Tuesday, 24 May 2016

Tracing your lesions through the MR Myelinoscope - news from the imaging department

Longitudinal Observation of Individual Multiple Sclerosis White Matter Lesions Using Quantitative Myelin Imaging
Kitzler HH, K√∂hler C, Wahl H, Eisele JC, Deoni SC; Rutt BK, Ziemssen T, Linn J. 
Poster # 1282, 24th annual meeting of ISMRM

One of you recently asked the question whether lesions on MRI can disappear, and I said yes they can, and that this has to do with several factors including lesion severity (lots of axonal loss or not), subsequent lesion repair, and the tools & techniques used to detect them (or not).  Now I just returned from Singapore after attending the International Society for Magnetic Resonance in Medicine (ISMRM), where I saw this work using an MRI technique optimised for detecting the myelin content in lesions (let's call it an "MR Myelinoscope").  It nicely shows that whilst lesions may look the same on our standard workhorse MRI, they may be quite in different "states" when looking through the MR Myelinoscope.

The panel above shows that over 12 months lesions on FLAIR (standard workhorse technique, top row) don't change very much, however the Myelinoscope (bottom row) shows dynamic change over time (see arrows): A lesion hardly visible at month 0 is largest at month 3 (demyelination), and then smaller (suggesting remyelination).



Panel showing 4 different lesion "states" (differences in myelination status over 12 months) using the MR Myelinoscope whilst standard FLAIR doesn't change.

Nice work indicating how crude our current standard MRI techniques are in monitoring the severity and dynamics of tissue changes within MS lesions.

Whilst the MR Myelinoscope technique is quite complex to implement, and therefore not available at many centres, it could be useful in trials of potentially remyelinating drugs where only a limited number of centres would be involved.

CoI: none

7 comments:

  1. Dear Dr K,

    Can the Myelinoscope be implemented on a standard MRI machine? Is the implementation hardware or software, could I somehow process my existing scans to create the Myelinoscope picture?

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    Replies
    1. Yes, it runs on a standard scanner, but in order to extract the relevant data a specific acquistion is needed. Unfortunately, you can't use your standard scans.

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  2. Replies
    1. All nuts and bolts in place now - no further sudden closures on the horizon.

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  3. Thanks for the entry. I asked my partner's neuro some time ago whether lesions disappear. She said no. I was curious when I saw the 30% of lesions disappear (whether due to repair or imprecise imaging techniques). At the time, I wanted to know if there was any lesions that disappeared or shrunk because they were having a lot of trouble deciding her phenotype. Given the reliance on conventional MRIs when going on or changing meds, is there any kind of estimation on the percentage of lesions not picked up by the conventional MRIs - but picked up by the 7t?

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  4. Thank you for your comments!

    Re Bozo Forgot:
    Given the higher signal yield of 7T the higher resolution combined with preserved conventional contrasts (e.g. T2 weighting) it might pick especially more very small MS lesions. But beside such quantitative aspects notable new insights into MS lesion composition become possible with new contrasts at higher field strength.

    However, more (field strength) does not always mean better. Since 3T machines at moment become the most spread workhorses at least in the Western world, using them ist the way to go. From the imagers perspective we need to refine what’s technically available in the best possible (here imaging biomarker’s specificity) manner.

    Dr.K, thanks for the consideration of our work in this Blog!

    Greetings to London from Dresden, Germany

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    Replies
    1. Thanks for the reply Hagen H. kitzler. It's great to hear directly from those involved in the reported studies!

      I think your answer re 7t MRIs is in line with this report - http://www.sciencedirect.com/science/article/pii/S0720048X11006450. My question was really asking whether we should be withholding immunosuppressants from those exhibiting new symptoms or what seems to appear as new progression on the basis of lack of new lesions shown on standard MRIs. I do appreciate your perspective and don't disagree.

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