<prompt> A dense renogram is obtained by:Dehydrating the patientIncreasing the dose of contrast mediaRapid Bolus injection of dyeUsing non ionic media  <response>: In a normally functioning kidney, rapid injection of the dye gives an uniform dense nephrogram because of appearance of contrast material in the proximal tubule and peritubular capillaries within 30seconds of injection and approximately 2 minutes later contrast agent begin to appear in the calyces. Ref: Diseases of The Kidney and Urinary Tract By Robe W. Schrier, Page 338, 706 