CT colonography: positioning order and intracolonic pressure

Area of Science:

• Medical imaging
• Gastroenterology
• Colorectal diagnostics

Background:

• CT colonography is an imaging technique used for colorectal cancer screening.
• Patient comfort during CT colonography is influenced by colonic distention and rectal pressure.
• The order of patient positioning (supine vs. prone) may affect rectal pressure and pain.

Purpose of the Study:

• To prospectively evaluate how the order of patient positions (supine and prone) impacts sustained rectal pressure during air-insufflated CT colonography.
• To identify factors influencing patient-perceived pain during the procedure.

Main Methods:

• 379 patients were prospectively assigned to either a supine-then-prone or prone-then-supine imaging sequence.
• Rectal pressure was measured, and patient pain was assessed via self-report and observable indicators.
• Colonic distention, retained feces/fluid, and diverticulosis were semiquantitatively scored; statistical analyses included t-tests, chi-square, and logistic regression.

Main Results:

• Higher rectal pressure was consistently observed in the prone position compared to the supine position (p < 0.001).
• Patients in the prone-first group experienced significantly less pain in the second position (18%) compared to the supine-first group (40%, p < 0.003).
• Pain was significantly associated with increased rectal pressure and the presence of diverticulosis (p < 0.001).

Conclusions:

• Imaging CT colonography with the prone position first leads to lower sustained rectal pressure and reduced patient pain.
• The prone-first approach is recommended to improve patient comfort during air-insufflated CT colonography.
• Diverticulosis is identified as a factor contributing to pain during the procedure.