title: Clinical application of the kidney to aortic blood flow index (K/A ratio).
abstract: The kidney to aortic blood flow index (K/A ratio) is the ratio of the slopes of the upstrokes of renal and aortic histograms, derived from regions of interest applied to sequential gamma camera images of the first transit of a 99mTc bolus. This index proved in our previous dog studies to have a good correlation with renal artery blood flow. In the 190 clinical studies of renal allografts reported here, the K/A ratios correlate well with independently established retrospective clinical-pathologic assessment of renal functional status. Normal range for the K/A ratio was established in 50 patients with no demonstrable renal disease. Tests of inter-observer reproducibility show a mean relative standard deviation of 7% for independently performed analyses on the same data.
mesh_terms: D001011:Aorta / Q000000981:diagnostic imaging / Q000502:physiology*; D006084:Graft Rejection; D006801:Humans; D007668:Kidney / Q000098:blood supply* / Q000000981:diagnostic imaging; D016030:Kidney Transplantation; D011877:Radionuclide Imaging; D012039:Regional Blood Flow; D013667:Technetium; D014184:Transplantation, Homologous
chemical_list: D013667:Technetium