Early diagnosis of polycystic kidney disease.

Polycystic kidney disease is the most prevalent hereditary renal disorder, accounting for over 5 percent of patients on chronic hemodialysis. Early diagnosis can aid in family planning, and "preventive therapy" may prolong useful life and defer dialysis. Intravenous pyelography with nephrotomography has been the standard procedure for definitive diagnosis, but ultrasonography, radionuclide scanning and computerized tomography have become increasingly useful. Ultrasonography is particularly valuable because it is free of radiation hazards. Impaired urinary concentrating ability is a frequent early sign of the disorder.