Reproducibility study for free‐breathing measurements of pyruvate metabolism using hyperpolarized <sup>13</sup>C in the heart
Bibliographic record
Abstract
Spatially resolved images of hyperpolarized (13) C substrates and their downstream products provide insight into real-time metabolic processes occurring in vivo. Recently, hyperpolarized (13) C pyruvate has been used to characterize in vivo cardiac metabolism in the rat and pig, but accurate and reproducible measurements remain challenging due to the limited period available for imaging as well as physiological motion. In this article, time-resolved cardiac- and respiratory-gated images of [1-(13) C] pyruvate, [1-(13) C] lactate, and (13) C bicarbonate in the heart are acquired without the need for a breathhold. The robustness of these free-breathing measurements is demonstrated using the time-resolved data to produce a normalized metric of pyruvate dehydrogenase and lactate dehydrogenase activity in the heart. The values obtained are reproducible in a controlled metabolic state. In a 60-min ischemia/reperfusion model, significant differences in hyperpolarized bicarbonate and lactate, normalized using the left ventricular pyruvate signal, were detected between scans performed at baseline and 45 min after reperfusion. The sequence is anticipated to improve quantitative measurements of cardiac metabolism, leading to feasible validation studies using fewer subjects, and potentially improved diagnosis, serial monitoring, and treatment of cardiac disease in patients.
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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 | 0.004 | 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 | 0.000 | 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".