MR properties of <sup>19</sup>F C<sub>3</sub>F<sub>8</sub> gas in the lungs of healthy volunteers: and apparent diffusion coefficient at 1.5T and at 3T
Bibliographic record
Abstract
Purpose To measure the transverse relaxation time ( ) and apparent diffusion coefficient (ADC) of 19 F‐C 3 F 8 gas in vivo in human lungs at 1.5T and 3T, and to determine the representative distribution of values of these parameters in a cohort of healthy volunteers. Methods Mapping of ADC at lung inflation levels of functional residual capacity (FRC) and total lung capacity (TLC) was performed with inhaled 19 F‐C 3 F 8 (eight subjects) and 129 Xe (six subjects) at 1.5T. mapping with 19 F‐C 3 F 8 was performed at 1.5T (at FRC and TLC) for 8 subjects and at 3T (at TLC for seven subjects). Results At both FRC and TLC, the 19 F‐C 3 F 8 ADC was smaller than the free diffusion coefficient demonstrating airway microstructural diffusion restriction. From FRC to TLC, the mean ADC significantly increased from 1.56 mm 2 /s to 1.83 mm 2 /s ( P = .0017) for 19 F‐C 3 F 8, and from 2.49 mm 2 /s to 3.38 mm 2 /s ( P = .0015) for 129 Xe. The posterior‐to‐anterior gradient in ADC for FRC versus TLC in the superior half of the lungs was measured as 0.0308 mm 2 /s per cm versus 0.0168 mm 2 /s per cm for 19 F‐C 3 F 8 and 0.0871 mm 2 /s per cm versus 0.0326 mm 2 /s per cm for 129 Xe. A consistent distribution of 19 F‐C 3 F 8 values was observed in the lungs, with low values observed near the diaphragm and large pulmonary vessels. The mean across volunteers was 4.48 ms at FRC and 5.33 ms at TLC for 1.5T, and 3.78 ms at TLC for 3T. Conclusion In this feasibility study, values of physiologically relevant parameters of lung microstructure measurable by MRI ( , and ADC) were established for C 3 F 8 in vivo lung imaging in healthy volunteers.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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".