MRI criteria of developmental lumbar spinal stenosis revisited.
Bibliographic record
Abstract
PURPOSE: It is somewhat surprising that radiographic criteria for lumbar stenosis have been transposed from radiography and CT to MR without scientific validation. As these radiographic criteria were developed via population studies with criteria defined by two standard deviations from the mean, we sought to perform the same methodology via MR. METHODS: The study was approved by the institutional review board; the requirement for informed consent was waived. One-hundred patients referred for possible metastatic disease, aged 4 to 94 were studied. Measurements were obtained on a midline sagittal T2-weighted (6000/120) image at each disc level, as well as at the mid-vertebral level. The distributive mean, and standard deviations were calculated and -2 SD was used as a "cutoff" for spinal stenosis. To assess for interobserver variation, 20% of the measurements were repeated by a second observer. To assess for intraobserver variation, another 20% of the measurements were repeated a second time at a minimum of a two month interval. RESULTS: The spinal canal was narrowest at L5-S1 (mean: 1.16 cm), and widest at L1-L2 (mean: 1.56 cm). Overall the narrowest measurements were at the intervertebral disc space and were narrower at the lower disc spaces. In our population, the lowest cutoff limit (two standard deviations below the mean) had a range between 0.38 cm at the L3-L4 disc space and 0.9 cm at the L1 vertebral level. Notably at the L3 level the size range was from 0.77 to 1.75 CONCLUSION: Traditional measurements of canal diameters may be too large when applied to soft tissue analysis on MR. We suggest using a cutoff of smaller than 0.90 cm for developmental 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 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".