An advent to MRI scans

The very very first MRI scan that the person body to be performed in 1977. Before this, us were basically making educated guesses about what was wrong with the spine. Today, the modern practice of spine surgery relies greatly on the interpretation of MRI scans.

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MRI scans part the human body into thin sections

Magnetic Resonance Imaging creates thin section pictures of the within of the human being body. This method allows united state to visualize anatomic frameworks from any type of angle and also direction. The two most typical slices that we look in ~ on MRI scans the the spine room the sagittal and also coronal slices. The saggital plane sections the human being body lengthwise. The axial aircraft creates a cross section of the person body.


An MRI photo looks like a photograph, but it is actually a computerized photo of the atom magnetic resonance that molecules within the human being body. These photos are premium to CT scans and also X-rays. The resolution and clarity that the photos is better, we deserve to see much more fine detail, and this test supplies harmless radio waves rather of ionization radiation.

MRI scans as a clinical tool

Magnetic Resonance Imaging is an remarkable tool that permits us to watch deep within the human being body v a degree of clarity the is absolutely amazing. We can visualize the tiny details of normal and also abnormal human anatomy. We can plainly see the intervertebral discs, spinal cord and also nerve roots. In enhancement to typical anatomy, us have also learned to determine a variety of findings the may cause neck and arm pain or ago and foot pain. The list of abnormal findings the we deserve to see on one MRI scan incorporate the following:

disc desiccationdisc degenerationdisc bulgingdisc herniationsannular tearsspinal stenosisneuroforaminal narrowing

We are going to look at examples of every of this conditions. However, prior to we do, the is important that you understand that after the age of 30, essentially every MRI scan the the human body is abnormal.

Every MRI scan ~ the period of 30 is “abnormal”

These 2 pictures describe why. The organic aging process causes transforms to every framework of the human body. The spine is no different. If we were come look in ~ the skin that the gentlemen on the right with a microscope, we would see proof of degeneration, ns of elasticity (which is referred to as elastosis), noncancerous skin growths (called keratoacanthomas), pigment changes such as liver spots, and thickening of the skin. These findings would all be defined as “abnormal”.


However, we could describe the skin on the best as “normal because that age”. We only explain it as abnormal when we compare it to the image of the baby on the left. Many people, even if they don’t have any ago pain, will still have evidence of abnormalities on MRI scans. Disc degeneration, bulging disks, and herniated discs occur very commonly and they might not be causing symptoms the pain. For example, in a paper published in the newspaper radiology, the researches found that roughly 90% of human being WITHOUT any background of ago pain in the critical 6 month still have evidence of annular tears, key degeneration, and disc bulging at one or many levels.

Therefore, the critical task once it pertains to interpreting MRI scan is CORRELATING the findings on the MRI scan through the patient’s complaints and also with the physical exam.

What a common MRI scan look at like.

This is an MRI scan of a 40 year old male. There space 5 intervertebral discs in the lumbar spine. We are going to begin with a normal level which has a common intervertebral disc. Every disc separates two bones dubbed vertebrae in the spine. In this case, this is the L3-4 disc. Above the bowl is the L3 vertebral body and also below the bowl is the L4 vertebral body. The center of the disc, the annulus pulpous is relatively white. The front and earlier of the disc, the annulus fibrosis is dark black, thick, and is not bulging into the spinal canal. The spinal canal is filled through white fluid, referred to as cerebrospinal liquid (CSF). Inside the CSF is the spinal cord and the nerve root that go down to the legs.


On the axial image, the neuroforamen are wide open and there is plenty of space available for the nerve roots.


Disc dessication

Using the same MRI scan, let’s look at a dessicated disc. Desiccation is the state of dryness, or the procedure of drying. The theory here is that when we are young, and also our discs space young, ours discs have a high water content.

When we space young, the center of the disc, referred to as the annulus fibrosis, has actually an electric charge the holds onto water an extremely well. The key is viscous, elastic, and also is a an excellent shock absorber. Through time, the center of the disk loses water content and the disc starts come “dry out”. I tell patients that all of our intervertebral discs begin out as fat plump grapes and eventually end up prefer raisins. As with us.

Disc Degeneration

Disc degeneration is a an ext advanced kind of key dessication. In addition to the cell core pulposus dry out, the key starts come collapse. Bone spurs type around the edge of the intervertebral disc. Bowl degeneration is the exact same thing as degenerative arthritis. This condition is inevitable. It’s simply as certain as death and taxes, and also it will occur to anyone if castle live long enough. The one point that predicts even if it is or no you will have actually degeneration of her discs is the variety of birthdays you have had. The more birthdays, the more evidence girlfriend are details to have of bowl degeneration.


Disc bulging and herniations

Disc bulges and also herniations come in every sorts of sizes and shapes. Together the disc starts come degenerate, it deserve to bulge out towards the spinal canal and the nerve roots. This first example is described by the radiologist as a “herniation”. This herniation is still had by the annulus. Together such, that is probably much more accurate to define this together a disc bulge.


In contrast, this instance shows a really huge disc herniation. In this case, the nucleus pulposus has actually herniated completely through the annulus and there is a large cost-free fragment of disc material filling the neural foramen and completely obstructing the normal path for the exiting and traversing nerve roots.

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Annular tears top top MRI scan

Annular tears are a an especially interesting recognize on MRI scans. They stand for a partial key herniation where just a few of the fibers of the annulus fibrosis remain. Here is a short video illustrating the usual findings in an annular tear.