Evidence map›Paper›PMID 35767553›Full record

ArticlePloS one2022

Effects of image homogeneity on stenosis visualization at 7 T in a coronary artery phantom study: With and without B1-shimming and parallel transmission.

Stefan Herz, Maria R Stefanescu, David Lohr, Patrick Vogel, Aleksander Kosmala, Maxim Terekhov, Andreas M Weng, Jan-Peter Grunz, Thorsten A Bley, Laura M Schreiber

Open access · goldAbstract read
In one paragraph

Article in PloS one, 2022. 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
0.1field-weighted citation impact, top 53% of its field
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

1 citing paper in PubMed, 1 citations in OpenAlex.

  1. Review
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

10 authors at 2 institutions in 1 country.

Stefan HerzComprehensive Heart Failure Center (CHFC), Chair of Molecular and Cellular Imaging, University Hospital Würzburg, Würzburg, Germany.ORCID 0000-0002-6360-0578
Maria R StefanescuComprehensive Heart Failure Center (CHFC), Chair of Molecular and Cellular Imaging, University Hospital Würzburg, Würzburg, Germany.
David LohrComprehensive Heart Failure Center (CHFC), Chair of Molecular and Cellular Imaging, University Hospital Würzburg, Würzburg, Germany.
Patrick VogelDepartment of Experimental Physics V, University of Würzburg, Würzburg, Germany.
Aleksander KosmalaComprehensive Heart Failure Center (CHFC), Chair of Molecular and Cellular Imaging, University Hospital Würzburg, Würzburg, Germany.ORCID 0000-0002-9313-9356
Maxim TerekhovComprehensive Heart Failure Center (CHFC), Chair of Molecular and Cellular Imaging, University Hospital Würzburg, Würzburg, Germany.
Andreas M WengDepartment of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany.ORCID 0000-0001-8943-3539
Jan-Peter GrunzComprehensive Heart Failure Center (CHFC), Chair of Molecular and Cellular Imaging, University Hospital Würzburg, Würzburg, Germany.
Thorsten A BleyDepartment of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany.
Laura M SchreiberComprehensive Heart Failure Center (CHFC), Chair of Molecular and Cellular Imaging, University Hospital Würzburg, Würzburg, Germany.
Universitätsklinikum Würzburg · DEUniversity of Würzburg · DE

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundTo investigate the effects of B1-shimming and radiofrequency (RF) parallel transmission (pTX) on the visualization and quantification of the degree of stenosis in a coronary artery phantom using 7 Tesla (7 T) magnetic resonance imaging (MRI).

methodsStenosis phantoms with different grades of stenosis (0%, 20%, 40%, 60%, 80%, and 100%; 5 mm inner vessel diameter) were produced using 3D printing (clear resin). Phantoms were imaged with four different concentrations of diluted Gd-DOTA representing established arterial concentrations after intravenous injection in humans. Samples were centrally positioned in a thorax phantom of 30 cm diameter filled with a custom-made liquid featuring dielectric properties of muscle tissue. MRI was performed on a 7 T whole-body system. 2D-gradient-echo sequences were acquired with an 8-channel transmit 16-channel receive (8 Tx / 16 Rx) cardiac array prototype coil with and without pTX mode. Measurements were compared to those obtained with identical scan parameters using a commercially available 1 Tx / 16 Rx single transmit coil (sTX). To assess reproducibility, measurements (n = 15) were repeated at different horizontal angles with respect to the B0-field.

resultsB1-shimming and pTX markedly improved flip angle homogeneity across the thorax phantom yielding a distinctly increased signal-to-noise ratio (SNR) averaged over a whole slice relative to non-manipulated RF fields. Images without B1-shimming showed shading artifacts due to local B1+-field inhomogeneities, which hampered stenosis quantification in severe cases. In contrast, B1-shimming and pTX provided superior image homogeneity. Compared with a conventional sTX coil higher grade stenoses (60% and 80%) were graded significantly (p<0.01) more precise. Mild to moderate grade stenoses did not show significant differences. Overall, SNR was distinctly higher with B1-shimming and pTX than with the conventional sTX coil (inside the stenosis phantoms 14%, outside the phantoms 32%). Both full and half concentration (10.2 mM and 5.1 mM) of a conventional Gd-DOTA dose for humans were equally suitable for stenosis evaluation in this phantom study.

conclusionsB1-shimming and pTX at 7 T can distinctly improve image homogeneity and therefore provide considerably more accurate MR image analysis, which is beneficial for imaging of small vessel structures.

Indexed as

Coronary VesselsRadio WavesConstriction, PathologicHumansMagnetic Resonance ImagingPhantoms, ImagingReproducibility of Results

Identifiers

PMID35767553
PMCPMC9242506
OpenAlexW4285740250

What Socratic holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.