Last revised by Rohit Sharma on 8 Feb 2024

Hemoperitoneum (plural: haemoperitoneums) is the presence of blood within the peritoneal cavity.

  • non-specific appearance of intraperitoneal free fluid 4
    • may be hypo-, iso- or hyperechoic 3
  • may demonstrate fluid-fluid levels with mixed internal echogenicity 3

The density of fluid in the abdomen suggests its composition (i.e. ascites/bowel contents/bile vs hemorrhage) 1:

  • recent hemorrhage (acute bleed) measures 30-45 HU
  • clotted blood measures 45-70 HU
  • old blood products/seroma or blood in patients with anemia may measure <30 HU

A collection of blood products can be homogeneous or heterogeneous (often low density with internal linear/nodular hyperdensities) 5; fluid-fluid levels are often present. 

  • acute (<48 hours) hemoperitoneum has non-specific signal characteristics 5
  • subacute (>3 weeks) may demonstrate concentric ring sign 5
  • fluid-fluid levels (hematocrit effect) with high T1 / low T2 signal noted dependently 5
  • low-density hemoperitoneum may be indistinguishable from ascites or other causes of peritoneal free fluid 2 
  • there may be a delayed increase in ascites attenuation after administration of IV contrast (up to 3 days)
    • there may be an increase of up to 25 HU 6
  • urine in the peritoneal cavity with density approaching that of water due to bladder injury

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