P08.06: Apparent heterotopic pregnancy created by mirror‐image artefact
Bibliographic record
Abstract
A 30-year-old G1P0 presented for first trimester screening ultrasound at 12 weeks gestation. Previous ultrasound at 7 weeks showed a single live intrauterine pregnancy. On the 12 week scan, an apparent second gestational sac and viable fetus was visualised posterior and cephalad to the uterus (see figure 1), raising the possibility of concurrent intra-abdominal ectopic pregnancy. MRI demonstrated a single live intrauterine gestation, precluding the diagnosis of heterotopic pregnancy. Sonographic findings were attributed to mirror image artefact, with images of two viable, simultaneously active fetuses seen on either side of a reflective interface – the distended, air-filled sigmoid colon adjacent to the uterine fundus. Mirror image artefact is created when ultrasound waves travel through a structure (the fetus), and meet a strongly reflective interface (the air-filled sigmoid colon). Sound beams are propagated back and forth between the two, with resultant delayed return to the transducer, creating a second “mirror image” that is projected deep to the original anatomic structure1. Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
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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 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.004 | 0.003 |
| Insufficient payload (model declined to judge) | 0.005 | 0.002 |
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".