Imaging of infracolic and pelvic compartment by linear EUS

The peritoneal cavity is subdivided into supracolic and infracolic compartments by transverse mesocolon, which attaches the colon to the posterior abdominal wall. Infracolic compartment is subdivided into right and left compartment by small bowel mesentery. Left infracolic space freely communicates with pelvic compartment. The infracolic compartment contains the coils of small bowel which is separated from paracolic gutter on either side by ascending and descending colon. Pelvic compartment mainly contains bladder, rectum and genital organ (prostate, seminal vesicle in male and uterus in female). The evaluation of different compartments of peritoneum is gaining importance in multimodality imaging. It has become essential that clinicians and endosonographers thoroughly understand the peritoneal spaces and the ligaments and mesenteries that form their boundaries in order to localize disease to a particular peritoneal/subperitoneal space and formulate a differential diagnosis on the basis of that location. In this article we describe the applied EUS anatomy of peritoneal ligaments, infracolic and pelvic compartments of peritoneum and there technique of imaging from stomach, duodenum, sigmoid colon and rectum. Imaging from stomach images the infracolic compartment through transverse mesocolon, imaging from duodenum images the infracolic compartment through the mesentery and imaging from rectum and sigmoid images the infracolic and pelvic compartments through the sigmoid mesocolon and pelvic peritoneum.