A Novel Window Into Human Vascular Remodeling and Diagnosing Carotid Flow Impairment: The Petro‐Occipital Venous Plexus
Bibliographic record
Abstract
Background Adaptive arterial remodeling caused by flow reduction from downstream stenosis has been demonstrated in animal studies. The authors sought to determine whether inward remodeling from downstream stenosis also occurs in humans and is detectable by ex vacuo expansion of the Rektorzik venous plexus (RVP) surrounding the petrous internal carotid artery. Methods and Results The authors analyzed 214 intracranial magnetic resonance imaging examinations that included contrast‐enhanced vessel wall imaging. RVP symmetry was qualitatively assessed on vessel wall imaging. RVP thickness (RVPT) was measured on the thicker side if asymmetric or randomly assigned side if symmetric. Maximum stenosis (M1 or intracranial internal carotid artery) was measured. Posterior communicating artery and A1 diameters (>1.0 mm and 1.5 mm, respectively) defined adequate collateral outflow when proximal to the stenosis. Seventy‐two patients had stenosis downstream from RVPT measurements. For those without adequate outflow (38 of 72), 95.0% with RVPT ≥1.0 mm had ≥50% stenosis compared with only 5.6% with RVPT <1.0 mm. For these 72 patients, higher RVPT (RVPT ≥1.0 mm versus <1.0 mm) and absent adequate outflow were associated with greater downstream stenosis ( P <0.001) using multivariate regression. For patients with downstream stenosis without adequate outflow, asymmetric RVP thickening was associated with greater ipsilateral stenosis ( P <0.001, all had ≥46% stenosis) when stenosis was unilateral and greater differences in stenosis between sides ( P =0.005) when stenosis was bilateral. Conclusions Inward internal carotid artery remodeling measured by RVPT or RVP asymmetry occurs as downstream stenosis approaches 50%, unless flow is preserved through a sufficiently sized posterior communicating artery or A1, and may serve as a functional measure of substantial flow reduction from downstream stenosis.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".