The ultrasonic characteristics of the renal pelvicalyceal echo complex.

The pelvicalyceal echo complex has a characteristic appearance as an echo-filled cylinder in which minimal sonolucency may normally be seen. Alteration in the pelvicalyceal echo complex is a helpful guide in the diagnosis of a variety of pathological processes involving the kidneys. Reliable diagnosis of moderate and marked hydronephrosis may be made by the appearance of uniformly sized, sonolucent collections in the pelvicalyceal echo complex which show communication with the renal pelvis. An adjacent simple renal cyst produces a sharply defined crescent shaped deformity of the pelvicalyceal echo complex, and scalloping is seen with multiple impinging renal cysts. Gross deformity of the central echo complex is seen with polycystic kidney disease, as well as in neoplasia. Edema and infiltrating hypernephroma may result in diminution of the pelvicalyceal echo complex. Amputation or a "V"-shaped splitting of the pelvicalyceal echo complex may be seen with neoplasia.