Understanding Glymphatic's Role In Proteinopathies (GRIP): A single centre case-control study protocol.
Paper
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The authors' code
Python · 205 lines · 6.1 KB · MIT
- import os
- import click
- import simple_mri as sm
- import numpy as np
- import matplotlib.pyplot as plt
- from gmri2fem import segment_tools as segtools
- from gmri2fem.csf_segmentation import create_csf_seg
- from gmri2fem.visualization import slice_volume
- from gmri2fem.segment_tools import find_description_label, find_label_description
- @click.command("csf-segmentation")
- @click.argument("subject", type=str)
- def main(subject):
- aparc_mri = sm.load_mri(
- f"mri_processed_data/freesurfer/{subject}/mri/aparc+aseg.mgz",
- dtype=np.int16,
- )
- mask_base_mri = sm.load_mri(
- f"mri_processed_data/{subject}/registered/{subject}_ses-01_acq-mixed_SE-modulus_registered.nii.gz",
- dtype=np.single,
- )
- csf_seg_mri = create_csf_seg(aparc_mri, mask_base_mri)
- sm.save_mri(
- csf_seg_mri,
- f"mri_processed_data/{subject}/segmentations/{subject}_seg-csf_mask.nii.gz",
- dtype=np.uint8,
- )
- def to_cortex_labels(description_list):
- """Map a cortical region-description to it's corresponding FreeSurfer name
- for both left and right hemisphere."""
- return [f"ctx-lh-{d.lower().replace(' ', '')}" for d in description_list] + [
- f"ctx-rh-{d.lower().replace(' ', '')}" for d in description_list
- ]
- ventricles = [
- "3rd-Ventricle",
- "4th-Ventricle",
- "Left-Lateral-Ventricle",
- "Right-Lateral-Ventricle",
- "Left-Inf-Lat-Vent",
- "Right-Inf-Lat-Vent",
- ]
- infratentorial = [
- "Brain-Stem",
- "Left-Cerebellum-Cortex",
- "Right-Cerebellum-Cortex",
- ]
- basal = [
- *to_cortex_labels(
- [
- "medial orbitofrontal",
- "fusiform",
- "frontal pole",
- ]
- ),
- "Optic-Chiasm",
- "Left-VentralDC",
- "Right-VentralDC",
- "Left-Hippocampus",
- "Right-Hippocampus",
- ]
- medial = to_cortex_labels(
- [
- "Posterior cingulate",
- "Rostral anterior cingulate",
- "Caudal anterior cingulate",
- "Superiorfrontal",
- "Precuneus",
- "Isthmus cingulate",
- "Paracentral",
- "Cuneus",
- "Lingual",
- "Pericalcarine",
- "Entorhinal",
- "Parahippocampal",
- ]
- )
- insula = to_cortex_labels(
- [
- "Insula",
- ]
- )
- groups = {
- "ventricles": ventricles,
- "infratentorial": infratentorial,
- "basal": basal,
- "medial": medial,
- "insula": insula,
- }
- lut_table = segtools.read_lut(
- f"{os.environ['FREESURFER_HOME']}/FreeSurferColorLUT.txt"
- )
- labels = np.unique(csf_seg_mri.data[csf_seg_mri.data > 0])
- grouped_descriptions = sum(groups.values(), start=[])
- grouped_labels = [
- find_description_label(x, lut_table) for x in grouped_descriptions
- ]
- groups["lateral"] = [
- find_label_description(x, lut_table)
- for x in labels[~np.isin(labels, grouped_labels)]
- ]
- relabeling = {
- group: [
- segtools.find_description_label(x, lut_table) for x in group_descriptions
- ]
- for group, group_descriptions in groups.items()
- }
- grouped_seg = segtools.collapse(csf_seg_mri.data, relabeling)
- grouped_seg_mri = sm.SimpleMRI(grouped_seg, csf_seg_mri.affine)
- sm.save_mri(
- grouped_seg_mri,
- f"mri_processed_data/{subject}/segmentations/{subject}_seg-csf_grouped.nii.gz",
- np.int16,
- )
- # Also create a lookup-table for identifying regions
- grouped_lut = segtools.canonical_lut(relabeling, "jet", permute_colors=None)
- grouped_cmap = segtools.listed_colormap(grouped_lut)
- segtools.write_lut(
- f"mri_processed_data/{subject}/segmentations/{subject}_seg-csf_grouped_LUT.txt",
- grouped_lut,
- )
- cerebellum = [
- "Left-Cerebellum-Cortex",
- "Right-Cerebellum-Cortex",
- ]
- labels = np.unique(csf_seg_mri.data[csf_seg_mri.data > 0])
- relabeling = {
- "cerebellum": [find_description_label(x, lut_table) for x in cerebellum],
- "ventricles": [find_description_label(x, lut_table) for x in ventricles],
- }
- relabeling["SAS"] = list(
- labels[~np.isin(labels, relabeling["cerebellum"] + relabeling["ventricles"])]
- )
- groups = {
- desc: [find_label_description(x, lut_table) for x in group_labels]
- for desc, group_labels in relabeling.items()
- }
- newlut = segtools.canonical_lut(relabeling, "viridis", permute_colors=None)
- newseg_cmap = segtools.listed_colormap(newlut)
- newseg = segtools.collapse(csf_seg_mri.data, relabeling)
- newseg_mri = sm.SimpleMRI(newseg, csf_seg_mri.affine)
- sm.save_mri(
- newseg_mri,
- f"mri_processed_data/{subject}/segmentations/{subject}_seg-csf_sas-ventricle-cerebellum.nii.gz",
- np.int16,
- )
- segtools.write_lut(
- f"mri_processed_data/{subject}/segmentations/{subject}_seg-csf_sas-ventricle-cerebellum-LUT.txt",
- newlut,
- )
- lut_table = segtools.read_lut(
- f"{os.environ['FREESURFER_HOME']}/FreeSurferColorLUT.txt"
- )
- fs_cmap = segtools.listed_colormap(lut_table)
- slice_ = ("sagittal", 184)
- t1w_mri = sm.load_mri(
- f"mri_processed_data/{subject}/registered/{subject}_ses-01_T1w_registered.nii.gz",
- dtype=np.single,
- )
- t1w = t1w_mri.data
- im_ref = slice_volume(t1w, *slice_)
- im_segmentations = [
- slice_volume(mri.data, *slice_)
- for mri in [csf_seg_mri, grouped_seg_mri, newseg_mri]
- ]
- fig, axes = plt.subplots(1, 3, figsize=(12, 6))
- for ax in axes:
- ax.imshow(im_ref, cmap="gray", vmin=0, vmax=np.quantile(t1w[t1w > 0], 0.95))
- ax.axis("off")
- for ax, seg, cmap in zip(
- axes, im_segmentations, [fs_cmap, grouped_cmap, newseg_cmap]
- ):
- ax.imshow(np.where(seg > 0, seg, np.nan), **cmap, interpolation="nearest")
- axes[0].set_title("FreeSurfer-based segmentation")
- axes[1].set_title("Grouped segmentation 1")
- axes[2].set_title("Grouped segmentation 2")
- plt.tight_layout()
- plt.savefig("figures/segmentations.png", bbox_inches="tight")
- plt.show()
- if __name__ == "__main__":
- main()
main.py at commit 20ee998, under MIT · at the source
Overview
19 affiliations
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- The Intervention Centre, Oslo University Hospital, Oslo, Norway
- Department of Physics and Computational Radiology, Oslo University Hospital, Oslo, Norway
- K.G. Jebsen Centre for Brain Fluid Research, Oslo, Norway
- Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
- Department of Psychology, Oslo University Hospital, Oslo, Norway
- Department of Pharmacy, University of Oslo, Oslo, Norway
- Department of Transplantation medicine, Oslo University Hospital, Oslo, Norway
- Norwegian Climate and Environmental Research Institute (NILU), Kjeller, Norway
- User representative, Norwegian Health Association, Oslo, Norway
- User representative, Norwegian Parkinson Association, Oslo, Norway
- Department of Geriatric Medicine, Oslo University Hospital, Oslo, Norway
- Norwegian Health Association, Oslo, Norway
- Department of Neurology, Akershus University Hospital, Lørenskog, Norway
- Department of Neurophysiology, Oslo University Hospital, Oslo, Norway
- Department of Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo, Norway
- Department of Mathematics, University of Oslo, Oslo, Norway
- Department of Neurosurgery, Oslo University Hospital, Oslo, Norway
Abstract
Alzheimer’s disease (AD), Parkinson’s disease (PD), and dementia with Lewy bodies (DLB) are proteinopathies characterized by pathological accumulation of amyloid beta, phosphorylated-tau, and alpha-synuclein. Impaired clearance of these proteins is thought to contribute to disease pathogenesis, whereas preserved or enhanced clearance may be compensatory. Beyond intracellular degradation within neurons and glial cells, an extracellular clearance pathway, the glymphatic system, facilitates cerebrospinal fluid flow into perivascular spaces, exchange with interstitial fluid, and subsequent clearance from the brain. Glymphatic transport may therefore be critical for removal of excess proteins and metabolic waste, and its dysfunction could promote protein aggregation and neurodegeneration. The Glymphatic’s Role In Proteinopathies (GRIP) study is an observational case-control imaging and biomarker study comparing glymphatic clearance in patients with AD, PD, and DLB versus healthy controls. We aim to recruit 70 participants: PD (n = 20), DLB (n = 10), AD (n = 20), and age- and sex-matched healthy controls (n = 20). The AD group will be stratified by pathology, with half amyloid-positive/
Reproduced under the paper's license (CC BY), from the paper cited above.
Repository
Its files are read in the Code ↔ Paper reader above.
jorgenriseth/grip-mixed
20ee9980ca659a71667dd2843fa903dbb58fd594, 3 November 2025Availability: 2 checks, the latest on 13 November 2026: the link answers
- 13 November 2026: the link answers
- 2 October 2026: the link answers
4 files
- main.py, Python, 205 lines
- mixed-processing.ipynb, Jupyter, 362 lines
- LICENSE, License, 21 lines
- README.md, Text, 359 lines
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The study generates data of a sensitive nature, including detailed clinical information and imaging data. All such data are stored and managed within the Services for Sensitive Data (TSD) platform, which provides secure, access-controlled storage in accordance with institutional and regulatory requirements. Access to the dataset is restricted and can be granted upon reasonable request to the project leader, subject to applicable ethical and legal approvals. We have, however, been able to make a full imaging series publicly available from one control(60), which can be downloaded from Zenodo: https://
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Version 1, 31 October 2026: the first record
Recorded: type, language, journal, volume, issue, pages, dates, 21 authors, 14 MeSH terms, 58 references.
Cite
This paper
Lian, S. L., Storås, T. H., Gløersen, E. M., Løvland, G., Hopp, E., Mossige, I., Hovd, M., Uggerud, H. T., Kardel, K. R., Bye, H. A., Buset, A. L., Valdmanis, K., Knapskog, A. B., Øksengård, A. R., Fladby, T., Nilsen, K. B., Mardal, K.-A., Ringstad, G., Eide, P. K., . . . Nordengen, K. (2026). Understanding Glymphatic's Role In Proteinopathies (GRIP): A single centre case-control study protocol. PloS one, 21(10), e0360617. https://
BibTeX
@article{lian2026underst
author = {Lian, Sofie Lysholm and Storås, Tryggve Holck and Gløersen, Ebba Müller and Løvland, Grethe and Hopp, Einar and Mossige, Ingrid and Hovd, Markus and Uggerud, Hilde Thelle and Kardel, Kristin Reimers and Bye, Heidi A and Buset, Anne Lise and Valdmanis, Kirsten and Knapskog, Anne Brita and Øksengård, Anne Rita and Fladby, Tormod and Nilsen, Kristian Bernhard and Mardal, Kent-André and Ringstad, Geir and Eide, Per Kristian and Toft, Mathias and Nordengen, Kaja},
title = {{Understanding Glymphatic's Role In Proteinopathies (GRIP): A single centre case-control study protocol}},
journal = {PloS one},
year = {2026},
month = oct,
volume = {21},
number = {10},
pages = {e0360617},
publisher = {PLOS},
issn = {1932-6203},
doi = {10.1371/
url = {https://
pmid = {42956044},
pmcid = {PMC13718934}
}
RIS
TY - JOUR
AU - Lian, Sofie Lysholm
AU - Storås, Tryggve Holck
AU - Gløersen, Ebba Müller
AU - Løvland, Grethe
AU - Hopp, Einar
AU - Mossige, Ingrid
AU - Hovd, Markus
AU - Uggerud, Hilde Thelle
AU - Kardel, Kristin Reimers
AU - Bye, Heidi A
AU - Buset, Anne Lise
AU - Valdmanis, Kirsten
AU - Knapskog, Anne Brita
AU - Øksengård, Anne Rita
AU - Fladby, Tormod
AU - Nilsen, Kristian Bernhard
AU - Mardal, Kent-André
AU - Ringstad, Geir
AU - Eide, Per Kristian
AU - Toft, Mathias
AU - Nordengen, Kaja
TI - Understanding Glymphatic's Role In Proteinopathies (GRIP): A single centre case-control study protocol
T2 - PloS one
J2 - PLoS One
PY - 2026
DA - 2026/
VL - 21
IS - 10
SP - e0360617
SN - 1932-6203
PB - PLOS
DO - 10.1371/
UR - https://
LA - en
ER -
CSL-JSON
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