159 pointsby hhs3 months ago6 comments
  • uecker3 months ago
    While this work is great, this will not directly lead to "sharper MRI scans". This is about better modelling of NMR signals, which may eventually lead to better MRI, but it is still pretty far away from imaging. If you want how we use simpler signal models in physics-based reconstruction to improve MR images, you can look at our paper: https://doi.org/10.1098/rsta.2020.0196
    • azalemeth3 months ago
      Indeed. Martin's a great name in the field -- the thing that has actually made most clinical proton MRI substantially better over the last twenty years has been parallel imaging (acquiring the magnetic resonance signal from different spatially separated devices known as RF coils) and associated reconstruction techniques such as compressed sensing.

      Given the fact that macrocyclic gadolinium complexes accumulate in the brain and the linear ones dechelate I think very few companies are pursuing new agents. I've done some work with different ions (like Dy, which has Curie paramagnetism) but a lot of focus in the field is trying to find alternatives to gad and reduce its use. There are plenty of great ways of getting more info out of a machine that spans quantum mechanics to medicine, from the established but now actually useful and routine (like advanced diffusion models) to the sort of utterly mad techniques I work on... [0]

      [0] https://www.science.org/doi/10.1126/sciadv.adz4334

      • olsondv3 months ago
        Advanced diffusion certainly benefited from the acquisition speed ups. That is its biggest challenge in my opinion preventing it from wider clinical adoption. It takes too long to get enough images for the models. Hyperpolarized MR will run into issue of lack of expertise in clinical imaging centers. There is already a shortage of good techs and MR companies are working to further automate the workflows. Unless there is a major benefit of the advanced techniques, people will stick to the bread and butter FSE and DWI.
      • alphydan3 months ago
        Funnily enough there's a different Martin (Martin Plenio) pushing the boundaries of MRI resolution using quantum effects (molecular hyperpolarization).

        https://www.uni-ulm.de/nawi/institut-fuer-quantenoptik/ag-pr...

        For a more technical intro, see https://arxiv.org/abs/2403.14521

        • uecker3 months ago
          Also cool, but it does not push the boundaries of MRI resolution. They try to bring a hyperpolarizer to market for a ¹³C-Pyruvate contrast agent, but it seems their hyperpolarizer is not yet certified. In any case, this will give metabolic information at low resolution so competes with PET.
  • iandanforth3 months ago
    FYI if you're getting a contrast MRI in the near future, avoid vitamin c. https://hscnews.unm.edu/news/unm-scientists-discover-how-nan...
    • wolfi13 months ago
      not only vitamin c but fruits containing oxalic acid if I read that right. But I'm far more interested in when such contrast agents are warranted, because I'm not aware that in Europe that contrast agent would be used that much for MRI
      • dcminter3 months ago
        For your anecdata I'm in Sweden and definitely had a contrast agent (presumably gadolinium based) for a recent MRI of my gallbladder/pancreas/liver area.
        • mstade3 months ago
          Same here, also in Sweden.
      • lurking_swe3 months ago
        see sections “Why Would I Need a Contrast MRI?” and “Which Types of MRI Require Contrast”

        https://www.ashospital.net/blog/why-do-i-need-contrast-for-m...

      • dorfsmay3 months ago
        > previous research has shown that even in those with no symptoms, gadolinium particles have been found in the kidney and the brain and can be detected in the blood and urine years after exposure

        So do you stop eating high oxilate and high vitamin C food for a year after the MRI? Are there foods or drinks that help flush gadolinium?

      • lostlogin3 months ago
        > I'm not aware that in Europe that contrast agent would be used that much for MRI

        I’m a New Zealand MR tech. Based on the practice of my European colleagues, they give it just as often as we do.

      • 30523 months ago
        I'm in the UK and getting one to diagnose ED/recurrent priapism.
    • elric3 months ago
      I have one planned soon. Of course the prescribing doctor didn't mention any of this, but I guess the research is still too fresh. Thanks for raising awareness.
    • sschueller3 months ago
      Many variants seem to be banned in Europe [1]

      [1] https://mblynchfirm.com/pharmaceutical-litigation/gadolinium...

    • Roritharr3 months ago
      Getting one on Monday, have a slight cold and took liposomal vitamin c just hours ago!

      Thanks for making me aware!

    • dwroberts3 months ago
      *If your scan involves contrast agent, which many do not
    • kyleblarson3 months ago
      My late grandfather had a severe reaction to contrast agent while getting an MRI and coded while in the machine. (They resuscitated him)
    • chrisweekly3 months ago
      thanks
    • vlovich1233 months ago
      I thought I read that in general it’s just better to decline contrast because it doesn’t actually add value to the scan.
      • jmhmd3 months ago
        It depends on the indication for the scan. Some indications do not require contrast, others MUST have contrast in order to have any value. If you refuse contrast without understanding the reason, you may be simply wasting your time and money.
  • Animats3 months ago
    Here's the paper.[1] No paywall this way; U.S. Government funded research. The paper claims an associated Github repository but there is no obvious link. There's no imagery in the paper, just the development of the math. So this may or may not help much.

    [1] https://www.osti.gov/pages/servlets/purl/3001752

  • ForOldHack3 months ago
    "However Gd is also retained in the brain, bone, skin, and other tissues in patients with normal renal function, and the presence of Gd can persist months to years after the last administration of a GBCA."

    This is therapy. May persist... I want to throw this here, because there is a lot of discussion here by not only a few patients but a few very knowledgeable researchers which is surprising for such an extremely niche field, and the discussion is amazing.

  • Insanity3 months ago
    After reading the article I get what it’s saying.. but isn’t any MRI _technically_ physics-based.
    • Karliss3 months ago
      The term is "physics based model" it has somewhat specific meaning in context of mathemtical/physics modelling. It has nothing to do with all physics required to make MRI work. A model doesnt have to be based on physics to be usefull. You can often get some recognizable image by dumb stronger signal=> brighter pixel logic without fully modelling how why it changes. As long as change in material correlates with change in signal (doesn't even have to happen uniformly) you can get some picture and leave the interpretation to human. A simpler example would be temperature control. You can have simple hysteresis based approch of temperature under threshold turn on heater, above threshold turn off. Or you can have physics based model of what the heating power is, what's the heat capacity of chamber, what's the heat capacity of object, how the temperature diffuses within object, what's the thermal resistance of interfaces between heater, target and temperature sensor. Many everyday systems systems are controlled by generic PID controllers without physically modelling how exactly the process reacts to input, PID can be be considered a mathematical control model with sufficient parameterization to approximate various physical systems. You could also make an AI based model and create a signal processing function that way. For many drones PID coefficients are tuned by hand, it was quite a surprise when one of controller manufacurers had made a physics based model to calculate suitable defaults based on drone mass, momment of inertia and maximum thrust.

      Technically the tittle isn't lying. Researchers created new physics based model which is more detailed and makes less simplifications compared to old physics based model. The qualification also clarifies that potentially sharper image won't be achieved by new device model or a picture of 3d model printed on marketing materials.

      • omnicognate3 months ago
        Nice that it's called physics-based rather than the grammatically weird "physically based" used in computer graphics.
    • BobbyTables23 months ago
      Does seem like advertising “rack and pinion” steering on a car…
  • ForOldHack3 months ago
    I suspected this was blahtering AI, and this confirms it: "By solving this equation, they were able to capture the full spectrum of molecular motion and relaxation." The equation is solved buddy, and has been since Plank solved it. It's the discreet calculation of its values give is a digital image that can be contrast enhanced by differing molecules, the physics has not changed, and the equation has not changed. <Downvote>
    • gosub1003 months ago
      > discreet calculation

      why do they have to be discreet about doing some math? who is going to be bothered by it?

      • lostlogin3 months ago
        I assume OP means discrete and not discreet.

        “Discreet and discrete are homophones. They sound the same but they have different definitions. Discreet means careful or intentionally unobtrusive. Discrete means distinct or unconnected.”

        I learned something though.

        https://www.grammarly.com/blog/commonly-confused-words/discr...

        • gosub1003 months ago
          If you have a bad Greek vacation, you can also Diss Crete.
          • tpoacher3 months ago
            sth sth "Disk-read" pun