(4/4) "These findings suggest that ALPS-derived metrics may not provide a direct measure of glymphatic function but rather reflect underlying axonal geometry. Interpretations of ALPS-derived metrics as biomarkers of glymphatic function must consider these anatomical complexities"

Diffusion tensor imaging along the perivascular space: the bias from crossing fibres Georgiopoulos et al. report that crossing fibres significantly affect diffusion tensor imaging along the perivascular space, raising concerns about its rel

(3/4) and this study by Georgiopoulos & team (academic.oup.com/braincomms/a...) showing biases due to crossing fibers. We extend this to undulations/dispersion.

Exploring Radial Asymmetry in MR Diffusion Tensor Imaging and Its Impact on the Interpretation of Glymphatic Mechanisms Background Diffusion imaging holds great potential for the non-invasive assessment of the glymphatic system in humans. One technique, diffusion tensor imaging along the perivascular space (DTI-ALPS)...

(2/4) motivated by this beautiful study by Adam Wright (onlinelibrary.wiley.com/doi/10.1002/...) where they show that radial asymmetry (what DTI-ALPS measures) exists throughout all WM, regardless of vascular orientation. We confirm this and show it exists at high b-values.

(1/4) Our recent work shows DTI-ALPS is confounded by white matter geometry (crossing fibers, undulation, dispersion), ALPS-asymmetry signature (ALPS measures asymmetry of diffusion) occurs throughout all WM, and ALPS-WM is not always orthogonal to PVS onlinelibrary.wiley.com/share/TPCABU...

"Perhaps this is why it is called research rather than search" ... one of my favorite quotes (can be applied to all research) ... from Novikov's "On Modeling" pubmed.ncbi.nlm.nih.gov/29493816/

Join the @ismrm.bsky.social Diffusion study group virtual meeting on June 30th for "Time-Dependent Diffusion: Microseconds, Seconds, Months". Register by finding the virtual meeting here: www.ismrm.org/virtual-meet...

Our newest manuscript now in Scientific Reports. Title says it all "The relationship of white matter tract orientation to vascular geometry in the human brain" - where does WM align (and not align) with vasculature? @masi-lab.bsky.social www.nature.com/articles/s41...

What’s everyone’s go-to for releasing imaging datasets? I have two small/medium sized I’d like to release. Considering openneuro, osf, NIHMS data repository, zenodo???

(3/3) come see Michael Kim discuss this @ismrm.bsky.social session "White Matter: Aging & Diseases" Monday at 8:15!

(2/3) we show these can be used to (A) define normative trajectories across pathways (B) identify developmental milestones (C) detect deviation from normal (examples in AD, MCI, epilepsy, Autism, ADHD, Depression, Anxiety) (D) provide centile scores for new out of sample datasets

White matter microstructure and macrostructure brain charts across the human lifespan Normative reference charts are widely used in healthcare, especially for assessing the development of individuals by benchmarking anatomic and physiological features against population trajectories ac...

(1/3) New work from our lab and @masi-lab.bsky.social creating White matter brain charts across the lifespan. Brain charts for 72 pathways, both microstructure (DTI) and macrostructure (volumes, lengths) - using data from >40 harmonized population studies.
www.biorxiv.org/content/10.1...

Bonus pretty pictures of rats, monkeys, racooons...all using lessons, guidelines, and recommendations from the papers above!

Considerations and recommendations from the ISMRM Diffusion Study Group for preclinical diffusion MRI: Part 3—Ex vivo imaging: Data processing, comparisons with microscopy, and tractography Preclinical diffusion MRI (dMRI) has proven value in methods development and validation, characterizing the biological basis of diffusion phenomena, and comparative anatomy. While dMRI enables in viv...

Considerations and recommendations from the ISMRM Diffusion Study Group for preclinical diffusion MRI: Part 3—Ex vivo imaging: Data processing, comparisons with microscopy, and tractography

onlinelibrary.wiley.com/doi/10.1002/...

Considerations and recommendations from the ISMRM diffusion study group for preclinical diffusion MRI: Part 2—Ex vivo imaging: Added value and acquisition The value of preclinical diffusion MRI (dMRI) is substantial. While dMRI enables in vivo non-invasive characterization of tissue, ex vivo dMRI is increasingly being used to probe tissue microstructur...

Considerations and recommendations from the ISMRM diffusion study group for preclinical diffusion MRI: Part 2—Ex vivo imaging: Added value and acquisition

onlinelibrary.wiley.com/doi/full/10....

Considerations and recommendations from the ISMRM diffusion study group for preclinical diffusion MRI: Part 1: In vivo small‐animal imaging Small-animal diffusion MRI (dMRI) has been used for methodological development and validation, characterizing the biological basis of diffusion phenomena, and comparative anatomy. The steps from anim...

Considerations and recommendations from the ISMRM diffusion study group for preclinical diffusion MRI: Part 1: In vivo small-animal imaging

onlinelibrary.wiley.com/doi/10.1002/...

Our first BSKY post and its a good one. Huge collaborative effort from the Diffusion Study Group @ismrm.bsky.social on "Considerations and recommendations from the ISMRM diffusion study group for preclinical diffusion MRI" led by @ijelescu.bsky.social & DSG team! Full papers below.