Together, sonography and renal isotope techniques can provide greater information than either technique alone. These studies can replace excretory urography in the diagnosis of hydronephrosis and renal infarction. Arteriography is no longer necessary for the diagnosis of a pseudotumor, which has a specific isotope and a helpful sonographic appearance. The diagnosis of a renal abscess opposed to pyelonephritis can be made in a more definite fashion than is possible with other imaging techniques. We believe that the sonogram and isotope studies are particularly helpful in trauma because there is a more realistic assessment of the absence of renal function with isotopes than with the excretory urogram. One may detect hematoma within and around the kidney by ultrasonography.