A Longitudinal Characterization of Cerebral Microbleeds in a Marginalized Population with High Rates of Mental Illness, Substance Abuse and Viral Infection (P3.390)
Bibliographic record
Abstract
Objective: To evaluate the incidence, regional localization, volume, and change in volume of cerebral microbleeds (CMBs) over a three year period in a marginalized urban population. Background: Living in a marginalized urban environment is associated with exposure to a large number of variables, including physical violence, infection and substance abuse, which can harm the brain. Additionally, many people living in this environment experience early life trauma and have severe mental illness. CMBs are small, chronic brain hemorrhages that may represent an index of this harm. Methods: Subjects living in Single Room Occupancy hotels in the Downtown Eastside of Vancouver, Canada were recruited for the Hotel study. Subjects had MRI brain scans at entry into the study, and once per year for the next three years. Data were acquired on a 3T Philips Achieva. Parameters for SWI: 3D flow compensated gradient echo scan, TE/TR 20/ms, voxel size=0.45x0.7x2mm3, reconstructed to 0.39x0.39x1mm3. Final SWI images were computed offline and lesions were marked using in-house developed software; lesion volume was measured across the manually defined regions. Results: The mean age of subjects was 45 years (80[percnt] male). Useful baseline scans from 245 subjects were collected at baseline, 217 scans at 12 months, 182 at 24 months and 79 at 36 months. CMBs were present in 22[percnt] of scans. These were localized to: frontal lobe (33[percnt]), temporal lobe (25[percnt]), parietal lobe (21[percnt]), occipital lobe (11[percnt]) and subcortical (10[percnt]). Modal CMB volume was 4.5-6mm3. 61[percnt] of scans showed a year-to-year decrease in CMB volume (-27[percnt]) and 28[percnt] showed an increase in volume (+29[percnt]), while 11[percnt] showed no change. Conclusions: Rates of CMBs in this marginalized population were greater than expected based on age. Further study is needed to determine the etiology and neurocognitive sequelae of CMBs in this cohort.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 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) | 0.001 | 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".