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Hyperpolarized 3He Ventilation Defects and Apparent Diffusion Coefficients in Chronic Obstructive Pulmonary Disease

2007· article· en· W2040022821 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

VenueInvestigative Radiology · 2007
Typearticle
Languageen
FieldPhysics and Astronomy
TopicAtomic and Subatomic Physics Research
Canadian institutionsLawson Health Research InstituteLondon Health Sciences CentreWestern UniversityRobarts Clinical Trials
Fundersnot available
KeywordsReproducibilityMedicineCOPDEffective diffusion coefficientVentilation (architecture)Nuclear medicineMagnetic resonance imagingPulmonary diseaseRadiologyDiffusion MRIInternal medicine

Abstract

fetched live from OpenAlex

OBJECTIVE: Hyperpolarized 3He magnetic resonance imaging (3He MRI) at 3.0 Tesla of healthy volunteers and chronic obstructive pulmonary disease (COPD) patients was performed for quantitative evaluation of ventilation defects and apparent diffusion coefficients (ADC) and for comparison to published results acquired at 1.5 Tesla. The reproducibility of 3He ADC and ventilation defects was also assessed in subjects scanned 3 times, twice within 10 minutes, and again within 7 +/- 2 days of the first MRI visit. MATERIALS AND METHODS: Hyperpolarized 3He MRI was performed in 6 subjects. Two interleaved images with and without additional diffusion sensitization were acquired with the first image serving as a ventilation image from which defect score and volume were measured and the combination of the 2 images used to compute ADC maps and ADC histograms. RESULTS: He MRI at 3.0 Tesla showed increased mean ADC and ADC standard deviation for subjects with COPD compared with healthy volunteers (ADC healthy volunteer (0.24 +/- 0.12 cm2/s), mild-moderate COPD (0.34 +/- 0.14 cm2/s), and severe COPD (0.47 +/- 0.21 cm2/s), and these values were similar to previously reported results acquired at 1.5 Tesla. Reproducibility of mean ADC was high (coefficient of variation 2% in severe COPD, 3% in mild-moderate COPD, 4% in healthy volunteers) across all 3 scans. Higher same-day scan reproducibility was observed for ventilation defect volume compared with 1-week scan reproducibility in this small group of subjects. CONCLUSIONS: ADC values for emphysematous lungs were significantly increased compared with healthy lungs in age-matched subjects, and all values were comparable to those reported previously at 1.5 Tesla. Ventilation defect score and ventilation defect volume results were also comparable to results previously reported in COPD subjects Reproducibility of ADC for same-day scan-rescan and 7-day rescan was high and similar to previously reported results.

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)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.082
Threshold uncertainty score0.641

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.001
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 head0.019
GPT teacher head0.279
Teacher spread0.261 · 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