Very intersting find. Though every time I see 'simple 3D grid' in combination with the brain, I think 'scanner or reconstruction artifact'. For my PhD research I've worked with DTI (Diffusion Tensor Imaging) data which was very hard to sensibly interpret as 'connectivity': The visualized structures depended very much on the parameters and reconstruction method used. And it was hard to match the visualized structures to actual physical structures.
I wonder if they verified in some other way (ie, microscope) that the simple 3D structures were really there. If so, very exciting news!
They addressed these concerns in several ways - firstly, yes there is microscopy on corresponding sections demonstrating that fiber-crossings were resolved correctly. Second, DSI imaging was performed on mouse hearts, as myocardium exhibits a strong directional organization but without the crossings shown in brain (negative control).
Unfortunately the full article is paywalled, but the Methods supplement is freely available and discusses these issues.
MRI is mathematical voodoo even when it's working - it's easy to fool yourself at any of several stages in the process. "New scanner gives 10x improvement in detail, shows amazing and unexpectedly simple result" is just screaming for verification.
But it needs it obviously enough and the claim is interesting enough that further verification (or falsification) should happen soonish, as research timescales go.
In fact, this group has already done very detailed validation in cat brains: in-vivo MR imaging followed by ex-vivo staining+microscopy for validation :
It is good to hear this, I had my doubts but no experience anywhere near MRI reading. Looking at those colourful tubes, it is not in the least bit obvious how much of it is pure modelling and how much is cleaned-up scanner output.
"New scanner gives 10x improvement in detail, shows amazing and unexpectedly simple result" is a pretty punchy-sounding headline, too. They should go with that next time!
I wonder if they verified in some other way (ie, microscope) that the simple 3D structures were really there. If so, very exciting news!