Advanced Abdominal Ultrasound

Ultrasound criteria of appendix ultrasound 

• >6mm
• Noncompressible structure 
• Pain with transducer pressure
• Presence of free fluid
• Signs of obstruction

 The criteria again are going to be an appendix that's enlarged greater than 6 millimeters it is a non-compressible structure the people will have pain with transducer pressure there may be the presence of free fluid and there may be signs of obstruction or ileus so the way that we scan.

we can use the linear probe if the patient size allows us and we can start by mowing the lawn at the edge of the liver or we can start down by the iliac crest if we start at the edge of the liver we're going to look for the gas in the colon as seen in this scan right here and we will follow that down until we see a tubular noncompressible structure and here we also see hyperechoic fat suggesting inflammation or stranding around the appendix just deep to the appendix we will see in this clip the iliopsoas muscle right here you can see the muscle fibers quite clearly so mowing the line what exactly does that means we can start at the iliac crest.

Laterally and move up with the probe and transverse view to the level of the umbilicus we should see the edge of the liver at this level we can go in a lateral to medial fashion to midline and use graduated compression down to the level of the pelvis again we're going to look for hyperechoic fat stranding and often times we will find the appendix anterior and lateral to the iliac vessels the iliac artery and vein this is an example of a false positive this represents stool in the colon and it will be somewhat compressible 

• An example of real appendicitis we can see in a pentacle lift we can see a fluid-filled appendix with a thickened wall that is surrounded by edema here you can see the dark edema surrounding the appendix is in short axis on the long view we can see a tubular fluid-filled appendix surrounded by edema and deep - that is the iliopsoas muscle next.

Ultrasound  Criteria  for Small bowel obstruction 

• View all four quadrants
• SOB>2.5 cm
• View to and fro motion for peristalsis in obstruction portion
• Large bowl dilated colon >5cm

we're going to talk about small bowel obstruction and this is a great application for ultrasound and something we want to start doing routinely if you look at how good ultrasound is for small bowel obstruction versus CT and Mr.

Ultrasound on the other hand has a positive likelihood ratio of 9 points eight for bedside ultrasound and if it's done formally it has a likelihood ratio of fourteen points one with a negative likelihood ratio of 0.1 three so it's both very sensitive and very specific for small bowel obstruction if you look at the likelihood ratios of ultrasound compared to CT and MRI you can see that ultrasound is a faster no radiation test which gives you a higher likelihood ratio CT has a positive likelihood ratio of three-point six and a negative likelihood ratio of 0.1 three MRI has a positive likelihood ratio of six-point seven which is very good but still not as good as ultrasound and a negative likelihood ratio of 0.12 so the sensitivity of x-ray is 46 percent its specificity is 67 percent so this is a great reason to go directly.

Ultrasound at the bedside to look for small bowel obstruction and what we're looking for is we're gonna look in all four quadrants oblique views we're going to include the pericolic gutters and small bowel obstruction is defined as greater than 2.5 centimeters of dilated bowel loops with lines going across the bowel we will view to and fro motion of peristalsis against the obstructed portion and collapsed distal bowel large bowel obstruction is a dilation greater than 5 centimeters this is an example of what we see in small bowel obstruction so we can oftentimes start where a person is maximally tender and you will find a dilated loop of bowel you see that we change our depth to usually less than 10 centimeters so we get a good view of the bowel anterior in the app and we can see that there's no normal peristalsis here that the obstruction

Intussusception usually we see this in 

kids but we have seen it in adults and usually we expect to find it in the right upper quadrant or sometimes in the right lower quadrant.

Clinically there is a classic triad but 

this is actually only seen in 30% of cases that triad is episodic colicky.

Abdominal pain in a right lower quadrant or 

a right upper quadrant mass guaiac positive current jelly stool alternatively if the child is younger they will more often present with a lethargy bedside ultrasound is most useful as a screening study in pediatric patients if you are concerned for intussusception so let's talk a little bit more about intussusception.

Intussusception can be transient intussusception usually these are smaller in size with a mean diameter of

one point five centimeters you do not see 

a lot of wall edema or swelling there is a short segment of intussusception and the preserved wall motion of the bowel and we will not be able to see an absence of a lead point if these signs are present that is a good indicator that this patient will not need to go to the operating room the last thing that.

 Advanced abdominal procedure for an ultrasound it's the most common cause of obstruction in infants it happens in two to five per 1000 births usually kid present with it at 2 to 6 weeks old and it's more common in males with a 4 to 1 male to female ratio the classic olive is not detected on the exam in 50% of children so that's why we need ultrasound we're going to start with a linear probe in the epigastric region we will identify that pylorus between the distended stomach on the left and the duodenum and gall bladder on the right

we can try using oblique views for 

difficult examinations and this is what we see we will see an elongated

the pyloric canal as evidenced by the green 

arrow and a thickened muscular wall of the pylorus so the muscular wall will be more than three millimeters the pyloric canal will be greater than 14 millimeters to make this diagnosis negative findings are pretty much the opposite of that if the pyloric length is shorter than 14 millimeters if the wall thickness is less than 3

millimeters and the diameter is less

than 12 millimeters this is probably not

pyloric stenosis in conclusion I'd like

you to consider ultrasound for your

diagnosis of appendicitis

intussusception SBO

& pyloric stenosis we can sometimes see

signs of mesenteric ischemia this is not

even considering the usual diagnosis we

use with ultrasound including triple a's

gall stones and kidney stones I think

that this is going to be one of the

the biggest area of advancement and bedside

ultrasound is being able to diagnose a

wide variety of causes of abdominal pain.