Learning objectives
To describe the anatomy of the peritoneal space, reflections, omenta and ligaments.
To illustrate the natural flow of peritoneal fluid in the abdominal cavity in order to understand pathways for the spread of diseases across the peritoneal spaces.
To analyze the main causes of ascites for each compartment and their differential diagnosis.
Background
Peritoneal space is a fluid-filled virtual cavity divided in different compartments due to serosal reflections, separating intraperitoneal from extraperitoneal organs.
Reflections form ligaments, omenta and mesenteries.
Normally a small amount of fluid is present in the peritoneal cavity, usually between 50 and 100 ml; ascites becomes clinically evident when fluid amount is >1500 ml. It can be early detected with ultrasound, CT or MRI.
Many pathological conditions can cause or are associated with ascites, including portal hypertension, neoplasms, infections, inflammatory, vascular, iatrogenic and traumatic diseases....
Findings and procedure details
To understand fluid distributions and pathways for the spread of diseases, a good anatomic knowledge is required.
Anatomy
The peritoneum is a thin serous membranae made of mesothelium, a single layer of cuboidal cells. It is divided into the parietal layer which covers the anterior wall of the abdominal cavity, the retroperitoneum and the undersurface of the emidiaphragms; the visceral layer covers the abdominal viscera and forms mesenteries and omenta. Abdominal cavity is closed in males and open in females since the ostia of the...
Conclusion
A variety of pathologic conditions may demonstrate nonspecific radiologic features, with the locationof the fluid as the major diagnostic clue. In fact, the pathological features detected at imaging are often not related to a specific organ but can occur far away from their site of origin. Understanding the anatomic relationships and flow pathways of the peritoneal space is essential to provide accurate diagnosis.
Personal information and conflict of interest
A. G. Tucci; Naples/IT - nothing to disclose M. Puglia; Pozzuoli (NA)/IT - nothing to disclose C. Panico; Naples/IT - nothing to disclose R. Lobianco; Napoli (NA)/IT - nothing to disclose A. Ragozzino; Naples/IT - nothing to disclose
References
-Peritoneal And Retro Peritoneal Anatomy And Its Relevance For Cross Sectional Imaging. Temel Tirkes. Radiographics 2012; 32:437–451
-CT Of Ascites. H.Jolles, C M Coulan. AJR 135:315-322, August 1980
-The Spread And Localization Of Acute Intraperitoneal Effusions. Morton A. Meyers, Radiology 95:547-554, June 1970
-Greater And Lesser Omenta: Normal Anatomy And Pathologic Processes. Eunhye Yoo Radiographics 2007; 27:707–720
-Patterns of peritoneal spread of tumor in the abdomen and pelvis. Khaled M Elsayes. World J Radiol 2013 March 28; 5(3): 106-112
-Diagnostica per immagini dell’addome. Problem Solving....