[Color-coded duplex sonography and the resistive index in dysfunctional kidney transplants]

Area of Science:

• Nephrology
• Radiology
• Transplant Surgery

Background:

• Renal transplant dysfunction can arise from various causes, impacting graft survival.
• Accurate and timely diagnosis of graft dysfunction is crucial for effective management.
• Color duplex ultrasound is a non-invasive imaging modality used in transplant assessment.

Purpose of the Study:

• To evaluate the utility of color duplex ultrasound in differentiating causes of renal transplant dysfunction.
• To assess the correlation between resistive index (RI) and specific graft pathologies.
• To analyze the color imaging patterns of transplant arteries in relation to graft function.

Main Methods:

• Prospective analysis of 182 color duplex ultrasound studies in 60 renal transplant patients.
• Assessment of resistive index (RI) and color imaging patterns of transplant arteries.
• Correlation of ultrasound findings with clinical diagnoses of graft dysfunction.

Main Results:

• Normal RI (<0.7) and arterial patterns were observed in grafts with normal function, cyclosporin toxicity, cytomegalovirus infection, acute tubular necrosis, glomerulonephritis, and postoperative functional nephrotoxicity.
• Significant elevation of RI and characteristic "blinking" of arteries with reduced peripheral arterial visualization were noted in acute/chronic rejection, obstructive uropathy, and arteriolosclerosis.
• Color duplex ultrasound demonstrated the ability to assess increased vascular impedance in transplant grafts.

Conclusions:

• Color duplex ultrasound can help differentiate causes of renal transplant dysfunction.
• Elevated RI and specific arterial imaging patterns are indicative of serious graft pathologies like rejection and obstruction.
• This imaging technique offers valuable insights into vascular impedance changes within transplant kidneys.