eprintid: 10127663 rev_number: 22 eprint_status: archive userid: 608 dir: disk0/10/12/76/63 datestamp: 2021-05-12 10:27:26 lastmod: 2021-09-24 22:08:48 status_changed: 2021-05-12 10:27:26 type: article metadata_visibility: show creators_name: Huang, C-C creators_name: Hsu, C-CH creators_name: Zhou, F-L creators_name: Kusmia, S creators_name: Drakesmith, M creators_name: Parker, GJM creators_name: Lin, C-P creators_name: Jones, DK title: Validating pore size estimates in a complex microfiber environment on a human MRI system ispublished: pub divisions: UCL divisions: B04 divisions: C05 divisions: F48 divisions: F42 keywords: crossing fiber, diameter, diffusion MRI, electron microscopy, microstructure, phantom note: © 2021 International Society for Magnetic Resonance in Medicine This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. abstract: PURPOSE: Recent advances in diffusion-weighted MRI provide "restricted diffusion signal fraction" and restricting pore size estimates. Materials based on co-electrospun oriented hollow cylinders have been introduced to provide validation for such methods. This study extends this work, exploring accuracy and repeatability using an extended acquisition on a 300 mT/m gradient human MRI scanner, in substrates closely mimicking tissue, that is, non-circular cross-sections, intra-voxel fiber crossing, intra-voxel distributions of pore-sizes, and smaller pore-sizes overall. METHODS: In a single-blind experiment, diffusion-weighted data were collected from a biomimetic phantom on a 3T Connectom system using multiple gradient directions/diffusion times. Repeated scans established short-term and long-term repeatability. The total scan time (54 min) matched similar protocols used in human studies. The number of distinct fiber populations was estimated using spherical deconvolution, and median pore size estimated through the combination of CHARMED and AxCaliber3D framework. Diffusion-based estimates were compared with measurements derived from scanning electron microscopy. RESULTS: The phantom contained substrates with different orientations, fiber configurations, and pore size distributions. Irrespective of one or two populations within the voxel, the pore-size estimates (~5 μm) and orientation-estimates showed excellent agreement with the median values of pore-size derived from scanning electron microscope and phantom configuration. Measurement repeatability depended on substrate complexity, with lower values seen in samples containing crossing-fibers. Sample-level repeatability was found to be good. CONCLUSION: While no phantom mimics tissue completely, this study takes a step closer to validating diffusion microstructure measurements for use in vivo by demonstrating the ability to quantify microgeometry in relatively complex configurations. date: 2021-05-07 date_type: published official_url: https://doi.org/10.1002/mrm.28810 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1863722 doi: 10.1002/mrm.28810 lyricists_name: Kusmia, Slawomir lyricists_name: Parker, Geoffrey lyricists_name: Zhou, Fenglei lyricists_id: SKUSM20 lyricists_id: GPARK63 lyricists_id: FZHOU86 actors_name: Dewerpe, Marie actors_id: MDDEW97 actors_role: owner full_text_status: public publication: Magnetic Resonance in Medicine event_location: United States citation: Huang, C-C; Hsu, C-CH; Zhou, F-L; Kusmia, S; Drakesmith, M; Parker, GJM; Lin, C-P; Huang, C-C; Hsu, C-CH; Zhou, F-L; Kusmia, S; Drakesmith, M; Parker, GJM; Lin, C-P; Jones, DK; - view fewer <#> (2021) Validating pore size estimates in a complex microfiber environment on a human MRI system. Magnetic Resonance in Medicine 10.1002/mrm.28810 <https://doi.org/10.1002/mrm.28810>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10127663/1/mrm.28810.pdf