A NONINVASIVE METHOD FOR MONITORING RENAL STATUS AT BEDSIDE

RATIONALE AND OBJECTIVES. The authors demonstrate the feasibility of m onitoring renal status continuously and noninvasively at a patient's b edside, avoiding both radioactivity and blood and urine samples, METHO DS. Gadolinium-153-labeled ProHance and a glomerular filtration rate ( GFR) standard technetium-99m-DTPA were coadministered to anesthetized normal and nephrectomized rats with their tails hanging in a PC 20 spi n analyzer, Blood samples and T1 measurements were collected and analy zed, RESULTS. Log time plots of Gd-153, (TC)-T-99m (from blood samples ) and T1 of the rat tails were all linear and parallel, Halftimes were 32 +/- 2, 32 +/- 6, and 32 +/- 6 minutes for the decay of the T1, Gd- 153 and Tc-99m, respectively, The halftime of the nephrectomized anima l was 2000 +/- 4000 minutes, CONCLUSIONS. T1 of an appendage remote fr om the kidneys reflects the concentration of gadolinium in the blood, which is in rapid equilibrium with tissue interstitial space gadoliniu m. The decay in T1 of the appendage reflects glomerular filtration, Th us, it is feasible to detect changes in renal status at a patient's be dside by monitoring T1 of a finger or wrist using a small, inexpensive magnet.