Assessment of microvascular dysfunction in acute limb ischemia‐reperfusion injury
Bibliographic record
Abstract
Background Ischemia‐reperfusion (I/R) injury involves damage to the microvessel structure (eg, increased permeability) and function (blunted vasomodulation). While microstructural damage can be detected with dynamic contrast‐enhanced (DCE) MRI, there is no diagnostic to detect deficits in microvascular function. Purpose To apply a novel MRI method for evaluating dynamic vasomodulation to assess microvascular dysfunction in skeletal muscle following I/R injury. Study Type Prospective, longitudinal. Animal Model Twenty‐three healthy male adult Sprague–Dawley rats. Field Strength/Sequence Dynamic T 1 fast field echo imaging at 3.0T with preinjection T 1 mapping. Assessment Injury in the left hindlimb was induced using a 3‐hour I/R procedure. Longitudinal MRI scanning was performed up to 74 days, with animals completing assessment at different intervals for histological and laser Doppler perfusion validation. Pharmacokinetic parameters K trans and v e were determined following i.v. injection of gadovist (0.1 mmol/kg). Vasomodulatory response was probed on gadofosveset (0.3 mmol/kg) using hypercapnic gases delivered through a controlled gas‐mixing circuit to induce vasoconstriction and vasodilation in ventilated rats. Heart rate and blood oxygen saturation were monitored. Statistical Tests Two‐way analysis of variance with Tukey–Kramer post‐hoc analysis was used to determine significant changes in vasomodulatory response, K trans , and v e . Results This new MRI technique revealed impaired vasomodulation in the injured hindlimb. Vasoconstriction was maintained, but vasodilation was blunted up to 21 days postinjury ( P < 0.05). However, DCE‐MRI measured K trans and v e were significantly ( P < 0.05) different from baseline only during acute inflammation (Day 3), with severe inflammation noted on histology. Data Conclusion While conventional DCE‐MRI shows normalization after the acute phase, our new approach reveals sustained functional impairment in muscle microvasculature following I/R injury, with compromised response in vasomotor tone present for at least 21 days. Level of Evidence : 4 Technical Efficacy : Stage 1 J. Magn. Reson. Imaging 2019;49:1174–1185.
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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 | 0.000 |
| 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) | 0.001 | 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".