Okay, it is one o'clock, so we are going to get started. Good afternoon, everybody, and welcome to the AAP's Virtual Didactics. My name is Jackie Dilworth. I am stemming in for Sterling, who is doing some fellowship interviews. I'm the Marketing Communications Manager for the AAP, and we are so grateful that you guys are taking advantage of these virtual didactics. We hope that this isn't your first and that you've been really learning a lot during this challenging time. And also remember that all of these webinars will be posted on our virtual campus after they are recorded. So you can feel free to take advantage of that anytime. As you know, the goals are really just to augment your curriculum during this crazy time and offload the stretched faculty, as well as providing support to you guys during COVID-19. Just a little bit of housekeeping. Everybody, as they join the webinar, they are video and audio muted. So please stay that way. If you have any questions during the presentation that you'd like to ask Dr. Ma, you can send them via chat to myself, or you can send them to the group, and we will see them and ask them, address them at the very end. And then onto our presenter, we have Dr. Rex Ma today from Rutgers New Jersey Medical School, and he will be presenting on MRI evaluation of the lumbar spine. Dr. Ma, if you would like to take over. Do you hear me okay? Yes, I can hear you fine. Great. So let me just start. Put other, we'll share screen if you want to continue. Okay. So now, all right. So, and play current slide. All right. Is there any way we can get rid of the side, I guess? Does everybody see a side with the pictures, with the videos on the side? Or is it something that, am I the only person that's seeing this right now? You mean the participant list? No, I see videos on the side. I guess, is it just, okay. Oh, I only see your present. Yeah, I only see- Okay, great. So I think it's just me. Yeah, I'm still trying to get used to this, but so, all right. So I'm ready to start. Basically, let's start nothing to disclose. So the topic of my talk today is actually MRI of the degenerative lumbar spine. And so what exactly do we really need this kind of lecture for us? You know, we do, when we get these MRI, we get the reports many times, right? And we'll be like, well, can we just use those reports and just kind of go with it and kind of not really have to look in the images? And I can try to make an argument that, no, I think it's probably best if we can actually look at some of the images. Number one is that low back pain and ridiculous symptoms are very, very common in all of the PMNR areas. No matter if you're doing musculoskeletal or neuro-STI, TBI, in all facets, you're going to be seeing folks with low back pain. So that's going to be important. Sometimes, and you're going to get these occasions where you're not going to get a report from the patient and you'll be like, uh-oh, what am I going to do with it? Well, you know, then you would want to be able to read it, at least get an idea. Another important part of why we need to do this is that often we need to correlate with the physical findings with the MRI. And many times the interpretation of the MRI, even if it was read by radiologists, may not be a specialist in MSK or spine radiology. So they may not be as detailed as you would like them to be. And then finally, I think learning to read MRIs and lumbar spine MRI is a great way to learn anatomy. I do a lot of teaching for musculoskeletal ultrasound in both the residency as well as various societies and what have you. And what I can honestly say is that learning MRI actually makes it a lot easier to learn musculoskeletal ultrasound. So for those of you who are in training, I would encourage you to try to learn to read at least some basic, I would say three or four regions of the MRI. And the ones I'm kind of thinking of would be the lumbar spine, cervical spine, shoulder and knee as your start. So I'm going to continue. So now what makes this lecture a little different than the rest of the lectures? I actually get radiology lectures. I've been involved with a lot of radiology lectures. And one of the things that I see is that they, a lot of times just present with slides of our images. And what they don't have is actually, how is this clinically relevant? And so this is what this lecture, I hope is going to be a little bit different, is that this lecture will not only present the images, but also find whether or not something is indications where it is, oops, sorry about that, clinically relevant, you know. And the number one question you want to ask when you get an MRI is, is this MRI going to change my management? That's a very important question to try to ask. Another question that you also want to ask is, what is the clinical correlation between the MRI and what you see? Now, a corollary to that question is, how many of these patients that you find with this finding is symptomatic and how many of them are asymptomatic? That is very, very important for you to know. Other things that you also want to know is that, what does these findings mean in terms of long-term? Does it, do these people who are symptomatic with these findings, how does it correlate with the MRI? What is the natural history of these findings for the MRI? That's also a very important question. And then finally, do we know if MRI can predict any lumbar symptoms in the future? And just to not spoil everybody, well, I'm gonna spoil anyway, but basically the current literature does not suggest that there's anything that MRIs can answer this question. I'm gonna put a lot of the articles that I used and I have a link at the end. So hopefully if you guys find any of these interesting, you can refer to that link and actually use it for a little bit, for yourself in the future to look into the details of those studies. With great powers come with great responsibilities. This is one of those statements that I say a lot and I think is never more true than talking about MRIs. And why is that? Well, first of all, we know that MRIs are pretty expensive. So are they really even worth getting in general for people with degenerative spines? And I just want to present some data to you. The randomized control trials and systemic reviews have shown that for patients who do not have any red flags, early imaging really does not improve the patient outcomes. So that's gonna be important. Also, what's important is that most patients with radicular symptoms will recover within weeks. And so if they do recover within weeks, then really there's no need for an MRI. Another thing that we also know is that the majority of the discs in general, oops, sorry about that, do not regress or resolve within, they usually resolve and regress within eight weeks of onset. So what is the conclusion to that? Is that for the most part, if you don't have any neurological deficits or red flags, really there is no reason to get a CT or an MRI for patients with non-specific low back pain. Another thing that you're gonna hear a lot about MRIs is that there's a high false positive rate. And sure enough, there's a whole lot of false positive. So for the most part, it makes it difficult to actually attribute your patient's symptoms to certain imaging. It can also cause, if you have a false positive, it can really cause a lot of emotional stress and over-utilization of unnecessary resources and interventions. This is a very interesting study by Deyo back in 2009 in that they found that there are states that look like they do a lot more MRIs and they tend to have a lot of spinal surgeries, a lot more spinal surgeries. But then the end point of it is that it doesn't really change the outcome of these patients, which is not what you were kind of looking for. So that's not so good. So this is really like an algorithm in terms of when you're gonna order. And really the basic thing is that you're gonna order an MRI when there is red flags, okay? You're gonna also order an MRI when there is no improvement for radiculous symptoms that are severe. And you may also want an MRI when you have no improvement in symptoms that are not as severe, but you try conservative treatment for a longer period of time. So before we go any further, let's look at a little bit with the relevant anatomy. So the anatomy is basically the things that you also, you want to see is what is in the vertebra. And basically there's the body, the pedicle, the paws, which is the small area between the superior and inferior articular process, the laminar, which is actually behind in the posterior aspect. There's also a bunch of processes. There's the transverse processes, there's the spinous processes, and there's also the superior articular process that connects with the inferior articular process to form the facet joint, okay? In addition, there's also going to be a disc, okay? And within the disc, the main thing that you also want to know is there is an annulus, there is a nucleus purposus, and there are end plate. And the thing that you want to know for MRI is what kind of consistency these are. For annulus fibrosus is mostly fibro cartilage. For nucleus purposus is fluid or gelatinous. And the end plate is actually mostly articular cartilage with a very small layer of fibro cartilage. In addition to that, you also know that in a spine, you also see fibro cartilage of the ligaments of the anterior-posterior longitudinal ligaments and the ligamentum flabum. Those are all, again, made of fibro cartilage, okay? Now, in addition, another part of the anatomy that you just want to make sure you review before you kind of tackle these MRIs is the spinal canal. The spinal canal is what's between, again, the posterior longitudinal ligament and the ligamentum flabum. And then what you're gonna find is that within the spinal canal, we know that the spinal cord ends at around L1, okay? And then underneath that, there's a thecal sac or a dural sac that ends around S2. And this is where the CSF is located, okay? And the other thing you also want to know about the spinal canal is that the nerve root actually exit the thecal sac like this, but it remains within the spinal canal. And when it does exit, it generally exits on the superior aspect of the neuroforamen. And the disc is located in the inferior aspect. So that's a very important factor when it comes to what nerve is gonna be involved. And another thing that's also important is to look at that surrounding the thecal sac within the spinal canal is epidural fat. As I said, with MRI, fat and fluid are gonna be very important for you to be able to differentiate. So now let's look at the sequences that we usually use for this. We usually use T1 and proton density for anatomy sequences, what I call anatomy sequences. The details of that, there's way too much of a, it's too complicated for it to explain. So if you did want to be more curious, you can read more about it. But I just like to just separate between the two. The other thing that I also separate is, those are the anatomy sequences. The other one that you also wanna talk about is the pathology sequences, which is also the same thing as kind of like the fluid sensitive sequences. Those are T2, STIR, anything fat saturated would be kind of considered to be that. And then finally, you're gonna, for the most part, don't need this in normal imaging for MRIs. But on certain cases, you may need to have contrast, and that's putting down linear in there. And that enhances the areas of vascularity. Generally not needed, like I said, but if you were talking about things like inflammation tumors, infections, things like that, that's when you really need that. And for our case, I may go over this case of whether or not a postoperative patient has scar tissue or reherniation. That's another indication for that. In terms of the planes, you usually look at the sagittals, and you look at the axials. And that's pretty straightforward. But the one thing you also want to know is that there's two types of axials. There is the angle axials right here, and there is the stacked or contiguous axials, okay? The angle axials are good in the sense where you're gonna see a real nice picture of the discs, especially when you're talking about the L5S1, this one is in kind of like an angle. But when you do that, it misses a whole lot of pathology somewhere between here and here. As opposed to the stacked or contiguous, it goes all the way from top to bottom. But what you're gonna end up being around this area, especially for somebody who has a hyperlipidosis, it's gonna look a little weird. It doesn't look normal that you would be used to. So it's something that you have to get used to. But it's, you know, in most places, and in our institution, we do both. You wanna use the scout line for the right-left orientation and level orientation. Another thing that you also wanted to make sure that you know is what do they basically look like on T1 and T2? I'm just gonna go these two. The main thing that you want to know is that in T1, the fat is, for the most part, the brightest structure. Unless, of course, it's fat suppressed. And the only time you really need to have fat suppression is with gadolinium. With T2, generally speaking, both the fat as well as the fluid is bright. Fluid is much more brighter than fat in T2, but it still lights up a good amount. But a lot of these sequences that you see with T2 and flu-sensitive suppresses the fat. And when you see that, that's when you're like, okay, that's where you will see only fluid at that point. So let's go through a sequence, okay? I'm gonna compare T1 to T2. This is a real patient from our institution. And basically, it's a sagittal view that goes from the cut from the left side to the right side. So, and what are the things that you can see with this? Well, in T1, again, fat is gonna light up. And so this is fat, this is fat, and all this is kind of flat fat. In T2, fat and fluid is gonna light up. So this is gonna light up, this is gonna light up a little bit, but now you start seeing these disks, which is filled with fluid. And those are the ones that will also, you will see as well. And as I am going now, I'm gonna go and just go a little bit towards the middle. Now you're seeing this a lot differently in terms of what your, the structures. So this is kind of like the spinal canal that I was talking about. And you see the fluid over here, okay? So you see actually fluid from the fecal sac, and you see the nerves over here. Now here, you don't see the nerves as well because there's not as good of a contrast. So those are some of the things that you're able to see. Other things that you're gonna be able to see is a very thin layer here, which is the posterior longitudinal ligament. And you, for the most part, see a very thin, dark layer, which is the ligamental flavor. Again, other things you will wanna see in T1, remember fat lights up. This lighter area is the epidural fat, okay? So that's the area that you're gonna see a whole lot in terms of, that's where you will look for the fat, okay? And you just kinda, I just kinda wanna show you how you would usually see a nerve. And then here's another good example of a nerve and a nerve. Both of them are able to see, and they're wrapped up by the epidural fat there, okay? As opposed to a fat suppress sequence, I just wanna show you what that looks like. And if you just kinda scroll down, you see that over here, the fat that you see here is not there anymore with this. And all you see is just fluid, lots and lots of fluid. So this one draws a lot of contrast between fluid and non-fluid. I'm just gonna go through that, not too much more. I don't think I have to go through too much of that. The angle axials. So basically what you would see in the angle axials, and what are some of the things that you would wanna see, is the nerves, the discontour. Now, at this point, I am kinda up here. I'm actually near the vertebral. So this is the vertebral body. As I'm going down, let's see if I can go down a little bit, you can actually see, this is a T2 axial. And, oop. And then you can actually see the annulus fibrosis with a fluid level right here, the T2 right over here. So that's actually the nucleus purposus, and this is the annulus fibrosis, okay? And then you also will be able to see the spinal canal very, very well with the thecal sac. And within the thecal sac, you actually see little, little nerves right over here, okay? In the back, there's the ligamental flavum. In the front, you see the posterior longitudinal ligament. If you go a little bit further down, you're gonna see the facet joints right over here, okay? The spinous process over here. And you're gonna see, this kind of looks what you typically see for an angle, okay? Now, this is also a good example of the nerves. That's gonna be coming out right over these two areas right there, okay? This is the, again, the nerves, two nerves coming out. Kind of looks like a Mickey Mouse. A lot of people call this the Mickey Mouse look, where you have the thecal sac and the exiting nerve, or the about to exit nerve roots, okay. And then I just continue with that. Now, the other view that you also, that we have, that we use, and I have absolutely no control over this, about what our institution use. So you just have to kind of get used to as many type of views of sequences as possible. They use the proton density for the stack trials. And so what we're gonna kind of see is that, look at the spinal canal looks very different over here. And I meant the fecal side was actually very different over here. And then so the fluid is not gonna be sensitive, but you do see fat around it. So you actually see the epidural fat around this area. So you see that rim right over here, that's the epidural fat. And you see the two nerves that's gonna be, that's about to exit over here. And again, you see the facet joints and stuff like that. Those are kind of most of the structures that you're gonna see in this. I'm not gonna spend too much longer, but I just wanna give you a view of actually how it would look like if I just go from top to bottom, instead of just give you a picture of something. Now let's talk about this. Let's talk about degenerative discs. One of the things that you want to start with is, what exactly is, there's something called normal degeneration, and there's something called pathological disc degeneration. And I think what these folks from the combined task force is, which is like a whole bunch of people from the North American Spine Society, the American Society of Neuroradiology, and American Society of Spine Radiology, came up with a whole bunch of nomenclature. They try to differentiate between what these two phenomenons are. And so for the ones that are, what they consider to be normal aging, they call this spondylosis deformis. And basically the best way I can explain this is that you have degeneration from outside in. And what does that mean? So it means that most of the degeneration that occurs is in the annulus fibrosis first. And then you're also gonna have vertebral body apotheosis, so osteophytes over this area there. And then what else, how is that different from abnormal pathological disc degeneration? Well, abnormal is thought to start in the nucleus pulposus. And because it starts in the nucleus pulposus, it actually can cause things like disc space narrowing, fissuring into the annulus pulposus, into the annulus fibrosis, and end plate, which is what I was talking about over here, you get erosions. And again, this is thought to be more of a pathological, but very important, even though it's pathological, it don't always necessarily mean symptomatic. So that's a very important distinction between the two. So what are some of the findings that we're gonna be talking about? Well, we're gonna talk about the degenerative disc, and there's actually a classification for that. We're also gonna be talking about annular fissures, and also kind of like the high intensity zone. And we're gonna talk about those motor changes that a lot of people always have questions with. We're gonna talk about Smore's nodes, and herniations, and bulges. Just keep in mind that all these things actually can occur together, or in any combination of that in the degenerative process. So let's start. In terms of the classification for disc degeneration, now, the one that I think there's a few classifications, but the one that most people use is called the Fermi classification of disc degeneration. And of course, named after himself, which is very popular among some of the, a lot of the radiologists. But what they found is that this is a five point scale that goes from normal to most severe. The reason why I say normal to most severe is that at the last one, some people call it, I think it's very severe. Some people call it extreme. So I just call it most severe, but it's a five grade scale, and it has good inter or inter-rater reliability. Now, the only time that it's really may not be discriminatory enough is when you have somebody who is in the elderly population. And this study kind of said that it might not be discriminatory enough. Of course, this person came out with a eight grade scale, but then that's gonna be a little bit too much. So I figured this would probably, I'll just give you guys the five point scale. And the five point scale basically means you have somebody who has in T2 images, good fluid in the nucleus pulposus. And then in grade two, you have a little bit of a inhomogeneous state in the middle of the disc. And then now the grade three is when it becomes undistinguishable between or less distinguishable between the nucleus pulposus and the annulus fibrosus. And then grade four is when you actually lose it completely and you start having the space narrowing. And then grade five is when you have complete collapse of this space. So that's what the grading is. Now, one of the things that people are kind of like, would be like, okay, what's the correlation with low back pain? There's actually a correlation to it. And a few things I just wanna point out. If you have a negative disc or a negative, everything looks pretty normal. The likelihood of being that disc causing pain is very, very low. So the negative predictive value for low back pain is high, which means that 98%, which means that, like I said, if you were negative for that disc, if you have normal findings, it's unlikely going to be coming from that disc, which is actually very powerful because sometimes you'll be like, you see a patient who don't have much findings and you'd be like, well, it doesn't look like this is what's causing your pain. There might be other factors involved. As you probably all know, it is very prevalent in asymptomatic patients, subjects. And this asymptomatic, these, the prevalence actually correlates with age. The older you are, the more you get in terms of degeneration. But that's, you know, most people kind of end there. But now the question, is there a correlation of degenerative disc with low back pain? And the answer is definitively there is, but not so much. So you got to be very careful with what you say. These are some of the studies that I found that took a look at these things. If a patient had low back pain early and they saw degenerative changes, their likelihood of getting, worsening degeneration and herniation is significant. And these guys actually followed them for 17 years. So that's pretty a good, that's a pretty long longitudinal study. But these people are not associated with severe low back pain or any increased frequency of spinal surgery. So that's a good thing. It is probably more prevalent in patients with back pain compared to asymptomatic patients. And these are actually systemic reviews by these two folks that compare that. So keep in mind that there is an association between the two. And it's more likely, especially with this guy, this study, they compare patients that are less than 50 years old. So if you were less than 50 years old and you see discogenic low back pain or discogenic changes, then you're more likely to be a cause of the low back pain. Again, there's a slight positive likelihood ratio for low back pain. For anybody, if you were going to divide it into like different grades, for Furman grade equal or greater than three. So the higher it is, the more likely that you have a low back pain. And another interesting thing is that even if you don't have low back pain, if you have a degenerative disc grade three or higher, you are very, very low back pain in the past. Let's talk about annular fissures. Annular fissures are, some people call it tears, okay? But what they are is the separations between annular fibers and aversion of fibers from the vertebral insertions. So basically just fibers into this area. Now, one thing that we don't want to use anymore is the term tear. Again, they don't want to use the word tear because it denotes a lesion from a traumatic source. And you don't want to kind of use that and because not everything is traumatic. So if you did want to kind of look at these fissures, the fissures can have lesions in three separate ways. And this is kind of similar to what a meniscus tear can be like for knees, for those of you who want to make a correlation in that the tears can be radial, okay? The tears can also be longitudinal, which is like kind of like separation between the outer to the inner fibers. And most of the time, this is what most people think of is a radial tear, which is basically a cut, a slight, I mean, radial like that, and then a transverse tear. But most people think of these annular fissures as a radial tear. So this is the one that most people are associated with. And then within the annular fissures, there are this condition called high intensity zones. This is area of high intensity on T2 weighted images. And this is an example of what you will see right over here, okay? So this is a T2 image and you see a little dot right over here in the annulus. And that's what they call a high intensity zone. This was first described by these two folks in 1992. And you look at it through a sagittal cut. What they think is that it's most likely either fluid from an annular fissure or a granulation tissue from that. So what is the clinical correlation to that? Well, a systemic review or reviews noted that it's likely related to some, you know, have some pain aspect to it. The medium prevalence of this for people with low back pain is 39%. But there's also a good amount of people who don't have low back pain that has a high intensity zone. And then the mean T2 signal in patients was significantly brighter. So that's something that to be like, so how bright it is. And for the most part, for us who are just reading it, it's gonna be really hard to quantify this because we're not really seeing the best resolution of the MRI. So this might be something that you could use. Association with asymptomatic patients. Again, there is with the same study that was about degenerative disc, there is association of people who have had low back pain and with high intensity zone. For the most part, because it is still with this, there's still so much people without low back pain that has it, you may wanna classify a little further. Other aspects that was really, how does it compare to discography? Well, from what the thought is, there is a strong concordance of pain on discography in low back pain with patients to high intensity zone. And this is a meta-analysis that show that there was a strong relationship with people who have low back pain and high intensity zone for a reproduction of pain with discography. The one thing you really have to be very careful with is that this is like a very, I would almost like to say a classic study in the sense where you see a patient who is, these are patients who are asymptomatic who have high intensity zone. And amongst those patients, 69% of the patients have pain on discography. So that's something that I think you have to keep in mind that discography may not always be the answer to whether or not something is discogenic or not. And in terms of long-term, what we find is that they typically do not change or improve spontaneously in the large proportion. And if it does occur, it does not correlate with the patient's symptoms. So that's an interesting configuration. So now this is just another way of, I don't think I'm gonna be spending too much time on this because really this was only started, this new classification was only started in 2016. And there's really only been one study that really talked about this. And it's some of the same people. So probably not the most relevant at this point, but know that in the future, there's probably, there may be a further classification of a high intensity zone. Now let's talk about motor changes, end plate changes. What is the end plate change? Well, it's really a intervertebral osteochondrosis. Again, first described by, again, the person himself and they named that himself again. What is motor changes? Well, it's a likely combination of end plate disdamage, hyperloading and systemic factors that causes these motor changes, the bone marrow changes. And again, it's thought to be vascular granulation tissues with within subchondral bone. What you would typically do is to evaluate T1 and T2 sagittal cuts. So this is what motor looks like. So this is the bone marrow, okay, near the disc. And you would be like, there's a type one where they thought, mostly thought to be edema. And what is edema gonna look like? It's gonna look dark on T1 and bright on T2. In type two, it's gonna be fatty replacement. And what would that look like? It will probably look like bright on T1 and bright on T2. And then there's also type three, which is osteosclerosis. And what is that? When it's like basically when there's no fat, no fluid, it's gonna be dark in both T1 and T2. So this is a good example of type three. Properties of motor changes. What are they mostly found? As you're probably gonna see, just like discs in general, most are seen in L4-L5 disc and L5-S1 discs. Or vertebral levels. Amongst the three, type two is most common pretty much by far. It can often be seen in older people. Type three, on the other hand, is relatively rare. One thing that you also wanna know is that type one, there's a natural history to a motor change. And type one can convert to other types, most often type two. And all become more extensive, according to these folks. And what that means is really of unclear clinical significance. Now, what about clinical correlation of motor changes? Well, a systemic review actually concluded that motor changes is associated with nonspecific patients. Again, similar to the other high intensity zone, it is found in low back pain, but it's also found in asymptomatic patients, individuals. And the rate to which it depends on who you read, it could go be as low as 3.7 to as high as 44%. If you compare it to discography again, specificity of the motor changes up to 96 to 100%. So, and positive predictive value is up to 91 to 100%, which is pretty good. So that's a pretty good correlation. But remember that carriage study that asymptomatic patients can have a positive discography as well. So, and I don't think these guys studied that. The review concluded that it is unclear if are clinically important when guiding or prescribing the right treatment for patient with low back pain. What probably is more associated with low back pain is the type one change in the motor change. In multiple studies, they found there was a strong correlation between that and low back pain. So type one is what you kind of wanted to see if you want to see somebody with low back pain that has the strongest correlation. Other things, the study concluded that no relationship between low back pain, with or without. So really, having motor change or not having change, that kind of really change a medical or surgical treatment at 10 year follow up. So that's interesting to know. One thing is also is that this person kind of did a review again and found that there is, of all the studies, there's a lot of bias in the current literature. So take everything you say with a grain of salt. I guess that's what we're gonna have to try to do at this point. Now, in the motor change are considered to be for end plate changes, but there's also something called end plate defects. And the one that is actually most known to be an end plate defect is a Schmor's node. A Schmor's node is basically nothing more than a herniation into the vertebra. And the reason why you have that is because of a degenerative disc or a vertebral fracture. And when you're looking at this, you actually can see a sagittal cut on T1 and T2. And this is what you will see. This will be like a Schmor's node here and a Schmor's node there. Now, what's the clinical correlation? Well, for the most part, it is not much. Asymptomatic in most majority, and it also has a very strong genetic component. It's typically seen in the thoracolumbar region. So the interface between the thoracic and the lumbar region is where you see that. Symptomatic, what you do see is Schmor's node and you have a edema around it, like this patient right over here. You see that fluid, this is a T2C, you see that fluid, this is a T2 sequence. You see a Schmor's node, you see edema around it. That usually is more likely to be symptomatic. And you usually resolve, but these symptoms usually respond spontaneously. Now, in terms of the treatment, one of the things that you do, of course, you want to treat it conservatively first to make sure that exercise and things like that. But for those of them that do not improve with conservative treatment, kyphoplasty, vertebroplasty infusion may offer some improvement in some of these patients. In addition to Schmor's node, there's a whole bunch of other types of end-plate defects. And this is another one of those newer classifications that I'm not really sure what the clinical relevance is yet, but I just want to present that just because it is out there. The types of end-plate defects can be divided into focal, which is kind of like this, which is also known as the Schmor's node. It can also be a corner, which is on the side, which is more like degenerative in nature, and also erosive. Not really sure what the relevance of this is, but it kind of looks kind of wavy. So that's an erosive change. So far, I only found one study that kind of concluded that focal and erosive end-plate defects were associated with a lifetime back pain. And all three of these kind of type were associated with somebody who had had a significant episode of back pain in the last 12 months. So this was a recent study, so I thought I'd put that in there. So now let's talk about the standardization of nomenclature for disc mythology. Now, one of the things, again, I talked about the combined task force. This is the one that I use a lot in terms of how I would name something and nomenclature. And the way that they actually came out with two versions, version one, version two. In the initial version, this is what they came out with. The classification of disc goes from normal to sequestration. And then the herniations were considered to be these, focal protrusion, and then broad-based protrusion, extrusion, and sequestration. In version two, they actually decreased the, eliminated broad-based protrusion. I really couldn't find why they did it, but that's, you know, they kind of eliminated that. So, and I'm going to go explain what each one actually means. Normal versus bulging disc, okay. Again, the way that they kind of characterize this, the disc is divided into four segments. You can call it percentage, or you can call it degrees. If a bulging disc is considered a bulging disc, if you have, you look at the vertebral body, if the disc goes out more than, I would say, 25 percent. So, anything that is more than 25 percent that goes away from the size of the vertebral body, you have a disc bulge. And this is, there's two types of disc bulge. There's the symmetric disc bulge, where everything kind of comes out a little bit, and there's an asymmetric disc bulge, which is only partially coming out a little bit, okay. So, that's your differentiation. And in terms of, again, how you would see it, you see on, probably the best thing to do is to find a cut that is the vertebra, and find a cut that is in the disc. And you look at the vertebra size, and you look at the disc size, and clearly in this case, number two looks bigger than number one, almost diffusely. So, I would call this a symmetrical disc bulge. Now, what about, what's disc bulge in clinical correlation? And again, it's not as you think it is. It is very common in asymptomatic people, 52 to 81 percent in at least one level. So, that we know is pretty prevalent, and I think most of you know that. Increases with age, we also know that, you know, 30 percent, 20 years old, 96 percent. But there is maybe a small association with low back pain, especially for folks who are less than 50 years old. And again, this is the same review that I mentioned earlier. And there's an association between asymptomatic patients, again, with the study that I mentioned earlier, with a history of previous low back pain. So, they do, so disc bulges do have a clinical correlation to low back pain, present or past. Now, protrusion is a little bit harder to explain, and I'm going to try to explain the best we can. Again, with version two, they only mention focal protrusion. And what does that mean? Focal protrusion is anything less than 25 percent of the circumference, or 90 degrees. Now, if you measure, you measure two distances. One is the base, and one is things that are distal to the base. If the base is always high, more than the rest of the disc, then you have a protrusion. Okay? Now, in the past, in version one, they have something called broad-based herniation, or broad-based protrusion, and that's when it is between 25 percent and 50 percent. Unfortunately, I guess that has changed a little bit, and they don't consider that. So, now, if you see this, this will be considered an asymmetrical disc bulge. Hope that clarifies a little bit about what the difference is between the two. For the most part, clinical relevance is that it's very common, fairly common, in asymptomatic patients, and then it increases with age, just like a lot of the disc bulging. Again, it's more prevalent. I keep saying the same thing over and over again. It's like, younger than 50 is more likely to be symptomatic. Extrusion. Extrusion is, now, let's look at this again. How do you define extrusion? So, you take the same measurement between the two, the base as well as what's within the disc. If the base, then, is less than what is within the disc. If that is the base, that is considered to be extrusion. And why do you want to make that differentiation? Because what we find is that in extrusion, it is pretty darn rare in asymptomatic patients. This is, I think, an outlier, but most of them are, like, under 5 percent, 3 percent, and what have you. So, it's pretty darn rare, okay? And more, again, same thing, it's more prevalent in patients in low back pain under 50. So, that's a very good thing. So, now, let's look at it in the MRI. So, you look at the base right over here. This is clearly wider than the base, okay? Same thing here. You don't, now, for protrusion, you only look at the thing with the axial view. In extrusion, you can also look at it in the sagittal view. If you look in the sagittal view, look at this, you can have that, and then you have the, and you have, like, almost like a mushrooming of the disc, okay? So, that's an extrusion. And then, finally, there is a condition called sequestration, and that's when, basically, an extruded disc, that completely separates from the disc, from the original disc material. And, again, this is even more rare than extrusion, and in some, in one of the studies, it has not been reported in asymptomatic patients. So, if you see someone with an extruded disc, then you would have, then you would, basically, it's a very symptomatic finding, okay? And then, you know, remember I said about using stacked contiguous axials versus the angle axials? So, just imagine if I only did the angle axials for this patient, you will completely miss this disc. So, that's why you want to make sure that you do a contiguous axial, so you don't miss things like a sequestered disc material. In addition to the nomenclature for how the disc, what the name of the herniations are, there's also where the herniations occur. And so, and for these guys, they actually separate it into four zones. There's a central zone, there's a subarticular zone, which is actually the, underneath the facet joints, there is the foraminal zone, which is underneath the pedicle, and there's the extra foraminal zone, okay? The subarticular zone is the one that gets people most confused in terms of the nomenclature, just because a lot of people call this the lateral recess, and some people call that the posterolateral area. So, both of which, all three of them are still used very often, so you can use all three of them. In addition to the side-to-side location, there's also superior to inferior. You have your disc level, you have your infrapedicular level, pedicular level, and the superpedicular level. So, those are all areas that you can have a disc herniation to it. In addition, so now let's talk about herniations in general. If you have a herniation, okay, what kind of nerve would it damage, or what compression would it be? Well, if you have a central one, you will mostly affect the lower, this is like the alfalfa disc. If you have a central herniation, you're going to affect these roots over here. If you have what is the most common one, which is the subarticular or the posterolateral, then what you're going to involve with, you're going to involve the nerve root that's going to be exiting in the next neural foramen. So, in the L4 disc, you will affect the L5 nerve root. And the reason for that, the reason why you don't affect the L4 nerve root is because the L4 nerve root has already exited. Now, if you did have a foraminal herniation, you could impinge to a degree of the L4. And extra foraminal, sometimes it can go migrate, but that's very, very rare. That can also affect the L4 nerve root and maybe even the nerve root above and below, depending on how it migrates. So, in addition to the type of herniation and where it herniates, the other thing that you also want to be very important to see is whether or not it contacts the nerve. So, you look at this in an axial view. And basically, what you're going to look for is whether or not the disc is displacing or compressing the nerve, okay? So, this is the nerve, this is the nerve, this is the nerve, no nerve here. So, these are grades. So, these are contact with the nerve, this is displacing the nerve. So, you see that this is where the nerve should be, but it actually goes over here. And here, you're completely obliteration of the nerve. So, and what are these clinical correlation to it? Well, in general, going back to the lumbar disc herniations, most lumbar disc herniations occur at L4, L5 discs, okay? Just like everything about degenerative discs occurs in L4, L5 discs. And again, as I mentioned earlier, posterior lateral subarticular lateral recess, whatever you want to call it, is the most common location. If you did see a displacement of compression, that is actually relatively rare in asymptomatic population. And if you have that, it is helpful to differentiate between symptomatic A and symptomatic lumbar disc herniation. One thing that is like nothing that we can really do, because we are at the mercy of the radiologist, but if the radiologist does do a flexion MRI, they actually can see more nerve contact than does conventional MRI. So, that just tells you that just because something's not compressing, it doesn't mean that it's not necessarily symptomatic. So, one of the things that we want to also look at is, what are all these things mean in terms of longitudinal studies? Overwhelmingly, and overwhelmingly being the majority of the patients, lumbar disc herniations improve with conservative treatments. So, you have to, that is almost always the number one treatment. And what we also find is that the outcomes of these patients do not usually correlate with the herniation type, the size of herniation, or change over time of the disc. So, it's not like, so what you see in the, currently is not what the patient is feeling. So, that's really an important factor. So, you have to make sure that the patient is doing well. Again, what we know is that most of them, if we were going to do a meta-analysis, that 66% of all herniations actually spontaneously regress, okay. There are difference of opinion to a different study that says that some patients do not improve, okay, some herniations. And, but what they didn't do with these studies, they really didn't specify the type of herniations. And it actually can be important about what are the type of herniations that do regress, and the ones that do not. And what we find is that the extruded disc, the large herniations, and the sequestrations have a greater tendency of resolution when you compare to the other types of herniation and disc bulges. So, that's going to be an important factor. And a systemic review of this, of these regression is that patients receiving conservative treatment, a regression of like around 30% of protrusions and 77% of extrusions of sequestrations. So, there's a lot more people who regress with these two than protrusion. An interesting study states that if you did have modic changes, which is, again, putting everything together, you're like less likely to have spontaneous resorption. Not really sure what to make of that yet, but I just thought that was interesting to put in there. Another interesting thing is that there's these trials called the Spine Patient Outcome Research Trials, called the SPORT trials. And I think there are many hospitals, including locally around the New York City area, Hospital for Special Surgery, Joint Disease Hospital, those are all participating in these studies. And what they did was they looked at three types of things, herniations, spinal stasis, and spinal stenosis of surgical versus conservative interventions and kind of what their long-term follow-up is. And the only one I'm going to be reporting to you is about herniations, just because with herniations, they did talk about the types of MRI herniations. The other ones didn't really talk about, oh, I'm not going to be going over them, so I'm not going to talk about those. But amongst the herniation types, for all herniation types, both conservative and operative group had significant improvement of both back and link symptoms. For the ones that, if you were going to be treating them, you know, in terms of outcome, it's probably for patients who have less, you know, this is kind of like a, you don't really know what to make of it. People who are less than six months will do better than people who do more than six months. That's kind of like when you think about it, it's like another kind of a statement. But for all these people and with all these trials, they actually found that operative interventions had somewhat of a better improvement than non-operative care for both timeframes. So something to think about. Not sure if that's going to change your management, but it could, you know, to, but you also have to consider there is risk of surgery as well. And then if you were going to be doing surgery, if you had somebody who have herniations in the high levels, they did better than people who have lower levels. So that's what they found in that study. I know it was important to share. Now, if you were going to do a MRI, let's say somebody who has surgery, what would you do? Well, you're going to have to ask, add gadolinium. And the reason why you have to add gadolinium is because you want to see whether or not there is scarring or there is epidural fibrosis from the surgery versus a recurrent herniation. If you were going to see somebody with scarring, what that's going to do is going to look, there's going to be some brightness in the area after you put the gadolinium, the post contrast, as opposed to if you do it with somebody who had herniation, you're only going to see at most a rim of lightening or brightening, and the majority of which is going to stay dark. So that's how you're going to differentiate between a herniation from scarring. Other things you can use is the margin, the mass effect, and whether or not something is contiguous with the disc. And not something I would go into too much, but all right. So now, let's see, I just want to see, does somebody have the time? I don't have the time list. It's 12.58, so we only have a couple of minutes. Okay, so I'm going to just basically, I'm not even going to, I wish I would, all right. So you know what I'll do, I'm just going to continue. I'm not going to have the cases then, because then I would just want to finish with a few things, with the, unfortunately, I had four cases, but I guess I just lost a little bit track of time a little bit. So, but anyway, so I'm not going to go with the cases, but I do just want to talk about a little bit more about spinal stenosis. And basically, the spinal stenosis is a condition where there is symptomatic patients with low back pain that goes down to the gluteal region, or to the legs, that has, you know, that, and you could have, have without low back pain. The algorithm for spinal stenosis, when it comes to imaging, is again, similar to other things, is that when you fail conservative treatment, that's when you get it. So you actually do imaging when there's no improvement, but also like this, this author actually says, you know, refer to fasciatry for continuing non-surgical care. So I thought that was really nice. The thing about the spinal imaging is that there's often a mismatch between the two. Asymptomatic individuals estimate to be around 11 to 38 percent, and usually the images acquired, that under-recognizes because we're not really low bearing or anything like that. One thing about, again, I don't want to go too deeply into it, is that there is a lot of classifications. In fact, one study actually reviewed 27 classifications for lumbar spinal stenosis. So for the most part, that's not so good in terms of like how you would interpret what is considered to be spinal stenosis. And it also makes it very difficult for patients, you know, between diagnosed patients and radiologists, what they use in terms of the spinal stenosis. It probably is an ideal to have a combined, like something similar to what the combined task force is for the herniations. Spinal, so basically, I'm not going to go through too much of these, but what it is, is there's a few ways of looking at it. There's the quantitative way of looking at it, and there's a qualitative thing of looking at it. And basically, the quantitative is really not that useful, because there's not that many studies that actually use quantitative lumbar spinal stenosis. Most of them probably use qualitative, and those are the ones that are usually, that are used most of the time. And when I mean qualitative, they basically would be like mild is like less than one-third, moderate is one-third to two-third, and severe is greater than two-third. There is a consensus conference that came about, but there's nothing that came too much about afterwards. So I'm not sure what to make of these guys' recommendations, but they did look at it, and four were chosen for how to evaluate lumbar stenosis. And these, or three of them, actually, to evaluate central, you just have to kind of compare whether or not, how much bunching there is with the nerve roots for the subarticular area. You just want to see whether or not there's any, by like one-third, two-third, and three-third of how much compression there is. And for the foraminal, it's actually the same as the Furman classification. Dr. Ma, I'm going to have to jump in. We're over time. Okay. But this has been phenomenal. Thank you so much. Oh, no problem. We'll look for an opportunity maybe to have you finish this lecture. This has been really good, and I think we have plenty to learn here. Yeah, so I guess if you have time, that's great. If you want me to finish it, you know, I'll be more than happy to talk about this at a different time. Okay, I will, we'll reach out to you and see if we can set something up. Great. Unfortunately, we have to wrap up before today. Okay. All right. Thank you again so much. We appreciate you joining us. Again, this has been a phenomenal lecture. I don't know if you can, there we go. All right. But thank you. So if people have questions, can they reach out to you directly there at your Twitter handle? Yes, absolutely. Or you can do my email rex.ma at gmail at ba.gov. So there's, yeah, I had in the beginning of the slide. Thank you so much. We appreciate you so much joining us today. And we will reach out to you directly and see if we can facilitate the rest of this lecture. I think it'd be, I think it'd be fantastic. Very good. All right, everybody. Have a good day. Thank you. You too. All right. Thank you.

MRI evaluation

lumbar spine

disc degeneration

disc herniations

protrusions

extrusions

spinal stenosis

conservative treatments

surgical interventions

clinical relevance