An improved spread-spectrum method for high-frame-rate color Doppler ultrasound imaging
Bibliographic record
Abstract
We recently introduced a spread-spectrum color Doppler imaging method that produces high-resolution, highframe-rate images without the use of compounding, thereby eliminating the tradeoffs among beam quality, frame rate, and the maximum unaliased Doppler frequency that exist for standard plane-wave imaging methods. In this manuscript, we extend the spread-spectrum method to significantly reduce tissue and wall clutter compared to our original approach. Our new method partitions the transmit sequence into multiple segments, each composed of a unique random ordering of the same set of plane-wave steering angles, so each angle repeats once per segment. The Doppler ensemble is then re-arranged into a sequence with periodically repeating angles, such that stationary clutter forms a periodic slow-time signal that is removed by applying a multi-tap comb filter. The improved clutter suppression of the new method is demonstrated using Field II simulations of imaging continuous flow through an 8 mm diameter vessel with a 5 MHz linear array.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".