Abstract T P35: Baseline Diffusion Weighted Imaging Lesion Volume Predicts Disappearance of Infarct on Fluid Attenuated Inverse Recovery Sequences Within 30 Days of TIA/Minor Stroke
Bibliographic record
Abstract
Introduction: Evidence of infarction on MRI is predictive of early stroke recurrence after TIA/minor stroke. It has recently been reported that diffusion-weighted imaging (DWI) changes are not associated with evidence of infarction on Fluid Attenuated Inverse Recovery (FLAIR) sequences 90 days later in 30% of patients. We completed a serial MRI study to determine the time course of infarct resolution. We tested the hypothesis that acute DWI lesion volume predicts infarct disappearance by 30 days. Methods: Acute TIA/minor stroke patients (NIHSS≤3) were prospectively imaged at baseline, 7 and 30 days after symptom onset. Lesion volumes were measured planimetrically by a blinded rater at each time point on DWI and FLAIR sequences. Mean and relative (to contralateral tissue) Apparent Diffusion Coefficient ((r)ADC) values were also calculated. Results: Acute DWI lesions were found in 94/172 patients. Median time between symptom onset and baseline MRI was 20.9(19.3) h. DWI volume decreased from baseline (1.51 ml (4.36)) at 7 days (1.13 ml (2.96), P =0.001) and at 30 days (0.40 ml (0.97), P <0.0001). DWI lesions at 7 days pseudo-normalized (infarct visible on FLAIR) in 3.4% and resolved without evidence of infarction in 8% of patients. Seventy-seven (82%) patients had persistent lesions on FLAIR at 30 days (FLAIR+). Baseline NIHSS scores were similar between FLAIR+ (1.40±1.21) and FLAIR– patients (1.18±1.19, P =0.64). Baseline rADC was similar in FLAIR+ (0.84(0.17)) and FLAIR– patients (0.89(0.21), P =0.155). Baseline DWI volumes were larger in FLAIR+ (2.08 ml (6.9)) than FLAIR– patients (0.69 ml (0.95), P =0.007). ROC analysis indicated that a baseline DWI volume <2.04 ml predicted absence of FLAIR lesion at 30 days with a specificity of 100% and sensitivity of 50.6%. Good functional outcome (modified Rankin Score ≤2) at 90 days was similar in FLAIR+ (54/62, 87%) and FLAIR– patients (12/12, 100%, P =0.339). Conclusion: Acute DWI lesions are transient and not always associated with visible infarction on FLAIR, even as early as 7 days after symptom onset. Delaying MRI results in a failure to demonstrate evidence of infarction in the majority of patients, particularly those with DWI lesion volumes below 2 ml.
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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 | 0.000 | 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) | 0.005 | 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".