Evidence map›Paper›PMID 35344614›Full record

ArticleMagnetic resonance in medicine2022

Cramér-Rao bound-informed training of neural networks for quantitative MRI.

Xiaoxia Zhang, Quentin Duchemin, Kangning Liu, Cem Gultekin, Sebastian Flassbeck, Carlos Fernandez-Granda, Jakob Assländer

Abstract read
In one paragraph

Article in Magnetic resonance in medicine, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 21 papers.

0numbers the graph read from it
0cells of the map it votes in
21citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from 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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

21 citing papers in PubMed.

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  5. Magnetization transfer explains most of the TMagnetic resonance in medicine · 2025
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  9. Cramér-Rao Bound Optimized Subspace Reconstruction in Quantitative MRI.IEEE transactions on bio-medical engineering · 2025
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Xiaoxia ZhangCenter for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York City, New York, USA.ORCID 0000-0003-3620-6994
Quentin DucheminLAMA, Univ Gustave Eiffel, Univ Paris Est Creteil, Marne-la-Vallée, France.
Kangning LiuCenter for Data Science, New York University Grossman School of Medicine, New York City, New York, USA.
Cem GultekinCourant Institute of Mathematical Sciences, New York University, New York City, New York, USA.
Sebastian FlassbeckCenter for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York City, New York, USA.ORCID 0000-0003-0865-9021
Carlos Fernandez-GrandaCenter for Data Science, New York University Grossman School of Medicine, New York City, New York, USA.
Jakob AssländerCenter for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York City, New York, USA.ORCID 0000-0003-2288-038X

Funding

TR&D 4: Revealing Microstructure: Biophysical modeling and validation for discovery and clinical careP41EB017183 · NIBIB · NEW YORK UNIVERSITY SCHOOL OF MEDICINE · PI Hersh Chandarana · 2014 to 2026
$19.3M
Development of Multi-Compartment MR-Fingerprinting for Subvoxel Estimation of Quantitative Tissue BiomarkersR21EB027241 · NIBIB · NEW YORK UNIVERSITY SCHOOL OF MEDICINE · PI ASSLAENDER, JAKOB, KNOLL, FLORIAN · 2019 to 2020
$462k
NIBIB NIH HHS P41 EB017183NIBIB NIH HHS R21 EB027241
6 · The paper itself

Abstract

purposeTo improve the performance of neural networks for parameter estimation in quantitative MRI, in particular when the noise propagation varies throughout the space of biophysical parameters. THEORY AND

methodsA theoretically well-founded loss function is proposed that normalizes the squared error of each estimate with respective Cramér-Rao bound (CRB)-a theoretical lower bound for the variance of an unbiased estimator. This avoids a dominance of hard-to-estimate parameters and areas in parameter space, which are often of little interest. The normalization with corresponding CRB balances the large errors of fundamentally more noisy estimates and the small errors of fundamentally less noisy estimates, allowing the network to better learn to estimate the latter. Further, proposed loss function provides an absolute evaluation metric for performance: A network has an average loss of 1 if it is a maximally efficient unbiased estimator, which can be considered the ideal performance. The performance gain with proposed loss function is demonstrated at the example of an eight-parameter magnetization transfer model that is fitted to phantom and in vivo data.

resultsNetworks trained with proposed loss function perform close to optimal, that is, their loss converges to approximately 1, and their performance is superior to networks trained with the standard mean-squared error (MSE). The proposed loss function reduces the bias of the estimates compared to the MSE loss, and improves the match of the noise variance to the CRB. This performance gain translates to in vivo maps that align better with the literature.

conclusionNormalizing the squared error with the CRB during the training of neural networks improves their performance in estimating biophysical parameters.

Indexed as

Magnetic Resonance ImagingNeural Networks, ComputerPhantoms, Imagingdeep learningmagnetic resonance fingerprintingmagnetic transferobjective functionparameter estimationquantitative MRI

Identifiers

PMID35344614
PMCPMC9050814

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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.