[Estimation of renal transplant dysfunction by color Doppler sonography]

To clarify various conditions in the transplanted kidney, invasive biopsy must be performed in most cases. In this study, we measured blood flow in the transplanted kidney by color Doppler tomography to examine the usefulness of measuring renal blood flow in clarifying various conditions.

Blood flow in the transplanted kidney was measured using peak flow velocity (PFV) and an index of resistance, the pulsatility index (PI), as parameters.

In acute cellular rejection, there were no changes in blood flow in the segmental arteries, while there was a significant decrease in the blood flow in the interlobar artery. In acute vascular rejection, it was difficult to measure blood flow in the interlobar artery. The values of parameters were low even in the segmental arteries, suggesting markedly decreased blood flow. In chronic rejection, the values of the parameters were low in proportion to transplanted kidney function. In addition, parameters were examined with respect to vascular stenosis, fibrous stroma and edema in the histopathology of the transplanted kidney. As a result, vascular stenosis and fibrous stroma affected the segmental and interlobar arteries, severely reducing blood flow. It was also shown that interstitial edema reduced blood flow in the interlobar artery.

Color Doppler tomography may facilitate diagnosis of certain conditions in the transplanted kidney biopsy.