Polyp measurement based on CT colonography and colonoscopy: variability and systematic differences

Area of Science:

• Gastroenterology
• Medical Imaging

Background:

• Accurate polyp measurement is crucial for colorectal cancer screening and management.
• Variability in polyp size assessment can impact clinical decisions.

Purpose of the Study:

• To compare measurement variability and systematic differences between optical colonoscopy and CT colonography for polyps.
• To evaluate different measurement techniques within each modality.

Main Methods:

• Gastroenterologists measured polyps using visual estimation, forceps, and linear probe during optical colonoscopy.
• CT colonography observers assessed polyp size using 2D and 3D techniques.
• Linear mixed models analyzed measurement variability and differences.

Main Results:

• Linear probe and forceps measurements showed comparable variability, both less variable than visual estimation.
• CT colonography techniques demonstrated lower measurement variability than optical colonoscopy methods.
• CT colonography consistently measured larger polyps compared to optical colonoscopy, with differences ranging from 0.7 to 2.3 mm.

Conclusions:

• A linear probe did not improve endoscopist measurement variability over forceps.
• CT colonography exhibited smaller inter-observer measurement differences than optical colonoscopy.
• Polyps were generally perceived as larger with CT colonography techniques.