Imaging performance of PEM-1: a high resolution system for positron emission mammography
Bibliographic record
Abstract
Positron emission tomography with /sup 18/F-fluoro-deoxyglucose (FDG) is known to detect the increased metabolism of breast tumours. The authors have built a positron emission mammography system which produces metabolic breast images co-registered with conventional mammography. Two position sensitive photomultipliers are coupled to four BGO blocks which are partially cut into 2/spl times/2 mm elements from both faces. This provides 72/spl times/72 BGO crystals in coincidence yielding over 26 million lines of response. A real time display is formed by performing a weighted back-projection onto seven image planes through the breast. The prototype instrument is currently being tested on phantoms. The spatial resolution in the central region has been measured at 2.05 mm FWHM, less than half that of a conventional PET scanner. The coincidence resolving time is 12 nsec. This device should be able to identify breast tumours <5 mm in diameter and provide 3-D localization registered with conventional mammography.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".