Eine neue Methode zur standardisierten Diagnostik nach Nierentransplantation

Abstract

Ultrasound (US) imaging is an important diagnostic tool following renal transplantation. Unfortunately, due to the heterogeneity of the recipients and their multimorbidity, imaging procedures in the early phase after kidney transplantation are difficult and of limited use. We performed a study to evaluate the use of a contrast enhancer for US examination as a standardized method in the follow-up of kidney transplant recipients.The study included 40 recipients: 32 were examined on the 5th to 7th day following transplantation and 8 patients at the time when clinically suspicious findings occurred (acute rejection, tumor, acute tubular necrosis). Following the intravenous application of the contrast medium, pictures were taken during the arterial and parenchymatous phase and compared with conventional B-mode and power Doppler pictures of the same visual plane. Three examiners assessed different parameters of the transplant organ (max. vascularized area, suspected hematomas, tumors, rejection, acute tubular necrosis). Findings were confirmed by histological results of a biopsy if rejection, tumor, or acute tubular necrosis were suspected. Application of ultrasound contrast medium significantly increased visualization of the vascularized kidney area. Also, US findings in the follow-up after acute rejection therapy corresponded with the clinical course; 19 hematomas could be detected with contrast medium compared to only 9 without. With contrast medium a perfusion deficit was detectable in three patients compared to one patient with power Doppler US. Also, US contrast medium helped to detect tumor vascularization in two patients in whom conventional sonography suspected no abnormality. Ultrasound contrast medium enhancement is a reproducible, reliable, and easy to apply method which is superior to conventional sonography in the follow-up after kidney transplantation. This method is also helpful to detect and control acute rejections and to better visualize hematomas, deficits of perfusion, and tumors.

Perfusion Disturbances of Kidney Graft Parenchyma Evaluated with Contrast-Enhanced Ultrasonography in the Immediate Period following Kidney Transplantation

“…Furthermore, our analysis demonstrated that the B+US-CD/PD/B-flow examination underestimated the size of ischemic areas [19,20,21]. CE-US however was able to show the true extent of the ischemia with a clear delineation of its borders.…”

Use of contrast-enhanced ultrasound to monitor rabbit renal ischemia-reperfusion injury and correlations between time-intensity curve parameters and renal ICAM-1 expression

“…It has been proven that CEUS can be used for real-time and dynamic observation of the renal blood supply, and TIC parameters closely correlate with renal blood flow perfusion [5]. Contrast-enhanced ultrasound (CEUS) is a safe, highly repeatable, non-invasive detection method without obvious contraindications and complications that has been widely used to evaluate acute and chronic rejection and renal function following renal transplantation [2,3,9,15].…”