Contrast-enhanced ultrasound of kidney allograft in patient with acute rejection. Case report and literature review

Kidney transplantation is recognized as the optimal modality of renal replacement therapy. In most cases the diagnosis of the causes of kidney allograft dysfunction and subsequent choice of treatment strategy are determined by the results of nephrobiopsy. The search for alternative noninvasive diagnostic modalities, including ultrasound, that could reveal the specific features of the most common causes of renal graft dysfunction remains relevant. Contrast-enhanced ultrasound (CEUS)is considered a promising modality for the diagnosis of renal graft dysfunction in general and of acute rejection in particular. The article presents the analysis of the results of multiparametric ultrasound in a patient with acute antibody-mediated rejection after voluntary complete withdrawal of immunosuppressive therapy. The subcapsular areas of hypoperfusion were found along with a decrease of allograft perfusion in general. The patterns of “slow wash-in – fast wash-out” of contrast medium in the medulla and “fast wash-out” in the cortex were also detected. The comparison of CEUS and histopathological data from the removed allograft identified the foci of cortical necrosis as the substrate of abnormal perfusion areas. Now it seems premature to evaluate the diagnostic capability of CEUS in complex ultrasound of renal allograft. Further research is necessary to determine the role of CEUS in the complex assessment of kidney transplant pathology.