Ten percent of American adults, more than 20 million people, have chronic kidney disease, which in the advanced state of end stage renal disease is most desirably and cost-effectively treated by kidney transplantation. However, 20-30% of transplanted kidneys fail in living recipients by 10 years, owing largely to insufficient monitoring methods. The goal of the proposed research is to improve noninvasive kidney transplant monitoring using a new ultrasound-based imaging method called Viscoelastic Response (VisR) ultrasound.

Renal transplantation is the most desirable and cost effective treatment for end stage renal disease, but 20-30% of allografts fail in living recipients by 10 years, and prolonging graft health is one of the major unmet needs for transplant patients. Although graft health is extended by preemptive treatments that prevent irreversible damage, intervention is inadequately motivated by current transplant monitoring methods. Noninvasive methods, including changes in serial serum creatinine levels, lack sensitivity and specificity. In the absence of reliable noninvasive biomarkers, invasive biopsy remains the standard for assessing transplant health, but surveillance or "protocol" biopsies are associated with morbidity and cost and are therefore controversial in stable, unsensitized patients. The lack of a demonstrated, noninvasive biomarker for allograft health - one that identifies early graft degeneration with sufficient sensitivity and specificity to motivate appropriate biopsy and enable timely intervention - represents a major gap in renal transplant management.

To fill this gap, the proposed re-search aims to demonstrate Viscoelastic Response (VisR) ultrasound, a novel acoustic radiation force (ARF)-based technology that noninvasively interrogates the viscoelastic properties of tissue, for monitoring renal allograft health. The investigators hypothesize that in vivo VisR ultrasound delineates renal allograft dysfunction earlier and with greater sensitivity and specificity than serum creatinine concentration in renal allograft recipients.

To test this hypothesis, the investigators will determine which VisR outcome metrics detect renal allograft dysfunction clinically by performing serial VisR imaging in living donor (LD) and deceased donor (DD) transplant recipients. Imaging results will be compared to biopsy findings to determine VisR's ability to detect dysfunction. The investigators will also compare serial VisR and serum creatinine outcomes in terms of ability to detect renal allograft dysfunction and the timeliness of detection.

Inclusion Criteria:

1. At least 18 years of age
2. Selected by treating physician to be in need of renal transplant surgery
3. Ability to provide informed consent
4. Ability to communicate with pertinent staff
5. Ability to understand and comply with study requirements

Exclusion Criteria:

1. Inability to provide valid consent

2. Inability to communicate with pertinent staff

3. Inability to remain motionless for at least 20 minutes

4. Renal transplant deeper than 4 cm

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This unblinded, open-label, exploratory study will be conducted in 100 consecutively evaluable patients (50 with renal allografts from living donors and 50 with allografts from deceased donors). Patients will be recruited from those already undergoing renal transplant surgery for end stage renal disease based on the standard of care at UNC Hospitals. Potential study participants will be patients 18 years of age or older who have been selected by their treating physician to be in need of renal transplant surgery for end stage renal disease at University of North Carolina Hospitals' Nephrology Transplant clinic. Participants will be enrolled in two groups, as living or deceased donor recipients. There will be no intervention beyond VisR ultrasound imaging.