COLOR DOPPLER SONOGRAPHY OF RENAL-ALLOGRAFTS - IS THE RESISTIVE INDEX A DIAGNOSTIC-TOOL IN THE LONG-TERM FOLLOW-UP

The retrospective study under report assessed the diagnostic capability of colour Doppler sonography (CDS) with measurement of the resistive index (RI) in the long-term follow-up of patients with renal allografts. 210 CDS examinations were performed in 115 patients. The time since transplantation ranged from 6 months to 22 years. The RI was correlated to laboratory parameters of renal allograft function (serum creatinine, urinary protein levels and serum-cyclosporine). In 97 of 210 examinations, serum creatinine was elevated (> 1,5 mg % or an increase of more then 0,3 mg % within the last 6 months). In 35 out of these examinations RI was > 70 %, in 62 RI was less-than-or-equal-to 70 %. Thus, with a threshold RI of 70 %, sensitivity of the RI in the diagnosis of renal allograft dysfunction is 36 % and specificity 62 %, respectively. There was no significant difference in the RI between examinations of allografts with normal function (68,2 % +/- 7,5 %) and those with dysfunction (68,5 % +/- 8,5 %). Furthermore, there was no significant correlation between the RI and any of the laboratory parameters. CDS with calculation of the RI cannot differentiate in the long-term follow-up between allografts with normal function and those with dysfunction.