Abstract 95: MRI Description of an Adult Primary Angiitis of the Central Nervous System in the French COVAC Cohort
Bibliographic record
Abstract
Introduction: Primary angiitis of the central nervous system (PACNS) is a potentially severe inflammatory disease of central nervous system vessels and despite its extreme sparsity, knowledge has improved within past decades. PACNS diagnosis, however, remains challenging, mainly because of the multiple mimickers and possible differential diagnoses. Previous MRI/MR Angiography descriptions of PACNS adult patients might have become outdated Hypothesis: To report an updated overview and pictural review of MR/MRA findings in adult PACNS, determine type/distribution of parenchymal, meningeal and vascular lesions in an independent multicentric inception cohort. Methods: Patients from the French mutlicentric COVAC cohort, adults with biopsy/angiographically proven PACNS were included if they had MRI/MRA available imaging upon diagnosis for retrospective review. Systematic imaging review was performed blinded to clinical data. Results: Among the 91 enrolled patients in cohort, 60 met inclusion criteria for this study. Mean age was 45yo (±12.9). Patients presented initially with focal deficit(s) (83%), headaches (53%), cognitive disorder (40%) or seizures (38.3%). MRI was abnormal in all patients, most common finding being ischemic stroke following a small arteries distribution with multi-territorial lesions (50% of evaluated patients), with a predominant anterior distribution. 57% of parenchymal hemorrhagic lesions were hemorrhagic transformation of ischemic strokes. 26% of patients had otherwise subarachnoid hemorrhage. 42% of patients demonstrated preeminent leptomeningeal enhancement. Seven had tumor like presentation. 77% of MRA studies were abnormal revealing proximal/distal stenoses in respectively 57% and 61% of patients. Only 11 patients demonstrated a typical beading aspect on MRA. DSA unmasked distal stenotic lesions in <10% of patients with normal MRA. Discussion: We present the largest to date MRI/MRA systematically assessed cohort of adult PACNS patients, extend our current knowledge of this rare and heterogeneous disease and present an extensive analysis of MRI and MR Angiography characteristics of PACNS in adults.
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.
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 | 0.002 |
| 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 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".