Blood‐oxygen level dependent MRI measures of cerebrovascular reactivity using a controlled respiratory challenge: Reproducibility and gender differences
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.
Bibliographic record
Abstract
PURPOSE: To evaluate the reproducibility and gender differences in cerebrovascular reactivity (CVR) measurements obtained using the blood-oxygen level dependent (BOLD) response to controlled changes in end-tidal partial pressure of carbon dioxide (PETCO(2)). MATERIALS AND METHODS: We obtained ethical approval to image 19 healthy volunteers (10 men, 9 women) on a 1.5 Tesla (T) MRI scanner twice on two separate days using identical procedures. CVR images were generated by collecting BOLD MRI data during controlled changes in PETCO(2) induced by a sequential gas delivery system. RESULTS: Using the intraclass correlation coefficient (ICC), we demonstrated excellent within-day CVR measures in gray matter (GM) (ICC = 0.92) and white matter (WM) (ICC = 0.88) regions, excellent between-day reproducibility in GM (ICC = 0.81), and good between-day reproducibility in the WM (ICC = 0.66). CVR values between men and women were significantly different in the GM and WM. Men exhibited a 22 +/- 2% greater CVR in GM and a 17 +/- 2% greater CVR in WM compared with females. CONCLUSION: Our results demonstrate the reliability of BOLD MRI CVR measurements obtained using a controlled cerebrovascular challenge. Using this technique, we also revealed significantly increased BOLD response to CO(2) in males compared with females.
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 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 | 0.002 | 0.001 |
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 it