There will be two parts. So starting with Dr. Cartwright, who is a professor in the Department of Neurology at Wake Forest School of Medicine. He has a master's in health science research and a clinical and research expertise in neuromuscular diseases. He is the co-editor of the textbook, Neuromuscular Ultrasound, editor of Neuromuscular Medicine and Outline of High-Yield Topics and has published extensively on the topic of neuromuscular disease. He has published more than 125 peer-reviewed papers and is a reviewer for 25 journals, including the Lancet, Nature Reviews Neurology, Neurology, and the New England Journal of Medicine. He has received funding for neuromuscular research from the Muscular Dystrophy Association, NIH National Institute of Neurologic Disorders and Stroke, Scholar Rock, Biogen, Sarepta, and Avexis. Clinically, he is the director of Wake Forest MDA Clinics and the Neuromuscular Medicine Fellowship and sees patients in the Wake Forest ALS Clinic, the EMG Laboratory, and the General Neuromuscular Clinic. He has clinical expertise in neuropathy, myopathy, muscular dystrophy, myasthenia gravis, SMA, ALS, Guillain-Barre syndrome, and CIDP. So we will be taking some brief questions after Dr. Cartwright's lecture, so please enter them into the chat as we go. Then we will move on to part two with Dr. Boone, who graduated from medical school in New Zealand before completing her residency in physical medicine and rehab at the Mayo Clinic in Rochester, Minnesota, followed by a clinical neurophysiology fellowship in the neurology department at the Mayo Clinic. She has been on staff at the Mayo Clinic since 2000 with a joint appointment as professor in the Department of Physical Medicine and Rehab and in the Department of Neurology. Dr. Boone has introduced diagnostic ultrasound into the clinical and academic practice of the Mayo EMG Lab, where over 12,000 patients undergo clinical neurophysiology testing annually. Her research has focused on the complementary role of neuromuscular ultrasound and electrodiagnosis, and she is currently working on quantitative muscle ultrasound, which she hopes to integrate into clinical practice as a screening tool and an imaging biomarker at the Mayo Clinic. So with that, I'm gonna go ahead and pass it off to Dr. Cartwright. I will stop sharing my screen here. Okay, how does that look? You can hear me? Okay, good. Good. Thanks, Dr. Smith. That was a very nice introduction. And thanks for inviting me to talk. And thanks to the AAPMNR for inviting me to talk as well. And to Dr. Boone, I always like working with Dr. Boone, so she's going to give an excellent talk here in a little bit. I'm going to talk about nerve ultrasound and sort of introduce the topic of neuromuscular ultrasound. Dr. Boone, I think, is going to focus a little more on muscle. So I'll focus my talk on nerve. Feel free to write in the chat. And also, I'll have five minutes or so at the end of my presentation to take questions. And so we'll hop right into this. There's a lot. It's hard to do all of nerve ultrasound or muscle ultrasound in 30 minutes. And so this is going to be more of an overview. It's not going to get super in-depth. It's going to be an overview of how we do nerve ultrasound, how we use it, why we use it, some of the background that supports it. And so we'll go ahead and get started. I have a few disclosures. I've got a couple learning objectives. I'm going to discuss what neuromuscular ultrasound is. I'm going to go over a brief history of neuromuscular ultrasound. I think that helps to understand the concept. I'm going to talk about a couple of different arguments for using ultrasound to complement electrodiagnostic studies. I'm going to give a technological argument and a evidence-based medicine argument. I'm going to talk a little bit about nerve ultrasound technique because, again, I'm trying to overview everything and how we actually do nerve ultrasound. I'll slip a quick little case in there, and then we'll have some conclusions. So my disclosures are that I get royalties for these two textbooks from Elsevier and from Kindle Direct. And then I really like ultrasound, so I occasionally get a little carried away. And so that's my other disclosure as well. So hopefully at the end of this presentation, you all will be able to explain the benefit of using ultrasound as a complement to electrodiagnosis, especially for nerve disease. And then just an overview of the literature that supports ultrasound as a diagnostic test for neuropathies in particular. So what is it? When we say neuromuscular ultrasound, what does this mean? It's fairly straightforward. It's basically using high-resolution ultrasound to image the peripheral nervous system. We frequently use it in complement with nerve conduction at EMG. It can be used to guide nerve conduction studies or to guide needle placement into muscles. And then there's definite overlap with what we call musculoskeletal ultrasound. Neuromuscular focuses a little more on nerve and muscle, and musculoskeletal a little more on bones, tendons, ligaments, joints, that type of thing. But there is a lot of overlap between the two. The more musculoskeletal you learn, the more it helps your neuromuscular, and vice versa. The more neuromuscular you learn, the better it helps your musculoskeletal ultrasound. So there is quite a lot of overlap between the two. So let's talk about why we're doing this. So a couple different examples here. So if we think about our colleagues in cardiology, for years, 40 to 50 years, they have used electrophys and imaging together. So they will get an EKG looking for AFib or LVH, whatever it might be, and then they'll also do an echo. And so they get the electrical information, the anatomic information, they put it together to make an accurate diagnosis. In neurology, our epilepsy colleagues do the same thing. They do an EEG, so they get the electrophysiology, they do an MRI, so they get the anatomic information, they put these together and make an accurate diagnosis. And as you all know, for years and years and years, back to the 1950s, we've had nerve conduction studies in EMG, but we haven't had a great way to image the peripheral nervous system. And so that's what we needed. We needed this anatomic part, and that's where neuromuscular ultrasound fits in. So oh my gosh, what just happened there? Well, let's see. Okay, there we go. Not sure how that happened. So anyways, so the first reports of nerve ultrasound, if you go back 30 plus years, the first study I'm aware of, and I don't think there's anything before this, is by Bruno Fournage in France that used ultrasound to look at some of the peripheral nerves. And he really did a really nice description in 1988. The first disease process was by Buckberger and colleagues in Austria. They looked in 1991 at the findings in carpal tunnel syndrome. And it's actually, it wasn't what I would have, well, you know, it's not what people expected. So people thought that nerves got pinched, and so they would get smaller and squeezed and compressed. And really what they found is that there is some pinching. But if you look at this, this is the ultrasound transducer, this is a ligament, there really is more of this fusiform enlargement. And so they talked about nerve enlargement, which was really not what a lot of people would have expected based on their understanding of what happens in entrapment neuropathies and carpal tunnel in particular. So the 1990s, the 2000s, more and more papers came out on carpal tunnel syndrome, as well as the anesthesiologists. So the anesthesiologists used, they used to use, and they still do, stimulation to figure out where then when they were close to nerves. And so they would inject some local anesthesia, and they still do that. But they started to use ultrasound. And so they started to understand the anatomy, the ultrasonographic anatomy, and started to write a lot of papers in the 2000s about nerve imaging with ultrasound. We started doing a course at the AANEM, the neuromuscular society in 2004. And we started one at my institution at Wake Forest in 2004. In 2010, we did a position statement that basically said the people that should be doing neuromuscular ultrasound are physiatrists and neurologists. People that are doing electrodiagnostic testing should be doing ultrasound. In 2011, that textbook on neuromuscular ultrasound was published. In 2012 was the first clinical practice guideline, and that was looking at carpal tunnel syndrome. And it was a level A recommendation that ultrasound can be used to assess individuals with possible carpal tunnel syndrome. And to this day, we still don't have an evidence-based guideline for electrodiagnosis for nerve conduction studies in EMG. We could. There's a lot of evidence out there, but you really have to compile it and put it together and critically assess that evidence. But we have it for ultrasound with a level A recommendation that it's an accurate technique. We will hopefully soon have one for ulnar neuropathy, an evidence-based guideline. And so that'll be coming out soon. So since 2012, there have been other textbooks on nerve imaging with ultrasound. Many, many papers have been written since then. And so the field has really just expanded. And so where is this going and why do we do this and why do we think it's important to learn it? This is kind of a crazy slide, but so I'm going to make two arguments. So the first is the technological argument. There's a whole, ultrasound is a technique that is driven by imaging, driven by computer processing. And so there's a whole technical argument that can be made, and then I'll make an evidence-based medicine argument. So the first argument starts with this crazy slide. So this crazy slide is talking about how many microprocessors you can get for $1,000. And across the bottom here is different decades. And then you have these different trends, the 1965, 75, 85, 95 trend. So 2005, 2015, 2025 are going to be up here. And then it compares it to different organisms here. And so basically computer processing power has gone through the roof. It's way up here now. It's way past the human brain and computer processing drives imaging. And so the imaging is getting better and better and better because of computer processing and that this does all kinds of things. So we now have ultrasound that is handheld and wireless. So this has come out in the last year. GE has a ultrasound device that doesn't even need to hook up to your smartphone with a cord. It does it through Bluetooth. And so you can be scanning on the patient and holding your ultrasound or put it up on the wall or your phone, put it up on the wall, put your tablet up on the wall and be scanning an individual. So you can fit it in your pocket. It's now being combined with EMG machines as well. So Natus, Cadwell, other companies that make electrodiagnostic testing now also have ultrasound as part of their electrodiagnostic platform. And so a couple more arguments for this. So the computer processing makes the imaging better. So the image quality keeps getting better and better. And so this is a radial artery from a child. And this is from 2012. So you can see it. That's the artery right there. This is anesthesia group that would scan it to cannulate the radial artery in a pediatric patient. And then they started using, this is a 12 megahertz transducer. So they started using a 30 megahertz transducer. So that vessel right there now looks like this. So that's the vessel. You can see the intimal media in there. You get this posterior acoustic enhancement. It's actually imaging is now, ultrasound imaging is now so good that you can see blood cells within vessels. And that's how powerful the imaging is. Computer processing is also driving other imaging. So this is not ultrasound. This is going to be an MRI. But really the goal, what we're trying to do here is we're trying to get to the point where we can, it's almost like a biopsy. And so we can't biopsy nerve because, well, you can biopsy sensory nerves, but you can't really biopsy motor nerves. You can maybe take a few fascicles, but if you took too much motor nerve, you're going to cause weakness, obviously. And there's only a few sensory nerves that we biopsy on a regular basis. So we don't have a ton of pathology to understand these diseases. And so we want imaging to basically get to the point where it's as good as a biopsy. And so this is going to be a seven tesla MRI of the median nerve at the wrist. And this is it. This is the nerve itself right here. You can see every little fascicle within the nerve. You can do T1, T2 imaging, you can do contrast. And really it's not quite a biopsy, but it's getting close. And so this is where we want to go with all of our imaging. This is a really high resolution ultrasound. So this was approved a couple of years ago, and this is a 70 megahertz ultrasound of the median nerve at the wrist. This entire thing here is the nerve, and you can see every single fascicle within the nerve. We've started to look at fasciculopathies now. So individual fascicles that are enlarged and diseased. We've started to do fascicle counting to understand what the normal number of fascicles are. And if we lose fascicles in ALS or polyneuropathies. And so the ultrasound imaging, just like MR and other techniques, is rapidly improving. We have other techniques with ultrasound. We can do three-dimensional, even four-dimensional imaging. We can do elastography to understand the texture of what we're looking at, of nerve or muscle or whatever it might be, how hard or how soft the tissue is. This is again back to MRI, but this is tractography. So this is a sciatic nerve from a rabbit, and you can see it's cut with a few axons left. This one's completely transected. Same thing over here in an adult individual with an L5 radiculopathy, where you can see they've lost axons, they've lost tracts. That's diffusion tensor tractography. So the imaging is really cool, some of the stuff that it can do. And it all comes, all of this technology came from the same area. So in the 1950s, there were medical oscilloscopes, and this is a tectronic medical oscilloscope from the 50s or 60s. And oscilloscope technology became nerve conduction EMG, and it developed also into ultrasound. And so ultrasound, nerve conduction, EMG, all come from oscilloscope technology. And so just to kind of emphasize this point of how much things have improved, if we looked at EMG, and we took an EMG voluntary motor unit tracing from 1960, it would look like this. So you put it in the patient's tibialis anterior, ask them to contract or ankle dorsiflex, and you get a voluntary motor unit, and it looks like that, that's 1960. And 2021, it looks like that, it's identical. And that's, this is a little bit of an exaggeration, back then it used to be analog, now it's digital, but you get the idea. That's what's happened. If you look at an ultrasound from 1960, we're going to do fetal imaging. So this is a fetus from 1960, they would do an ultrasound of a pregnant woman's abdomen, and they would get a little blip, they would shine it, they would point the sound wave through the skull, and so they could measure a biparietal width of the fetal skull. And it was, it was a different time back then, they would then do an x-ray of the pregnant woman's pelvis, and try to determine if the head was going to fit out the bony pelvis. And now we realize that x-rays of pregnant women is a bad idea. And so that stopped pretty quickly. But this is a fetal head from 1960. And again, if we think about this, EMG 1960, EMG 2021, fetal head 1960, and then this is ultrasound of twins in 2020, 2019, something like that, a couple years old. And so you can see the detail is incredible. And this is where it's going, it is just going to keep getting better and better and better. So that's the first argument for why we use ultrasound as a complement to electrodiagnosis is the technological advancement, the just power of imaging and computer processing. The second argument is the evidence based medicine argument. And this is a good one too, it's a little more dry, but it's important. So if you're into evidence based medicine, you can make a really good argument for doing neuromuscular ultrasound. For any medical imaging, you should have, you should meet these six criteria to support the use of a new medical imaging test. It is not often done. We often will start with a, you know, we'll have a 1.5 Tesla MRI and we'll just, the medical center will just buy a new three Tesla MRI. That's understandable. But really in order to support the evidence based support of a medical diagnostic medical imaging test, you should meet these six criteria. So the test should be valid and reliable, accurate. It should change the diagnosis. It should change the intervention. It should improve patient outcomes and it should be cost-effective. And ultrasound meet neuromuscular ultrasound meets all these criteria. So there, we did a study, there are other folks that have done studies looking at validity. So you scan someone's, you scan a cadaver's nerves and then you dissect down and you measure with ultrasound and then you dissect down and measure with calipers and the test is valid. What you get with ultrasound is what you see on the anatomic dissection. It's also reliable. So if you take, if you do inter-rater reliability, so you have raters of different capabilities. So you might have a medical student, a resident, a fellow, a new faculty member, an experienced faculty member. There's a lot of inter-rater reliability. It's very high. And then the intra-rater reliability, if I scan somebody and then scan them again a week later is also very high for nerve and muscle imaging. So neuromuscular ultrasound is valid and reliable. It's accurate. And this is basically sensitivity and specificity. I would say for something like carpal tunnel syndrome, it's probably not quite as accurate as electrodiagnosis, as nerve conduction studies, which are maybe 95% plus sensitive and specific, but ultrasound is like 92, 93% plus sensitive and specific. So it is very accurate. There's several different studies, prospective studies and case series looking at how often it changes the diagnosis. It depends on what the referral is for, but anywhere between 25 and 40% of the time, ultrasound will change, alter or refine the diagnosis for someone referred with a nerve condition. And in that same number, 25 to 40%, it will change the intervention. So you might see a tumor that wasn't expected that completely changes the intervention or a intraneural ganglion cyst that needs to be removed that changes the intervention. So we've satisfied the first four. We did a clinical, a randomized controlled trial several years ago to see if ultrasound improved outcomes. And so what we did is we took 120 individuals that were referred to our EMG lab with a mononeuropathy. We scanned all of them with ultrasound, and then we randomly assigned half the patients to get the report sent back to the referring physician. And then we followed all these patients over six months. And we did 17 different outcome studies. The ultrasound group where it was sent back to the referring physician had improvement in 14 out of the 17 outcome studies that we, outcome parameters that we measured. Not all of those reached, actually, most of those did not reach statistical significance, but two of them did reach statistical significance, showing that it improved outcomes in those individuals. And that was totally blinded. The patient was blinded. We were blinded. The examiners. the raters were blinded, and it only looked at six months in 120 patients to start, 100 patients completed the six-month study. And then finally, after we showed that it was, that improves outcomes, one of our colleagues in England, Dr. Mandeville, took our information, took our data, and put it into a cost-effectiveness analysis. And because ultrasound is very inexpensive, it came out as extremely cost-effective to do neuromuscular ultrasound. So neuromuscular ultrasound meets all six criteria for an effective medical imaging test. Okay, so we're going to switch now. We've made the argument why we do this, and now we're going to talk about how we do it. So I'm going to start off with the nerve properties. So first of all, you think about the shape. I'm going to start with the sagittal view. This is the median nerve. This is the nerve itself right here. You can see MN right there. This is a longitudinal or sagittal view. This is the skin. This is deep. This is the radius and scaphoid. These are the flexor tendons. And this is the nerve. It has a linear shape to it. So you keep that in mind. Then you do a cross-sectional view. And in cross-section, nerves can be oval. They can be a complete circle. They can be triangular. This one I would say is kind of irregular. They're often a little bit irregular. This is the median nerve at the wrist. And so in cross-section, nerves take a variety of shapes depending on which nerve and which location. And then we have the echogenicity. Connective tissue is bright, nerve fascicles are dark or hypoechoic. And so you overall kind of get this speckled appearance. In the longitudinal view, again, this is the median nerve. We sometimes call it a train track appearance where you can see the hypoechoic fascicles and the hyper or bright connective tissue, kind of looks like a train track. And in cross-section, we often say it looks like a honeycomb. You can see those individual fascicles that look like a honeycomb in cross-section. Then there's a bunch of other properties. There is something called anisotropy, which is basically if you image a structure and then you change the angle of incination, a structure that's very anisotropic will change quite a bit from bright to dark. Nerves stay pretty much the same when you rock the transducer, whereas tendons are very anisotropic. Nerves are mobile. In the longitudinal plane, they'll slide. In the cross-sectional plane, they will move around as the tendons move. Healthy nerves do not have normal, do not have any blood flow in them on Doppler signal or very minimal blood flow. And then all of us that do nerve conduction EMG, we know the typical location and continuity, and each nerve has a typical pathway that we pay attention to. So what do we do here? So some people will start with the sagittal view, attain sort of this general gestalt of the nerve, the shape, the echogenicity, the location, the vascularity. They look for any surrounding abnormal structures. They might perform height measurements in the longitudinal view like this at the site of entrapment and at the site proximal or distal to it. I think that we get the majority of our information from the cross-sectional view. So we do that longitudinal view. It is important to do two views at the site of interest, but the cross-sectional view, I think, gives us more important information. So again, we evaluate the shape, the echogenicity, the mobility, and location. We look for any abnormal structures, and then we measure the cross-sectional area airing just the inside of the hyperechoic epineurium. And there's published reference values for cross-sectional area for the median nerve at six sites, the ulnar nerve at seven sites, the vagus, the musculocutaneous, the radial at a couple of sites, the fibular, the tibial, the sciatic, the sural. There are lots of published reference values. And this is, again, just a cross-sectional view of the entire carpal tunnel right here. This is the median nerve right there. That's the flexor pollicis longus tendon, and that's the entire carpal tunnel, which you can see with a single view. So I'm going to do a quick case here. I don't know. I always find this case interesting because I could relate to it. So we were doing a workshop at a conference several years ago in Phoenix, Arizona. And after the workshop, a woman came up. She was a physician, and she said that she is sure that she has an ulnar neuropathy at the elbow. She's got a tunnel sign at the elbow. She's got this numbness and tingling that goes down to her fourth and fifth digits. She did electrophys testing, and she had done nerve conduction studies many times on herself, and they were always normal. And so she asked if we could scan her ulnar nerve to see what it looked like. And so we said, sure, and we scanned it. And this is what it looked like. This is a longitudinal view. This is the ulnar nerve right here. And then it enlarges significantly into the very large hypoechoic with some hypoechoic signal structure. This is a cross-sectional view. This is the medial epicondyle. This is the olecranon. And this, the nerve itself, the ulnar nerve should be about nine millimeters squared. It should be about this big. And this was like 130 millimeters squared. So 15 times what it should have been, nine, 10, or 10, 13, 14 times it was huge. And we think it was a neurofibroma. I think it was a neurofibroma, but the patient was gonna follow up locally and she wasn't, she was just a attendee of the course. But that was a great example because she had done nerve conduction studies every single way she could think of. She had someone EMG her ADM and her FDI, and just was not able to show that she had an ulnar neuropathy even though she knew clinically that's what she had. And so nerve signal was conducting normally through this structure, which I think was a neurofibroma, but she had a really powerful tunnel sign and lots of symptoms because of this abnormal structure. We use ultrasound for a lot of different things. So we use it for mononeuropathies all over the place. Ulnar at the wrist, ulnar at the elbow, median at the wrist, fibular head. We look for tumors. We look at trauma. We look at brachial plexopathies. We look at polyneuropathy. It can help be helpful in differentiating CIDP and CMT. We use it for motor neuron disease, looking for fasciculations. We look at the diaphragm. Dr. Boone will talk about that in her talk. We look at inflammatory muscle disease, muscular dystrophies. We use it to guide nerve conduction studies and EMG. We use it for all kinds of procedures. And so in conclusion, a few take-home points. One is this computer processing is just going to keep getting better and better. Ultrasound is just going to keep getting more and more impressive. It is really helpful to have an anatomic correlate to go along with your electrodiagnostic testing. And then there's a ton of evidence-based studies and research that support the use of neuromuscular ultrasound for both carpal tunnel, ulnar neuropathy, and other mononeuropathies. And that is all I have. Thank you all for listening. And I'm happy to do some questions. Thank you all. Thank you so much, Dr. Cartwright. I know that was a lot of information to squeeze into a small amount of time. I don't see any questions coming into the chat right now, but if you do have any questions, go ahead and pop them in. We'll wait another minute or so, and then we will move on to Dr. Boone's presentation. Yeah, it is a lot to squeeze in there. So we do entire courses on neuromuscular imaging that will be two or three day long courses. And even that, it feels like we're squeezing a lot in. And so we also do many fellowships and different teaching options like that. So it's a lot to squeeze into 30 minutes, but it's helpful to do an overview and give an introduction. It looks like there might be questions. Yeah, there's a couple in there. Okay, let's see. Do I have an email address that I'm willing to share? Sure, I'm not quite sure how to do that, but I can work with the AAPMNR to share an email address. Oh yeah, I'll bring down my slides. There's a question about, do we have an upcoming course? We do have a course at Wake Forest. We do it every spring. It'll be May 5th and 6th of 2022, hopefully in person. Speak on the use of ultrasound after nerve reconstruction and grafts. That's a great question. Where to start with that? So we've done a lot of imaging of reconstruction and grafts. An interesting thing with reconstruction is trying to follow the fascicles to see how well they lined up. If you do like an end-to-end anastomosis. Nerve grafting, you often can't see through the graft itself. And so you can very easily see the graft, but it is hard with keratin and other forms of grafting to actually see through the graft. But you can to some degree, it just depends on what the graft is made out of. And then let's see. Talk about how I got good at this. Well, the great thing is it's painless. So you practice on yourself. You start by scanning yourself and it's totally painless. And then you get a friend or a family member and I don't know, you buy them dinner or something and convince them that you're going to scan them for a little bit. You get an anatomy textbook and you scan and you look at the textbook and you go back and forth. And then you start by doing, I started by doing carpal tunnel. And so you do, you see a lot of carpal tunnel in your EMG lab and you start doing median at the wrist. And then you get comfortable with that. You do ulnar at the elbow. And once you're comfortable with those two, then you can start doing radial at the spiral groove and the lower extremity. And you can just sort of go from there. And then how much you practiced as, yeah, well, we practiced a lot. I mean, we still, I still learn all the time. I mean, I'll learn from Dr. Boone's talk. I'll learn from listening to other folks talk about how they image things and how they position the patient and the anatomic relationship of everything they're looking at. There's a question about mini fellowships. So we do mini fellowships. The COVID has limited that. And so we aren't doing them right now. We hope to do them again starting in January but it just depends on what the medical center tells us. So we've had people come for a couple of days. We've had people come for six months. It's, we've done all kinds of different mini fellowships. Okay. I think it's Dr. Boone's time. Is that right, Dr. Smith? Yeah, we'll go ahead and move on. Thank you again so much for your time here. Really lucky to have both of you as speakers today. So we will go ahead and move on. We'll let you share your screen, Dr. Boone. Okay, hopefully this will work. All right. Does that look right? Can you hear me? Looks good, yes. Okay, all right. So we're good to go. I'm going to just launch into this then because like you say, there's not a lot of time to fit a lot of information in. So hopefully my slides will, sorry, I'm just trying to advance my slides. Okay, here we go. So I'm just going to kind of go over the fundamentals of muscle ultrasound. Mike talked more about nerve ultrasound. I don't have anything to disclose. This is just a couple of pictures of normal muscle in short axis on the left and long axis on the right. So on the left, you get the starry night type appearance with the black muscle fibers and then the white around the black, you know, interspersed within the black tissue is the normal fibrous connective tissue in muscle, the epimysium and endomysium. And that's what you see on the right. You see it in more of a, that's a longitudinal view. So you put your transducer in line with the long axis of the muscle and you get this more striated appearance. So muscle is very easy. Normal muscle is very easy to image. And it's a great thing to start looking at when you're doing EMG, for example. Just keep in mind that different muscles will look a little different depending on their structure. So, you know, biceps breakout is a unipenite muscle on the left there, whereas tibialis anterior is a bipenite muscle here and it has a central fibrous partition. So what can we use muscle ultrasound for? There's a lot of things. Obviously you can look at the lesions. So when you see something that shouldn't be there, you can try to figure out what it is, whether that be a hematoma or a tumor or just some replacement of normal muscle tissue. You can use it anatomically to localize disease. So in the case of biopsy or EMG, you can really hone down on where is gonna be the most useful area to test, especially in children, that's very helpful. And then you can also use it to look at the pattern of involvement. So different diseases, you know, that can be a real clue to muscle diseases like inclusion body myositis, where you tend to get a significant involvement of the finger flexors and the quadriceps. You can take a look and see if those muscles are more involved on ultrasound. It has been shown to be a good biomarker to follow disease progression. And as Mike mentioned, it's not invasive, it's painless. So it's ideal from that point of view with no radiation involved. And then in those cases where EMG really isn't feasible, especially in small children, it can really be a nice tool to start the investigative process with. So this is just an example of what you can see in muscle. So we have a normal gastrocnemius muscle up here on top, and then down below you see a big hematoma in there. Very easy to identify with ultrasound. So situations where muscle ultrasound is helpful include myopathies. You can see changes in acute myositis. You can see changes in critical illness myopathy, congenital myopathies. And then, as I mentioned, it's really nice for selecting that part of the muscle to biopsy or which muscle to biopsy or to EMG. You can also see changes in muscle when you have a focal neuropathy. So that can help identify which nerve is affected based on which muscles are involved. Diaphragm, it's an excellent tool for evaluating the diaphragm. I'll touch on that a little bit. It's a nice tool to use as an adjunct to EMG and ALS when you're always trying to give the patient diagnostic information without having to needle hundreds of muscles and put them through this painful test multiple times. And then in children, it's ideal because it is non-invasive and painless. So muscle ultrasound is basically, we're talking about 256 shades of gray. So we have this way of quantifying muscle echo intensity, which I will speak to more in some of the upcoming slides. But on the left, you have a healthy appearing muscle here. And then on the right, you have a very unhealthy appearing muscle with neuromuscular disease involving that muscle. And what's happening to the ultrasound beam, you always want to think about what you're doing when you're putting an ultrasound probe on a patient. And you're bouncing these ultrasound beams down into the tissue and then looking at how they bounce back towards you. So they normally have a controlled direction. When you get replacement of muscle tissue with fat or fibrous tissue, that affects how those ultrasound beams are reflected back and they get more dispersed, they get absorbed more and you get this decreased attenuation and change in echo intensity so that everything looks whiter when there's muscle disease. So you can obviously evaluate this visually when it's that obvious. I mean, it's pretty clear that this is abnormal on the right and initially that is what was used all the time. There was this HICMAT scale that HICMAT came up with, which is basically based on how well you can see a bone shadow underneath the muscle or deep to the muscle. So you're bouncing your ultrasound beam down through here and bouncing it back off the bone. This is a normal muscle for grade one. Grade two, you just have slight changes but you still have a nice bone outline here. Grade three, you start to lose that bony outline, although you can still see it. And then in grade four, you completely lose any bony image. So that's one way to grade it that has been shown to be reasonable. And using pattern recognition of changes that can help you to determine what's going on. So a lot of myopathies will give a kind of a generalized change in muscle echo intensity increased, everything's whiter, kind of a ground glass appearance here. Neurogenic processes often in things like spinal muscular atrophy, you get this kind of moth-eaten appearance where you've got a surviving motor neuron here with the muscle fibers that it's attaching to, but then the ones that have died off, you get this very white appearance. And then some things like dematomyositis will have a very patchy involvement of the muscle. So again, that's can be helpful for biopsies or for EMG. Dematomyositis, if you don't get in the right spot with EMG, you might not see anything abnormal. And so there are some various visual clues. This patient has thickened fascia here with fasciitis going on. This patient has a calcification where you're getting this posterior acoustic shadowing because the ultrasound beam is not getting through that calcification So those can be tips for dematomyositis. You can see that calcification. They can be tips to the diagnosis. This is just an example of how you can see regional changes. So in this case of inclusion body myositis, the flexor capillaris looks fine. It's still quite dark, whereas the finger flexors deep to it are quite abnormal. And this is a myopathy case where it really affected the medial gastrocnemius, but not the underlying soleus. And then this is just to show you why we really need to quantify muscle changes, echo intensity changes. You know, young muscles, like in this case, they're really very healthy and they don't have a lot of fibrous tissue or fatty tissue within them. But as people get older, that meat starts to look a lot different. There's a lot more white in that meat. And this is gonna show up as increased echo intensity. So this is just showing you three normal muscles, totally healthy people, but this is a 20 year old on the left. And then it gets a little bit brighter and when they're in their 50s, and then when they're in their 80s, it really gets quite white and starts looking abnormal, even though that's a perfectly fit and healthy 80 year old. So you have to know what's normal for that patient's age, because it does change a lot after the age of 18. Muscle echo intensity increases, sorry, decreases. When kids are really little, it changes quite a bit. And then once they get to about the age of four or five, it stays pretty stable until they get into their 20s. And then it gradually starts to increase their echo intensity. This just is an example of why we are not very good at looking at muscle images and telling if they're abnormal or not. So that when you look at this strip here, you know, it's, it's all the same. Okay, but here, we're seeing quite a difference. It looks much brighter here than it does here. But actually, that is when you place the strip here, and I'm not sure if my animation is going to work. Here we go. You can see you see that same change where it looks brighter here and darker here. But that was that piece that looked exactly the same all the way across it when it had a background that was the same behind it. So what we've come up with to try to get over some of these issues with visual quantification of muscle echo intensity is quantitative grayscale analysis using the computer. And we take a muscle image usually in short axis here to be our Santeria, and then we place a region of interest. So we take, we choose a part of the muscle to analyze. And then we, we make this graph from all the different echo intensities within that piece. And then we can look at that mean echo intensity for that area we selected and compare it to reference values. And you come up with a z-score, kind of like bone densitometry, so that once the levels start getting above two standard deviations above normal for that person's age and body habitus, then you can be fairly confident that those are abnormal muscles. And you basically can, you know, based on your findings, if you scan a few different muscles, you can determine yes or no as to whether there is a neuromuscular disease based on the abnormalities of disorders that can help you say whether it's more likely to be a myopathy or a neuropathy depending on where the abnormalities are. And as I said, it can also help you decide where to biopsy or where not to biopsy. So it's obviously a perfect tool for kids. They really don't mind when you place an ultrasound probe on them because it doesn't hurt. So as a screening tool for children, when you're trying to rule out neuromuscular disease, the visual evaluation is, you know, probably at best 70% sensitive because of those difficulties with the, the problem is the grade two and the grade three. Grade four is obviously abnormal. Grade one is usually obviously normal. Grade two and grade three are the ones that are tricky to decide if they're abnormal or not. So then we came up with quantitative evaluation, and a lot of this was done by one of my colleagues and someone I've collaborated with, Sigrid Pillen in the Netherlands and Nens van Alphen. And we just followed up with a study ourselves of 150 kids presenting for EMG to see how good we were at picking up disease with muscle ultrasound. And you know, they're pretty good values here, 75 to 90% positive predictive value and 80 cent, 86% negative predictive value. So it's a nice initial screening tool. You know, if you have a high index of suspicion and you get a positive test, you go on to things like biopsies. If you have a low index of suspicion and you just want to reassure the parents, you can go by your clinical acumen and then add in that you've got a negative muscle ultrasound test that makes you more comfortable saying, let's leave this alone for a year, see how the kid does, and then bring them back another year and we'll repeat the muscle ultrasound and see if it's changed any. Using it as a biomarker, several different investigators have looked at that and it has been a nice tool for showing change over time. Craig Zegman, one of our collaborators has done a lot in Duchenne muscular dystrophy. It's also been shown to be useful as a biomarker in spinal muscular atrophy and fascio-scapular humeral dystrophy. So it tends to be more sensitive and specific if you use a superficial region of interest, that's that box you put on the muscle. So these days we tend to select a rectangle right below the upper part of the muscle, just deep to that initial fascia. You put a box on here and then you get your grayscale value from that and follow that and it correlates with increasing age, you get increasing echo intensity in Duchenne and as the function decreases you also see increasing echo intensity as shown in this graph from Zegman's paper. Correlating age, grayscale goes up in these kids with Duchenne and then echo intensity as their function declines, their echo intensity goes up. Sorry, I'm having some issues with my slide. Oh, there we go. Okay, so in the EMG lab or clinically in clinic, you know, you can just eyeball muscles with ultrasound and see if there's atrophy. This is a normal biceps on a patient on the one side and then on the other side where they had brachial plexopathy they have a severely atrophic muscle, it's much smaller, in thickness and it's much whiter. You really can't see any of that black muscle tissue within this or this fibrous tissue. This was a severely denervated biceps, but other examples like serratus anterior is a really nice one. Sometimes it's not that easy to needle if the person's overweight and you can't feel the ribs, you can just look at the muscle and see if it's severely atrophic and make a diagnosis of a long thoracic neuropathy just in that way without even having to put a needle in. This shows fasciculations. Ultrasound is a fantastic tool for looking for fasciculations. You can see these little areas of the muscle that are twitching. So the entire muscle does not twitch, it's just one little pocket of muscle fibers which are connected with one motor neuron that's, you know, fasciculating. So it's a really nice tool. I use that a lot when I'm doing EMGs to rule out ALS. I'll look at the trapezius, the sternocleidomastoid, try to find findings in the cranial muscles since that really is key to your diagnosis. Or you can sometimes find them in the abdominal muscles or the diaphragm and that can really help without having to needle those muscles. There have been quite a few papers looking at ultrasound and ALS. It definitely has been shown to increase the diagnostic yield and I think it's especially helpful in those atypical cases or early in the presentation where you're not seeing enough clinically or even necessarily on EMG to really be able to tell the patient yes or no they have this this horrible disease. There's various things that we see changes. Obviously the fasciculations, it's a great tool for that. It can screen a much larger part of the muscle than your needle is reaching with EMG. You can also see increased echo intensity or echo variance. You can see the muscle atrophy and then peripheral nerves have been shown to decrease in size actually in ALS. And then as I already mentioned, you can use it to look at the diaphragm in a nice non-invasive way to see if that's involved. It's a great tool. Ultrasound is a fantastic tool for Botox. I do a lot of Botox injections for spasticity and this is just looking at the finger flexors so you can wiggle each the FDS one through four and see exactly where they are because a lot of times patients will have two fingers that are much tighter than the other two and you can direct your Botox this way. Plus you can avoid that big nerve right there and not stick your needle in that so that's nice for the patient. So it's a really good tool. Even if people can't activate, you can wiggle it passively. You can move the finger passively at the joint that some, you know, that muscle controls and you'll be able to tell what part of that muscle you're looking at belongs to each digit. I use it occasionally when I'm doing EMGs to make sure I get in the muscle I want to be in. This is showing the supinator muscle. So first of all you can avoid any, you know, the radial nerve lives here in the in the fibrous tissue between the two heads and supinator but you can make sure you don't hit the nerve but you can very easily get into the muscle. It's especially helpful for muscles that you don't do very often or that are deep. It's helpful in patients who are anticoagulated and, for example, if you have to, if you really need to stick flexor digitorum longus or posterior tibialis there's a lot of veins in that area and if somebody's on Coumadin I'm a lot more careful about needling those muscles and just throwing on ultrasound first and making sure you're not going to put your needle right through a vein is a very simple thing to do especially with these new machines where we have the EMG and the ultrasound in the same, in the same machine. It's really nice. It facilitates your clinical practice. Just looking at my time here. Okay, I think we're okay. So just going to run through the diaphragm a little bit. This is a tool we now use a ton. Ulshan, the diaphragm is quite easy to do in normal people so it's very easy to practice on yourself. We place the probe here in the lower chest wall. This is the zone of apposition where that dome of the diaphragm is coming up next to the ribs before it curves over the abdominal organs. You have the liver on this side and the spleen on this side. So I try to span two ribs as you see in this picture is a rib and a rib. So you know in this case we've got the probe going this direction and his ribs are going this direction. So I try to cross two ribs and then I look and the first layer is usually going to be abdominal wall muscle because that comes up and attaches to the lower costal margin. There's a little bit of skin here and then abdominal wall muscle and then the first layer of muscle between the ribs is going to be intercostals and then right deep to that layer is going to be the diaphragm and with these new probes they're so good the resolution a lot of times you can actually see the diaphragm extending under the rib because the way the beam is they compound the the imaging and they're able to send some of the ultrasound beams this way and some that way as well as some directly perpendicular and you just get these great images with a really good resolution. So anyway you can look at this muscle here the diaphragm and determine how thick it is and then have the patient it's at rest when they breathe out. So at the end of a breath out you can measure it and then it thickens as they breathe in because it shortens and then becomes thicker. So then you measure it again at the end of a big breath in. So you need some patient cooperation for this to really be helpful. So this shows a normal diaphragm this layer here and then they're going to take a big breath in and it's going to thicken a lot before the lung comes in. So just watch that one more time here the diaphragm this is the intercostal layer above it diaphragm and then it thickens thickens and then in comes the lung. So you could measure that and you could tell that it's more than doubling in thickness. So it's very normal this patient. So this is just in a clinical example of how we found it really useful in our practice. This is actually how we started using it. We had a patient come to us to our rehab unit who had had a surgery a cervical spine surgery. He was super fit healthy guy in his 60s. He liked to hike and everything and then he had cervical stenosis. So he had a elective surgery for that and about three days and about three days after the surgery he developed rapidly ascending quadriplegia turned out to be from an epidural hematoma. So he was about two or three months out from this when he came to the rehab unit and he wanted to know if he was a candidate for a phrenic nerve pacemaker because he just didn't want to keep living like this ventilator dependent. So he wanted to make an informed decision. So he was on a Coumadin for a heart valve so he could not come off it and he had to keep his INR up around four. So nobody was willing to needle his diaphragm and we had two different people do nerve conduction studies where they thought they got some small responses on both occasions. So the overall impression was that he had some diaphragm function so you know thought was maybe it will improve. So then they requested a third study when he really wanted to know about the pacemaker and so this time we were like well let's do it with ultrasound you know and then we can needle it and this is when we first started looking at the diaphragm before we had any of our normal values or anything. So we were able to see his diaphragm on both sides and we could see that when we shocked the phrenic nerve up at the supraclavicular fossa his diaphragm was not contracting. So those responses they had obtained earlier were volume conducted responses they were not true diaphragm muscle responses. And because he was on the anticoagulation we did the needle we just told him you know obviously there's a risk we could give you a hematoma but we'll be watching with ultrasound and you know realistically what's going to happen if you get a hematoma in the diaphragm. It's not going to cause a compartment syndrome it's just going to cause a bit of pain probably. So anyway we were able to do the needle and sure enough he had severe fibrillation potentials on both sides. On one side he had a few motor units but very few. So it turned out that he had severe anterior horn cell involvement as well as cord involvement from this epidural hematoma. So his phrenic nerve was not working and hence a phrenic nerve pacemaker was not going to do anything for him. They work when you've got you know severe central dysfunction but you don't have good phrenic nerve function. And so we ruled that out as an option and then that was before they were doing. Now they do some direct muscle stimulation in some cases but even then you need you need to have some function left I think for that really to work. So it helped us a lot unfortunately he chose not to continue living on the ventilator but at least we were able to give him a you know give him specifics of what what was going on with his diaphragm and we could only do that because we had ultrasound. So this slide is just a quick summary of kind of the use of neuromuscular ultrasound the usefulness of it I guess. You know visual screening is only about 70 percent sensitive but quantitative muscle screening is really quite good for things like spinal muscular atrophy is excellent. Sensitivity is 100 percent. Circulation screening is 20 percent better with ultrasound than with EMG. Finding ALS versus mimics you know ruling that out it's got good sensitivity and specificity. And then there was also a study looking at quantitative muscle ultrasound in those patients that show up with myalgia and exercise intolerance and fatigue and it was pretty good with the negative predictive value. So it's again a nice little screening tool that's easy to do quickly in the office. And then with diaphragm ultrasound we looked at it with phrenic neuropathy and we got really good results. The sensitivity was 93 percent the only cases we missed were patients that had mild old phrenic nerve injuries so they had some big motor units on the needle exam but they functionally were doing okay. And the specificity was 100 percent so we didn't get any wrong and say that they had phrenic neuropathy when they didn't. So it was really nice. So basically looking towards if you want to start using ultrasound in your practice really muscles are great to look at. They're so easy and for people who are in residency for EMG it's a fantastic way to see you know see the muscles like flexor carpi radialis and pronated teres. You know sometimes you're in one and you want to be in the other. Tensor fasciae latae you can't always find that even though you think you should be right in it. You can just put your ultrasound probe on and see exactly where the muscle is. And then you know in PMR we're getting we're using a lot for musculoskeletal ultrasound so we're all getting quite good at finding our needle with ultrasound. So you can use that in your EMG practice all the time. Using it for biopsy or EMG needle guidance it's very helpful for that. It's good for screening for fasciculations. That's something easy to do that's quick doesn't add much time at all to your test and then using it for diaphragm dysfunction has been a huge help in our practice there. It's really been helpful in the severely abnormal diaphragms that are very challenging to needle because they're less than a millimeter thick so you a lot of times you don't even get any electrical activity when you put your needle through that diaphragm because it's completely atrophic and it doesn't even fibrillate when it's that severely involved. And then in patients presenting with possible ALS it's a nice thing to combine with with EMG. So the approach that you should take with muscle ultrasound is just do it as Nike would say. This is a great tool in your practice and if you have it available you just start like Mike said you start practicing on yourself start practicing on your your friends your family and it's not that hard to get the skills. That's all I have. I'd like to thank you for inviting us to speak Sarah and hope everybody's enjoying the conference. Thank you so much Dr. Boone. We just have a about a minute or two here but if you all have questions go ahead and put them into the chat now so we can take at least a couple here. So I'll stop sharing the screen. So that one, I don't see, do you see any for me? I see the one about, that must be for Mike, about mini fellowships. We've got one, any suggested texts for Botox with ultrasound guidance? So I'm trying to think, I have, I'm not someone that uses textbooks a lot, I must say. I find that now, anything that I'm doing in clinical practice, I can usually pull up a YouTube video, like if I'm doing a joint injection that I never do, you know, some weird ankle joint or something, I just pull up the latest, you know, what's the latest on YouTube, and you can usually find something pretty good on the internet. There's, or just Googling articles, you know, scientific articles, so there's a really nice article out there, I think it just came out in 2020 that I, on the topographical representation of the fascicles and the flexor digitorum superficialis muscle for Botox, and flexor digitorum profundus, which is really nice when you're trying to target, you know, a couple of different fascicles rather than the whole muscle. You'd be surprised, the topography is not what you'd expect, like the muscle to the long finger is, and the index finger are much bigger, and one of them spreads all the way across kind of the width of the muscle. So that, I'm just trying to, oh gosh. I have the picture, I've taken the picture, has a nice colored image, and I just have that in my office when I'm working with residents, I show it to them. The person that did it, I think it was Hodge, but it was published in 2020 in Muscle & Nerve, I believe. Anyway, there's, you know, I just kind of go to the literature, usually. The thing with Botox, I use Oxygen quite a bit when I'm doing Botox. I always use EMG guidance, too, because I like that to sort of see how active the muscle is. But if I'm doing Botox with ultrasound, most of the time I'll do a short X, you know, an out-of-plane technique because it's so much quicker. And you can, you know, you can just see your needle moving down until it gets into the muscle layer that you want to be in and quickly confirm that you're in the right spot. Or you can even just do ultrasound before you put your needle in and look at the depth and the location of the muscle you want, and then you just go in with your needle to one centimeter or two centimeters depth, and you can be much more confident you're going to be in the right spot. All right. Well, thank you so much to both of you. Hopefully we can continue to share some more neuromuscular ultrasound content with you through the AAPMNR. We've seen how useful it can be as a diagnostic tool today. And I think that's it from us. Thanks everyone for coming. Yep. Thanks for listening.

neuromuscular ultrasound

peripheral nervous system imaging

nerve conduction studies

electromyography

muscle imaging with ultrasound

diagnosing neuromuscular disorders with ultrasound

muscle ultrasound for biopsies

evaluating the diaphragm with muscle ultrasound

screening tool for children

improving patient outcomes