Comprehension: Abdomen
In a frontal (AP) view of the abdomen, note the outline of the lateral edge of the psoas muscle. The kidney and psoas muscles can be seen because retroperitoneal fat, which allows a greater passage of x-rays than the tissue of the kidneys and muscle, surrounds these structures. The right kidney is usually seen moderately lower than the left because of the overlying liver. Swallowed air can be seen in the stomach in this film. The position of the inguinal ligament, extending between the anterior superior iliac spine and the pubic tubercle, has been drawn on the left. Phleboliths (calcified blood clots) in pelvic veins are seen; this is a variation from normal in older patients and not pathologic.
