 A saline lock and intravenous line will be inserted at two different sites and two drops of saturated solution of potassium iodide SSKI will be administered at least 30 minutes and no more than six hours prior to the administration of 125I-iothalamate to prevent uptake by the thyroid. Baseline laboratory tests will include serum creatinine, cystatin C, blood urea nitrogen BUN, C-reactive protein CRP, electrolytes and albumin. 