Direct spread of subperitoneal disease into solid organs: radiologic diagnosis.

The subperitoneal space is the continuous space interconnecting the peritoneum and retroperitoneum and the abdominal organs. This report expands the concept of direct spread of disease via the subperitoneal space to include direct extension into the solid abdominal viscera (i.e., liver, kidneys, and spleen). Discussion of the anatomy, case presentations, and imaging with computed tomography, ultrasound, and magnetic resonance are presented. This unifying concept provides an understanding for direct spread of disease presenting clinically or being imaged within a solid abdominal organ.