Bone measure on MRI+ my MRI + POWER RATIO

pattismith

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Maybe someone has an idea on this issue...Atlas Dens Interval measure...
There is a dark line around my bones on the MRI. Is it just a part of the bone that looks dark (red measures would be the good ones), or is it a separate structure (not bone related, so green measures would be acurate in that case).
Trying to measure my Dens-Atlas-interval, if I use these two possibilities, I found two different measures, with the red one twice as much as the green... Which would be accurate?

darklinebones.jpg
 

pattismith

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@sb4
looking at Dr B measures on this pic (a member of PR with AAI ), we can suppose that the black line around bones is part of the bone, which means that my ADI is probably fine

starmeasurebologneseb.jpg
 

pattismith

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@sb4

I found another measurement used in spine injury to detect atlantooccipital dislocation: The POWER RATIO

https://www.orthobullets.com/spine/2014/occipitocervical-instability-and-dislocation

1569227242886.png 1569227343257.png

1569227276173.png
Classification system for atlanto-occipital dislocation (AOD). A, Type I or anterior dislocation of the occiput with respect to the atlas. B, Type II or vertical displacement. C, Type III or posterior displacement.


"measurements
  • used to diagnosis occipitocervical dislocation
    • Powers ratio = C-D/A-B
      • C-D: distance from basion to posterior arch
      • A-B: distance from anterior arch to opisthion
        • significance
          • ratio ~ 1 is normal
            • if > 1.0 concern for
              • anterior dislocation
            • ratio < 1.0 raises concern for
              • posterior atlanto-occipital dislocation
              • odontoid fractures
              • ring of atlas fractures"
I did my Power Ratio Measurement: 32.13/46.68 = 0.69!!
So clearly have an Atlanto-occipital posterior dislocation/ horizontal instability in neutral position

CDAB0,69.jpg
 

valentinelynx

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@pattismith you are on the right track it seems. You are an awesome researcher! As I commented on a different thread, the ADI is supposed to be measured on a CT scan or plain X-ray film because MRI does not show the true borders of bone, only the marrow. I learned this from a talk by Dr Bolognese. Strange that I didn't learn that in medical school! We didn't have much exposure to radiology (no pun intended...)
 

sb4

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I second that you are providing great value with your research. I also note @valentinelynx that it indeed is very hard to read bone stuff on my MRI images. Hence my latest shameful attempt:
ratio.png

I am really not sure if I have gotten my opisthion bone correct. Very hard to tell on all my images where it is. What do you think? If these measurements are correct then my POWER ratio is 0.56 however, again, I am not confident I have gotten the opisthion correct. Also my MRI doesn't look like Type 1, 2, or 3...
 

pattismith

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@sb4
I think your measurement is correct.
In Dr Gilete web page, I found this mri of a patient with cci. Although his Grabb Oaks is bigger than ours, his Power ratio is like mine 0.69...yours is even lower....Maybe Dr Smith could explain your low Power Ratio?

1569265258637.png
 

pattismith

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@sb4
I did some more investigations on the Powers Ratio, some articles say just that it must be less than 1, other one between 0.55 and 1 (sometimes 0.9), so it isn't really a measure that was much investigated.
Posterior dislocation is considered rare, this may be a reason why the lower limit is not well known.
Nervertheless, your ratio seems really low, and may get some attention.
 

pattismith

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While docs were not interested to look deeply into my neck MRI, I paid more attention to it.
After I discovered the deviation of my neck to the left, I was curious to find the cause....

And I found two structural anomalies, likely to be present at birth (anomaly of the right internal jugular vein), or from the teenage (slight scoliosis of neck and upper thoracic spine).

Here a normal axial T2 neck MRI, with the right internal jugular (on the left) is bigger than the left IJ vein:

normalesIJV.jpg


here my neck MRI with asymetry, and small right internal jugular vein (collateral veins also seem more developped on the right side):

veinesjugulaires.jpg

On this sagittal MRI, on the left side of the median plane, the cord appears at C3-C4-C5 in first. It fits with the spine curve to the left side at that level.

scoliose1.jpg

On this picture taken on the right side of the median plane, the upper cord still apparent, which fits with a deviation of the skull to the right of the thoracic axis.

1570162870599.png
 

sb4

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@pattismith That does look like quite a big difference. I remember reading about neck veins being bigger causing symptoms when I was investigating the Driscol theory. You say you have EDS?

Where you using Axial T2 or GE to obtain that image? I couldn't see anything that resembled veins on T2 but saw things that looked like normal veins on GE.
 
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Can anyone take another look at my MRI? I'm yet to get it evaluated.

Yes I have a borderline clivoaxial angle, but what struck me as strange is that my clivus bone is abnormally small. It's nearly non-existent. The clivus bone in the above picture is at least five times larger than mine.

clivus.png
 

pattismith

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@pattismith That does look like quite a big difference. I remember reading about neck veins being bigger causing symptoms when I was investigating the Driscol theory. You say you have EDS?

Where you using Axial T2 or GE to obtain that image? I couldn't see anything that resembled veins on T2 but saw things that looked like normal veins on GE.
No I don't have EDS nor hypermobility. But I have some problematic laxity in the hips and spine.

My neck axial MRI is T2 only. Maybe you have T1 neck MRI? (CSF around the cord is dark), like the left google image below:

1570190147737.png
@Bowser ,

my clivoaxial angle is borderline too (and so is sb4),
but I never paid attention to the clivus size, I have no idea of any significance....
 

sb4

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vein.png

The one on the left is T2, the one on the right is GE. Taken from the same location. I can see why Bolognese likes supine MRIs as mine are quite blurry.

I speculate that the 2 white circles on the top half of the image to the right could be veins but IDK. What do you think @pattismith
 

pattismith

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@sb4
The 2 white circles are likely arteries.
Neck veins are smaller upright than supine, so we may not see them on your MRI