Evidence map›Paper›PMID 42424098›Full record

ArticleMagnetic resonance in medicine2026

Fast Localized Calibration for Spatial-Spectral Excitation Without Fly-Back Gradients.

Michael Schär, Sandeep K Ganji, Robert G Weiss, Allison G Hays

Abstract read
In one paragraph

Article in Magnetic resonance in medicine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

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3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

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5 · Who and what money

Authors and funding

4 authors.

Michael SchärRussell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.ORCID https://orcid.org/0000-0002-7044-9941
Sandeep K GanjiNorth America Clinical Science, MR R&D, Philips, Cambridge, Massachusetts, USA.ORCID https://orcid.org/0000-0002-0247-7596
Robert G WeissRussell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Allison G HaysRussell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.

Funding

Noninvasive assessment of coronary endothelial function by multi-slice MRIR21EB030626 · NIBIB · JOHNS HOPKINS UNIVERSITY · PI SCHAER, MICHAEL · 2021 to 2023
$655k
Johns Hopkins Discovery Award 2019NIBIB NIH HHS R21 EB030626NIH HHS NIBIB R21EB030626
6 · The paper itself

Abstract

purposeStandard spatial-spectral excitation pulses apply a fly-back gradient between sub-pulses, limiting, for example, how thin the slices can be (> 4 mm). Without fly-back gradients, slices can be as thin as 1.7 mm but require a phase calibration for the sub-pulses with inverted gradients due to system imperfections. Here we propose and test a fast (< 1 s), localized pre-scan enabling thin-slice frequency-selective excitation.

methodsThe calibration pre-scan determines the correction phase between even and odd sub-pulses by measuring the phase difference of two FIDs excited with either the last or second-to-last RF sub-pulse of the spatial-spectral pulse. Non-localized and localized versions of the calibration pre-scan are tested and validated for water-only excitation in phantoms and the human heart. As an example, breath-held coronary MR angiography is performed with a spiral multi-slice sequence employing the proposed pulses with a slice thickness of 1.7 mm.

resultsThe proposed calibration pre-scan takes 11.1 ms per slice, whether it is localized or not. Localized calibration phases are validated with an image-based calibration map. Slice profiles are visualized for pulses with different time-bandwidth products. Fat is suppressed to below 20% and 25% of the surrounding water signal in both phantoms and the human heart, respectively. High-quality coronary angiograms are demonstrated in all test subjects.

conclusionSpatial-spectral pulses without fly-back gradients can be calibrated quickly (up to 90 slices in 1 s), enabling thinner slices, higher excitation angles, or pulses with sharper slice profiles using waveforms with higher time-bandwidth products.

Indexed as

Image EnhancementImage Interpretation, Computer-AssistedMagnetic Resonance AngiographyAlgorithmsCalibrationHumansPhantoms, ImagingReproducibility of ResultsSensitivity and Specificitycoronary angiographyfat suppressionlocalized calibrationmagnetic resonance imagingRF pulse designspectral‐spatial excitation

Identifiers

PMID42424098
PMCPMC13527238

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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.