This Week's Science News

MRI at Record Resolution, A Pentagon Official Speculates On Alien Probes, Sensors for Plant Health, and everything else you need to know

[Below follows the transcript of the video with references.]

MRI at Record Resolution

A team of American radiologists and computer scientists based at Duke University has taken a magnetic resonance image at record resolution.

Magnetic Resonance Imaging, MRI for short, was invented about 50 years ago. It works by applying a strong magnetic field to a sample. This aligns the magnetic moments of atomic nuclei. Then one uses a second, oscillating, field to look for resonances among the nuclei. These resonances can tell you what type of atomic nuclei are present at which location. The most common nuclei you look for in living tissue are hydrogen and oxygen.

The new device has now captured an image of a mouse brain at a resolution more than 1000 times better than previously. They did it by using an amazingly powerful magnet. It has a field strength of a whopping 9 point 4 Tesla  rather than the typical 1 point 5 that most hospitals use. On top of that, they used advanced image processing on supercomputers to squeeze info out of their data. You can see the difference to the old imaging method here in these images of mouse brains. The old is on the left. New on the right. Both are thinking about cheese, I assume.

Image: Johnson et al., PNAS 120:17 e2218617120 (2023)

If you think that was impressive, look at this.

Image: Johnson et al., PNAS 120:17 e2218617120 (2023)

This is track-density image of a mouse brain. It’s a 3D-reconstruction of MRI images that basically shows where water molecules flow. They make it down to a resolution of 5 microns, whereas typical MRIs have a resolution of a few hundred microns. So that’s an improvement by more than a factor 20 in each direction of space. It won’t be long, and they can tell whether the mouse is thinking about Cheddar or Parmesan.  

This Could Explain Why The Sun’s Corona Is So Hot