RT Journal Article SR Electronic T1 Assessment of Rapid Changes in Renal Blood Flow with 191mIr, an Ultra-Short-Lived Radionuclide JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 508 OP 511 VO 45 IS 3 A1 S. Ted Treves A1 Alan B. Packard A1 Leo C.T. Fung YR 2004 UL http://jnm.snmjournals.org/content/45/3/508.abstract AB We investigated the feasibility of using 191mIr (half-life, 5 s) to measure rapid dynamic alterations in differential renal blood flow. Methods: A nonobstructive constant renal pelvic pressure model was used. The renal pelves of 6 New Zealand White rabbits were drained by use of bilateral catheters, and increased hydrostatic pressure was achieved by raising 1 catheter to 16, 25, 30, or 35 cm above the level of the renal pelvis. The contralateral kidney served as the control. 191mIr first-pass angiograms were obtained at baseline, after the induction of elevated pressure in the renal pelvis, and after the pressure was returned to normal. A minimum of 3 sequential angiograms were obtained at each point. Results: The differential blood flow values (mean ± SD) were 47.5% ± 7.3% at baseline, decreased to 42.3% ± 2.6% when the renal pelvic pressure was elevated (P = 0.001), and returned to 51.1% ± 4.0% after the pressure was returned to normal (P = 0.0017). There was no significant difference between baseline and postcompression values (P = 0.4807). Conclusion: It is possible to use 191mIr first-pass angiography to evaluate rapid dynamic changes in differential renal blood flow in an experimental animal model.