Hello and welcome to the Cervical Spine Imaging Interpretation session. We designed this session to help early career physiatrists or any interested physiatrists review basic cervical spine imaging concepts. At a lot of these conferences, we spend a fair amount of time discussing zebras, case presentations and disease pathologies that are interesting and rare, but luckily don't actually come up that often in our everyday practice. After all, when you hear hoof beats, you should be thinking horses and not zebras. And I think I particularly enjoy coming to the annual assembly because AAP Mar does do a good job of organizing sessions that feature exotic as well as the mundane. And in this presentation, the co-presenters and I really hope that we can help to re-familiarize yourselves with the appearance of classic cervical spine pathologies. And we want to help you recognize horses, even if they're dressed in tweed suits. And especially we want to re-emphasize the radiological findings that you should be looking out for when you're considering discogenic, physiogenic or radicular pain. So brace yourselves, get on your cowboy hats because a stampede of horses is coming your way. I'm going to get us started with just discussing when and how you should be ordering your MRI cervical spine, perhaps as a spine modality that physiatrists most often order in our patients. And I'll be sharing with you the frameworks that I use to systematically review the cervical spine MRI. My name is Patricia Zheng. I'm assistant professor of clinical orthopedics at the University of California, San Francisco, and I have no disclosures. So in fairness, we're going to be discussing MRIs of the cervical spines a lot today, but they're not the only modalities with which you can evaluate the cervical spine. Of course, there are x-rays, which are easily obtained in the office. And technically, theoretically, they can help us evaluate for fractures and alignment, though obviously, CTs might be better for that. To me, x-rays are really good for dynamic evaluation. So if you want to see how the patient's spine is stacked when they're upright and when they're facing forward, that's helpful. My surgical colleagues like to use flexion extension films. So you can actually see if the adjacent vertebral bodies actually slip when the patient bends forward and backwards. And that's kind of a sign of instability that may need surgical correction. As I kind of mentioned, CT is somewhat better for alignment and for looking for fractures because it really shows a bony anatomy. Obviously, when the alignment problem is so large, like what you see in this picture, I hope you can appreciate that with any modality. But because the cortex is so well-defined in a CT, it's really easier to find fractures this way. And so here you can see a type 3 addundum fracture on the CT coronal image. As physiatrists, we're mostly non-operative, so we don't tend to see a lot of acute fractures or malalignment problems. And that's probably the reason why most of us spend the majority of time ordering and interpreting MRIs of the cervical spine. The MRI is really good for showing us the soft tissues of discs, nerves, cord, ligaments. It can show us if a process is replacing the bone marrow, something like multiple myeloma or metastasis. Actually, MRI is even more sensitive and specific for occult fractures because we can appreciate periosteal or adjacent soft tissue edema. And of course, if you're looking for infection or malignancies, MRIs are very, very helpful. There's two questions that were often asked about MRIs. So one of them is, when is it not safe to get an MRI? As you can imagine, the magnetic field of a 1.5 Tesla magnet is about 30,000 times the strength of the Earth's magnetic field. So if there is an implanted device or a foreign body that's susceptible to this magnetic field, they can be yanked out of the patient. And if you have any questions about whether your patient's particular device or hardware is MRI compatible, of course, it's helpful to talk to your favorite radiology tech or radiologist. But what do you do if it's 501 and you go down to the radiology cave and it's entirely dark and empty? Well, there are some websites out there, including this one, MRIsafety.com, where you can actually type in the patient's device, and it would actually tell you if it's MRI compatible, or if you might need to use, say, a lower strength MRI, like the 1.5 Tesla instead of the 3 Tesla. Because the MRI takes about 35 to 40 minutes to actually accomplish, it's not really possible for unstable patients. At my center, pregnancy is kind of a little bit of a relative contraindication to MRIs. Of course, there's no radiation involved in MRIs, but we do have to disclose to the patient and document it at our center that there may be yet unknown effects on the fetus. And if you are wanting an MRI with contrast, then, of course, there is risks and benefits associated with that. And all MRI scanners have weight and especially width limits. And so, especially for your more current patients, we might have to consider alternatives. And one alternative might be something like a CT myelogram. So in this, you actually perform a lumbar puncture and instill contrast right into the fecal sac. The patient is then placing a reverse Trendelenburg position. And hopefully, through the CT, then we can visualize if there's any significant stenosis around the canal or the neuroforamen. The other question that often comes up is, when should I order an MRI with contrast? So that could be very helpful, the contrast. If you're looking for a lesion that's a little suspicious for neoplasm, contrasting a case of looking at infection can really help to differentiate whether a flu collection is an abscess. And because often after surgery, you know, we are concerned about infection, or if the surgery was for neoplasm, we're concerned about whether we got everything we should. Often, right after surgery, MRIs are ordered with contrast. So if you're months and months past, and you're not concerned about infection, you're just wondering about a decompression. Sometimes at that point, contrast is no longer needed. And if you're looking at a lesion in the cord, you should obviously talk to your friendly radiologist, but MRIs with contrast are very useful for that. Because MRIs are so complicated, it's helpful to keep a framework in mind when you're interpreting your MRI cervical spines. The one that I use myself is ABCD, and apparently because I'm really bad with alphabets, F. A is of course for alignment, you probably don't need an arrow sign or specifically MRI to tell that something's really severely wrong here with alignment. B is for bone. What per wisdom a radiologist shared with me is that on T1, the bone marrow signal should actually be brighter than that of the disc. And so here you see a lot of very dark bone marrow signal, and this is actually a case of unfortunately a very diffused metastasis. C for me is canal slash cord, and it's good that they both start with C because you tend to look at them together. So here, when you see that there's significant spinal canal stenosis, you want to make sure to look at the cord and see if you can see any evidence of myelomalacia. Of course, sometimes the canal can be patent, and you might still spot something odd in the cord. This is a patient actually of mine. He was very young. He had axial neck pain. This MRI was actually read as normal, but when I was taking a look, I was like, is there actually an intramedullary cavity there that's a little bit larger than normal, maybe concerning for a synrex? Luckily, the patient is neurologically intact. There was no evidence of chiari malformation. Neurosurgery took a look and really thought this was just a prominent central canal. What we're looking for in a cord is, of course, also any evidence of myelomalacia like we see here in a patient who unfortunately became really super therapeutic on warfarin and developed a very large compressive epidural hematoma. This is actually some months after his decompression surgery. He unfortunately still has a chronic epidural fluid collection, but you can see right there where the arrow sign, what is actually called a snake eye sign on the axial cut, so bilateral symmetric ovoid foci in the anterior horn cells, and that's kind of pathognomonic, can be indicative of compressive myelopathy. D is for discs. Most of the time as physiatrists, we're looking for disc herniations, but of course, you can also see things like tuskitis. Here you see erosive changes around the disc space, and there's a lot of marrow edema on both sides, and you can actually see fluid in the disc. F is foramen, so I tend to look at my discs and the neuroforamen on both sides at the same time, so you can see here there's a disc protrusion that's extending into the foramen there, and here you can actually see this patient had an outside scan, and they actually did a bleak cut, which really evaluated the neuroforamen well. You can see that the disc actually protrudes into the foramen itself and likely is accounting for the radicular symptoms, so that's kind of a whirlwind tour of the algorithm that I use. It's rather basic and bare bones. I hope this review was helpful for you. In general, when I was looking, I don't think there's a lot of online journal articles that are particularly good for reviewing MRI algorithms for MRI review, so I would actually recommend these two book sources if you have access. Of course, if you have any questions, please feel free to email me, and with this, I'm going to pass this presentation to Dr. Byron Schneider, who will be taking you through his personal setup for MRI cervical spine review. Hi, my name is Byron Schneider, and I'm going to go over a nice quick review today on a systematic way to go through a cervical MRI in a relatively normal image. I have no relevant disclosures. Quick review on T1 sequences, fluid is dark, fat is bright. T2, both fluid and fat are bright, and on stero fat suppressed images, fluid is bright, but fat is now dark. So the algorithm A is for alignment, looking in the sagittal plane predominantly in both T1 or T2 sequences. B is for bones. I typically will scan through in the sagittal plane. You want to look at both T1 and T2 sequences with the highest concern for any lesions that are hypo intense on both, and if you see any abnormalities to cross-reference with axial sequences. C is for the cord. You'll do this in the T2 images on the sagittal and axial views, looking for any evidence of myelomalacia or cord edema, which will obviously be bright on T2, and if it's edema dark on T1, then you can cross-reference if needed. D is for the disc. You scan in the T2 sagittals initially, and you can go through axially as well to better characterize any disc herniations. E is for the exiting nerve roots. This is most easily done in axial T2 view, although some cervical MRIs now have oblique films at which you could use these oblique sequences on a T1. F is for the facet joints, easily done in T2 sequences, both axial and sagittal planes. G is for the gutters, looking for any abnormalities in the surrounding soft tissue, such as atrophy or sarcopenia. H is a reminder to look at historical images for comparison, if available, and I is for inflammation, which you can do on STIR sequences, again, both axial and sagittal planes. So as I pull up the MRI here now, as you see here, we have a nice T2 sequence, which allows us in the sagittal plane to evaluate alignment. The posterior edges of the vertebral bodies are largely contiguous. There's no significant listhesis here. As you scroll back and forth, they all seem to be in the same plane, suggesting that there's no scoliosis either. So the alignment here looks pretty good. Next would be bones. Since we're already here, we can start in the T2 sequence again, looking for any hypo or hyper intense lesions, which are not evident. You can scroll back and forth. You don't want to miss anything that's off of midline. With the focus on the vertebral bodies, though, rarely you'll find something in the posterior elements, even in the cervical spine. So there's nothing there on the T2 sequences there, so we don't necessarily need to cross-reference with any T1 sequences. Next would be the cord. So you see a nice homogenous signal throughout the cord here, no evidence of myelomalacia or edema. Again, scrolling back and forth. Then now is when you want to pull up your axial sequences on T2, looking for any evidence of what is sometimes called snake eyes, or two little bright spots within the cord. Again, evidence of myelomalacia. And there's nothing here of concern either. And this is STIR sequence, so any edema would have been even brighter than normal. So moving on from the cord, you now want to look at the discs. Pulling up a T2 sequence, again in the sagittal plane, you can scan back and forth. If you're looking at disc morphology, you do see a little disc herniation here, which we can better characterize on the axial plane, although even here it looks like it might be extending inferiorly somewhat. If you're looking at the disc quality, the nucleus should be quite bright. It's fluid-filled compared to the hypo-intense or dark annulus. And note, you want to compare the signal of the nucleus propulsus to the signal of the vertebral bodies, as these should also include marrow. So on T2 sequences, they should also be quite bright. And if they're dark, that may be of concern. Coming now through on your T2 axial sequences to look at the discs, we can start at the C2 here. And as you scroll down, a normal cervical disc will look somewhat like this. You might not get the scalloped appearance in the lumbar spine. As we scroll down, you see here this small central protrusion indenting the thecal sac. There's no evidence of cord signal change there, so not much to be worried about. You can continue to scan all the way down, and there's no other disc abnormalities at any level. As for the exiting nerve roots, we can stay in this imaging sequence here and simply scroll back up. At a normal level, you'll see adequate space between the facet joints and the vertebral body or the disc on both levels or both sides for the nerve root to exit. So as you scroll up at every given level, you want to keep an eye out for the exiting nerve roots and the foramina to make sure there's adequate space. You'll also note here you see entrance of the vertebral artery as it courses up just anterior in the foramen. So at every level here again, the foramina are all patent when you get up to C2, so you're done looking at the exiting nerve roots. F is for the facet or the facet joints. You can simply scroll back down again if you want to look at the joints. In a young healthy person, the joints are going to be small. There won't be any effusions within them, minimal osteophytes. As you scroll down, you just want to keep an eye on each joint, at each level, on each side, looking for any pathology, any cysts, anything of that nature. And again, this is a relatively healthy spine with no significant pathology. You can then pull up your sagittal sequences again, and if they went out far enough lateral, you can now look at the facet joints. They're not totally imaged here. And scroll over to the other side. Unfortunately on here, we don't see any great anatomy, but when we come back to look for any abnormalities indicative of facet edema, we may get a better view. G is for the gutters. You can do this in the axial plane predominantly, either T1 or T2, looking for any sarcopenia or muscle atrophy. At times, you or the radiologist may note any cysts anteriorly in any of the other organs. But you see symmetry here. You don't see any increased signal within the muscles, and there's nothing to worry about here. Another thing you can do if you're planning any procedures while looking at the gutters is to draw your attention back towards the vertebral arteries, especially if you're doing a transforaminal injection, and look back up. These are nicely located in the anterior part of the foramen. H is for historical images. We don't have any to compare to. And lastly, I is for inflammation. So if you pull up a STR sequence now, so here we see the fat has now been subtracted out, and it's dark. So any fluid where it should not be will be bright, indicative of potential pathology. So that may appear in the presence of hemotic changes, so any edema in the end plates, which are not present here. Scrolling more sagittally, you can look at the facet joints to see if there's any edema within the joints or in the C1-2 articulation. Come back to the other side, and again, there's no edema within the joints or the C1-2 articulation. If you wanna be extra careful, you can scroll through in the axial sequences, again, looking for anything bright that will jump out at you, which you don't see here. I think the last two things to quickly mention, although they don't fit perfectly into the algorithm, if you are doing procedures, you may wanna pull up your sagittal sequences to evaluate the presence of any epidural fat in the interlaminar space. So this young healthy person has minimal epidural fat, but there still should be adequate room to perform their procedure. And lastly, if there's any evidence of, or concern for any problems in the upper cervical occipital junction, you may wanna look at the PANAS and make sure there's not any enlargement there. So there you have it, a quick, easy way, systematic approach to reviewing a normal cervical MRI. Thank you very much. Thanks very much to Patricia and to Byron for setting the stage for this talk. I'm Zach McCormick, I practice at the University of Utah, and I will talk about cervical radicular pain due to neurofibrominal stenosis. These are my disclosures, there are none that are relevant specifically to what I'll talk about today. So this is a personal patient of mine who I've seen for the last few years. She is 61, she had a remote cervical fusion, C6 to C7, and also pseudoarthrosis. So when I initially met her, she'd been having chronic neck pain for some time, right periscopular pain with radiation to her forearm, as well as all the way down to her thumb. She described pain that was worse with prolonged sitting, especially head forward, shoulder forward posture, better with standing and walking in general. She didn't describe any particular difficulties with fine motor skills, buttony buttons, grip strength, things like this, and didn't describe any balance or gait changes. She had tried quite a bit of conservative care over the years, as well as other interventional care by the time she got to me, but multiple courses of physical therapy, various activity modifications, a variety of medications. Certainly I did not put her on the somahydrocodone combination, but she came to me with those medications, that regimen. When I examined her, she was pretty restricted, but overall had a fairly normal neurologic exam, actually negative spurlings, interestingly enough. So here are the x-rays that we obtained. So our AP view, and then our flexion extension views. You can actually see that there's a broken screw on that AP view, and you can appreciate it as well, and the C6 vertebral body on the FlexX views. And you can also appreciate that there's not a lot of new bone formation between C6 and C7, the vertebral body. So there's the pseudoarthrosis, and I'll show you a spec scan as well. Helps confirm that. And she's lost quite a bit of disc height at the adjacent segment, cephalad, to the C6 fusion level. So here's her CT spec scan images, and we see that there's certainly some metabolic uptake at the end plates, at the C6-7 level, the level that should be ideally fused, but this is her pseudoarthrosis. So now we'll move along to her MRI images. These are her T2-aided images. You can see in the left panel, these are the sagittal cuts with the scout line shown as the white horizontal line. In the right panel, you're seeing the axial cut that corresponds to that scout line. So as we make our way down, here we're at the C2-3-3-4, that's the 4-5 cervical disc. And as we move down towards the C6-7 disc, there we are. As you look at the neuroforamen on the patient's right side indicated by the red arrow, quite a bit of foraminal zone narrowing from a broad disc osteophyte complex. And as we continue down to the C6-7 level, so a little bit of central canal narrowing from that disc, but ultimately the foramen is open. So ultimately looking at this, it seems like one more time through it. So here's that 4-5 disc, pretty open foramen on the right. Here's that 5-6 disc, quite a bit of narrowing. And then again, the 6-7 disc level, fairly open. So indicative of the fact that this is consistent with C6 nerve root compression, that C6 nerve exiting at the 5-6 foramen. And then if we look at the oblique cuts, make our way over. So again, if you take a look at the oblique cuts panel on the left, you're seeing that oblique view, you can see the scout line in the right panel in this case on the axial image. And you get a sense that that disc osteophyte is really narrowing the foramen hard to even make out where the nerve root is until we get a little bit out to the outer margin of the foramen. So again, if I move back towards the central canal, and then one more time through the foramen, it gets very, very narrow until we get outside the foramen. And then we can actually see the nerve root exiting. Okay, so cervical radicular pain and due to neuroframedal stenosis. So incredibly common. And this is usually the situation that we see, not so much necessarily the patient with fusion and pseudoarthrosis and some of the things that made this particular patient a little more interesting and complicated, but the presence of a disc osteophyte complex and perhaps a degree of bony narrowing from a facet joint. Much more likely to be the case as opposed to herniated nucleus pulposus, which would be perhaps more common in a younger patient in the lumbar region. And this is gonna present with neuropathic features. So generally, potentially neck pain, periscapular pain, pain in the arms, of course, gonna depend on the nerve root affected. We can look for dynamic instability. This patient in particular did not have, did not specifically have dynamic instability, but we tend to look for this. Does influence decision-making on our X-rays. And then as we heard about from Dr. Zhang and from Dr. Schneider, MRIs, typically the test of choice, obviously to make this diagnosis. In cases where MRI is contraindicated, as we heard more about from Dr. Zhang, CT myelogram becomes the backup option. So management, generally we think about obviously more conservative therapies first. In physical therapy, every patient's gonna be a bit different, but we often will trial things like nerve glides. We'll trial cervical traction. We'll work on posture and ergonomics, head back posture, shoulder back posture. NSAIDs and neuropathic pain agents may be helpful. We certainly may try epidural steroid injections depending on a patient's response to non-invasive care. And then ultimately, if nothing is working, surgical decompression has become an option. So a little bit about epidural steroid injections. This comes from a recent systematic review from our group at Utah. Specifically looked at the effectiveness of cervical transforaminal epidural steroid injections. You get a sense of the published studies here from this table. So as low as rates, success rates in the high 20s, just highest success rates in the 70s, depending on the study, when success was defined as at least 50% pain reduction. These are forest plots. And really the outcome literature only informs us about outcomes at one month and three months and there's much less study of the effectiveness of cervical transforaminal injections beyond three months. But you get a sense here, these are studies that use particulate steroid. So of course we no longer use particulate steroid in cervical transforaminal injections, but this is a layout of the studies. And then you can see the diamond at the bottom of the figure showing the overall composite responder rate across the studies. And this is actually studies where dexamethasone was used, so non-particulate steroid, which would be consistent now with current clinical practice guidelines and safety. You get a sense here that interestingly, actually better results, at least in these studies, with dexamethasone compared to particulate steroid sort of goes against conventional wisdom to some degree, but this is what the literature shows us. So again, that diamond at the very bottom of the forest plot showing the composite responder rate a bit above 50% of patients reported at least 50% pain reduction. And that was essentially the conclusion of this systematic review, was that about half of patients experience approximately 50% pain reduction up to three months, but we really don't have great data beyond that. And the level of evidence is actually very low according to graded criteria, mainly because we don't have sham control trials and the comparative pragmatic trials that we do have, they compare epidural steroid injection with one agent versus another, but not compared to the usual care. So ultimately not the strongest evidence-based, but that's what we have to inform us. What about catheter guided injections? So this is another approach that can be used. You can see here, this is a C7 T1 interlaminar access within catheter advancement and the lateral recess on the patient's left side. Patient isn't prone here, obviously. And you can see die flow exiting the C6, C7 foramen there. So targeting the C6, excuse me, C7 root. So we took a look at, this is a randomized trial that we conducted a number of years ago comparing the catheter-based targeted approach to a usual simple C7 T1 interlaminar injection without a catheter. Take home from this was that we did see a trend towards improved outcomes or greater likelihood of reporting successful pain relief, at least 50% reduction in the catheter group compared to the group that had a standard C7 T1 interlaminar injection. But ultimately this did not reach statistical significance at any time point that we measured. And then similar outcomes with regard to function, global impression of change and medication reduction. So trends towards favoring the catheter group, but not statistically significant. And then finally, this is a study that we published more recently looking at targeted catheter-based injection with particulate steroid compared to a dexamethasone-based cervical transfemoral injection. So really a pragmatic trial where of course it's safe to use particulate via the catheter approach, not safe via the transfemoral approach. And these are tornado plots and they're a bit small, but what you can see is in the upper left-hand panels, this is catheter versus transfemoral with regard to dominant pain, meaning whatever was greater between neck or arm pain. That's A. And then in the B panels, you can see the same comparison, excuse me, for neck pain specifically. The C panels are for arm pain specifically. And then finally you see NDI, so functional changes comparing the two groups. And what you get a general sense of is, this is at six months, there do seem to be more responders in the catheter group. But again, like our other study, this did not reach statistical significance. So it seemed that maybe there was a subtle advantage to the catheter versus the transfemoral approach, but not statistically significant. So ultimately back to our patient, when we saw her, we ultimately did trial a cervical transfemoral injection. You can see the oblique view, needle entering posterior inferior foramen there. Then over to the AP view, a bit of contrast outlining exiting nerve root. And then of course, this is the DSA or digital subtraction imaging run. Of course, these are live runs. I'm just showing you snapshots, but you get a sense that there's no vascular uptake and that we are highlighting that exiting C6 nerve root. So this is a complex patient. We continue to manage her pain through multimodal strategies. But here are key points just to take with you as summary items. And thank you very much. I will pass the virtual microphone over to Dr. Pobescu. Hi, thank you, Dr. McCormick. Thank you, Dr. Zhang, Dr. Schneider. I'm gonna try to discuss the cervical discogenic pain along with some clinical cases these protrusions and extrusions. I work as faculty at the University of Penn in the Penn Spine Center. And I'm enjoying every day working with the fellows and our residents. No significant disclosures for this talk. And this is my favorite quote from Dr. Conant who was transformative for higher education in the United States. You can read more about him. So cervical discogenic pain is really a very, it's a zebra and it's a horse, but better recognize both of them. Because really we don't have clear diagnostic criteria for discogenic pain syndrome in the cervical spine. What do we need to know? What do we need to do? Do we need to route other more evidence-based structure finding, pain finding structures? Or do we need to use the dynatomal maps that were described by Dr. Slibman and Dr. Plasteris in 1998 doing diagnostic blocks? And, or do we need to assign as discogenic pain for other pain generators like vertebral body end plates? And we need to know that regarding the zebra or the horse that we find, we need to realize that can influence further treatment. Let's talk about the cervical intervertebral discs that are really different than the lumbar discs. The annulus is not concentric. The annulus is well-developed only in the anterior disc. Remember the cervical disc herniations occur posteriorly in the spinal canal. An annulus serves more of an interosseous ligament rather than a constraint to the nucleus. So even a cervical discography study done correctly, it might be difficult to interpret for interpretation. The age changes in the cervical intervertebral discs are different than lumbar discs, right? The nucleus past the second decade is a firm, dry fibrocartilaginous plate. The internal fissures are normal structural findings with age, and they might be found in asymptomatic individuals. So the cervical disc participates less in load-bearing, nuclear annular structure is less well-defined, and you don't have a true posterior annulus. And the cervical spine innervation might help to understand the pain generators with utilizing diagnostic blocks. Let's set boundaries. It seems that that's the hardest thing to do nowadays, to set boundaries. And in this view, we have the uncinnate lines, which are the red vertical lines that delineate the lateral borders of the spinal canal. You see the uncinnate lines as a yellow, uncinnate processes as a yellow border on the image in the middle of the field, which is a CT myelogram of the cervical spine, also on the cadaveric axial section. Here's an example of how those uncinnate processes look on an MRI of one of our patients. So you need to identify those, and you need to identify where in the spinal canal the discernations can occur, and most of them occur in between those yellow lines. The morphology and nomenclature we borrowed from the lumbar spine. It's a borrowing proposition, right? So it's not specifically developed for the cervical spine. And let's make sure that we understand what's the difference between a soft cervical disc herniation versus disc osteophyte complex, and why? Because the soft disc herniation has a very positive and very favorable natural history. On the left side of our friend here, the PMR bold green shirt friend we have, on the top of the screen, a soft disc herniation in an MRI axial view that shows a brighter on T2 images of the disc, which is a right paracentral disc, and the bottom image with a dark arrow shows no osteostructure within that disc. As opposed to the pictures on the right side of our little friend there, we have the top image of an MRI in axial T2 that shows a disc that is dark, which collaborates with the CD scan and the bottom of that picture on the right side which showed an osteostructure, so that's a disc osteophyte complex. And again, natural history is favorable to solve these herniations, but for amyloid stenosis and radicular pain is most frequently caused by disc osteophyte complex. This is a lady, a very successful executive, she's 41, developed the right C7 radiculitis with severe shoulder blade pain, and you can see this is our T2 weighted nonfat suppressed images on the left side is a sagittal, mid-sagittal, on the right side is an axial view, you see a small disc protrusion, that's a central disc protrusion, not affecting the cord. If you go down on the scan, you see on the right side axial picture, you see a disc extrusion because the base of the disc is smaller than the larger diameter of the disc extrusion or like herniation, and affects the C7 nerve root. She, and this is just a parasagittal view, so on the left side of the screen you see the parasagittal view, right parasagittal through the disc, so how it indents the fecal sac. The rest of the scan seems normal and you start wondering how do you know for sure that that's the pain generator for her mid-scapular pain, and one way is to determine if blocking the C7 nerve root at C6-7 for AMEN gives you complete relief. Maybe that was what Dr. Slibman and Dr. Plasteras wanted to determine with their study at Penn in 1998 that the C7 nerve root, when it's affected, you have posterior upper trap pain, you have posterior shoulder pain, you have mid-parietal scapular pain, so that's an option and that's what we did as a first step because everything else really did not work for this wonderful person that couldn't even sleep at night because of her pain. She had two days of good relief after a right C6-7 transpiraminal injection, you have the image on the left, and then she received an intralaminar injection at the same level which is, I would say, rarely done at that level and that happened in August 2018 and as a couple of days ago she still did not need further treatment, surgery, medications, physical therapy, chiropractic care, so no expense after the second injection. So maybe we were just able to manage the acute episode of pain. This is a nice gentleman that started to develop left shoulder blade pain severe while on a golf course and had seen a concierge physician, a pain specialist, and had some trigger point injections, some medications, had an MRI of the thoracic spine that was read as normal, and had two thoracic intralaminar injections for that mid-scapular pain. We saw him in the office and the only abnormality was some tendon gait difficulty, otherwise no Hoffman, no Clonus, and the x-ray did not show instability but the MRI of his cervical spine showed some quite interesting findings at the C6-7 and you see are coming on the right side of the screen, a disc extrusion compressing the spinal cord and you see a very dark signal. The spinal cord is actually very uncomfortable, I would say there. The good news is that he had no signal abnormality below the level of the spinal cord compression, so that means that we caught this fairly acute and, you know, we decided that that might be a good idea to pursue the appropriate treatment, which is not something that a physiatrist can offer. This is an extension of the disc extrusion inferior or called up to the C6-7 disc and that was the treatment, and after the treatment he had no need for further medical care. This is just another example of a horse, where our horse this time was a very pleasant, unbelievably hard-working nurse that works with us that had pretty much three or four visits, two visits to the primary care physician for a left shoulder blade pain and arm pain and nothing really worked for her. We can see on the right side of the screen a left almost pyramidal disc protrusion and affecting the left C7 nerve root. Again, she had shoulder pain that bothered her the most and neck pain. We suspected that's the source of her pain and we need to manage the acute episode knowing hopefully that, you know, the natural history might be favorable for her, and the rest of the spine looked fine. Of course, she got an MRI of the thoracic spine in the emergency room because she had mid-scapular pain. Well, probably she did not need that. She received one procedure and that procedure was performed in 2018 in October. Since then, she takes no medications, no physical therapy, and works every day. She's a productive member of our society. So the question is, do we get lucky or do we know how to identify these very common findings as disc herniations and know how to manage the acute pain? Because the expectant treatment shows that there's a favorable history to soft disc herniations and any medications can only temporize the effect. Of course, the patients need to follow proper ergonomics, avoid end range motion exercise, trial of cervical traction, and sometimes the injections can get the patients over the hump. And we need to remember that the best data for spine surgery comes from a one-level disease, one-level ACDF or artificial disc replacement. Again, natural history is favorable to soft disc herniation. This is a take-home point. We do have controversial diagnostic criteria for cervical discogenic pain. Most common lesion for cervical radic is a pyramidal stenosis, unconvertible facet hypertrophy, loss of disc height, and your diagnosis can influence procedural decision-making. Again, we as physiatrists are the quarterbacks of spine care, so know when a patient needs surgery. Thank you, and I think Dr. Sturos will take it on from here. Thank you. Thank you. For this portion of the talk, I will be focusing on cervical zygapophyseal joint pain. I have no pertinent financial disclosures. The primary objective is to identify cervical zygapophyseal or Z joint degenerative changes on imaging that may help guide spine interventions. I will go through some background data to set up three patient cases with imaging and then hopefully tie it back together with a few general take-home points. To start, we will briefly discuss how Z joints are graded or described on imaging. It begins with Kellgren and Lawrence and their Sentinel paper illustrating osteoarthritis on plane radiographs in the 1950s. They used a four-point grading scale with one being the least and four being the most severe, as shown in the table taken from a review by Kettler et al. in 2006, which looked at existing grading scales for degenerative changes in lumbar and cervical spines. As you can see, this is a qualitative scale of varying degrees of osteophytes, subchondral sclerosis, and joint space irregularity. This original grading system has been slightly modified and expanded more recently to cervical CT scans with the goal of being more quantitative in one study and easier to use in another. And there really isn't any validated grading scale utilizing MR imaging currently. So once we're able to describe Z or facet joint arthrosis on imaging, does it correlate with pain? In a study looking at 500 cervical facet joints on CT that were obtained for non-spinal reasons, 33% of all joints were found to have arthritis, although 57% were considered mild. And this graph nicely depicts an increase in prevalence with age, which is not surprising but important to keep in mind. In symptomatic patients, cervical facet joints have been described as a etiology in chronic axial neck pain in 25% to 66% of patients in a 2008 review and in 50% to 60% of patients after whiplash injuries. So more specifically, and to help increase our pretest probability when thinking about these injections, we can add our knowledge of pain referral patterns from cervical Z joints and the prevalence data broken down by levels. So on the left here is a figure from Dwyer et al that shows the provoked overlapping pain locations, which has been shown in follow-up studies to correlate positively with responses to diagnostic blocks in the expected levels of painful joints. So this article describes 134 patients with symptomatic facet pain, and they found most commonly symptomatic levels were C23 at 36% followed by C56, and then C67 with 17%. Other joints were found to be less symptomatic and less than 5% of cases in this study. So what image findings can we use in conjunction with clinical history and known prevalence data to further increase our pretest probability or the likelihood of pain originating from facet joints in the cervical spine? So in the lumbar spine, there was a recently published consensus statement that showed moderate evidence to support utilizing single proton emission CT or SPECT to identify painful lumbar facets prior to medial branch blocks. There was weak to no evidence to support other imaging modalities in this statement. This article describes the ability to detect facet synovitis on MRIs in the lumbar spine using STIR sequences and found that increasing or increased signal appeared to be correlated with a patient's pain. Here's a comparison between SPECT imaging and MR STIR sequences in the lumbar spine in facet joints, and the authors here found some intermodality agreement when accounting for underlying prevalence, but that was inconsistent and should not be used interchangeably in research or clinical practice. So overall, structural findings of facet arthrosis on imaging have not been shown to be predictive of facet joint pain diagnosed with medial branch blocks or with intraarticular injections as seen in this study here. So now let's look at a few patient cases that when seen in a similar context may help with planning cervical facet injections. So our first patient that we'll go through is a 58-year-old male with a six-week history of primarily left-sided axial neck pain. These images are from his electronic patient intake form, and either this guy has really large thumbs or his pain does not localize to one particular facet referral pattern. On exam, he does seem to have more left-sided symptoms, and given his pain's severity and persistence, an MRI was ordered. So this is the midline sagittal image to help us orient with the vertebral bodies labeled anteriorly. So as we scroll to the left or click to the left, let's keep an eye on the posterior elements where his facet joints will come into view. So since I don't have a pointer, this green circle will act as the proverbial arrow sign that we occasionally see on imaging. And here it's highlighted a T2 hyper-intense lesion in the inferior articular process of C2, which is darker or hypo-intense on the corresponding T1 sagittal image. So to go further laterally, the joint space comes into view, and here we can see the intra-articular fluid or bright signal between the articular pillars there with a posterior osteophyte complex. So starting superiorly on the axial images through the C2 vertebral body, we start to see the periarticular edema, which is already asymmetric when comparing to the patient's contralateral side. So scrolling inferiorly, we see this T2 hyper-intensity that we first saw jump out at us in the original exaggerated images. Coming more into view, this is ultimately described as a bony cyst, which can be can be seen rarely in isolation, but in this case in the setting of clear facet arthrosis. This just further depicts the axial images more inferiorly. So ultimately, this patient underwent a LAP-C2-3 intra-articular facet steroid injection for the reasons described here. As you can see on his fluoro images, the needle tip is in the LAP-C2-3 joint from an AP view pre-contrast, and here is his post-contrast image confirming intra-articular flow both in this AP and here in the lateral image. So this injection was performed nearly four weeks ago, and as of the morning of this recording, has ongoing 50% relief and is actually pretty happy about his results. The patient, or this patient, is an example of where pain referral patterns were less helpful and imaging findings aiding like in determining pain generators are at least 50% of it responding to intra-articular steroids. So our second patient is a 63-year-old female with left axial pain with radiation into her upper scapula or in a C4-5 or C5-6 distribution based on that research presented earlier by Dwyer, April, and Bagdu. So jumping right into this MRI, we'll see increased stir signal around the left C4-5 joint. The sagittal stir sequences on the left correlating with the vertical line seen in the axial image on the right. When we focus in on the C4-5 joint, we can see increased signal or brightness in the articular pillars. So further laterally, the superior articular process of C5 lights up even more in this image on the left. And for comparison, this is the right side, which does not have that bright periarticular stir signal at the C4-5 level. So due to the increased stir signal and what we have discussed earlier about facet cinnabitis in the lumbar spine, an intra-articular steroid injection was performed in this case as well. This is the both AP and lateral images were obtained, but I'm just showing the lateral images here. This one's pre-contrast and post-contrast confirming appropriate intra-articular flow. So she had ongoing 85% improvement in her pain, but states at her two-month follow-up that it was starting to come back. And for our final patient, this is a 64-year-old female with a one-year history of left mid-cervical pain, presumed to be facet-mediated with, radiating pain both superiorly and inferiorly. Here is her T2 MRI with a line on the sagittal image through the C3-4 facet joint on the left, as seen and highlighted on the axial image. Here you can see a fairly severe arthropathy that is unilateral and at a level that is much less common than other levels, as mentioned earlier. So to help illustrate further, this is her adjacent level at C4-5, which has significantly less degenerative changes and more symmetric with her contralateral facet. So this patient underwent a C3-4 medial branch block with 100% immediate relief post-injection, and she'll be returning shortly for her second diagnostic block. So in conclusion, Z-joint degenerative changes on cervical imaging do not consistently correlate with pain. There are known cervical facet referral patterns and more common levels that are effective, which are C2-3 and C5-6. And the following imaging may help localize pain generators for diagnostic or therapeutic injections. So one severe unilateral facet arthropathy with periarticular cysts or subchondral cysts. Increased periarticular stir signal may indicate synovitis and potentially predict a positive response to intraarticular steroid injections in the cervical spine. And finally, asymmetric arthropathy at an atypical level may also help localize for injections. These are my references, and thank you. Thank you, Eric. And thank you to the rest of the speakers for all of those great talks. Patricia, good job putting this together. I'm pulling anchor here and giving the final talk of this session about AO and AA joint. Next slide will demonstrate my disclosures. The only disclosure that's perhaps relevant here is that there's very little evidence in the literature to provide an evidence basis for AO and AA joint injections. Treatment of those joints with injections is largely based on experience in treating arthropathies in synovial joints with injections. So that's really the basis. In the few places where there is some scientific basis, some of that comes from expert opinion through the SIS guidelines. And I will note through my talk where SIS guidelines are being invoked. And as president of SIS, I point that out, thus a potential conflict of interest. Where research studies, typically for the most part, case reports inform us on this topic, I will also provide that information in my talk. So I'm gonna go through these five separate topics as we go through the talk, the nomenclature, clinical presentation, some red flags to be aware of on imaging, some injection perils and injection pearls. In terms of nomenclature, I would like to, I guess, make most clear that we're not talking about facet joints. These are the suboccipital joints. They are not facet joints. They are synovial joints, but it's not correct to call them facets. The occiput to C1 articulation or the occipital cervical articulation is often called the AO joint, atlantooccipital joint. Between C1 and C2, there's actually several joints and articulation between the dens and the anterior ring of C1 as well as the lateral articulations. Generally speaking, when we're talking about C1-2 joint pain, we're talking about the lateral articulations or the AA joint. And remember, they're not facet joints. The clinical presentation of these really has to do with their function. About 50% of the motion of the head happens at these two joints with flexion extension at OC1 and rotation at C1-2. So they're pretty important joints in terms of our range of motion. But they're also potential important causes of cervicogenic headache. And here are the SIS guidelines for probable cervicogenic headache. And it includes unilateral headache that starts in the neck and includes any of these three features that are listed in bullet point fashion here. The referral patterns have been somewhat defined. There's more data on the cervical facet referral patterns than on these, but what we do know from some relatively good studies are that the AO joint tends to have a larger referral pattern, whereas the AA joint really focuses pain in that suboccipital region. So very focused suboccipital pain, lateral AA joint pain should be one of the things on your differential. Also, interestingly, the AA joint can refer to the ear. So if you have somebody with suboccipital pain and headache, the primary culprit, generally speaking, would be C2-3 because it's just much more common. However, AA and AO even become a possibility if that pain refers to the ear, then it's more likely perhaps to be an AA joint pain because it's been shown that a spread to the ear can occur with relative frequency in that population, whereas patients with C2-3 joint pain did not have a spread to the ear in any of the patients that were studied. When I'm examining patients with suboccipital pain and possible cervicogenic headache, I like to screen the biomechanics of the usual culprit, C2-3, as well as the suboccipital joints just by doing some simple testing with a patient. So for C2-3, we often do an extension and rotation test. That may or may not be positive, but it is a so-called facet loading maneuver. To look at the AO joint, you're really looking at pain with flexion and extension. And I like to do it with a patient, supine on the table, get them to relax. I put their head in just a little bit of traction, and then I try to nod their head for them. So I'm just kind of rocking that AO joint and see if that provokes their pain. Then for the AA test, flexion and rotation test as shown in the image to the right side of the screen is an AA isolation test. And this test tends to isolate forces to the AA joint because about 50% of range of motion occurs from that joint. When you flex your neck maximally, you place the facet joints into a stiffened arrangement where the facet capsule is at its maximum stretch. And thus the facet joints contribute very little to rotation in that posture. And most of the rotation is isolated to the AA joint. And so if that provokes a person's focal, ipsilateral, suboccipital pain, then it's a positive flexion rotation test and indicates a possibility of AA joint pain. Now, when you're focusing in the suboccipital region, it's important to understand how to review for proper alignment in the cervical spine. And when I'm looking at a cervical radiograph, the very first thing I do, whether it's MR, X-ray or CT is I look at the lateral view or the sagittal view. And I look to see, you know, does the DENS sit just below the clivus? And the clivus is that sort of wedge-shaped part of the sphenoid bone that creates the anterior border of the foramen magnum. And it should sit right on top of the DENS. That's important because cervical cranial instability can be a real issue. The second place I look at is the borders of the spinal canal that protect the spinal cord. And this is to see if there's good alignment of the posterior longitudinal line and good alignment of the spinal laminar line. So step one, I look to see, does the clivus sit on top of the DENS? Step two, how smooth are the posterior longitudinal and spinal laminar lines? And does it look like things are in good alignment? And when not, you can have something like this on the right side, which is a cranial settling or basilar invagination where the DENS is poking up into the foramen magnum. And this is a potential cause of sudden death, which is bad for those that you don't remember that from early days of medical school. And not something we deal with too often in the spine clinics, but if presented with this, you should be very alarmed. All right, so let's talk about a real world case of suboccipital pain in my clinic. This is a patient I saw came to me with this MRI. He had pain in the suboccipital region. It's kind of bilaterally. And he asked me, he said, when I nod, why does my neck go clunk clunk? And he showed me, did it for me. And sure enough, you could hear this audible clunk clunk. And usually we think of crepitus and crepitus type things in the neck is very common. But for some reason, I was looking at his MRI and I said, well, maybe, let's see what's going on here. So kind of focused in. And I could see that on one side, on the left side, he had a fused C2-3. And on the right side, he's actually fused from C2 to C4 through the lateral mass. And so I thought, well, maybe this guy has AA pain because he has several congenital fusions below the AA joint. And maybe that's causing him to have bilateral AA joint pain. And maybe that's crepitus from arthrosis of the AA joint. And you can see, at least on the left side, the AA joint doesn't look too great. But also looking at this, I thought to myself, I'm like, well, that DENS looks a little bit funny. So why don't we work this up a little more and why don't we get some flexion extension views and take a look and see what's going on. So we did that in the clinic that day. Here's his extension view. And oh boy, here's the flexion view. And you can see this guy has dislocation of his DENS and instability, which is quite severe. And he walked down the hall to talk to one of the surgeons who walked him over to the hospital and took him in for surgery the next day with a collar on between the time he was in clinic and went to surgery. But this guy had been walking around for quite a while with this clunk clunk when he nodded his head. So that gentleman wasn't a good candidate for an injection, but occasionally you may decide you want to do an injection of the AO or the AA joints. This is the view that you try to capture when you're going to do that injection. And this is from Curtis, this image is courtesy of Milton Landers and SIS. I like to call it a bow tie sign. You can kind of see in the image, the DENS is the knot of the tie and off to each side of the DENS is sort of a bow tie appearance. The upper side being the AO joint and the lower side being the AA joint. And the AA joint target is at the lateral one third, medial two thirds, a line of the AA joint in order to attempt to avoid the vertebral artery, which tends to be more lateral and the C2 dorsal root ganglion, which tends to be more medial. Now that being said, SIS guidelines do specify injection in that location, but here's one place where we have a little bit of evidence showing us that even that is not necessarily perfectly safe. Two studies looked at the incidence of vertebral artery being located in the usual location of injection of the AA joint. So in that lateral third portion of the joint, and both of these studies were convenient studies using arteriography and CT to see, how many people had arteries that were in unusual locations and might be vulnerable to injection. And you can see that both studies came up with very similar numbers about 0.7 or 0.5%. So one out of 200 joint injections would have a vulnerable vertebral artery. The reason to possibly try to look at this three dimensional imaging before considering an injection here to see if there is any anomalous course of the vertebral artery. And indeed there's a case report of a patient who had a posterior circulation stroke as a result of AA injection. While they don't state that the injection was misguided in the case report that was published, in anesthesiology I'll point out two mistakes from this study. The first is in the title. You can see it says, posterior circulation stroke after C1, C2 intra-articular facet steroid injection. It's not a facet joint people. I'm sorry, I get on my soapbox about nomenclature at times and that's one of them that irritates me. The second thing is that you can see in the images on the right, the injections posterior to the joint. And it's in the location the vertebral artery could be if you had an anomalous course of the vertebral artery. So that contrast patterns is posterior to the joint, not in the joint. And clearly they injected into the vertebral artery because the patient had a posterior circulation stroke. All right, I'll finish with a little bit of an injection pearls. And you're probably thinking, what does a motorbike have to do with injection pearls? And that is that I always tell my trainees a story that I'm gonna tell all of you. And that is in 1983, I was a little kid in Central Indiana and my father brought home a dirt bike for me to have fun with. And I was really excited, couldn't wait to get out and ride it. And I was getting ready to jump on the bike to take it for a ride. My dad had started it up and he said to me, well, hang on Matt, before you can get on this bike, you need to know the two rules. And I said, oh, okay, what's that? He said, rule number one is that you have to always wear a helmet. If I ever see you on this bike without a helmet, then you'll never touch it again. I'll sell it, it'll be gone. Simple enough, smart enough. And rule number two, rule number two is you need to respect this machine. You're gonna have a lot of fun on it. You're gonna get good at riding it. And you may start to think that it can't hurt you or that you're better than this machine. You've got it mastered. And as soon as you think you've got it mastered, you'll lose your fear that you can get hurt and you will get hurt. So always respect the machine. And that was good advice, I thought. Fortunately, I never really got hurt on it. Followed the rules, I wore the helmet, I respected the machine. And I thought about that when I was a fellow at Stanford in 2001 and reports of strokes and cervical myelopathies from inadvertent injections into arteries started to appear. And I remembered, hey, there's a reason that you need to have respect for these things and you need to be afraid. And so I tell all my fellows that I train, if you ever stop being afraid that you can hurt somebody, if you lose the fear of doing these procedures, then just stop doing them. And I maintain that respect today. But sometimes you mess up a little bit. And this is a case, a colleague of mine at Stanford, a physician came to see me with C1-2 joint pain and isolated there on exam. He had focal suboccipital pain and he had stir signal changes in the right C1-2 joint that you can see on his MRI here. So we took him into the procedure suite to do an injection. And on the left side, you can see the AP view of the needle into the proper location. On the right side, you can see the injection of contrast in the joint after successfully completing the injection. This is when the injection was done. What the images don't show you is about four or five minutes before this, I was really close to getting the needle into his joint and I needed to move it up just a little bit to get in that posterior capsule, but he was having a lot of tenderness. And so I broke one of my rules of safety, which was never inject lidocaine as you're trying to enter the C1-2 joint because of a possible proximity to the vertebral artery. But I thought, this is a colleague, I'm up against the bone, nothing will happen. Injected a little lidocaine to try to make it more comfortable for him. And he had a seizure right there on the table. It was actually Patricia's first day of fellowship when that happened. I'm sure she can tell you the horror story of it. And I think I said to Patricia, as he was having a seizure, I said, well, I think he's having a seizure from the lidocaine. We'll know in about 30 seconds to a minute if it's that, or if we dissected his vertebral artery and he's stroking out and we're in a much worse situation than that. And fortunately he recovered. We told him what happened. He was like, wow, that's interesting. I told him I was gonna abort the procedure. He said, no way, finish it up. You're right there, get it done, which we did. And he responded successfully to the injection. So in conclusion, I'd like to just, as a Pearl, respect the needle, mind your rules, be afraid of what you're doing. You can always hurt people and always wear a helmet. That's me with my kids on the local trails and same rule applies to them. They have to wear a helmet. Thanks everybody. And hope you enjoyed this session. Any questions that you have can be directed toward the different presenters and we'll be happy to carry forward discussions and answer questions that you have. Thank you.

cervical spine imaging

interpretation

pathologies

imaging modalities

MRI

disc herniations

cord abnormalities

ABCD framework

cervical discogenic pain

cervicogenic headache

interventions