Does anyone understand a Quantiitave Iron Data Report? The chart has 1000 normal controls, 1000 MS patients, and then me. The amount of Iron is displayed in a negative number.
My amount is High-iron tissue mean phase of -10.062.
The left side of the chart HITMPV(ppb) are all negative numbers. The bottom of the chart shows various ages. Does anyone understand the use of the negative numbers?
Quantitative Iron Data Report Question
I don't understand it but I'm curious: what are the numbers for the normal controls and what are the numbers for the MS population?
"However, the truth in science ultimately emerges, although sometimes it takes a very long time," Arthur Silverstein, Autoimmunity: A History of the Early Struggle for Recognition
got my answer
I got an answer, very good one.
Short answer:
We are actually measuring the phase values. Iron decreases the phase (darkens the image). The value you see on the graph is the amount of "darkening" theoretically caused by iron. The lower the value (ie more negative), the more iron that is present. See below for explanation of the use of parts-per-billion.
Long answer:
All MR images are made from observing "spinning" protons (in a quantum-physical sense). The presence of iron near protons changes this rate of spin, creating a phase difference that can be observed. In this case, iron causes the spins to dephase negatively, resulting in lower phase values for those protons near iron. One complicating factor is that the amount of phase change from iron is also dependent on the magnetic field strength of the scanner. To adjust for that and make the number comparable across labs with different equipment, we express the amount of phase change not in absolute terms (radians), but rather in relative terms (parts per billion). So, the ppb measurement isn't an absolute quantification of the iron atoms, but rather of the observed phase values. There have been theoretical approaches proposed for converting from this phase value directly to a "true" absolute iron concentration (which confusingly would also be expressed in ppb), but these conversions are based on a number of assumptions that may not always hold. Thus, we prefer the more "honest" approach or reporting directly what we observe, which is the phase values, and showing how they stand relative to other experimental groups (via the scatter-plots in the background and regression lines in the foreground).
We will be sending a "how to read this report" document in the near future.
I hope that adequately answers your questions. Please let me know.
Short answer:
We are actually measuring the phase values. Iron decreases the phase (darkens the image). The value you see on the graph is the amount of "darkening" theoretically caused by iron. The lower the value (ie more negative), the more iron that is present. See below for explanation of the use of parts-per-billion.
Long answer:
All MR images are made from observing "spinning" protons (in a quantum-physical sense). The presence of iron near protons changes this rate of spin, creating a phase difference that can be observed. In this case, iron causes the spins to dephase negatively, resulting in lower phase values for those protons near iron. One complicating factor is that the amount of phase change from iron is also dependent on the magnetic field strength of the scanner. To adjust for that and make the number comparable across labs with different equipment, we express the amount of phase change not in absolute terms (radians), but rather in relative terms (parts per billion). So, the ppb measurement isn't an absolute quantification of the iron atoms, but rather of the observed phase values. There have been theoretical approaches proposed for converting from this phase value directly to a "true" absolute iron concentration (which confusingly would also be expressed in ppb), but these conversions are based on a number of assumptions that may not always hold. Thus, we prefer the more "honest" approach or reporting directly what we observe, which is the phase values, and showing how they stand relative to other experimental groups (via the scatter-plots in the background and regression lines in the foreground).
We will be sending a "how to read this report" document in the near future.
I hope that adequately answers your questions. Please let me know.
I think mohzi may be referring to the Quantative Iron MRI @ Buffalo Neuroimaging Analysis Center (self-pay CCSVI testing option).. It may be a Dr. Haccke protocal??? The machine was a GE tesla 3.0 machine.shye wrote:How does one get this type of MRI? Special machine? Only in certain big cities? or ???
I was just there May 24th and 25th.. My Iron load was -9.275 which they said was high for my age... higher than the avg. ms'er my age.
They plot where you are on a graph and show the average person(s) line, and the average MS'er line... and plot where you are in reference to the averages.
An example (using estimates since the graph is not very detailed) for a person 40.. The avg. non-ms may show an iron load of say -7.5 and the avg ms'er the same age is at -8.5
On avg. the typical ms pt shows higher iron deposits than the avg. non-ms (healthy) person.. keep in mind (lol) that a bunch of other neurological conditions present with high brain iron load also (parkinsons, alzheimers).. so for now these tests don't reveal much.
It may be possible (some day) to correlate high iron load with ccsvi... but for now, it's anybodys guess.. I think Hackke will crack this nut if he already hasn't.
As far as getting this type of MRI... I'm guessing that any neuro. could order it.
- Forgot to add: As one ages we accumulate iron naturally.. so the older you are the higher the greater the iron load accumulation...
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It sounds like SWI to me. see:
http://www.ms-mri.com/index.php
And within: http://www.ms-mri.com/presentations.php there is a paper at the bottom explaining SWI further. This web-site came alive back in October 2009 (http://www.thisisms.com/ftopic-8344-0-d ... c-swi.html)
http://www.ms-mri.com/index.php
And within: http://www.ms-mri.com/presentations.php there is a paper at the bottom explaining SWI further. This web-site came alive back in October 2009 (http://www.thisisms.com/ftopic-8344-0-d ... c-swi.html)