Cardiac studies in rats with /sup 11/C-acetate and PET: a comparison with /sup 13/N-ammonia
Bibliographic record
Abstract
Regional myocardial blood flow (MBF) can be assessed noninvasively with dynamic positron emission tomography (PET) and /sup 13/N-ammonia or /sup 11/C-acetate. The latter can also be used to estimate the myocardial oxygen consumption (MVO2) from the same time-activity curve. In this work, we explore the feasibility of such techniques for evaluating myocardial parameters in normal and ischemic rats (/spl sim/350 g) by dynamic imaging with the Sherbrooke small animal PET scanner. Scans were acquired in list mode for /sup 13/N-ammonia and /sup 11/C-acetate as two consecutive 15-min dynamic scans separated by a 5-min interval, without moving the rat from the scanner. Regions of interest (ROIs) were defined on four segments of the myocardium to extract the time-activity curves. Three-compartment models were applied to fit the /sup 13/N-ammonia and /sup 11/C-acetate data with three and four rate constants, respectively, plus blood volume. A reasonable agreement was observed between MBF estimates extracted from /sup 13/N-ammonia and /sup 11/C-acetate. MVO2 estimates, as given by the k/sub 2/ rate constant, were obtained with good reproducibility, indicating that myocardial metabolism can reliably be assessed concurrently with MBF using /sup 11/C-acetate. It is concluded that myocardial blood flow and oxygen consumption can be evaluated in rats with small animal PET scanners through high-rate, list-mode, dynamic imaging and kinetic modeling of /sup 13/N-ammonia and /sup 11/C-acetate.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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.
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 teacher head, 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".