Lumbar Spine Radiology Tutorial

0:01 welcome back this is Dr Motley and today we're going to do a lumbar spine tutorial the standard radiographic projections of the lumbar spine are AP lumbar or sometimes AP lumbo pelvic combined with a lateral lumbar projection there are several additional projections that can be done in the lumbar spine including lumbar obliques which are going to be done as a separate tutorial as well as AP angulated spot or PA angulated spot projections as well as lateral lumbo sacral spot projections these projections are typically used to see uh the lumbo sacral Junction very well of course I'm referring to the AP and lateral uh lumbo sacral spot projections to see the lumbo sacral Junction very well and of course lumbar

0:47 obliques are to assess the pars interarticularis as well as the facet joints so let's begin with some basic radiographic Anatomy the thoraco lumbar region is a very important region because as true with any transitional area of the spine anomalies can occur now this is T12 and of course you can see the T12 ribs which are here sorry I just had to make my pen a little thinner T12 rib on the left and here's the L1 segment now the most important thing to do is to count how many non rib bearing segments you have in this particular case we are demonstrating five non rib bearing segments which suggests that there's no transitional area anom ales I am not visualizing any ribs coming off

1:32 of the L1 segment now this is important to um observe because counting levels can be thrown off if you mistake the L1 segment for the T12 segment for example so just be sure to count your lumbar segments before you start writing a report uh of course the vertebral bodies we can see very well each vertebral body has a superior and inferior end plate now this patient has a little bit of lateral curvature as you can see here they have a very very mild right convex curvature of their lumbar spine but anytime the lumbar segments are slightly tilted the Superior in plate can look slightly ovoid or circular as if you're looking at a can a soda can from the side and tilt it slightly towards you

2:18 you can see the superior surface of the can so just understand that with any curvatures in the spine the vertebral end plates may look exclusively linear as in this case or may look semicircular as in this case up here moving on the intervertebral disc space obviously we're familiar with the Lucent region between each intervertebral segment here are our pedicles also known as the eyes of the spine here are our transverse processes extending off laterally which takes care of the more front all right let's move on to the posterior Arch now the posterior arch in the lumbar spine is seen very well let me just is draw it out for you and then we can go through and identify each structure within that

3:05 posterior Arch these portions of the posterior Arch are the superior articular processes which have a articular surface on them to make the Facet Joint these are the inferior articular processes that also uh will articulate with the segment below the region in between the articular processes let me just draw it on the other side this this region here the region between the articular processes this region is called the pars interarticularis region and this region is important because we can have findings here that may lead to patient symptomatology and we'll talk about that a little bit more in the oblique tutorial simply because the pars is seen

3:50 the best on oblique projections just next to the pars inter articularis is the lamina and of course the spinus process now these structures can again can be seen very well on the AP projection but combined with the lateral we can get clear visualization of all these structures now to continue on with our anatomy let's make our way down here to the sacrum here is the sacral base here is the sacral iliac joint and you can see those on both sides now depending on whether you have a AP lumbal pelvic or whether you have a AP lumbar you will see a variable amount of the pelvis you can also see margin of an anterior sacral foramen which are all almond shaped here is slight visualization of a posterior sacral foramen which are more p-shaped and so

4:37 anterior for raymen are almond shaped posterior for raymen are p-shaped and the reason why I'm giving you these food analogies so that you can remember the letter they begin with to uh appropriately describe the circular shape of a posterior sacral forment versus a more ovoid shape of a anterior sacral for rmen what else can we see on the lumbar spine well we can definitely see the shadow of the soaz here's the margin of the soaz musculature and you should be able to see the soaz margin very well there are certain conditions that can obscure our visualization of the sfe excuse me soas shadow such as spinal infections such as AES in the

5:23 abdomen along with some other abnormalities of course we can also see ribs and sometimes you can see kidney Shadow which we don't see very well but would live somewhere in this vicinity here we don't see the rib margin exquisitely however you can tell the density change between here and the more Lucent area here and this grayness is caused by the liver in the abdomen you'll see a variable amount of bowel gas so just be aware that there can be loosen seas that can mimic lesions and bones that are actually gas Shadows so if you can follow the shadow outside of the bone you can be sure that it's not within the bone and therefore comfortable to call it a bow gas now you can see the facet joints here notice

6:09 that there's a slight lucency here and you'll notice that it's between the superior articular process of one segment and the inferior articular process of another segment making the Facet Joint we're going to now move on to the lateral projection here here is the lateral projection of the lumbar spine in this projection we can see the lumbar vertebral bodies very nicely notice that the vertebral segments are visualized here vertebral body inferior in plate Superior in plate now as we know from our previous tutorials that the next structure that comes posterior to the vertebral body is always going to be the pedicle and here we can see the pedicle

6:55 very nicely the next structure is going to be the articular pillars here's the superior articular process here's the inferior articular process and here in this area is the pars interarticularis pars interarticularis again lives directly between the superior articular process and the inferior articular process now this region can undergo stress fractures typically in adolescent patients or young patients you should be able to see a lucency from the lateral projection if a pars defect defect is is present however remember that we're looking through both bars interarticularis both the right and the left side which can make a unilateral pars defect very difficult to visualize on a lateral

7:41 projection the oblique projections will isolate one/ half of the posterior Arch to be seen very very well and in this case we can identify pars defects that may be unilateral or subsequently bilateral to finish out with our anatomy here is the spinus process now the lamin in the lumbar spine are very very short can be visualized in oblique projections very well but on the lateral projections not seen very well intervertebral disc spaces here is the sacral base here is the anterior margin of the sacrum here this little inconspicuous lucency is the S1 S2 rudimentary disc area we can also see ribs here's a posterior aspect of a rib and here's some more anterior

8:28 aspects of the ribs now of the things you may see is a lot of calcification within the costal margin costal condal Junction this is normal physiological calcification this patient doesn't have any just as a note to self you can see a significant portion of calcification in this area whether it's on an AP or a lateral projection uh which is indicative of calcification of the costochondral junction this is an incidental finding and means nothing to the care of your patient and these are the structures of the lumbar spine I don't think we missed anything I oh I failed to mention that you can see intervertebral foramen on a lateral projection in the lumbar spine in the lumbar spine if we take just a quick axial view here's the lumbar vertebral body in this region the pedicles come straight posterior word now this is

9:15 different than the cervical spine in which the cervical pedicles actually extend quite posterior lateral from the vertebral body and since we know that the pedicles are the superior and inferior margins of the intervertebral fmen their orientation will dictate on which view we can see through the intervertebral foran so again in the lat in the lumbar spine they come straight posterior which is why when we take a lateral projection we can see directly through the intervertebral veren As Seen very nicely here whereas in the lumbar excuse me in the cervical spine the orientation of the pedicles off of the body are at a 45° angle and therefore we need to oblique the patient to the Bucky

10:02 in order to visualize the invertebral forment now as an instructor this is a question that is very commonly missed uh in terms of what view can you adequately visualize lumbar spine into vertebral pamen you simply have to remember that they're seing on the lateral projection and also that the oblique projections are taken for a different reason which is in fact the pars interarticularis I would recommend to watch this video in conjunction with the lumbar oblique tutorial and in order to evaluate the anatomical structures on oblique projections I hope this tutorial was useful and have a great day