Evidence map›Paper›PMID 31317566›Full record

ArticleMagnetic resonance in medicine2019

Understanding the physical relations governing the noise navigator.

R J M Navest, S Mandija, A Andreychenko, A J E Raaijmakers, J J W Lagendijk, C A T van den Berg

Abstract read
In one paragraph

Article in Magnetic resonance in medicine, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing 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

2 citing papers in PubMed.

  1. Article
  2. Article
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

6 authors.

R J M NavestDepartment of Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands.ORCID 0000-0002-0152-2092
S MandijaDepartment of Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands.
A AndreychenkoDepartment of Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands.
A J E RaaijmakersComputational Imaging Group for MRI Diagnostics & Therapy, Centre for Image Sciences, University Medical Center Utrecht, Utrecht, Netherlands.
J J W LagendijkDepartment of Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands.
C A T van den BergDepartment of Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeThe noise navigator is a passive way to detect physiological motion occurring in a patient through thermal noise modulations measured by standard clinical radiofrequency receive coils. The aim is to gain a deeper understanding of the potential and applications of physiologically induced thermal noise modulations.

methodsNumerical electromagnetic simulations and MR measurements were performed to investigate the relative contribution of tissue displacement versus modulation of the dielectric lung properties over the respiratory cycle, the impact of coil diameter and position with respect to the body. Furthermore, the spatial motion sensitivity of specific noise covariance matrix elements of a receive array was investigated.

resultsThe influence of dielectric lung property variations on the noise variance is negligible compared to tissue displacement. Coil size affected the thermal noise variance modulation, but the location of the coil with respect to the body had a larger impact. The modulation depth of a 15 cm diameter stationary coil approximately 3 cm away from the chest (i.e. radiotherapy setup) was 39.7% compared to 4.2% for a coil of the same size on the chest, moving along with respiratory motion. A combination of particular noise covariance matrix elements creates a specific spatial sensitivity for motion.

conclusionsThe insight gained on the physical relations governing the noise navigator will allow for optimized use and development of new applications. An optimized combination of elements from the noise covariance matrix offer new ways of performing, e.g. motion tracking.

Indexed as

Magnetic Resonance ImagingMotionComputer SimulationElectromagnetic RadiationHealthy VolunteersHumansLungMaleMusclesPhantoms, ImagingRadiotherapyRadio WavesSignal-To-Noise RatioSkinbody resistancemagnetic resonance imagingphysiological motionradiofrequency receive coilthermal noise

Identifiers

PMID31317566
PMCPMC6771522

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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.