Impact of Levovist ultrasonographic contrast agent on the diagnosis and management of hypertensive patients with suspected renal artery stenosis: a Canadian multicentre pilot study.
Bibliographic record
Abstract
OBJECTIVES: To compare the diagnoses obtained with unenhanced ultrasonography (US), contrast-enhanced US and captopril-enhanced renal scintigraphy and to determine whether use of a contrast agent improves ability to assess the renal arteries with duplex Doppler US. SUBJECTS AND METHODS: The study was an open-label controlled trial involving 78 patients with hypertension suspected to have a renovascular cause. The patients underwent captopril-enhanced scintigraphy or routine unenhanced US (the usual diagnostic methods at the centres where the study was conducted) and contrast-enhanced US (with Levovist, Berlex Canada, Lachine, Que.). The patients were followed for 3 months after the diagnostic tests were performed. RESULTS: Enhanced US yielded a diagnosis for a significantly greater proportion of patients than did unenhanced US (77 [99%] v. 64 [82%] of 78 patients; p = 0.002) or captopril-enhanced scintigraphy (71 [99%] v. 58 [81%] of 72 patients; p = 0.002). Diagnosis was possible with both enhanced and unenhanced duplex Doppler US in only 64 (82%) of the 78 patients, and the diagnosis was the same with both methods for 63 (98%) of these 64 patients. In contrast, diagnosis was possible for only 58 (81%) of the 72 patients who underwent both enhanced US and captopril-enhanced scintigraphy; the same diagnosis was reported in 53 (91%) of these 58 cases. During follow-up, 11 patients (21 kidneys) underwent angiography. Significant stenosis was detected in 6 (55%) of the patients (8 [38%] of the kidneys). Both the enhanced and unenhanced US results agreed more often with angiography than did captopril-enhanced scintigraphy (9 [82%] v. 8 [73%] of the 11 patients). The proportion of patients in whom the left and right renal artery could be assessed by duplex Doppler US increased significantly (by 58% and 43%, respectively) with use of the contrast agent. CONCLUSION: Enhanced US had a higher rate of successful diagnosis than unenhanced US and captopril-enhanced renal scintigraphy. Enhanced US might therefore be suitable as a screening method for hypertensive patients with suspected renal artery stenosis.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.003 | 0.006 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".