Evidence map›Paper›PMID 36201151›Full record

ArticleMedical physics2023

MRI of radiation chemistry: First images and investigation of potential mechanisms.

Joshua Wancura, James Egan, Erno Sajo, Atchar Sudhyadhom

Open access · greenAbstract read
In one paragraph

Article in Medical physics, 2023. 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
0.9field-weighted citation impact, top 28% 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

2 citing papers in PubMed, 7 citations in OpenAlex.

  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

4 authors at 2 institutions in 1 country.

Joshua WancuraDepartment of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
James EganDepartment of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, Massachusetts, USA.
Erno SajoDepartment of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, Massachusetts, USA.
Atchar SudhyadhomDepartment of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Brigham and Women's Hospital · USUniversity of Massachusetts Lowell · US

Funding

A Multimodal Imaging Approach Towards the Reduction of Proton Beam Range UncertaintiesR21EB026086 · NIBIB · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · PI SUDHYADHOM, ATCHAR · 2018 to 2020
$594k
NIBIB NIH HHS R21 EB026086NIBIB of the National Institutes of Health R21EB026086
6 · The paper itself

Abstract

backgroundParamagnetic species such as O PURPOSE: We present the first reported instance of x-ray-induced MR signal changes in water phantoms and investigate potential paramagnetic relaxation enhancement mechanisms associated with radiation chemistry changes in oxygen and free radical concentrations.

methodsImages of water and 10 mM coumarin phantoms were acquired on a 0.35 T MR-linac before, during, and after a dose delivery of 80 Gy using an inversion-recovery dual-echo sequence with water nullified. Radiation chemistry simulations of these conditions were performed to calculate changes in oxygen and free radical concentrations. Published relaxivity values were then applied to calculate the resulting T

resultsCompared to pre-irradiation reference images, water phantom images taken during and after irradiation showed little to no change, while coumarin phantom images showed a small signal loss in the irradiated region with a contrast-to-noise ratio (CNR) of 1.0-2.5. Radiation chemistry simulations found oxygen depletion of -11 µM in water and -31 µM in coumarin, resulting in a T

conclusionObserved radiation-induced MR signal changes were dominated by an oxygen depletion mechanism. Free radicals were concluded to play a minor secondary role under steady-state conditions. Future applications may include in vivo FLASH treatment verification but would require an MR sequence with a better signal-to-noise ratio and higher temporal resolution than the one used in this study.

Indexed as

Magnetic Resonance ImagingOxygenFree RadicalsPhantoms, ImagingSignal-To-Noise RatioFree RadicalsOxygenmagnetic resonance imaging (MRI)MR-linacradiation chemistryreal-time beam imaging

Identifiers

PMID36201151
PMCPMC9930196
OpenAlexW4302307361

What OpenQuestion holds

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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 OpenQuestion graph.