Contrast‐Enhanced Ultrasound for the Evaluation of Renal Transplants

Abstract

Contrast-enhanced ultrasound has emerged as a useful imaging modality for the evaluation of the transplant kidney. Advantages over traditional imaging modalities such as computed tomography and magnetic resonance imaging include the ability to visualize a lesion's enhancement pattern in real time, the lack of nephrotoxicity, and relatively low cost. Potential uses of contrast-enhanced ultrasound include characterization of solid and cystic transplant renal masses, assessment for pyelonephritis and identification of its complications, and evaluation of transplant complications in immediate and delayed settings. Contrast-enhanced ultrasound will likely play an increasing role for evaluating the transplant kidney, as an accurate diagnosis based on imaging can direct treatment and prevent unnecessary interventions. Key Words-angiomyolipoma; contrast-enhanced ultrasound; perirenal hematoma; posttransplantation lymphoproliferative disorder; renal cell carcinoma; renal transplant E nd-stage renal disease is a major source of morbidity and mortality in the United States. According to the 2018 United States Renal Data System, the prevalence of endstage renal disease has increased over time, having more than doubled between 1990 and 2016. 1 Although many patients with renal failure can be successfully treated with dialysis, renal transplantation is the definitive treatment for end-stage renal disease. Renal transplantation is more cost-effective than dialysis and results in an improved life expectancy. 2 Contrast-enhanced ultrasound (CEUS) is already frequently used for evaluation of the native kidneys. The 2019 "ACR-AIUM-SRU Practice Parameter for the Performance of Contrast-Enhanced Ultrasound" 3 provides guidelines for the appropriate use of CEUS in the kidney, including further characterization of solid and cystic renal lesions, assessment of renal perfusion, detection of renal abscesses in patients with pyelonephritis, and evaluation of the renal vasculature. More recently, CEUS has been used to evaluate the transplant kidney. Applications of CEUS in the transplant kidney include characterization of transplant renal masses (both benign and malignant), evaluation for infection and its potential complications, and assessment of perirenal collections and other posttransplant complications. Here, we provide a pictorial and descriptive review of the CEUS appearances of various entities that can affect the transplant kidney.

Clinical Evaluation of Cystic Renal Masses With Bosniak Classification by Contrast‐Enhanced Ultrasound and Contrast‐Enhanced Computer Tomography

“…35 CEUS is a promising method in the diagnosis of CRMs due to its safety profile, 36 well-tolerated and fast procedure, with no nephrotoxicity exposition of radiation. 13,37 The results of refined proposed Bosniak classification for CEUS (EFSUMB 2020 and version 2019) doing as well as CECT (V2019), also our study proves that the EFSUMB 2020 version 13,15 holds promises for a good complement to the current Bosniak categorization.…”

Renal arteriovenous fistula complicated with malignant hypertension: a case report

“…The sulfur hexafluoride contrast media excreted through respiration and had no harm to the kidney [18]. Contrast-enhanced ultrasonography has been applied in renal transplantation, renal masses characterization, and children nephropathy to evaluate the blood supply of kidney [20][21][22]. For patients with renal dysfunction, contrast-enhanced ultrasound also had diagnostic value to detect RAVF [19].…”

Kidney Transplantation and Diagnostic Imaging: The Early Days and Future Advancements of Transplant Surgery

“…To improve the specificity and sensitivity of ultrasound examinations, the application of ultrasound-compatible contrast agents is being studied. These contrast agents can provide a more elaborate insight into functional changes, such as studies by Grabner et al, and anatomical changes, such as those described by Kazmierski et al [62,63]. Studies have explored the use of MRI techniques, both functional and anatomical, prior to and after kidney transplantation [64,65].…”