Evidence mapPaperPMID 41334620Full record

ArticleJournal of Parkinson's disease2026

MRI susceptibility map weighted imaging (SMWI) as a neurodegeneration biomarker in the prodromal to overt alpha-synucleinopathy continuum.

Laura Falcitano, Francesco Calizzano, Pietro Mattioli, Oliver C Kiersnowski, Laura Avanzino, Nicola Giovanni Girtler, Andrea Diociasi, Mattia Losa, Federico Massa, Silvia Morbelli and 8 more

Abstract read
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Article in Journal of Parkinson's disease, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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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

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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

0 citing papers in PubMed.

No citing paper in PubMed yet.

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

18 authors.

Laura FalcitanoIRCCS Ospedale Policlinico San Martino, Genova, Italy.ORCID 0000-0002-8258-2184
Francesco CalizzanoDepartment of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy.
Pietro MattioliIRCCS Ospedale Policlinico San Martino, Genova, Italy.ORCID 0000-0003-2563-5830
Oliver C KiersnowskiIRCCS Ospedale Policlinico San Martino, Genova, Italy.ORCID 0000-0001-6016-0514
Laura AvanzinoIRCCS Ospedale Policlinico San Martino, Genova, Italy.
Nicola Giovanni GirtlerDepartment of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy.
Andrea DiociasiDepartment of Internal Medicine and Medical Specialities (D.I.M.I.), University of Genoa, Genoa, Italy.ORCID 0000-0002-5986-0406
Mattia LosaDepartment of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy.ORCID 0009-0008-2942-1307
Federico MassaIRCCS Ospedale Policlinico San Martino, Genova, Italy.ORCID 0000-0001-5667-204X
Silvia MorbelliDivision of Nuclear Medicine, Department of Medical Sciences, University of Turin, Turin, Italy.ORCID 0000-0002-7833-6095
Beatrice OrsoDepartment of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy.ORCID 0000-0001-9983-7940
Elisa PelosinIRCCS Ospedale Policlinico San Martino, Genova, Italy.
Gaia BonassiDepartment of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy.
Stefano RaffaIRCCS Ospedale Policlinico San Martino, Genova, Italy.
Matteo PardiniIRCCS Ospedale Policlinico San Martino, Genova, Italy.
Mauro CostagliIRCCS Ospedale Policlinico San Martino, Genova, Italy.ORCID 0000-0001-9073-1082
Luca RoccatagliataIRCCS Ospedale Policlinico San Martino, Genova, Italy.
Dario ArnaldiIRCCS Ospedale Policlinico San Martino, Genova, Italy.ORCID 0000-0001-6823-6069

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background and objectiveNigrostriatal dopaminergic degeneration is commonly assessed using dopamine transporter (DaT) SPECT. Iron sensitive MRI is a promising technique to assess substantia nigra, yet few studies explored its application in the prodromal stage of alpha-synucleinopathies. Here, we used susceptibility map weighted imaging (SMWI) to assess the swallow tail sign, a radiological marker for substantia nigra integrity, to detect neurodegeneration across the alpha-synucleinopathy continuum.Methods3T-MRI was performed on 115 subjects: 27 overt alpha-synucleinopathies, 34 prodromal alpha-synucleinopathies, 28 Alzheimer's disease and 26 healthy controls. SMWI was obtained with 3D multi-echo gradient-echo imaging. The presence/absence of the swallow tail sign was visually evaluated on SMWI by two neuroradiologists, blinded to the diagnosis. Swallow tail sign's visual assessment was compared across groups to investigate its sensitivity and specificity in identifying alpha-synucleinopathies. Additionally, we compared the SMWI visual analysis sign with both substantia nigra quantitative susceptibility mapping (QSM) and DaT-SPECT.ResultsThe two radiologists' inter-rater agreement was substantial (kappa = 0.8). Visual analysis showed good sensitivity (0.85) and specificity (0.82) in identifying patients with alpha-synucleinopathies. When the subjects were grouped based on DaT-SPECT results, sensitivity increased (0.92), while specificity decreased (0.74). Visual scoring was associated with quantitative substantia nigra MRI assessment obtained with QSM (p < 0.001). Lastly, subjects with the swallow tail sign rated as absent showed significantly lower (p = 0.019) uptake at DaT-SPECT (-1.857 ± 1.343) compared to those with the swallow tail sign rated as present (-0.385 ± 1.850).ConclusionsVisual analysis of SMWI swallow tail sign represents a new and reliable approach for evaluating substantia nigra neurodegeneration across the alpha-synucleinopathy continuum.

Indexed as

Alzheimer DiseaseMagnetic Resonance ImagingNeuroimagingProdromal SymptomsSubstantia NigraSynucleinopathiesAgedBiomarkersFemaleHumansMaleMiddle AgedSensitivity and SpecificityBiomarkersalpha-synucleinbiomarkersdat-SPWECT neurodegenerationMRI swallow tail signREM sleep behavior disordersusceptibility weighed imaging

Identifiers

PMID41334620
PMCPMC13347558

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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 Socratic graph.