Abstract T P402: Acute Microemboli and Clinical Outcome after Subarachnoid Hemorrhage: Magnetic Resonance Diffusion-Weighted Imaging Study
Bibliographic record
Abstract
Introduction: Aneurysmal subarachnoid hemorrhage (aSAH) is a life-threatening stroke that can be treated with endovascular coiling. Coiling can be associated with microemboli, although the extent to which they are due to aSAH versus the coiling procedure has seldom been investigated. We investigated the implications of these microemboli on clinical outcome. Hypothesis: We hypothesized that the presence, number, location and volume of microemboli would correlate with clinical outcome. Methods: We retrospectively analyzed diffusion-weighted imaging (DWI) scans and apparent diffusion coefficient maps obtained within 7 days of aneurysm rupture in 140 patients. We analyzed the DWI scans of 80 patients with unruptured intracranial aneurysms (UIA) who underwent coiling at our institution as a control group. We assessed the presence and location of microemboli, quantified their volume and number, and correlated these factors with clinical variables and intervention details. Results: The aSAH and UIA groups did not differ in the presence of microemboli. The location of the lesions significantly correlated with the aneurysm location (p<0.05), suggesting they are catheter-induced and not attributed to early brain injury after aSAH. The presence of microemboli correlated with the development of cerebral infarction. Left-sided microemboli were associated with angiographic vasospasm and anterior microemboli were associated with infarcts. Conclusions: Microemboli commonly occur in coiled aSAH patients and have implications on clinical outcome. They are secondary to the coiling procedure and were not increased by presence of aSAH. Catheter-induced microemboli may initiate an early ischemic burden that contributes to angiographic vasospasm and cerebral infarction. That left-sided microemboli contribute to angiographic vasospasm is consistent with prior studies suggesting a left-sided approach significantly contributes to procedure-related microembolism. This suggests that improvements in endovascular practices are required to lower the risk of ischemic damage, especially when employing a left-sided approach.
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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 | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".