ArticleNeuroImage. Clinical2022
T1w/FLAIR ratio standardization as a myelin marker in MS patients.
Article in NeuroImage. Clinical, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
12 citing papers in PubMed, 2 syntheses or guidelines pooled it.
- Population-Level Age Effects on the White Matter Structure Subserving Cognitive Flexibility in the Human Brain.eNeuro · 2026Pooled it
- Intensity scaling of conventional brain magnetic resonance images avoiding cerebral reference regions: A systematic review.PloS one · 2024Pooled it
- Altered T1w/T2w-FLAIR Ratio in White Matter Hyperintensities as an Indicator of Structural Integrity Loss: Association with Alzheimer's Disease and Vascular Dementia.medRxiv : the preprint server for health sciences · 2026Article
- TAnnals of clinical and translational neurology · 2026Article
- Assessment of Optimal T1/T2-Weighted Combinations for Myelin Sensitivity: Effects of Echo Time and Exponents.Magnetic resonance in medicine · 2026Article
- Evaluating the T1w/FLAIR ratio as a proxy for myelin: Associations with myelin water Imaging, diffusion metrics, and cognition.Neuroradiology · 2026Article
- The role of modifiable risk factors on the cerebral myelin content and cognition: findings from The Maastricht Study.GeroScience · 2026Article
- Longitudinal changes of choroid plexus volumes and MRI ratios in multiple sclerosis.Brain communications · 2026Article
- Microstructural white matter alterations and cognitive impairment in anti-NMDAR encephalitis: evidence from T1w/T2w ratio analysis.Frontiers in immunology · 2026Article
- Exploring factors driving the evolution of chronic lesions in multiple sclerosis using machine learning.European radiology · 2025Article
- Relevance of choroid plexus volumes in multiple sclerosis.Fluids and barriers of the CNS · 2025Article
- Approximating R1 and R2: A Quantitative Approach to Clinical Weighted MRI.Human brain mapping · 2024Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
introductionCalculation of a T1w/T2w ratio was introduced as a proxy for myelin integrity in the brain of multiple sclerosis (MS) patients. Since nowadays 3D FLAIR is commonly used for lesion detection instead of T2w images, we introduce a T1w/FLAIR ratio as an alternative for the T1w/T2w ratio.
objectivesBias and intensity variation are widely present between different scanners, between subjects and within subjects over time in T1w, T2w and FLAIR images. We present a standardized method for calculating a histogram calibrated T1w/FLAIR ratio to reduce bias and intensity variation in MR sequences from different scanners and at different time-points. MATERIAL AND
methods207 Relapsing Remitting MS patients were scanned on 4 different 3 T scanners with a protocol including 3D T1w, 2D T2w and 3D FLAIR images. After bias correction, T1w/FLAIR ratio maps and T1w/T2w ratio maps were calculated in 4 different ways: without calibration, with linear histogram calibration as described by Ganzetti et al. (2014), and by using 2 methods of non-linear histogram calibration. The first nonlinear calibration uses a template of extra-cerebral tissue and cerebrospinal fluid (CSF) brought from Montreal Neurological Institute (MNI) space to subject space; for the second nonlinear method we used an extra-cerebral tissue and CSF template of our own subjects. Additionally, we segmented several brain structures such as Normal Appearing White Matter (NAWM), Normal Appearing Grey Matter (NAGM), corpus callosum, thalami and MS lesions using Freesurfer and Samseg.
resultsThe coefficient of variation of T1w/FLAIR ratio in NAWM for the no calibrated, linear, and 2 nonlinear calibration methods were respectively 24, 19.1, 9.5, 13.8. The nonlinear methods of calibration showed the best results for calculating the T1w/FLAIR ratio with a smaller dispersion of the data and a smaller overlap of T1w/FLAIR ratio in the different segmented brain structures. T1w/T2w and T1w/FLAIR ratios showed a wider range of values compared to MTR values.
conclusionsCalibration of T1w/T2w and T1w/FLAIR ratio maps is imperative to account for the sources of variation described above. The nonlinear calibration methods showed the best reduction of between-subject and within-subject variability. The T1w/T2w and T1w/FLAIR ratio seem to be more sensitive to smaller changes in tissue integrity than MTR. Future work is needed to determine the exact substrate of T1w/FLAIR ratio and to obtain correlations with clinical outcome.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.