Colonoscopy is the cornerstone for colorectal cancer screening, diagnosis, and post-treatment surveillance. Procedural quality is influenced by patient anatomy, particularly variations in colonic configuration such as sigmoid redundancy, looping, and low-lying transverse colon. These features prolong insertion time, increase patient discomfort, and elevate physician workload.
Evidence suggests that prior CT imaging can provide objective and individualized information on colonic anatomy-such as redundancy, angulation, and tortuosity-potentially predicting procedural difficulty. However, existing studies are mainly retrospective or descriptive, lacking prospective randomized evidence on clinical utility.
This single-blind, randomized controlled trial evaluates whether image-assisted colonoscope insertion, based on pre-existing abdominal/pelvic CT scans, can improve cecal intubation time, enhance patient experience, reduce operator workload, and improve overall examination quality compared with standard colonoscopy.
Age 18-80 years, or expected natural survival >3 years
Undergoing colonoscopy at Peking Union Medical College Hospital
Presence of an abdominal/pelvic CT scan performed within ≤5 years and no - - - major abdominal surgery afterward
Patient or legal guardian able to understand the study and provide written consent
No available CT or CT quality insufficient for anatomical evaluation
Prior colonic surgery affecting anatomy (e.g., right hemicolectomy, transverse colectomy)
Severe cardiopulmonary dysfunction or coagulopathy
Pregnancy
Parallel
CT-Based Image-Assisted Colonoscope Insertion
Other interventionThis intervention uses pre-existing abdominal or pelvic CT imaging (within 5 years, without major abdominal surgery) to assess individual colonic morphology prior to colonoscopy. Key CT-derived features include colonic redundancy, looping patterns, fixation points, and segmental angulation. Based on these findings, the endoscopist receives a structured, standardized briefing before colonoscope insertion, including predicted difficult segments and recommended insertion strategies. No additional imaging, radiation, or invasive procedures are used. The intervention aims to improve insertion efficiency, reduce patient discomfort, and lower operator workload compared with standard colonoscopy without image guidance.
Cecal Incubation Time (minutes)
Time from scope insertion to visualization of the cecum
Pain Score (VAS 0-10)
Patient-reported pain assessed using a Visual Analog Scale (VAS) ranging from 0 (no pain) to 10 (worst pain imaginable).
Physician Workload
NASA-TLX Score (0-100)
Willingness for Future Colonoscopy (5-point Likert scale)
Patient willingness to undergo repeat colonoscopy assessed using a 5-point Likert scale.
Polyp Detection Rate (PDR) (%)
Proportion of colonoscopies in which at least one polyp is detected.
Agreement Between CT-Based Prediction and Procedural Findings
Agreement between pre-procedural CT-based anatomical predictions and actual procedural findings, including predicted looping type, colonic redundancy, and insertion difficulty grade, assessed using Cohen's kappa statistics.
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DONG WU
Lead sponsor
Peking Union Medical College Hospital
Sponsor institution
