Welcome to How to Read Cervical MRI Like a Pro. My name is John Hyman, and I'm an assistant professor of neuroradiology at the University of Texas Medical Branch at Galveston. Just as a caveat to today's lecture, when I was asked to develop this educational module, I did not realize that there would be a webinar associated with it. So the slides are intended to be inclusive, meaning that they have a lot of information on them that I won't be covering orally. But if you're viewing this webinar from home, feel free to pause it and read the additional information on the slides as I go through them. So let's begin. Just to give a little outline before we begin, I'm first going to start talking about some MRI basics, just to give you a little brief background about the modality itself. I'm going to go over what the standard MRI sequences are and what they're used for when looking at a cervical spine MRI. We're going to look at some spinal anatomy as seen by MR imaging. I'm going to talk about how to approach or read a cervical spine MRI. And then finally, we're going to go over some common cervical spine pathologies that might be encountered. So MRI basics. MRI stands for magnetic resonance imaging. Contrast on MRI is due to inherent T1 and T2 properties in the tissues. That's different than CT, which is due to density of tissue. It does not use ionizing radiation, which is useful for letting your patients know if they're concerned about that. And it's primarily good at imaging soft tissues. It can be useful for looking at bony marrow, but for cortical bone and things like that, CT is often a better modality. Compared to CT, MRI takes much longer to perform, 30 to 40 minutes per study. Without contrast, it's typically more expensive and it's less readily available, particularly in emergent settings. Also relative to CT, an MRI gantry is narrow and deep and can be a problem for patients with claustrophobia. Gadolinium is the contrast agent used in MRI as opposed to iodine for CT, but they don't cross react. And true gadolinium allergies are actually exceptionally rare. However, there is a concern in patients with renal failure of developing nephrogenic systemic fibrosis, although small and not commonly seen with the newer agents, but there's no risk in patients with a GFR over 30. So there are some contraindications to MRI. The first thing to know about MR is the MR magnet is a superconducting magnet, and it's incredibly strong. What this means is that it can cause ferromagnetic materials in the patient to move when placed in the field. So patients who have metallic foreign bodies or are at risk for having metallic foreign bodies, such as if you were a welder or you might have iron particles in your eye, these kind of patients have to be screened, possibly with additional imaging before going into the magnet. Moreover, the magnet can cause certain medical devices like pacemakers and neural stimulators to malfunction in the magnetic field. And finally, and people forget this, even if the metal isn't ferromagnetic, being in the magnetic field can cause can induce a current in a wire and that can cause skin heating and burns. So patients that go into an MRI have to be conscious. Sedated patients, if there's any metal on them, can't go into the field because they're not able to tell the technologist if they're developing heating and discomfort. So the second question, I think, for providers is, you know, when should I order an MRI? And then if I am going to get an MRI, when should I give contrast? So these are broad questions and often don't have black and white answers. In general, as I mentioned, MRI is a useful modality for looking at the soft tissue. So if you want to know anything about the cord itself, if you're looking for myelopathy or lesions inherent to the cord, you're going to want to get an MRI. And then in terms of contrast, if you're looking for an active process, such as a tumor infection or inflammatory condition, including, you know, MS, you're going to want to give contrast. If, on the other hand, you're just looking for evaluation of chronic neck pain or radicular pain, you know, you're questioning, you think, you know, it's something structural like a disc. These indications often do not require contrast to look at degenerative changes. And if you have questions, I've included a link here to the American College of Radiology Appropriate Use Criteria, which gives evidence-based guidelines based on multi-specialty consensus guidelines, and they can be viewed at the ACR website. Those are broken down into basically clinical questions like radicular pain or myelopathy. So I think that's a useful resource for providers. Other kind of miscellaneous considerations in MRI. In the post-operative patient, susceptibility artifact from metallic fusion can severely limit evaluation at the level of the hardware. So if you have a patient with, you know, a multi-segment fusion, there are some things you can do. The first thing you want to do is try and get the patient scheduled on a 1.5 rather than a 3-Tesla magnet, which is going to limit artifact. Additionally, you might check with your radiologist to see if metal reduction sequences are available at your institution. Finally, CT myelogram is an alternative in these patients and any patients that can't get an MRI for other reasons. And it will at least give you a look at spinal canal narrowing, although for evaluating the neural parameter, it's not particularly more sensitive than just a CT without contrast. CT can be limited by streak artifact, but you can often at least evaluate whether there's, you know, severe canal stenosis on a myelogram. So these are a couple of examples of that. On the left here, you see a C2-C7 posterior fusion and C3-C6 ACDF. So that's a lot of hardware. And then this is the same patient. This is a sagittal FAT-SAT contrast enhanced MRI of that patient. You can see all this susceptibility artifact over the posterior elements, over the cord. I mean, basically, this is non-diagnostic. You can't evaluate the cord here at all. This is a sagittal T2 of the same patient. This is done on a 1.5-Tesla magnet. And you can see that there's still susceptibility artifact, you know, directly over where the hardware is. But you actually get a diagnostic look at the cord. And that includes this little area of hyper-intense T2 signal at the level of the C2-C3 disc, indicating some chord edema at that level. And here's what a CT myelogram looks like. So what a CT myelogram is procedurally is it's identical to a lumbar puncture, meaning this is, you know, a minimally invasive procedure. We take a spinal needle and we introduce it into the subarachnoid space in the lower back and inject iodinated contrast into the fecal sac. We then, in the case of a cervical myelogram, place the patient in Trandellenberg so that dense contrast will flow cranially. And then we just get a normal CT. And this is what you see here. The cord is here. And then this hyper-dense material in the intrathecal sac is contrast, outlining the cord within the subarachnoid space. So even in patients with, you can see hardware here, and there's a little bit of streak artifact from this posterior hardware at the laminectomy site. But you can tell here that there is no, you know, severe canal stenosis at any level. The contrast is flowing distally all the way into the cisterns at the base of the brain. So let's look now at a couple of the standard sequences for cervical MRI. Depending on where you are, these may vary a little bit. But generally speaking, these five sequences here are going to be obtained in every cervical MRI. You have a sagittal T2, a sagittal T1, a sagittal STR, and then an axial T2 and an axial GRE sequence, which is a gradient-based sequence that also has T2 waiting. So how do we identify these sequences? The mnemonic that's taught to radiology residents is T2H2O. So on T2-weighted sequences, fluid is typically bright. And when we look at this sequence, you know, we can see the spinal cord here, and then we can see the fluid outlining the cord is bright. That's a T2-weighted sequence. The subcutaneous fat is also bright. So fat is actually bright on T1 and T2 sequences, this being a T2. And this is a STR sequence. STR stands for short tau inversion recovery. Inversion recovery sequences, TRIM is another example, saturate signal from some type of molecule. In the case of STR, it's fat. So you can see on this case that the subcutaneous fat and the merofat have been saturated. And the reason for that is it's still a T2-weighted sequence. See, the fluid is bright. So edema fluid in vertebral bodies is going to stand out, whereas if you have edema on the T2, you're going to have bright T2 fluid superimposed upon bright merosignal, and it's harder to see. So this is kind of people think about this as the pathology sequence, either when you're looking at the cord or when you're looking for inflammatory changes or, you know, infectious changes in the vertebral bodies themselves. So the sagittal T2 used for spinal canal narrowing, you see the canal very nicely, ligaments and facets off the midline, and then cord lesions and edema. And the same thing for the STR, you're going to look at the cord, but also you're going to look at the mero here, osseous lesions, acute fractures, you know, meroedema is going to be more conspicuous on this sequence. And then the sagittal T1, fluid is dark, merosignal is bright. So this is good for looking at infiltrative processes in the mero, and it's also good just for looking at general structure. The axial GRE is best for cord lesions. This is actually going to be your best cord contrast. And you see here nicely, you can actually see the anterior and posterior horn cells within the spinal canal there. And then the axial T2 is, I use both these for looking at the neural foramina, which you see here and here. Additional sequences you might see, these are post contrast sequences. These are also fat suppressed, but they use a different technique. And so you can get incomplete fat suppression at the edges of the field like here. And sometimes you might see DWI sequences, which can be used to look for cord infarcts. Some people use them to look for discitis osteomyelitis and to separate it from acute in-plate degenerative changes, what we call MODIC type 1 changes. Other uncommon sequences that you might see sometimes, if you're looking for trauma sequences, they may include the sagittal sequences up through the skull base to look at ligaments, skull based ligaments on proton density sequences. And some places may also include a coronal sequence in order to look at curvature. Another sequence that sometimes you might see are oblique, sagittal oblique T2 sequences to look at neural foramina on FOS. So I want to touch base on what it means when we say something is enhancing. People have a tendency to refer to any bright MRI signal as an enhancement. But what really does enhancement mean? Well, gadolinium, the contrast material causes T1 shortening, i.e. it makes things bright on T1 weighted images. When gadolinium is injected intravenously, it can leak out of the vasculature into the interstitium, resulting in those tissues becoming T1 bright or enhancing. And this happens in areas where there's infection, inflammation or tumor, particularly with neovascularization. So it only makes sense to talk about enhancement on T1 weighted post-contrast sequences. And then a caveat is that if something is bright on the T1 pre-contrast sequence and also bright on the T1 post-contrast sequence, it's difficult to say whether that's enhancing or whether it just has intrinsic T1 shortening. So. Here's an example of that. Here's a sagittal T1 fat set post. So this is a post-contrast sequence. You might be tempted to call this enhancing, but if you look at the sagittal T1 pre-contrast, it's also bright here. So this doesn't actually represent enhancement. It represents intrinsic T1 shortening. And this was a subacute hematoma in the cord. Blood products are one of the things that can be bright on T1. So in order to call something enhancing, you have to really compare it to a T1 pre and make sure that it's truly a difference. In other words, bright on the post and not bright on the T1. So this might have been due to an underlying cavernous malformation or some other lesion. That's some basics about MRI. Let's move on now to look at imaging anatomy as seen on MRI of the cervical spine. So there are seven cervical vertebrae that includes the atlas who holds the globe. So that's the uppermost cervical vertebra seen here, just as the anterior and posterior arches. And then the axis, which is what the cranium rotates on, on its axis. This is where you nod. This is where you turn your head. Yes and no. So called the axis. There are a number of ligaments and the major ligaments are anterior and posterior longitudinal ligaments seen here and here. The ligamentum flavum, which is here. The supraspinous ligament, which is here along the top of the spinous processes. The tectorial membrane, which goes from the dorsal clivus down to the C2, also called the axis. The apical ligament of the dens, which is here. And then the cruciate ligament is named. You don't see it well on the axial, but it holds basically C2 to the anterior arch of C1 and forms a cross. There's a transverse and a vertical component of that. And then there are alar ligaments, which are also seen better on the coronal, which anchors C2 to the skull base, to the occipital convals. So we also see the spinal canal cord, of course. And then there are a number of joints in the cervical canal, the intervertebral joints themselves, the facet joints, which are synovial joints, and then special joints called uncinate joints that are better appreciated on coronal sequences. So these are the synovial joints or the zygopophyseal joints. And this is a parasagittal T2, whereas this is a midline sagittal looking at the cord. So looking specifically at bones and joints, let's talk briefly about the uncovertebral joints, sometimes called the joints of lusca. Uncinate means hook, and it's describing this hook-shaped morphology of these joints. You only have these in the cervical spine. You don't actually see these in the thoracic or lumbar spine. And in the cervical spine, they can contribute to neuroforaminal narrowing on the disc side. So that's what you see here. You have some neuroforaminal narrowing coming from this uncinate hypertrophy here. And again, I like to correlate if I have a CT or a radiograph to look at because they're easier to see on these coronal sequences. So this is a relatively normal uncinate joint. And as you come down here, you see all this bony hypertrophy and arthropathy associated with these uncinate joints. And then this is what it's going to look like on the MRI. So there are a couple other components here. We can see the vertebral bodies, the neuroforamina, the lamina, the spinous process. This is the pedicle. So remember on the cervical spine that the pedicles sort of have this oblique orientation, unlike the thoracolumbar spine where they're coming straight back, which is why we don't talk about pedicle screws and posterior spusions in the cervical spine the way we do in the thoracolumbar spine. It's more like a lateral mass screw that goes in here. The transverse processes, which contain the vertebral artery and the foramen transversarium, that can be important in fractures where that goes across the foramen. Also, again, when you're doing surgeries and you're looking at screw placement, you have to make sure that those screws stay osseous and don't protrude into the neuroforamina. They can cause vascular damage to the arteries or they can cause damage to the nerve roots if they get into the axillary recess here. Another final thing to consider is bone marrow signal. You know, marrow signal abnormality is one of these forest for the trees kind of thing. It's often missed even by people who kind of know what they're looking at because it's easy to see when one thing is not like the others. In other words, if you have one vertebral body that's bright and the other ones are dark, that kind of jumps out. But if you have all the vertebra are abnormal, it can be difficult to see. So remember that marrow in the spine is fatty and or it should be fatty. And so it's typically bright on T1. And if you look at this spine, the vertebral bodies are brighter than the adjacent discs. If you look at this, that's reversed. These vertebral bodies are hypo intense relative to the vertebra. Again, this is a T1. See that the fluid is dark and the subcutaneous fat is bright. So this can be due to a lot of different things. It can be due to red marrow reconversion. But it can also be indicative of something more sinister, like an infiltrative marrow process, diffuse osseous metastases or lymphoma, leukemia, myelodysplastic syndrome, something like that. So paying attention to the marrow abnormality is something we also want to look at. Finally, let's move on to intervertebral discs. So the intervertebral disc is composed of the nucleus pulposus in the middle and the annulus fibrosus on the outside. So this is notochordal remnant. It's, in young patients, bright because it's hydrated. This is kind of what gives your spine some spring to it, if you will. It allows it to compress. And then the annulus fibrosus is fibrotic, and so it's dark on MRI sequences. And when you get disc herniations, what we're ultimately going to talk about is either the pulposus extruding through a defect in the nucleus and the annulus fibrosus or thinning of the annulus fibrosus, allowing the whole thing to protrude or bulge posteriorly. So this is a stir, again, bright on T2, but this is a fat saturated sequence. That's why these look dark. And this is showing normal discs. This is actually a lumbar spine, not a cervical spine, but just to kind of show the discs here. And this is what they should look like. So as I said, the nucleus pulposus can herniate through the annulus and protrude into the spinal canal, resulting in cord compression. And this is a large extrusion. You see the edema and the cord here. So there's, you know, I would describe this as severe canal narrowing with cord compression and associated cord edema. And this is a cervical spine here. You see the epiglottis. So this is a surgical emergency. You know, this patient is going to be at risk for developing, you know, a paraplegia, depending on what level this is at, if he's not decompressed. And then the spinal canal and spinal cord, we're looking at axials here. This is a T2, this is a GRE, and this is a myelogram. So we have epidural fat along the outside. That's going to be bright. Then you have the dura mater. Then you have the spinal cord. And then you have CSF surrounding the spinal cord within the dural sac. That's called the subarachnoid space. It's often referred to as the intrathecal space, but technically the intrathecal space includes both the subarachnoid space, which is seen better here, and the subdural space, which is a potential space that we don't often see on MRI. This is the reason I've included this CT myelogram. You couldn't do this if you tried, but it happens from time to time by accident. So what they did was they tried to do a myelogram and their needle probably pulled back a little bit, so they got some of the fluid into the subarachnoid space, but this lobular hyperdense signal here is actually in the potential space of the subdural space. So these are actually both intrathecal, but this part here around the nerve roots is subarachnoid, and this crescentic hyperdensity here is actually subdural. And then as we saw in that other slide earlier, you can have, you see the anterior horn of the spinal cord here and the posterior horn here. You're really only going to get that kind of detail on a GRE, and even then it's got to be, you know, no motion, and the higher the Tesla, the better the resolution you're going to have. So just remember that the cord is the reverse of the brain, meaning that the gray matter is central, the anterior and posterior horn cells are gray matter, and the white matter tracts are peripheral. Okay, and then we can look at nerve roots, the ventral nerve root, the dorsal nerve root, and then they come together to form the spinal nerve and the neuroforamen. That's out here, and there's an important anatomic clinical correlation here that I want everybody to remember. At C6, there are eight cervical nerve roots, but only seven cervical vertebra. So what that means is that you have an extra nerve root, and that's the C8 nerve root. So at C6-C7, the C7 nerve root is exiting. At C7-T1, the C8 nerve root is exiting. That's opposite from the thoracolumbar spine. At T6-T7, the T6 nerve root is exiting, whereas, you know, if this were in the cervical spine, C6-C7, the C7 nerve root is exiting. So it's named for the above vertebral body in the thoracolumbar spine and the below in the cervical spine. So at C2-C3, this is actually incorrect. It should be the C3 nerve root exiting at C2-C3, not C2. This is a typo. And so that's an important thing to know when you're correlating clinically, you know, radicular symptoms with imaging symptoms and neuroforaminal maring, etc., both in the cervical and the lumbar spine. And then looking briefly at ligaments, again, here's the tectorial membrane, the apical ligament of the DENS, the anterior and posterior longitudinal ligament, the ligamentum flavum, and the supraspinous ligament. This isn't something that we look at routinely on cervical MRI, but in cases of trauma, it can become important because these ligaments can rupture, particularly if you have disruption of the ligaments of the craniocervical junction, you know, that can herald a catastrophic injury. But even disruption of ligaments in the posterior spine can result in spinal instability and, you know, require fixation. So as I was mentioning earlier, sometimes this is not a standard sequence, but in trauma sometimes they will include axial images all the way through the upper skull base, and you can see the transverse ligament, which is part of the cruciate ligament, anchoring the odontoid process to the anterior arch or the body of C1. Okay, so let's go on now quickly to talk about how to read a cervical MRI or any MRI. The first thing you have to do is develop a constant search pattern, meaning you don't allow yourself to be drawn into the first thing that you see, you know, because then you can make mistakes like satisfaction of search. You see one thing, you miss the next thing. So most, you know, all good radiologists, I would say, force themselves to go through every study in the same way, no matter how benign it seems. And by doing that, you're going to avoid, like I said, satisfaction of search. And often incidental or unexpected findings can be just as important as what you're actually looking for. So there's no wrong or right search patterns, as long as your pattern is thorough and you stick to it. This is an example. Go figure it's the way that I look at a cervical spine. I look at the vertebral body height, curvature, and alignment. Then I look at the cord, plus or minus contrast enhanced sequences if they're there. I look at marrow signal intensity, osseous lesions, plus or minus enhancement if it's there. I look at the discs. And then a lot of times you'll see people do this like line-by-line description of degenerative changes, if you're looking for radicular pain or something like that, where they talk about the different things that can cause or most commonly cause radicular pain or myelopathy, which is disease related to the discs, to the zygopathocele or synovial facet joints, and then in the cervical spine to onsen hypertrophy. And then finally, I kind of look at what we call the corners. You're going to get a little bit of the brain, sometimes a little bit of a lung apathy, vertebral arteries, thyroid, etc. Things like that that could also potentially have pathology. So I use the T2 sequence to look at vertebral body height, curvature, and alignment. You know, this is where I'm going to look at compression deformities to see if they're acute or not. I'll look at hyper intense or I'll look for hyper intense stir signal to see, you know, if there's acute marrow edema there. You want to evaluate the cord on at least two sequences. The reason for that is because the cervical spine, MR, is prone to artifacts. Susceptibility artifact is one, but there can also be CSF flow artifacts, pulsation artifacts. You remember that the GI tract or a portion of the GI tract is just anterior to the cord, so peristalsis from the esophagus and things like that. All of these things can cause signal abnormality over the cord, particularly on sensitive sequences like STIR and GRE. So I like to look, if I see like a, you know, what I'm going to call signal abnormality in the cord, I really want to see it on two independent sequences, you know, a sagittal and axial T2 or an axial GRE or a sagittal STIR. I use the T1 for the background marrow signal, STIR to look for acute lesions, and then post contrast sequences in the cord and the marrow to look for acute or, you know, active processes. And then, you know, mostly or a lot of times what you're looking for degenerative changes, so I kind of split the difference. I look at both the sagittal and axial T2 when I'm evaluating canal stenosis and neuroforaminal narrowing. So curvature and alignment. Curvature describes the shape of the entire spine. Terms describing curvature include lordosis, kyphosis, and then in the lateral direction scoliosis, right, dextro curvature, levocurvature. Whereas alignment describes the relationship of one vertebral body to the one directly beneath it. That's the term spondylolisthesis is the umbrella term. And by convention, this is described in reference to the superior vertebral body in reference to the inferior vertebral body. So if L4 is anterior to L5, you're going to call that anterolisthesis of L4 and L5 as opposed to retrolisthesis of L5 under S4, and that's just convention. Alignment in the lateral dimension is called translation. You could say there's leftward translation of L4 and L5, for example. And malalignment is important to pay attention to because it can cause neuroforaminal narrowing directly, but it also results in altered biomechanics that can result in, you know, facet arthropathy and asymmetric disc narrowing that can secondarily cause canal stenosis and neuroforaminal narrowing. So I want to spend the last portion of the talk going over some common cervical pathologies, and I have broken these down into four kind of main categories, which are degenerative changes, probably what you're going to see most commonly, but then we're also going to look at some examples of trauma, some examples of infection, and then a couple primary tumors of the spinal canal and spinal cord. So this is obviously not a comprehensive list, but these four things are probably going to account for greater than 90% of the things that you're going to end up getting an MRI cervical spine for. And then the principles used to evaluate these can be applied to a much wider range of cervical spine pathology. So this lecture specifically focuses on MRI cervical spine, and some pathologies including acute trauma are often better evaluated on other modalities such as CT. So keep that in mind when we look at trauma. For example, it's going to be trauma where cervical MRI is needed, meaning that there's, you know, disc, I mean, ligamentous disruption or cord injury itself. So before I get into this, I want to look real quick at ACR appropriateness criteria for surgical imaging. Because again, oftentimes, you know, as a provider, the question is, what should I order and what resources do I have available to help guide me? So these are screenshots, but these are screenshots from the ACR appropriateness criteria, and these are available on their website. And you can search by modalities, or you can search by, I guess, body type. So you can go to neuro, and then look specifically at MRI cervical spine, and then within there, it's subdivided by variants of pathology. So this variant is new or increasing non-traumatic cervical or neck pain with no red flags. And then it'll give you this narrative rating table for, you know, what's considered appropriate, may be appropriate, or not appropriate. So this can really help if you're struggling to know what kind of study to order for a given situation. So, and I just included a couple of them here for convenience, the ones related to MR cervical imaging. So if a patient has new or increasing non-traumatic cervical or neck pain with no red flags, and this is more, you know, this is fleshed out and detailed, including their references on the website itself. Initial imaging, what should you get? Radiography of the cervical spine is usually appropriate, meaning this is probably the best study to get, although in some cases it may be appropriate to get an MRI cervical spine. If you have new or increasing non-traumatic cervical radiculopathy, not just neck pain, then MRI of the cervical spine without IV contrast is the most appropriate study to get. So the take-home flag is, if the patient has no red flags and they have radiculopathy present, MRI without contrast is the study you want to get. If they have chronic cervical or neck pain, initial imaging, radiography, again, MRI cervical spine in the case of acute pain may be appropriate, but there's some disagreement there. Chronic cervical or neck pain, no neurological findings, and you've already gotten radiography and it shows degenerative changes. What do you get next? Now you're going to go to the MRI cervical spine. And again, this is because it can show you more sensitively, like, let's say you're planning a surgery or even a minimally invasive procedure such as, you know, a facet injection or a, you know, an epidural steroid injection. This is going to be, this can help guide you to what level to do in order to get the most benefit, but this is after already showing that degenerative changes exist. And then, this is pretty simple. For neck pain, plus or minus radiculopathy, with suspicion for infection or the patient has a known malignancy, this is when you're going to want to add contrast. So these are MRI cervical spine with and without contrast. And that's, again, any time you're suspecting a non-structural pathology, they have a cancer, they might have a cancer, they have MS, they, you know, they have a discus osteomyelitis, so they're at risk for it, you're going to want to go ahead and add contrast to that study to look for active processes. And then the take-home for this is, if you're suspecting myelopathy, no matter the cause, traumatic, painful, sudden onset, you want MRI cervical spine. This is the only study that really is going to evaluate the cord well and be able to tell you anything about myelopathy. So before we get into degenerative disease, let's look at some technology, I mean some terminology. When describing degenerative changes, we talk about what they are and where they are, what the effect of them is, and then try and grade how severe it is. So, for example, I might say something like, at the C5-C6 level, a central posterior disc osteophyte complex and right-sided unscented facet arthropathy result in moderate canal stenosis and severe right neuroforaminal narrowing. So that tells you the level, what's causing it, how severe it is, and what the effect is, moderate canal stenosis and neuroforaminal narrowing. So the major degenerative causes of spinal canal stenosis and neuroforaminal narrowing, we talked about briefly already, it's disc osteophyte complexes. Unlike in the lumbar and thoracic spine, where you have isolated protrusions and extrusions, in the cervical spine, there's often a bony component to the disc coming back. So we typically describe it as disc osteophyte complexes or PDOCs, you might hear that, posterior disc osteophyte complexes. Although, particularly in young patients, these do occur and they can often be more emergent because they reflect an acute process as opposed to this, which often reflects like an ongoing kind of chronic degenerative process. And then facet or zygopathyseal joint arthropathy and then uncertain hypertrophy. There's plenty of other things that can cause narrowing, posterior longitudinal ligament thickening and ossification, ligamentum flavum hypertrophy, which you can see when you have spondylolisthesis, reversal of the normal cervical curvature, malalignment, a developmentally narrow canal, and then any number of, you know, lesions, masses, you know, epidural hematomas or abscesses or things like that that can get into the cord and cause narrowing. So let's look at a couple cases. This is a sagittal T2, remember, fluid sprite. Then you have PDOCs, so posterior disc osteophyte complexes at 4, 5, 5, 6, and C6, and resulting in, I would say, moderate canal stenosis. You know, it's more than minimal, but it's not causing any cord compression or anything like that, I just call that moderate. Now here we've come, parasagittal or off the midline, and we're looking at a T2, and we're looking at multilevel facet arthropathy left, which is here, compared with relatively normal facet joints on the right. So you see how, you know, there's a lot of heterotopic bone here, synovial hypertrophy. These just look kind of messy, whereas these look pretty clean. You know, you've got the articular pillar here, a little, the facet is here, and there's not a lot of arthropathy. So these are, you know, this is facet arthropathy, and by comparison, that's a relatively normal-looking side. So here's some other examples. Here's a sagittal T2 showing a small PDOC at C6, C7. This is the axial at this level, and you've got severe neuroforaminal narrowing. I'm showing that here, and it's coming from the disc side, right? So the disc side along the posterior lateral margin, and that's in keeping with uncinet hypertrophy. The right side looks pretty normal, but on this side, and this star is sitting on the nerve root, you know, you have severe narrowing here, and that's a PDOC. I'm sorry, that's an uncinet hypertrophy here. So here's another example. Parasagittal T2 sequence showing diffuse moderate to severe facet arthropathy all along here, and on the axial, you see moderate to severe bilateral neuroforaminal narrowing, secondary to bulky facet arthropathy that's here and here, as well as ligamentum flavum thickening. And there's some motion degradation here, so the canal isn't seen that well, but this is the spinal canal, or this is the spinal cord in the canal, and there's no evidence of compression here. The problem is predominantly with the neuroforamen. So here's another sagittal and axial T2 through the C6-C7 disc space, and this is showing a isolated left foraminal disc protrusion resulting in moderate neuroforaminal narrowing and possible mild impingement on the extinct nerve root here. This is just to show this other sequence that I was talking about that some places will get, this is a sagittal oblique. So on a true sagittal, because of the orientation of the neural frame, and you're not looking at it like down the barrel, it doesn't have that keyhole appearance like you get in the lumbar spine. And so here's the nerve root here. You can do these sagittal obliques, which kind of open up the neuroforamen and show the nerve root within the neuroforamen, but these are not commonly acquired. Here's a 51-year-old male with neck pain and electric shocks from the neck down to the bilateral lower extremity. This is a T2 sagittal sequence, and it's showing some hyper-intense signal in the cord. So this looks like myelopathy here, but the thing is, why does he have myelopathy? There's not really significant canal stenosis here. There's no evidence of cord compression. I mean, lower down, he's got some PDOX causing some mild cord impingement, but there's no cord signal abnormality here. So this case was a little bit of a mystery to me, but I looked and this doesn't look correct. It looks like there's a defect, basically, in the odontoid process here. So here's flexion extension radiographs on that same patient, and it's showing abnormal motion. Well, first of all, you see the defect in the DINs. So this probably represents a fragmented ossoedontoidium, which is a chronic developmental anomaly, but it's resulting in dynamic instability here. So you see that when this patient flexes his neck, C2 has abnormal motion. I mean, C1 has abnormal motion relative to C2, and while we don't see it here because he's not in flexion, this guy, whenever he flexes his neck, he's probably causing severe canal stenosis and cord impingement here. And so over time, through chronic repetitive microtrauma, he's developed this myelopathy in the cord there. So this is a different patient. Oh, actually, I'm sorry. This is the same patient. This is showing the CT, frequent falls, neck pain, numbness, weakness, extremities to three weeks. Now, this is a different patient. He just, he has cord compression here. So the point of this, of showing this is to illustrate the point that CT is not sensitive for the evaluation of myelopathy. This was the presenting sagittal CT. And if you look at this, you really aren't gonna say anything about canal stenosis. It doesn't really look like there's canal stenosis at any level here. Mild degenerative changes, no traumatic injury, no high-grade nearing suspected. But when you get the sagittal, the MR, you see this PDOC here, which is at this level. Again, not really seen here, and it's actually causing a severe canal stenosis and cord compression. And compare this T2 hyperintensity in the cord here that's a little more amorphous than what you're looking at here. This is chronic myelomalacia. This is acute edema. So this is somebody that you may be able to do something for. You know, he probably needs to be fused or decompressed here. And this is that chronic myelomalacia for comparison there. Okay, this is another example, just kind of showing the same thing. If you look at this level, it doesn't look that bad. I mean, if I were gonna say anything on the CT, I would think this is the level that has the most nearing. But when you get the MRI cervical spine, there's an unsuspected large discal component here that's causing severe canal stenosis, cord compression, and some mild cord edema. So again, the take-home point, CT is not sensitive for evaluation of the spinal cord. And if a patient is having myelopathic symptoms, I mean, an MRI is really the study that you're gonna need to get for correct evaluation of that. In this case, it's a sagittal CT showing grade one anterolesthesis of two on three, that's here. Post-surgical changes of two to four laminectomies and multilevel advanced disc disease. You know, these discs look pretty terrible. Sagittal T2 in the same person shows chronic myelomalacia at three, four, that's here. Without cord impingement, this is probably why he had the laminectomies in the first place. You know, there was probably severe canal stenosis at this level prior to his surgery, but anterolesthesis and a PDOC at two, three result in severe canal stenosis and cord edema at this level. So he actually has a problem up here, even though it looks like he's decompressed here. So again, you really want the MRI to evaluate this. And then on the sagittal STR, the cord edema at two, three is a little bit more conspicuous. And just to hammer the point home that this is gonna show acute changes even better than the C2. The myelomalacia there looks pretty similar. This is the axle at that level showing the severe canal narrowing and cord compression. So the initial evaluation in trauma is almost always CT or plain radiographs depending on the level of suspicion for injury. MRI cervical spines reserved for cases where cord or ligamentous injury is suspected, particularly if this would necessitate surgical intervention. You gotta remember that MRI takes time about 30 minutes and the patient has to be able to lay still to get quality imaging. So you have to kind of weigh that in a critical, where timing is critical. There's also something called Skewora, spinal cord injury without radiographic abnormality, which is kind of like those cases I was showing where the CT is negative, but the MRI is gonna be positive for findings. So cervical vertebra are much less likely to have compression deformities than thoracolumbar vertebra. And that's just because they're not as weight bearing. So you have to have an increased threshold. This is showing, there's clearly some height loss here and a little bit of compression, but when you get the MRI, it shows this edema and all these other vertebra also have subtle in-plate. You could call them, you know, minimal compression deformities or contusions. So you really need to have a heightened sensitivity or a lower threshold in the thoracolumbar spine. These are age indeterminate. You get the MRI and it shows you these are acute or subacute because there's still edema or ongoing microfracturing. So here's a 41 year old male status post-trauma. Sagittal CT shows mild degenerative changes, prevertebral soft tissue swelling, but no traumatic osseous injury. There is a mild offset of the spinal laminar line here. Again, this guy's young. You get the sagittal T2, it shows severe canal stenosis and cord compression at the level of C3. And this is a follow-up sagittal T2 some months later showing that he had, you know, he ended up developing myelomalacia in the cord at that level. So this is just another example of the fact that, you know, there's obvious injury here because of the prevertebral soft tissue thickening. And in conjunction, although this is subtle, if, you know, they've got symptoms, you want to go to the MR and you see all this edema here from that acute compression. Here's a motor vehicle collision, sagittal T1. I mean, sorry, a sagittal CT showing accommodative fracture at the base of C2. Widening of the C2, C3, inner spinous space, widening of prevertebral or thickening of prevertebral soft tissues. And then the sagittal T2 shows this prevertebral effusion, a ton of edema here and, you know, a cord contusion in the, you know, in the upper cervical cord here. So a surprising number of incidental type two odontoid fractures are seen in the elderly, both on CT and MRI. This patient had a cervical decompression for degenerative changes in the sagittal CERD demonstrates hyper intense signal in the odontoid neck, multi-level laminectomies, this is post-surgery. And the same patient had a fall a week prior to that. And this was on an outside hospital and it wasn't called. And that's a subtle, subtle non-displaced type two odontoid fracture to the odontoid neck there. You kind of see it on the sagittal radiograph. So this was missed. And then you see that edema on the cervical spine showing that this really was probably a week old fracture from his fall. And these were the uploaded outside hospital CT. So I was actually able to contact the neurosurgeon because I read this one and knew they were planning for surgery and they went ahead and proceeded with the surgery, but were aware of the fracture and, you know, took appropriate steps to stabilize the spine during intubation and whatnot. So here's a grade one anterior lesthesis of C6 on C7 showing accommodated fracture of the C6 articular pillar. And then, you know, you have traumatic anterior lesthesis contributing to severe canal narrowing with cord compression and cord edema. You know, these are probably locked, you know, at least perched, probably locked facets here. And this is showing all the edema in the parasagittal spine. Another case showing perched facets here and locked facets. This is moved anterior. So this has to be decompressed in the OR under traction. And the interesting thing about this is as severe as this looks, this guy, because he had a patchless cord, I mean, a patchless canal actually didn't suffer a cord injury. So it's just a reminder that every patient is different. You really need the MRI. I would have been very worried about cord compression here because of the severity of this injury. But luckily for him, you know, he had no long-term sequela. So let's move on now and look at some infection cases. This is a sagittal radiograph showing an ACDF and there's notable thickening of the prevertebral soft tissues here. Just, this is the same patient one year prior. He had basically no thickening. So, you know, this is abnormal. And here's the MRI showing a hypodense, a peripherally enhancing collection around the fusion hardware. So this is basically, you know, hardware infection with development of a prevertebral abscess. And this is gonna have to be drained. There's another patient. This is a prison inmate with neck pain and muscle spasm. This is a sagittal T2 sequence. And this is, these are sagittal T1 and an axial T1 post-contrast showing these large peripherally enhancing collections in the prevertebral space. So this is some kind of dischitis osteomyelitis. And this is, especially again, in the prison population, you would be worried for something like tuberculous dischitis osteomyelitis or POTS disease. And indeed, that's what this is. Whereas, you know, bacterial staph dischitis osteomyelitis is usually centered on the disc space and is often quite destructive. This can be an indolent process. And the imaging findings are often quite out of proportion to the cervical, I'm sorry, to the clinical findings with POTS. So this one, on the other hand, there's a 50-year-old diabetic. You've got hyper-intense or you have enhancement in the vertebral bodies and the disc space. You've got enhancement within the, circumferential enhancement within the epidural space. So this is more classic of like a bacterial dischitis osteomyelitis. And this is the kind of thing that can also cause, you have to watch this. If you have a big abscess, you can get a cord compression that requires, you know, decompression and surgical drainage. Sometimes they can just be treated. This was a case of rapidly progressive dischitis osteomyelitis with vertebral body collapse. So this is the case I was showing. This is 8-26. This was 8-31. A couple of days later, you see how chewed up those vertebral bodies are. And he, you know, and he ends up getting collapse of the vertebra and a focal kyphotic deformity here. So let's now look at tumors real quick. And tumors come in a couple varieties. You can get tumors of the bone or, you know, the spinal canal. And then you can also have tumors of the, you know, within the canal and they can be intramedullary, meaning they're in the cord parenchyma. They can be extramedullary, but intradural, meaning they're not within the cord, but they're within the dural space. And finally they can be extradural. So intramedullary tumors are commonly astrocytoma, ependymoma. You can also get hemangioblastoma. Metastases to the spinal cord are pretty rare. You don't really see that very often. If you see a lesion within the cord, it's probably one of these three, if it's neoplastic or, you know, it's an inflammatory or infectious process. Cavernous malformations, I would also include on this list, you know, can be intramedullary tumors. Extramedullary are gonna commonly be meningioma, peripheral nerve sheath tumors. You know, these are schwannomas or neurofibromas. And then extradural includes these, but also includes any masses coming into the, the epidural space from the spine itself. You know, like we saw those, you know, epidural flood mounds, you know, in trauma, you can have an epidural hematoma, you can have, you know, basic, I mean, any kind of viscosteophyte complex technically is an extradural mass, right? So anything protruding in from the spine or even surrounding soft tissues is an extradural lesion. So here's an example of an astrocytoma. I think it's been operated on in the past. You know, this is, you got a laminectomy bed with a seroma here, but this hyper intense T2 signal, mild enhancement, expansion of the cord. It's obviously intramedullary. There's a claw sign. You can see normal cord parenchyma expanding around this lesion. This is a primary spinal cord tumor, intramedullary in this case, an astrocytoma. Astrocytomas and ependymomas can be like quite difficult to differentiate based on imaging and their incidence in the population is also pretty similar. So a lot of times you just kind of get the differential, you know, it's an intramedullary tumor, probably astrocytoma or ependymoma. So here's an example of an intramedullary intradural lesion. And you know, it's intradural because it's expanding the subarachnoid space. If it was extradural, it would be pushing the subarachnoid space. And, you know, this is a peripherally enhancing, peripherally enhancing, centrally hypo-enhancing mass resulting in some canal stenosis and cord impingement. So this, again, is probably given the incomplete enhancement gonna be a peripheral nerve sheath tumor of some variety, but in this location, meningioma is also, you know, what you would wanna consider. And in this case, it actually ended up being a meningioma. The patient became quadriplegic in the recovery room, an emergent MRI was done, and it showed this hypo-intense collection in the laminectomy bed and dorsal epidural space. And that was in keeping with an acute post-operative hematoma that's causing cord compression here. And again, you see CSF here. So this is an extradural collection. It's bleeding that's compressing the, compressing the fecal sac from the outside. Here's the cord here being compressed. So he emergently, he was emergently decompressed and they found that he was oozing from the bone margins. This is a follow-up MRI showing persistent cord edema at C6-C7, but resolution of that acute compression. Here's a hyper-intense STIR lesion, expansile filling, basically completely replacing the spinous process here, showing, you know, this is pre-contrast, post-contrast showing enhancement. So that's in keeping with a plasma cytoma, which is sort of the localized form of multiple myeloma. And again, that's an example of something causing, you know, external compression of the cord. So just to kind of review real quick, before you order an MRI cervical spine or any study for that matter, be aware of the kind of information it can tell you and its limitations to make sure you get the right study for the clinical question you're asking. And to do that, you want to provide an accurate history with a specific clinical question, if you can, that will increase the likelihood of getting the correct study and having the question specifically addressed. Remember that protocoling goes into this. So, you know, there are different types of, even within cervical MRI or brain, you know, that you can get and the radiologist, you know, wants to get you the right answer and the right study, but the more information you can provide them, the more likely you are for that to happen. And then before you review an MRI, be familiar with the sequences present and what to specifically look for on each type of sequence. And then when you're reviewing the MRI, go through the study in a systematic way, you know, get in the habit of looking at each study the same way, in this, you know, every time, resist the urge to jump to obvious findings or to look specifically for what you expect to find. If it's there, you're gonna come to it in your search pattern. And then in that way, you won't miss unexpected or more subtle findings. So I thank you for your time. And that concludes my webinar. Thank you for having me.

lecture

Cervical MRI

John Hyman

neuroradiology

MRI basics

cervical spine MRI

pathologies

diagnosis

appropriate use criteria