ABSTRACT
Scanning Technique Evaluation of the retroperitoneum on ultrasound (US) usually consists of evaluation of the various organs in each compartment of the retroperitoneum since the retroperitoneal fascial planes are not seen on US unless involved by disease processes. Spread of disease in the retroperitoneum occurs initially within the anatomic boundaries of the compartments; it is important to evaluate areas that may be slightly remote from an involved organ, if they are connected by fascial planes. However, as noted, spread in atypical locations may be secondary to interfascial planes (8). Infection around the kidneys can track into the pelvis since the perirenal fascia is open caudally.
