Canadian Association of General Surgeons and American College of Surgeons evidence based reviews in surgery. 15. Biphasic CT with mesenteric CT angiography in the evaluation of acute mesenteric ischemia: initial experience.
Bibliographic record
Abstract
Question: Is biphasic computed tomography (CT) with mesenteric CT angiography effective in diagnosing acute mesenteric ischemia (AMI)? Design: Prospective cohort study. Setting: Two tertiary care centres in Canada. Patients: Sixty-two patients had clinically suspected AMI, with a finding of abdominal pain and at least 1 of the following symptoms: pain out of proportion to clinical findings; biochemical evidence of ischemia, namely, elevated lactate levels or unexpected metabolic acidosis; or patients' risk factors for ischemia, such as previous ischemia or symptoms of chronic ischemia, severe vascular disease, atrial fibrillation without therapeutic anticoagulation, low flow (history of hypotension or vasopressor therapy) or hypercoagulable states. The patients consisted of 21 men (age range 32–87 [mean 60] yr) and 41 women (age range 32–87 [mean 65] yr). All patients were examined before CT angiography by a specialist (either a general or vascular surgeon or an internist). Description of test and diagnostic standard: All patients were examined with 4-row multidetector row CT. Mesenteric angiography was performed with 1.25-mm collimation, starting 25 seconds after intravenous (IV) administration of contrast material, which was delivered at a rapid rate of injection (4 mL/s) for maximum enhancement of the arteries during the arterial phase. Water was given as an oral contrast agent so that 3-dimensional CT angiograms could be reconstructed from high-density oral contrast material. The results were compared with findings from surgery, autopsy, serial CT, laboratory tests or by following patients until they recovered spontaneously. Main results: AMI was diagnosed in 26 patients, 11 of whom died of bowel ischemia while in hospital. The initial interpretation of the radiologist had 100% sensitivity and 89% specificity. The likelihood ratio of a positive test was 9. A finding of any one of pneumatosis intestinalis, venous gas, superior mesenteric artery (SMA) occlusion, celiac and inferior mesenteric artery occlusion with distal SMA disease, or arterial embolism was 100% specific but only 73% sensitive. A finding of bowel-wall thickening in addition to a focal lack of bowel enhancement, solid-organ infarction or venous thrombosis was 50% sensitive and 94% specific. By using either of these criteria for a diagnosis, a sensitivity of 96% and specificity of 94% was achieved. Conclusion: Biphasic CT with mesenteric CT angiography is effective in diagnosing AMI.
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 | 0.016 | 0.048 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.002 |
| Bibliometrics | 0.011 | 0.013 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.004 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.014 | 0.005 |
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".