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Summing Coincidence Errors Using 152Eu Lungs to Calibrate a Lung-counting System: Are They Significant?

2004· article· en· W2028786907 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueHealth Physics · 2004
Typearticle
Languageen
FieldPhysics and Astronomy
TopicRadioactive Decay and Measurement Techniques
Canadian institutionsNuclear Waste Management OrganizationHealth Canada
Fundersnot available
KeywordsImaging phantomNuclideCalibrationCoincidencePhysicsEnergy (signal processing)Nuclear medicineRange (aeronautics)Calibration curveNuclear physicsRadiochemistryChemistryMaterials scienceMedicineMathematicsStatisticsPathologyDetection limit

Abstract

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The use of a lung phantom containing 152Eu/241 Am activity can provide a sufficient number of energy lines to generate an efficiency calibration for the in vivo measurements of radioactive materials in the lungs. However, due to the number of energy lines associated with 152Eu, coincidence summing occurs and can present a problem when using such a phantom for calibrating lung-counting systems. A Summing Peak Effect Study was conducted at three laboratories to determine the effect of using an efficiency calibration based on a 152Eu/241 Am lung phantom. The measurement data at all three laboratories showed the presence of sum peaks. While one of the laboratories found only small biases (< 5%) when using the 152Eu/241 Am calibration, the other facilities noted up to 30% positive bias in the 140 keV to 190 keV energy range that prevents the use of the 152Eu/241 Am lung phantom for routine calibrations. Although manufactured by different vendors, the three facilities use similar types of germanium detectors (38 cm2 by 25 mm thick or 38 cm2 by 30 mm thick) for counting. These results underscore the need to evaluate the coincidence summing effect, which appear system dependent, when using a nuclide such as 152Eu for the calibration of low-energy lung counting systems and highlight the problem of using a general calibration curve in place of specific nuclide calibration factors.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.599
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.044
GPT teacher head0.321
Teacher spread0.276 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it