Quantification and variability in colonic volume with a novel magnetic resonance imaging method

Area of Science:

• Gastroenterology
• Medical Imaging
• Human Physiology

Background:

• Segmental colorectal volume is clinically relevant for various diseases.
• Accurate measurement requires reliable and valid methods.
• Current methods lack precision for detailed volumetric analysis.

Purpose of the Study:

• To assess the reliability and validity of a novel semi-automatic MRI technique for measuring segmental colorectal volumes.
• To quantify inter-individual and intra-individual variability in colorectal volumes.
• To evaluate the impact of defecation on segmental colorectal volume distribution.

Main Methods:

• A semi-automatic MRI technique was employed to measure four colorectal segments: cecum/ascending colon, transverse colon, descending colon, and rectosigmoid colon.
• Inter- and intra-individual variability was assessed in 25 healthy males over a 52-day period.
• The effect of defecation on segmental volumes was studied in seven healthy males.

Main Results:

• No significant differences in segmental colorectal volumes were found between two observations (p > 0.05).
• Inter-individual variability ranged from low (cecum/ascending colon, ICC=0.44) to high (rectosigmoid, ICC=0.82).
• Intra-individual variability was low (CV=9%), and rectosigmoid volume decreased by 44% after defecation (p=0.003).

Conclusions:

• Semi-automatic MRI offers a reliable, valid, and high-resolution method for assessing segmental colorectal volume, morphology, and fecal accumulation.
• This imaging technique avoids contrast agents and irradiation, making it suitable for clinical and interventional studies.
• The method is valuable for characterizing defecation physiology and can be applied in future research and clinical settings.