P22.01: Preliminary investigation of the utility of <scp>MRI</scp> for measuring the hematocrit in fetal anemia
Bibliographic record
Abstract
The detection of fetal anemia by middle cerebral artery peak systolic velocity is less reliable with advancing gestational age (GA) and prior transfusion. We sought to investigate the feasibility and accuracy of a new MRI method for measuring fetal hematocrit (Hct) in vivo in anemic fetuses. We recruited 4 pregnant women suspected of carrying anemic fetuses between 19 and 38 weeks GA. Two fetuses had Rh alloimmunisation, one had alpha-thalassemia and two had twin anemia-polycythemia sequence. The fetuses underwent MRI scans either immediately before or after their intrauterine transfusions (IUT), or both. The scans were performed on a 1.5T Siemens scanner and included T1 and T2 mapping of the intrahepatic umbilical vein. We used vessel T1 and T2 to calculate Hct according to our previously published technique [Portnoy et al. ISMRM 2015]. MRI Hct was compared with the Hct from cordocentesis samples obtained during IUT. The Hct values we calculated from T1 and T2 times showed excellent agreement with the gold-standard laboratory Hct (see figure 1). The mean difference between the MRI-predicted Hct and the laboratory values is 3.7%. Our method was accurate for a wide range of fetal hematocrit, from anemia to polycythemia, and for both before and after IUT. 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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.023 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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) | 0.000 | 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 teacher head, 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".