Siawoosh Mohammadi
Physicist | MRI, biophysics, microstructure, in/ex vivo histology | Prof. @uniluebeck.bsky.social, PI @UKEhamburg, affiliated @lipmpib.bsky.social, @mpicbs.bsky.social | Views are my own
micromri.uni-luebeck.de/institut
- Reposted by Siawoosh MohammadiI am now hiring a PhD student in deep learning for medical images, to work at the Department of Biomedical Engineering (IMT) for our ELLIIT project on federated learning. Application deadline February 19. web103.reachmee.com/ext/I011/853...
- Reposted by Siawoosh MohammadiHow do priors influence speech processing? Do they enhance expected signals or highlight the unexpected (prediction errors)? @fabianschneider.bsky.social' s work shows: It depends!
- Same sound, different perception: Do expectations change what you hear?👂🧠 We paired faces w topics and played the same ambiguous speech w different faces. The brain sharpened sensory signals toward predictions and showed gated prediction errors at higher levels. Read @plosbiology.org. Blueprint👇
- Reposted by Siawoosh MohammadiKein Internet, kein Telefon: Das iranische Regime legt im Kampf gegen die Massenproteste die Kommunikation des Landes lahm. Die Menschen gehen offenbar trotzdem weiter auf die Straße. Auch wenn sie um ihr Leben fürchten müssen.
- Reposted by Siawoosh MohammadiNew paper in Imaging Neuroscience by Bradley G. Karat, Jelle Veraart, et al: Revisiting the interpretation of axon diameter mapping using higher-order signal representations doi.org/10.1162/IMAG...
- Reposted by Siawoosh MohammadiPreprint on PANDORA by Aslan Abivardi: A massive archive of UK Biobank brain imaging from 82K subjects. For each of 98 sub-modalities (e.g., FA from dMRI), the images are collated into a convenient subjectsXvoxels HDF5 file. pages.fmrib.ox.ac.uk/pandora/web/ www.medrxiv.org/content/10.6...
- Reposted by Siawoosh MohammadiFor 15(!) years I’ve been teaching introductory #MRI to grad students, and struggled to find a textbook for a wide variety of backgrounds. I'm happy to share an online textbook I created, fully open source (including code for generating figures and plots shown): larsonlab.github.io/MRI-educatio...
- Reposted by Siawoosh MohammadiA new MRI protocol can scan the human brain and its venous network in under 7 minutes at 0.35 mm iso. resolution, marking it as a potential tool for diagnosing cerebrovascular diseases and monitoring neurodegeneration. scim.ag/3LkRfRY
- Reposted by Siawoosh MohammadiFrigon et al. investigate the histology and MRI registration quality of ex vivo human brain blocks fixed with solutions used in anatomy laboratories: doi.org/10.52294/001... @ohbmofficial.bsky.social
- Reposted by Siawoosh MohammadiVery happy to have contributed to this wonderful/tentacular work alongside so many amazing colleagues and friends! It opens up new ways of understanding grey matter heterotopia associated with altered cortical function and #epilepsy in humans. 🧠🧪🔥 www.nature.com/articles/s41...
- 1/5 Big congratulations to Dr. Laurin Mordhorst on completing his PhD! 🎓 His dissertation focused on axon-radii mapping—a challenging problem and a significant step forward for quantitative neuroimaging.
- 2/5 A key milestone: Laurin developed the methods to build a truly unique validation dataset with >40 million axons. More details here: DOI 10.1016/j.neuroimage.2022.118906 Open dataset: DOI 10.5281/zenodo.17431227
- 3/5 With these data, Laurin delivered the first quantitative validation of axon-radii mapping in humans and pinpointed the most important source of bias in the model: DOI 10.1162/IMAG.a.1030 - For details see this thread: bsky.app/profile/siaw...
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View full thread5/5 Thanks to the examiners for an intense discussion: Jelle Veraart @cai2r.net and Marko Lindner (TU Hamburg) and to the funding sources: @dfg.de , @erc.europa.eu , and @uniluebeck.bsky.social
- Reposted by Siawoosh MohammadiSubmitting a grant you’re not eligible to get
- 1/3 Huge congratulations to Dr. Björn Fricke on graduating! 🎓 Björn started his PhD with us in 2020— COVID and the extension phase of my Emmy Noether project made the start somewhat complicated. For example, I couldn’t immediately offer a full 3-year PhD position.
- 2/3 With support from the examination committee (Lars Ruthotto and Rene Werner) and his co-supervisor @ktabelow.bsky.social, we developed a solid, realistic work plan—and Björn executed it with impressive focus and persistence.
- 3/3 Björn turned ACID into a coherent, polished toolbox and published it @imagingneurosci.bsky.social: doi.org/10.1162/imag... ACID wouldn’t be what it is today without you! Especially, the BIDS standard implementation - still uniquely valuable. Luckily, you’ll stay with us a bit longer! 🙌
- Reposted by Siawoosh MohammadiMein Eindruck ist, dass wir in aktuellen politischen Debatten extrem auf Narrative reinfallen. Die Wirtschaft am Abgrund, ohne KI geht es nicht, Entbürokratisierung sonst Wirtschaftskrise, die Wirtschaft will das Verbrenneraus kippen. All diese Erzählung verkürzen komplexe Realitäten auf 1 Richtung.
- 1/ Our new paper is out in Imaging Neuroscience! 🎉 We validated in-vivo MRI–based axon radius mapping by comparison to large-scale human brain histology (> 46 M axons & 35 CC-ROIs). Title: “MRI-scale histology validates spatial sensitivity of in-vivo MRI-based axon radius estimation”
- New paper in Imaging Neuroscience by Laurin Mordhorst, Siawoosh Mohammadi, et al: MRI-scale histology validates spatial sensitivity of in-vivo MRI-based axon radius estimation doi.org/10.1162/IMAG...
- 2/ Why care about axon radii? They strongly affect conduction speed and are thought to change in development, aging, and disease. If we can measure them with MRI, axon radius could become a powerful, non-invasive biomarker.
- 3/ The big problem: until now, MRI-based axon radius estimates in humans were missing quantitative validation. Existing histology was too sparse and covered only tiny patches of tissue, making proper spatial comparisons to MRI basically impossible.
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View full threadThanks go out to Laurin Mordhorst for making this tour-de-force paper and all coauthors (a few of whom I found @bsky): @lukejoeledwards.bsky.social @nikweiskopf.bsky.social @tstr137.bsky.social To the funding sources: @dfg.de and @erc.europa.eu We thank you for your support!
- Reposted by Siawoosh MohammadiNew paper in Imaging Neuroscience by Laurin Mordhorst, Siawoosh Mohammadi, et al: MRI-scale histology validates spatial sensitivity of in-vivo MRI-based axon radius estimation doi.org/10.1162/IMAG...
- Reposted by Siawoosh MohammadiBeim Kish Marathon im Iran mussten die über 5000 Frauen und Männer zwar getrennt laufen. Die Hijabpflicht wurde aber durchwegs ignoriert. Gegen die Organisatoren wurde ein Strafverfahren eröffnet. Aber auch das wird nichts daran ändern, dass sich die Frauen durchsetzen.
- Reposted by Siawoosh MohammadiThread of French and Dutch research institutes slowly unsubscribing from web of science (and thence impact factors).
- Reposted by Siawoosh Mohammadi*13th MindBrainBody Symposium* 📆 Mar 9-11, 2026 🏠 #Berlin & virtual (deadline: Jan 8, 2026) Keynotes: - @ulrikebingel.bsky.social - Karl Friston (online) - @tinalonsdorf.bsky.social - Sonja Kotz - Julian Thayer ...& so much more: prizes, posters, talks, food, drinks, encounters. Let's meet!
- Reposted by Siawoosh MohammadiDrittmittel in der Forschung: Neue Studie zur Vergabe - Lübecker Forscher Sören Krach schlägt frühe Lotterie vor: Geld für die eigene Forschung zu beantragen, ist aufwendig, die Vergabe von sogenannten Drittmitteln oft ungerecht. Wissenschaftler aus Lübeck schlagen nun ein neues Verfahren vor: Das…
- Reposted by Siawoosh MohammadiI am happy to share a recent collaboration with @huiskenlab.bsky.social and @aakhte.bsky.social , who developed a great technique for performing fast and, above all, isotropic light-sheet microscopy. www.nature.com/articles/s41...
- Reposted by Siawoosh MohammadiMexiko hat gestern ein Klimaziel für 2035 vorgelegt, das von Fachleuten als wirklich ambitioniert bewertet wird #COP30 www.wri.org/news/stateme...
- Reposted by Siawoosh MohammadiEine exklusive Forsa-Umfrage für Table.Briefings zeigt: Auch unter CDU/CSU- und SPD-Wählern fordern viele mehr #Klimaschutz. Und selbst in der wirtschaftlich schwierigen Lage soll das deutsche Klimaziel nicht aufgeweicht werden, so die Befragten. 1/3 table.media/climate/them...
- Reposted by Siawoosh MohammadiIhr glaubt gar nicht, wie häufig grad in französischen Nachrichten die deutsche Regierung zitiert wird: Sie taugt stels als Beispiel für den Rückschritt in der Klimapolitik vor der Klimakonferenz: Schließlich will sie das EU-Verkaufsverbot von neuen Diesel- und Benzin-Autos ab 2035 kippen #rollback
- Reposted by Siawoosh MohammadiWe just published a paper in PNAS, showing microstructural changes to the hippocampus in aging and presymptomatic Alzheimer's disease - in humans, in vivo. We continue to show the value of structural MRI beyond simply measuring large-scale atrophy! Read here: ow.ly/1NvV50XkXnX
- The search for early signs of Alzheimer's disease continues: Brain scans reveal microstructural changes in the hippocampus that signal early stages of the disease, including demyelination, increased iron deposition, and changes in water content. In PNAS: ow.ly/1NvV50XkXnX
- Reposted by Siawoosh Mohammadi#neuroscience2025: Come and meet four of us of the @jonasobleser.bsky.social lab and some of our work at Society for Neuroscience San Diego 2025 next week, we will have 4 posters in the TUESDAY PM (1-5 pm) SESSION: @uniluebeck.bsky.social @sarahtune.bsky.social
- Reposted by Siawoosh MohammadiWe wrote a blog post about common misconceptions of basic EPI parameters. Test your knowledge of EPI myths. layerfmri.com/epimyths/ 1/3
- Reposted by Siawoosh MohammadiPlease repost! I am looking for a PhD candidate in the area of Computational Cognitive Neuroscience to start in early 2026. The position is funded as part of the Excellence Cluster "The Adaptive Mind" at @jlugiessen.bsky.social. Please apply here until Nov 25: www.uni-giessen.de/de/ueber-uns...
- Wow!
- Reposted by Siawoosh MohammadiBy comparing differently tuned glomeruli, this work shows that the brain uses different circuit layouts for specialised vs general smells, offering new insight into how odour meaning is encoded. buff.ly/XDmo4Ue
- Reposted by Siawoosh MohammadiOf course most exciting for me: cytoarchitectonic proof that the VIM exists (and is not a subunit of VL as implied by the Jones nomenclature).
- Reposted by Siawoosh MohammadiHow are auditory features represented across the #AuditoryPathway? @bathellierlab.bsky.social show that #auditory feature tuning emerges through a mix of gradual & stepwise changes, with early representation of simple features & later refinement of complex ones @plosbiology.org 🧪 plos.io/4oi0XCY
- Reposted by Siawoosh MohammadiWhen #HHMIJanelia released the #Drosophila hemibrain in 2020, rendering all cell types at once with full shading/shadows was too hard, so the video showed them region by region. Technology has since advanced, and I went back and rendered them all together. I like how it shows the internal structure.
- Reposted by Siawoosh MohammadiGreat render of the beautiful drosophila hemibrain! 👇
- When #HHMIJanelia released the #Drosophila hemibrain in 2020, rendering all cell types at once with full shading/shadows was too hard, so the video showed them region by region. Technology has since advanced, and I went back and rendered them all together. I like how it shows the internal structure.
- Reposted by Siawoosh Mohammadi
- Reposted by Siawoosh MohammadiWe are looking for “Data Scientist or ML/AI expert” who will work at the cutting edge of data science and neuromaging in a collaboration between @mpicbs.bsky.social and the Max Planck Computing and Data Facility (MPCDF). Deadline: 10th Nov. 2025. Apply here:
- On my way to Marseille - waiting at Munich airport for my flight. Unfortunately, there was (time-wise) no affordable way from Hamburg to Marseille with the train. So, I had to take the flight option. But still, I am looking forward to seeing all my colleague and friends in person at the ESMRMB!
- Reposted by Siawoosh MohammadiHippoMaps: an open-source resource for studying the human hippocampus at different scales and with different modalities. www.nature.com/articles/s41... @jordandekraker.bsky.social @borismontreal.bsky.social @jclauneuro.bsky.social @neuroak.bsky.social @sofievalk.bsky.social @donnagift.bsky.social
- I am looking forward to the meeting!
- ⏳ 1 week to go until #ESMRMB2025 in Marseille! Get ready for a legendary edition: inspiring talks, collaborative WG sessions, eye-catching posters, treasure hunt, escape room & more! 📅 Full program: esmrmb2025.org #MRI #Research #Networking
- Three of our group from Lübeck will be in Marseille. Laurin Mordhorst will present his final PhD work with the title "Reaching the Tail: Validating MRI Axon Radius Mapping with MRI-Scale Histology"
- Frank (Francisco J. Fritz) will present his amazing data on our ERC study. The title of his presentation "Quantitative MRI study of excised brain tissue in drug-resistant epilepsy patient: from in-vivo to ex-vivo" And here is a little teaser
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View full threadThere are two other speakers taking about qMRI, in the session: Sebastian Weingärtner - TU Delft Title: Quality assessment of quantitative MRI Amy MCDOWELL - UCL Title: Use of quantitative MRI in a clinical populations
- Better late than never! Here is a little summary of my notes during one of the sessions of the Nordic (@ismrmnordic.bsky.social) and DACH-ISMRM from two weeks ago in Kiel.
- Marc Jonuscheit from Düsseldorf presented his work on 31P-MRS in the liver in tyoe-1 diabetes and controls. They combined T1 and P_i concentration measurements on a clinical MR system.
- Jan-Malte Oeschger from our group in Lübeck presented our travel-head study on optimising an 1-hour clinical quantitative MRI protocol.
- Judith Schirmer used sodium MRI at 7T to characterize cysts in kidneys using in vivo and ex vivo measurements.
- Reposted by Siawoosh Mohammadi🚨 I am over the moon 🌓 to announce that I am joining University College Dublin @ucddublin.bsky.social as an Assistant Professor this fall to start the Uncertain Mind (UMI) lab 💫 I am looking for PhD/Postdoc candidates to join (more below 👇 ). Please RT as the deadline is pretty soon 🙏
- Reposted by Siawoosh MohammadiAm Samstag (!), 20.09.2025 ist wieder Klimademo! Infos: fridaysforfuture.de/klimastreik/
- Reposted by Siawoosh MohammadiReconstructing long-range axons from dense brain images is tough. This study introduces a novel method that separates axon identification from global statistical rules, showing big improvements over existing tools for mapping neuronal projections. buff.ly/OBKr9cM
- Reposted by Siawoosh MohammadiLaunched in 2023, Imaging Neuroscience is now firmly established, with full indexing (PubMed, etc.) and 700 papers to date. We're very happy to announce that we are able to reduce the APC to $1400. Huge thanks to all authors, reviewers, editorial team+board, and MIT Press.
- Reposted by Siawoosh MohammadiI want to do a session on principles of designing scientific figures with my lab. Any recommendation for good online material? #PsychSciSky #neuroskyence #Neuroimaging
- Reposted by Siawoosh Mohammadi🌟 Mansfield Lecture 2025 🌟 #ESMRMB2025 proudly welcomes Prof. Oliver Speck (University of Magdeburg)! 🎤 Title of the lecture: "It's the Magnet, stupid!" One of the highlights of the meeting you definitely don’t want to miss. 👉 You can still register via esmrmmb2025.org
- Reposted by Siawoosh MohammadiShort-range human cortico-cortical white matter fibers have thinner axons and are less myelinated compared to long-range fibers despite a similar g-ratio @PLOSBiology.org
- Reposted by Siawoosh Mohammadi#Myelination enables faster signal propagation in the brain, but takes more energy & space. @philipruthig.bsky.social &co reveal how short- & long-range #WhiteMatter fibers differ, showing how these variations affect neural communication & processing efficiency @plosbiology.org 🧪 plos.io/4mq5tOy
- Reposted by Siawoosh MohammadiHow are human brain regions connected? Are the connecting axons thicker and more myelinated the longer these connecting fibers are? In our recent paper we find that indeed, they are! Read the skeetorial below ⬇️⬇️⬇️ plos.io/4mq5tOy #neuroscience #neuroskyence #whitematter #deeplearning
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View full threadReposted by Siawoosh MohammadiThat leaves me to thank my excellent co-1st author David Edler von der Planitz, and our collaborators and co-supervisors @siawooshmr.bsky.social, @nikweiskopf.bsky.social, Evgeniya Kirilina, and Markus Morawski! A collaborative project of @mpicbs.bsky.social and @unileipzig.bsky.social!
- Reposted by Siawoosh MohammadiThanks to all (co)authors & reviewers for their contribution to this study on #layer specific changes in #sensory #cortex across the #lifespan in #humans & #mice now out in @natneuro.nature.com Here is a short summary of our findings 1/6
- 🧠 The human brain ages less than thought and in layers – at least in the area of the cortex responsible for the sense of touch. See study @natneuro.nature.com by @estherkuehn.bsky.social and colleagues at DZNE, @hih-tuebingen.bsky.social and @uni-magdeburg.de: 👉 www.nature.com/articles/s41...
- Reposted by Siawoosh MohammadiNews from ENIGMA-Epilepsy! 🧠 Our latest study links polygenic risk for TLE-HS to cortical thinning in kids—mirroring patterns in adult patients. Early imaging-genetics insights could reveal interplay of epilepsy risk and phenotypes before symptoms emerge. Read more 👉 doi.org/10.1093/brai...
- Reposted by Siawoosh MohammadiKlar kann Katherina Reiche darauf hoffen, dass CCS Gaskraftwerke klimaneutral macht. Aber vielleicht kommt auch die Zahnfee und zaubert das CO2 einfach weg, das wäre ähnlich realistisch. Kommentar zur Energiepolitik der BuReg für den DLF. share.deutschlandradio.de/dlf-audiothe...
- Reposted by Siawoosh Mohammadi#bignews: @unibonn.bsky.social now has a Centre for Artificial Intelligence and Neuroscience and it is already growing! Welcome to Bonn, Professor Floris de Lange @predictivebrain.bsky.social ! New #caian website and more updates will follow within the next few weeks. www.caian.uni-bonn.de/en/news
- Reposted by Siawoosh MohammadiNew paper in Imaging Neuroscience by Jochen Schmidt, Nikolaus Weiskopf, et al: High-resolution quantitative T2 mapping of the human brain at 7 T using a multi-echo spin-echo sequence and dictionary-based modeling doi.org/10.1162/IMAG...
- Reposted by Siawoosh MohammadiUltra-high gradient connectomics and microstructure MRI scanner for imaging of human brain circuits across scales rdcu.be/ewDRc
- Reposted by Siawoosh MohammadiI've always wanted to explore fMRI time series as a smooth, real-time movie. Now I can with LayNii IDA. Plus, with voxel-wise correlations on the fly. Fast, intuitive, and surprisingly insightful. 40 ms TR fMRI data from @practicalfmri.bsky.social ! @layerfmri.bsky.social @afni-pt.bsky.social
- Reposted by Siawoosh MohammadiExcited to share our new work just published in @Nature_NPJ Parkinsons! Led by my brilliant PhD student Elior Drori, we present a detailed look at brain microstructure in Parkinson’s using advanced quantitative MRI (qMRI). 🔗 www.nature.com/articles/s41... 🧵
