Duplex Doppler evaluation of renal allograft dysfunction: Doppler signal quantitation and pathologic correlation

Area of Science:

• Nephrology
• Radiology
• Transplant Surgery

Background:

• Renal transplant dysfunction can stem from various causes, including rejection and toxicity.
• Accurate diagnosis is crucial for timely and appropriate treatment of renal transplant dysfunction.

Purpose of the Study:

• To evaluate the diagnostic value of quantitative duplex Doppler sonography in differentiating causes of renal transplant dysfunction.
• To compare the efficacy of the Pourcelot resistive index and a variant resistive index in diagnosing renal transplant dysfunction.

Main Methods:

• Prospective study of 60 patients with 65 episodes of renal function impairment.
• Quantitative duplex Doppler sonography performed before biopsy and therapy.
• Analysis of arterial Doppler signals using Pourcelot resistive index and a variant resistive index.

Main Results:

• Morphological analysis of Doppler signals lacked discriminative value.
• The variant resistive index achieved 71% specificity in excluding acute rejection, significantly higher than the Pourcelot resistive index (28%).
• Histology confirmed diagnoses including acute rejection, acute tubular necrosis, cyclosporin nephrotoxicity, and chronic rejection.

Conclusions:

• Quantitative duplex Doppler sonography, particularly using a variant resistive index, is valuable for diagnosing renal transplant dysfunction.
• This non-invasive method aids in differentiating acute rejection from other causes, guiding clinical management.
• Further correlation with microangiography in nephrectomy specimens supports Doppler findings.