MRI after ADR

[2cool4U]

The attached image file is a single image from a lumbar MRI. It is not my spine. The large area of distortion obscuring L5 and S1 is from an artificial disc, specifically a Charite in this case. I have noticed a lot of discussion on the site about MRI after ADR surgery. A complete MRI study consists of multiple images obtained in different orientations. Metal artifact does vary slightly depending on the exact type of image being obtained. However, it is usually this apparent. I thought you folks might appreciate the visual example. I will try to find a CT image obtained after ADR to demonstrate how metal affects CT images.

[kimmers]

Yeah,

TConner, that is about what it looks like.
I looked at mine and called it a big blot.
Definitely, cannot tell what is going on at the ADR level.
Thanks for the image.
BTW, it looks like L3/4 is a black disc. Is that so?

Kimmers

[2cool4U]

Yes, the L3/L4 level is abnormal. There is loss of water content, but disc height is preserved. This patient was imaged due to persistent pain after ADR, but I don't know any more followup.

[kimmers]

Persistent pain after ADR? HUm.

Sounds familar.
So I think I asked you this before. What is the best imaging test after ADR?


Kimmers

[2cool4U]

It really depends on the symptoms. If signs point to a new problem, the MRI is the easiest way to go and doesn't involve anything invasive. Some MRI sites will always give IV contrast if you have had back surgery. That is because scar tissue around nerve roots and disk ruptures around nerve roots can look exactly the same and therefore the diagnosis can't be made. IV contrast (multiple brand names) will cause scar to look brighter but ruptured disk material won't, so you can make the distinction. This is important, as the treatment for symptomatic scar is different from ruptured disks.

However, IV contrast is probably not needed after ADR since the surgical level can't be seen anyway and the disk has been completely removed. MRI done in this situation is usually for evaluating all the other levels, and in that case IV contrast isn't needed. However, not many MRI sites are familiar with ADR, so when they hear "back surgery" on the phone or see it written on your history form, they automatically give contrast. The good news here is that the contrast agent is very safe. It is not chemically related to the slightly riskier IV contrast agents used for body CT's. However, giving it does add about $100 to the cost of the MRI, takes another 5 minutes, and requires a painful injection.

Routine CT is not very valuable in assessing the lumbar spine except in trauma situations. It does give info about facet joints, but nerve roots and disc disease are not well seen.

CT myelography is probably the best method overall, but in my opinion should be preceded by an MRI just in case the MRI answers the question. CT myelography involves a lumbar puncture under fluoroscopy in which 10-20 cc's of contrast (the same contrast given intravenously for other CT's). Some radiologists then do routine x-rays, while others may skip them. The patient is then taken for a CT of the spine within 2 hrs. of the injection.

Now, there will still be artifact at the ADR level on CT, but it's a little easier to account for and you can still get some info about the dura, nerve roots, etc. at the ADR level. In the MRI picture in the original post, you can see that the entire ADR level is distorted. On CT, picture a star pattern of bright streaks with the center of the pattern being the metal. Often, you can see structures between those streaks or you can manipulate the grey scale on the computer screen to make them less obstructing.

And there you have it. I considered all of this prior to my surgery, and decided to proceed knowing that I might need a myelogram in the future. I've done hundreds of myelograms during my career, but most of them were done in my early years. MRI gradually took over and myelograms are now rare. We do them when patients have pacemakers, aneurysm clips or other devices that prevent MRI. I'm not at all concerned about having a myelogram should I ever need one, but I'm hoping that my single level disease has been adequately treated.

[kimmers]

Thanks TConnor,
that explains a lot.
I knew the MRI would have artifact before I had the ADR surgery, too. But you cannot control everything.

The workers comp doctor I saw last Thursday, asked me if I had a myleogram yet. I was told they are not supposed to give you any advice, but he indicated that my doctor might want to do a myleogram.

At one point, I also thought I had one-level disc disease but when I felt I tore something back in late August, I thought i had problems with another disc. This severe sciatica has kind of cemented this idea. I figured if it went away, i might just have a temporary problem. But because it has lasted since September, I think it is another disc. Plus the dermatone of my numbness and pain matches with the L5/S1 disc.

So now it is just a waiting game. Seeing if the epidural will "kick in" or all I will get is the one to two days that the sciatica seemed a little less. I am glad you are not afraid of the myleogram, most people I have spoken to personally didn't mind the test so much. That is of course, if they didn't get a headache.

My back pain has also increased this month, leaving me with the feeling that things are going south. I am leaving it up to the docs because both my neuro and pain doc are reallly good. I just don't like the feeling that I am in more pain and all the things it means like loss of independence and loss of interest in the things I like to do.

Hope you are feeling good,

Kimmers

[JudyW]

My post ADR MRI was an "inkblot" also. I figured if i had problems with facets at that level they couldn't be seen because of the distortion but I don't know. I just had a post op MRI on my shoulder after a labral tear repair and it had some artifact distortion also. All that metal, plastic, and whatever else is in my body...bionic woman...I wish!!!