and SMV position when there's malrotation is altered.

So the normal is, as we already talked about here, so you've got the superior mesenteric artery, again, always has this little echogenic collar of fat is posterior to left of the superior mesenteric vein.

When you have malrotation, typically the superior mesenteric vein will be more anterior or even on the other side of the superior mesenteric artery.

Unfortunately, that's not universal as we'll talk about.

There are false positives and negatives.

You may see a dilated duodenum and you may see a mesenteric whirlpool sign.

So here's a fairly typical case.

This was a child we were evaluating for pyloric stenosis and had an absolutely normal pyloric channel.

But when we looked at this, we saw that the SMV was on the opposite side of the superior mesenteric artery.

So this child went to upper GI and certainly this is an abnormal position of the duodenojejunal junction.

It should be up here.

So this child had malrotation, had vomiting presumably due to that.

And because of the severe consequences of untreated malrotation and volvulus, went and had a Ladd's procedure to get fixed.

Another child evaluated for pyloric stenosis, had a very dilated duodenal bulb.

We did not see any fluid to go past this.

This also ended up being a midgut volvulus, a slightly newer case.

An 11 day old actually had nonbilious vomiting, but on every single image we saw this very long pyloric channel dilated duodenum, abnormal position of SMA SMV and at upper GI had classic corkscrew sign of midgut volvulus.

The whirlpool sign's been written about looking at superior mesenteric artery with superior mesenteric congenital veins around it.

This particular case, this is what we saw on grayscale and Doppler here, is this child's upper GI again, showing a classic corkscrew appearance of midgut volvulus, another child with mesenteric whirlpool.

As we go down from top to bottom, I think you can appreciate swirling of vessels and intestinal structures.

Here's dilated veins around the superior mesenteric artery seen in a child with midgut volvulus.

So this has been talked about for a long time.

Unfortunately, you know, up to 3% of children with normal position the SMA and SMV can still have malrotation.

And thus, just looking at the presence of the SMA and SMV cannot exclude malrotation.

And this gets into an area that's a little bit controversial and that they're still being work done on is what's the definition of malrotation?

So for a radiologist, it's what's the position of the duodenojejunal junction for a surgeon?

They typically are more interested in does the duodenum go behind the superior mesenteric artery?

And certainly on CT.

When we talk about malrotation, that's what we're looking for.

We're looking for the duodenum going behind the superior mesenteric artery.

So what if we applied that same criteria to ultrasound?

And Dr. Yousef from Chicago has written some very nice papers showing that if you see the third portion of the duodenum posterior to the superior mesenteric artery, that you've excluded malrotation.

So this is a pretty controversial view.

Not everyone believes this.

And there are certainly some aspects of technique that have to be worked out.

However, embryologically, this still makes sense, even though it does violate traditions, it's not always easy to do these examinations.

Not everyone's as good as Dr. Yousef at doing ultrasound and experience is still limited, but this still seems like another promising avenue for ultrasound into the diagnosis of malrotation and volvulus.

Abdominal Pain in Children

So let's talk about abdominal pain in children for a little bit.

There are literally dozens of causes, and many cases never reach any official diagnosis.

Again, we're usually trying to differentiate between medical and surgical treatment.

And in that end, imaging plays an increasingly important role.

So much that it seems like people don't even examine patients anymore.

They just go right to an imaging test.

Appendicitis

Appendicitis is still the most common cause for emergent surgery in children.

There's approximately a four per 1000 incidence and an 8% lifetime risk.

Classic symptoms are periumbilical pain moving to the right lower quadrant with fever, leukocytosis with nausea, vomiting, and anorexia.

The clinical exam and presentation is much more difficult and much less reliable in very young patients.

Imaging is typically either ultrasound or CT.

There is lots of literature on that.

I think the pendulum is very much swinging toward ultrasound, certainly as a first line examination with CT or MRI being used as a follow up or problem solving tool.

There are certainly issues of expertise and time as and what sort of alternative diagnoses you can see, but certainly I think most pediatric imagers would agree that ultrasound is the first way to go.

So ultrasound is very useful in children, even though we have some very large children out there.

Generally using high frequency linear transducers, sometimes curved linear.

For larger children, you need to use graded compression technique because many appendices will be retrocecal and you have to push the gas out of the way.

And that can sometimes be difficult due to pain.

So I usually start with the where does it hurt approach.

And I only let them show me with one finger.

If they can't really localize it to any one spot.

My internal suspicions drop, but I start scanning right where they say they hurt the most.

So if that's unrewarding and I can't find anything, then I will find the ascending colon and I will slowly move inferior to the cecal pole.

I will find the terminal ileum, and I know that the origin of the appendix is gonna be just inferior to that.

So again, if it's not right where they're pointing, I'll find my ascending colon work my way down ileocecal valve, and then I know the appendix should be just below that.

So you've got to do graded compression.

You scan around with light pressure to get yourself oriented, and then you slowly start pressing harder.

And I think it's very important not only to watch the screen, but watch your patient's facial expressions while you're doing this, because that'll often give you some indication if you have a stoic child who won't tell you it hurt if you're seeing them grimacing where your scanning in a particular location that should tip you off, you're in an area of abnormality.

So there's other things you can do to help improve your odds.

Other maneuvers to improve detection.

And I refer to this very nice article from about 10 years ago.

I really like this maneuver.

Posterior compression with the other hand 'cause I can push gas and air and bowel out of the way.

And I've had good luck with that.

Occasionally, you know, having a full bladder, not an empty bladder, looking deep in the pelvis on larger patients, rolling them up, left lateral decubitus.

And again, larger patients doing a curved array using a curved array transducer can be useful.

Typical measurements, the normal appendix is six millimeters or less.

There is some literature suggests that that's kind of a variable measurement in that between six and eight millimeters is sort of a gray zone.

It may only be seen in five to 10% of examinations.

I think with good practice, good sonographers and radiologists can see it in at least 50%.

Even if you don't see it, you have to document the landmarks of the psoas and iliac vessels that show you're at least in the right area.

The normal appendix should be compressible.

It may contain gas or fluid, but again, it will be compressible.

So just a few images of normal appendix.

These are all less than six millimeters.

You can see normal layers.

Gut signature of the wall, it's compressible, it's thin, there's no surrounding fluid or inflammatory change.

Another nice normal appendix, normal bowel wall.

This one draped right over the iliac vessels.

Another one in a slightly thicker child.

But again, normal appendix, normal thickness, no tenderness.

They can be filled with fluid. That's okay.

But again, you see normal bowel wall, no surrounding induration of the fat or other suspicious findings.

The vascularity used to be said that a normal appendix wouldn't have any vascularity.

Clearly, as our equipment has gotten better, you can see vascularity in a normal appendix that really depends upon your machine.

So what is appendicitis?

Well, it's enlarged greater than six millimeters, especially greater than eight millimeters.

It's non-compressible. You may have an appendicolith.

You may see hyperemia with color Doppler depending on the degree of inflammation or ischemia.

And then very importantly, especially in kids as adjacent to echogenic fat or fluid.

So not much doubt about this.

Very large inflamed appendix.

It's quite large over a centimeter in size and pay attention to the inflammatory mesoappendix and fat around it.

'cause that's a very good indicator in children that you do have appendicitis.

Another case, very large appendix, almost a centimeter in size.

Very hyperemic with power Doppler interrogation.

A little bit of induration of the para-appendiceal fat.

Another case slightly more heterogeneous, but again, nine millimeters thick.

Thickened wall still has normal bowel wall layers, but a little bit of abnormal echogenicity in the fat hyperemia and a non-compressible appendix.

And at gross pathology, these are clearly abnormal appendices.

Big thickened inflamed tubular structures.

So other things to look for is look for mucosal detail.

So here's a normal terminal ileum, and you can see normal bowel layers.

And here is a dilated abnormal appendix.

And you can see you don't see normal bowel layers.

You also don't see only see intermittent flow around it.

And that's because this is an appendix that's in the process of becoming gangrenous and dying.

Similarly, here's a larger patient using a curvilinear probe.

We see this abnormal appendix.

The patient was very tender, very poor bowel wall detail, and also not much hyperemia 'cause this was an infarcted appendix.

Here's one that's leaving a little further.

This is echogenic fat around it.

Patient was exquisitely tender over this area, and this patient actually has pneumatosis within the wall of the appendix and a completely gangrenous necrotic appendix.

Again, look at all the echogenic fat around it.

A very good secondary sign.

You really do need to see the tip of the appendix, because sometimes you can just get inflammatory changes to the very tip of the appendix.

This is an older case, but everything else was normal.

But only right at the tip was it dilated, was there a little bit of abnormal fat and a little bit of hyperemia.

And again, just one more plea to really use echogenic fat.

It's a very good secondary finding.

Certainly an abnormal appendix.

But if you look at the surrounding fat, if you had any doubts that this wasn't appendicitis, this should really tip you over.

Look for appendicoliths. They're commonly associated.

They're not always seen on plain radiography.

Ultrasound's much more sensitive.

Here's a small one, slightly larger one.

Here's a very large appendicolith in the appendix.

Just another couple. Here's one out near the tip.

Here was one that was larger and near the base.

And again, while you're looking around, make sure you look down into depth of the cul-de-sac.

Look for any potential abscesses look up in Morrison's pouch.

Okay, this is a very large appendiceal abscess from a perforated retrocecal appendix.

And again, look down in the pelvis.

Here's another couple of post-appendiceal abscesses.

So how good are we? We're really pretty good.

The sensitivity is probably 85, maybe a little bit higher percent.

Using color Doppler can help using these other ancillary findings like echogenic fat can help if you have a absolutely normal right lower quadrant ultrasound, even if you don't see a normal appendix that still has a negative predictive value up to 95%.

And that's important because not seeing the appendix is not necessarily a failure of the examination.

There is still very good value in that exam for that patient.

What are some false negatives?

Well, you can have very early appendicitis.

You can have a tip appendicitis.

You don't see a retrocecal appendix, which can be difficult.

A perforated appendix where the contents will be discharged and it won't be enlarged.

False positives can happen in cystic fibrosis, Crohn's disease, or Meckel's diverticulum.

Here's a child with Crohn's disease, had an abnormal appendix, also had creeping fat, some lymphadenopathy and some other abnormal thickening of the colon.

Here's a child from an example of inflammatory bowel disease from the literature from the people at Children's Hospital of Philadelphia.

Again, this can sometimes be confusing.

Children with inflammatory bowel disease and CF can get appendicitis.

But those become difficult diagnoses and you can't use the traditional cutoff values for that.

Intussusception

Intussusception is another pretty common disease of childhood.

And this is invagination the bowel into itself.

Ileum, invaginating into the colon is the most common.

The vast majority of these children are under two years of age.

It is almost unheard of without a pathologic lead point under three months of age.

That's because there's not enough lymphoid tissue in the terminal ileum to act as a lead point.

95% of these or more are idiopathic generally due to enlarged lymph nodes.

The rest may have duplication, Meckel's diverticulum or other masses acting as a lead point.

The classic triad of presentation is intermittent colicky abdominal pain, a palpable mass and rectal bleeding.

Some controversy about the plain film findings.

You may see a soft tissue mass or small bowel obstruction.

Supine films can certainly be normal and using decubitus or prone views can help.

Here is a 10 month old with abdominal pain.

Not a very specific bowel gas pattern.

Does have some abnormal dilated loops.

Wonder about that little soft tissue mass.

And that did turn out to be an intussusception.

So really in the last 10 years, ultrasound has become really the gold standard for diagnosis.

It's as close to a perfect test as we really have in imaging.

And what you're looking for is the invaginated bowel, which can have a pseudo-kidney appearance that's been described multiple layers.

Looking at echogenic and invaginated mesentery, often see lymph nodes.

You may see a pathologic lead point and you can also use it to assess for bowel viability or for potential success of intussusception reduction.

So to look for this, you need a high frequency linear curvilinear probe.

You need to carefully search the entire abdomen.

Most of these will be found in the right abdomen and you just use some gentle compression.

Gas is really not a problem because if they have an intussusception, that's gonna just displace the gas out of the way and you'll easily be able to see the solid mass.

So a slightly older case. Here's the real kidney.

Here is the pseudo-kidney of an intussusception.

In transverse views, you can see the layered appearance.

A more recent case showing you the intussusceptum or the recipient bit of bowel, the intussusceptum inside, along with some of its echogenic fat from the mesentery.

Another case with some path correlation.

You can see lymph nodes within the intussusceptum.

You can see that there is still flow within the intussusception indicating that the bowel is still viable.

Just another case here is the intussusceptum.

Okay, intussusceptum inside with lymph nodes.

Again, long segment of intussuscepted bowel.

Some older literature, but still has proven value that if you have positive blood flow, that is good for a reduction rate.

If you have absent blood flow, that's a bad finding.

Have necrosis, probably not gonna be able to reduce that.

Child reduction enema is the treatment of choice.

Some people still use liquid media.

Air is probably safer than liquid agents success rate is upwards of 90%, depends upon the duration that the intussusception has been there and whether or not there's a lead point.

And clearly, if you're not successful with the air enema, you're gonna need surgery for that.

So these are just some images from an air reduction.

You start off, you can see this soft tissue mass as you put air into the bowel.

Distended up here is the intussusception.

You gradually push that back and eventually the mass disappears and you see filling of small bowel loops indicating that there's been a successful reduction.

And again, if you're not successful, they'll have to go to surgery.

And here you can see a mass within the cecum and the surgeon gradually pulling out the intussusception ileum, decompressing.

The colon recurrence certainly can happen in upwards of 5% of cases.

You can diagnose 'em and treat them the exact same way.

Again, this can happen without the presence of a pathologic lead point.

So don't worry about having to do recurrent evaluations or reductions on these patients.

As you start looking, you'll find small bowel intussusceptions.

These are transient.

They can be seen in lots of viral illnesses.

They're pretty common with Henoch-Schönlein purpura as well.

Most are under three and a half centimeters long.

And they rarely require surgery, but they look like ileocolonic intussusceptions just smaller.

So here's a couple of typical ones.

Longitudinal transverse.

Again, these will be very transient.

We can't do anything about them.

And when you see them go back a few minutes later and odds are it won't be there.

Other Entities: Duplication Cysts

A couple of other entities.

Here's a term newborn with vomiting.

Distension, failure to pass meconium, has some abnormal dilated loops of bowel.

We were asked to do an ultrasound.

We see this abnormal mass.

This was actually not appreciated.

The first time around is an abnormality child came back.

Here's the mass again.

And what this is, this is a duplication cyst.

So these are GI tract duplications.

They're usually round, but they can be tubular.

They often have a GI signature 'cause they are pieces of bowel.

And these can cause complications from intussuscepting causing obstruction.

If they have gastric or pancreatic mucosa, they can bleed, they can get secondarily infected.

So this was a child that had some vomiting.

Actually had a CT scan first, which showed this abnormal cystic mass adjacent to the gallbladder.

And we made an ultrasound of it.

This is a classic duplication cyst with a gut signature in a bowel wall.

Just another instance.

These are very common down in the right lower quadrant.

Here is a child who is having some pain, has this complex cyst with some internal debris.

But if you look very carefully with the linear transducer, you can see this bowel gut wall signature and it operation.

This was again, a duplication cyst with a typical GI tract wall.

Summary

So when we're evaluating the neonatal abdomen and the young child's abdomen, plain radiographs are still probably the first line of evaluation, but ultrasound is a very close second.

Like with everything you have to understand the normal bowel appearance.

Pay attention to peritoneal cavity for both little calcifications cysts and for free air Doppler can certainly help decide when things are inflammatory or when hypoechoic structures are cysts or vascular.

The vomiting child.

We're really looking for hypertrophic pyloric stenosis or volvulus.

That's usually the distinction for inflammation.

Appendicitis is our most our number one choice, but inflammatory bowel disease and the older child needs to be considered when you have obstruction.

Think about intussusception from between three months and two years of age.

And the neonatal period, small bowel atresias.

And things like Hirschsprung's disease and problems in meconium are gonna be more common.

Necrotizing enterocolitis can be very well evaluated with ultrasound and is probably more sensitive than plain radiographs.

Please refer to that material from Dr. Faingold and Daneman from Hospital for Sick Children.

That talks about the stages where you can find air and what the complications are.

And while we don't spend a lot of time looking for masses in kids, do be aware of the classic ultrasound findings of duplication cysts.

'cause they can occasionally cause complications in these patients.