Renal transplantation: the normal morphological and Doppler ultrasound examination.

If ultrasound imaging and image-directed Doppler examination of the renal allograft is to provide information with respect to graft complications and graft failure, then a clear understanding of normal characteristics is required. Criteria for abnormality of a graft will include change in size, in parenchymal pattern, and in blood flow characteristics in the main and branch renal arteries and within the renal vein. Normal measurements for the renal allograft are presented as well as morphological and numerical data relating to cortico medullary differentiation. A wide range of values for indices quantifying Doppler data is recorded in the literature. Mean values and standard deviations from the mean are presented. The importance of different parameters as potential indicators of disease are stressed, but the limitations, usually as a result of normal variation and lack of specificity, are presented. The normal features of color-coded Doppler vascular supply, perfusion, and drainage are described.