A222 QUANTITATIVE ASSESSMENT TO DETERMINE CHANGES IN COLONIC CURVATURE WITH SUPINE VERSUS PRONE PATIENT POSITION USING COMPUTED TOMOGRAPHY COLONOGRAPHY
Bibliographic record
Abstract
Dynamic positional changes during colonoscopy are commonly used in clinical practice, in particular moving from side to side. It has been shown to improve both adenoma detection rates as well as cecal intubation times. However, perhaps due to an additional level of inconvenience, there have been few studies comparing the anatomy and changes in colonic curvature when patients are in the prone position, which may help to prevent anterior bowing of the scope, particularly in patients with high abdominal circumference. To correlate changes in both the number of colonic curves and degree of change in curves with patients in supine versus prone positioning during computed tomography colonography (CTC). 104 CTC studies, obtained between January and April 2017 at Hotel Dieu Hospital in Kingston, Ontario, were screened and included based on image quality and adequacy of distention. Per standardized protocol, all patients undergoing CTC are imaged both in supine and prone positioning. Ten of these studies were then randomly selected for preliminary analysis (4 female and 6 male). Median age and BMI of these patients were 68.5 years (range 50–87 years) and 26.2 kg/m2 (range 21.9–34.1 kg/m2) respectively. Using an automated process developed for this study, curves were identified and measured via centerline points placed digitally through the colonic lumen, and compared between supine and prone patient positioning. Results were further stratified based on colonic segment (whole colon, ascending, transverse or descending). There were a significantly higher total number of curves in supine compared to prone positioning (P=0.006). When only the total number of curves containing ≥ 60 degrees of change in angulation were identified, there was no significant difference between supine and prone positioning, regardless of colonic segment (whole colon P=0.55; ascending P=0.62; transverse P=0.30; descending P=0.22). Likewise, there was no significant difference found when comparing the mean degree of change in angulation between the two positions (whole colon P=0.58; ascending P=0.53; transverse P=0.97; descending P=0.25). Based on our preliminary analysis of ten patients, there are more curves found in supine positioning compared to prone, but no significant differences were found between the two positions when only more acute angles are included. Based on these results, we will complete analysis of the remaining CTC studies. We expect that with a larger sample size, more significant differences will become evident. None
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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 | 0.002 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 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".