Normal patterns on 99mTc-ECD brain SPECT scans in adults.
Bibliographic record
Abstract
UNLABELLED: Normative ethyl cysteinate dimer (ECD) SPECT data must be available to successfully apply ECD SPECT to clinical studies. The purpose of this study was to determine ECD SPECT scan patterns of healthy adults. METHODS: Forty-eight healthy volunteers (22 men, 26 women; age range, 22-95 y; mean age, 47.6 +/- 19.2 y) underwent high-resolution ECD SPECT. For visual analysis of regional brain ECD uptake, we used a scale of +3 to -3, in which +3 and -3 indicated highest ECD uptake and deficit, respectively. For quantitative analysis, we measured the region-to-cerebellum ratio (R/CE) and the region-to-cerebral cortex ratio (R/CO) for 17 regions (13 cortical, 3 subcortical, and 1 cerebellar). RESULTS: On visual analysis, no subject had a score of -3. All subjects had a score of -2 for the hippocampus and a score of +3 for the medial occipital cortex, except for 2 subjects who had a score of +3 for the striatum and thalamus. A frontal eye field and posterior parieto-occipital junction were identified in 60% of subjects with a score of +1 and 79% of subjects with a score of +2. On quantitative analysis, a significant regional variation (ANOVA, P < 0.0001) was seen in R/CE, ranging from 0.709 (hippocampus) to 1.26 (medial occipital cortex). However, regional right-to-left differences and intersubject variability of R/CE were small (asymmetry index, 3.6% +/- 0.8%; coefficient variation, 6.6% +/- 0.7%). R/CE declined significantly with age in 6 regions, including the anterior and posterior cingulate cortex, superior prefrontal and parietal cortex, striatum, and hippocampus (1.0%-2.0% per decade, P < 0.05), whereas R/CO in the cerebellum increased significantly with age (1.0% per decade, P < 0.05). CONCLUSION: Although regional ECD brain perfusion patterns vary significantly, including variability caused by the age-related effect, intersubject variability is small. Recognition of these normal patterns is important for clinical interpretation of ECD SPECT studies.
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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 | 0.000 |
| 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) | 0.002 | 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".