A dense renogram is obtained by

C i.e. Rapid (Bolus) injection of dye Dense nephrogram or intensified renal images are obtained (iatrogenically) by - - Rapid/bolus injection of same contrast dose concentration (preferred method)(2. - Increased contrast concentration is less preferred than rapid injection method. The quantity that can be used safely depends on weight & hydration of patient. - Abdominal (ureteric) compression may be used to temporarily obstruct the upper urinary tract but is demanding. - Dehydration method used in past is not used now b/o more chances of precipitation of proteins in renal tubules, obstruction, oliguria & anuria.