Evidence map›Paper›PMID 36057962›Full record

ArticleJournal of applied clinical medical physics2022

Understanding entrance-air-kerma as a quality-control metric for dual-energy x-ray absorptiometry.

Matthew Allan Thomas, Jorge Ernesto Jimenez, Samuel John Fahrenholtz, Khushnood Hamdani, William Daniel Erwin

Abstract read
In one paragraph

Article in Journal of applied clinical medical physics, 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
–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

1 citing paper in PubMed.

  1. 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

5 authors.

Matthew Allan ThomasDepartment of Imaging Physics, UT MD Anderson Cancer Center, Houston, Texas, USA.
Jorge Ernesto JimenezDepartment of Imaging Physics, UT MD Anderson Cancer Center, Houston, Texas, USA.
Samuel John FahrenholtzSection of Medical Physics, Department of Radiology, Mayo Clinic Arizona, Phoenix, Arizona, USA.
Khushnood HamdaniSection of Medical Physics, Department of Radiology, Mayo Clinic Arizona, Phoenix, Arizona, USA.
William Daniel ErwinDepartment of Imaging Physics, UT MD Anderson Cancer Center, Houston, Texas, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeThe low exposures, unique x-ray beam geometry, and scanning design in dual-energy x-ray absorptiometry (DXA) make measurement and quality-control strategies different from traditional x-ray equipment. This study examines the dependence of measured entrance-air-kerma (EAK) on both dose sensor type and scan length. The feasibility of using EAK to compare scanner output between different scan modes, individual scanners, and scanner platforms was also established. Finally, the congruence between measured and vendor-reported EAK was analyzed.

methodsFour Hologic DXA scanners at two institutions and all four available scan modes were tested. EAK was measured directly by three types of Radcal dose sensors: 60-cc pancake ion-chamber (IC), 180-cc pancake IC, and solid-state detector. The coefficient of variation (COV) was used to assess the dependence of EAK on scan length. Variations in EAK between the types of dose sensors as well as measured versus vendor-reported values were evaluated using Bland-Altman analysis: mean ±95% prediction interval (PI): 1.96σ.

resultsDose sensor variations in EAK were minimal, with a -3.5 ± 3.5% (mean ±95% PI) percent difference between the two sizes of IC's. The solid-state detector produced highly similar measurements to the 180-cc IC. These small differences were consistent across all scanners and all scan modes tested. Neither measured nor vendor-reported EAK values were found to show relevant dependence on scan length, with all COV values ≤4%. Differences between measured and reported EAK were higher at -6 ± 48%. Likely errors in vendor-reported EAK calculations were also identified.

conclusionIt is feasible to quantify DXA scanner stability using EAK as a quality-control metric with a variety of solid-state and IC dose sensors, and the scan length used is not critical. Although vendor-reported EAK was consistent among scanners of the same platform, measured EAK varied significantly from scanner to scanner. As a result, measured and reported EAK may not always be comparable.

Indexed as

Absorptiometry, PhotonHumansQuality ControlX-Raysbone mineral densitydual-energy x-ray absorptiometryentrance-air-kermax-ray absorptiometry

Identifiers

PMID36057962
PMCPMC9588270

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Registered trials

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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.