Infusion Versus Bolus of an Ultrasound Contrast Agent
Bibliographic record
Abstract
RATIONALE AND OBJECTIVES: To determine the efficacy of an ultrasound contrast agent infusion using Doppler intensitometry estimation of backscatter enhancement in blood. METHODS: Multiple intravenous injections of BR1 (SonoVue) were performed in chronic dog studies, using bolus (0.05-2 mL) and infusion (3-40 mL/h during 6 minutes) administration. The pulsed Doppler signal from the femoral artery was recorded and analyzed for mean Doppler power and integrated fractional enhancement. RESULTS: For bolus injection, time-intensity curves exhibited a rapid first pass (peak 30 dB for 0.45 mL) followed by a slower washout. Integrated fractional enhancement exhibited a linear relation with the dose (R2 = 0.99). For infusion administration, peak enhancement increased with the infusion rate from 8 to 22 dB. At rates exceeding 30 mL/h, the enhancement was stable with a plateau-like pattern. CONCLUSIONS: Infusion of BR1 is easily achieved and allows the duration of enhancement to be increased as long as desired. Stable enhancement is obtained for rates greater than 30 mL/h.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".