Comparison of a corticopelvic transfer index with renal transit times.

The aim of this study was to compare a simple measure obtained visually from serial images, the corticopelvic transfer index (CPI), with renal transit times obtained by deconvolution. The CPI was defined as the time interval between the appearance of the tracer in the renal cortex to its appearance in the renal pelvis. Four groups of subjects as determined by clinical data and renal transit times were investigated retrospectively: 86 normal kidneys, 20 kidneys with renovascular disorder, 17 kidneys with obstructive nephropathy and 26 kidneys with dilated pelves without obstructive nephropathy. There were good correlations only between the CPI and mean parenchymal transit time (MPTT; r = 0.6) and the whole kidney transit time index (WKTTI; r = 0.8). It was concluded that in centres where gamma-camera studies with deconvolution analysis are not possible, the CPI could be a useful parameter in renal radionuclide scintigraphy for suspected renovascular disorders.