the MRI essentially shows two
separate views of the spine a side view or a sagittal view and a bottom up view called the axial view on the side view we literally take a samurai sword and we
slice the spine like a loaf of bread into different
sections and that is represented by this side view here on the MRI the bottom-up view is essentially axial slices and you can see here the disc which would be located right
here the center of the canal here where you see the nerves and then the two facets on either side
in the back which she is represented on the MRI
here and here now we’re going to examine a normal lumbar spine we have two views of the spine we have this side view here and we have the bottom-up view here on the side view you can see that this side view
corresponds to this line in the cut of where we are cutting the spine in half literally so if this arrow or this line is right
in the center of the spine this is the center cut of the side of the spine move this line anywhere and we can see cuts for example to the
side of the spine here we can move these lines to get to the other side of the
spine there so this line that we’re looking at on the right side indicates where the
cut is on the side of the lumbar spine here to get to the anatomy this is the spinal cord the spinal cord ends about right here and then the spinal cord exits into the
cauda equina which are the peripheral nerves which sit in the center of the canal we don’t see the nerves coming all the
way down because they start to exit if i move this cut over to the side you can
actually see the individual nerve roots on one side we go back to the center and then cut on the other side and again
you can see the individual nerve roots on the opposite side the white material in the center here is cerebral spinal fluid which is
essentially water on this particular scan called a T 2 scan water is white you can also see the fat in the back
here the fat is also white mimicking the water these are the vertebral bodies that i’m circling here an in-between
the vertebral bodies are the discs the vertebral bodies are named for the
five lumbar segments so this is an L one L two L three L four and L five the lumbar spine as we talked about
before sits on the sacrum and this is the sacrum the sacrum has some of the
discs but they’re not relevant and this is
really one bone we name the discs for the vertebra they are sandwiched in
between so for example this is the L five
vertebra and this is the sacrum we call S one
so this is the L five s one disc as we go up this is the L four five disc the L three four disc the L two three disc the L one two disc and the T 12 L 1 disc
as we are now in the thoraic spine the vertebra themselves have a normal grayish hue which is a little indeterminate that’s what bone looks like which is filled with osseous structures and with fat the edges of the bone on the side you’ll
see these little black and white areas these are where the veins of the bone
exit called the basi- vertebral veins and they’re normal if we follow back here we can see this spinal processes of the vertebra in the very back an in-between we see both muscle and ligament that hold these vertebral processes
together we can take the side and come to the outside where the nerve holes are and now we can visualize the boney tunnel called the foramen where the nerve
exits in this case this is the L two nerve sitting in its white fat which is
nature’s packing in the L two three foramen here is the three four foramen and this is the L three nerve right here in it’s fat packing here is the four five foramen with the L four sitting in it’s fat
packing and the l five s one foramen with the l five nerve there we can conversely go to the opposite
side and see the exact same thing with the nerve roots exiting out the
foramen if we then go to the top down view here we can look at the angulation and cut of the spine and visualize the spine is what it
would look like if you took a samurai sword and looked up at the spine from there we’re going to start at the L five S
one disc at this view this is the dural sac the sac of nerves all these black dots within this white
sea of water are the nerve roots and these are the nerves that hae already exited out of this sac these nerves exit like branches on a tree so this is the five one level and as we march up we can get to the four five level before five level here you can see the
normal disc which has the jelly on the inside the
outer plies of the tire on the outside the back of the disc being either flat or
little concave all of the nerve roots sitting in the area here of the dural sac and then these are the two facets and back some people say that facets looks somewhat like hamburgers with the
buns where you have the meat a little
mustard on the inside and the two buns on the outside these
are normal facets we can march up then and go to the next level and three four and again see the same
thing the jelly filled donut the outer plies of the tire the sack of nerves we get a little higher we can see the
actual forcet joints and this is a normal level we can continue to go up and see more
here is the basi vertebral veins and some of the veins within the
vertebral body itself so when you look at these images these are normal