Kinetics and dosimetry of I-131 hippuran in renal transplant patients

Radionuclide renograms, performed with I-131 hippuran, are one of the diagnostic examinations performed to assess the function of a transplanted kidney. During the first month after transplantation, the kidney may function normally, may have a period of acute tubular necrosis, or may be rejected. It may have a variable course, including acute or chronic rejection, after this time. The renogram, performed on patients at intervals after transplantation dictated by the patient's course, was imaged from the anterior position and stored by the computer for analysis. Analog images were also recorded. The computer was used to create activity vs time curves for the kidney, bladder and background. The radioactivity in urine and blood samples from patients was measured in a well counter and compared to a reference standard. The renogram and the blood and urnie values have been fitted to a model. The model allows for a portion of the injected activity to be excreted in the bile and for the holdup of some of the activity in the kidney. The dose to the kidney in nearly normal patients is calculated to be 0.04 rads per 200 uCi while in a kidney with severe I-131 holdup it is 2.74 rads per 200 uCi