By means of a renal scan made with chlormerodrin Hg 197, the kidneys are outlined on the skin of the patient's back; the outlines are projections of the kidneys on the skin. After such identification, percutaneous renal biopsies were successful in six out of seven attempts. If the patient has uremia, pyelograms often do not outline the kidneys properly. However, scintiscanning is usually successful even when blood urea nitrogen levels are greatly elevated.
Baum S, Rabinowitz P, Malloy WA. The Renal Scan as an Aid in Percutaneous Renal Biopsy. JAMA. 1966;195(11):913-915. doi:10.1001/jama.1966.03100110081021