[New concepts in the prognosis of renal obstructions based on radiological examination data].

The study deals with obstructed kidneys not visualizable by normal radiography. The various radiological techniques after endovenous urography are analysed as to what extent the data obtained enable the surgeon to choose between radical and conservative measures. The usefulness and limitations of i.v. urography with high doses of contrast medium, of retrograde pyelography (with or without concomitant study of renal function), of selective intra-arterial arteriography and perfusion, of minimum nephrostomy with repeated nephrostograms and of translumbar pyelography are discussed. The last technique, involving urine aspiration and anterograde pyelogram is simpler than other methods and is of greater interest in the prognosis of hydronephrotic kidney.