Imaging description

Given the frequency that CT of the abdomen and pelvis is performed to evaluate the trauma patient, intraperitoneal “free” fluid is encountered quite often. Although a small quantity of isolated free intraperitoneal fluid is usually attributed to physiologic fluid in women of reproductive age, it is also seen in males.

Whilst in the past it was believed that free fluid identified on CT was an indicator of occult bowel, mesenteric, or solid organ injury, and it mandated laparotomy [1], it is now generally accepted that conservative management with a non-operative approach for hemodynamically stable patients who have a small quantity of free pelvic fluid is safe (Figure 69.1). These patients should have no clinical or imaging signs of bowel injury [2, 3]. The change in approach to small quantities of free pelvic fluid is likely related to the evolution of CT itself. Decreasing reconstruction slice thickness, and the introduction of routine multiplanar reformations likely increases the sensitivity of CT for the detection of small quantities of free intraperitoneal fluid [4].