Evaluation of Transplant Renal Artery Stenosis by Contrast-Enhanced Ultrasonography: Comparison with Digital...

Contrast-enhanced ultrasonography (CEUS) is a potential and safe imaging method to evaluate the transplant renal artery. To evaluate the degree and location of transplant renal artery stenosis (TRAS) by CEUS compared with digital subtraction angiography (DSA) as the reference standard.

This retrospective study included a cohort of 47 patients with TRAS who underwent ultrasound followed by DSA as the gold standard from March 2018 to January 2025. The degree and location of TRAS were evaluated using CEUS and were compared to that of DSA. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of CEUS for evaluating stenosis ≥50% and stenosis ≥70% were calculated.

The diagnostic accuracy of CEUS in grading TRAS and diagnosing the location of TRAS was 83.8% and 97.3%, respectively. No significant differences were observed in assessing stenosis ≥50%, stenosis ≥70%, and the location of TRAS between CEUS and DSA (P = .250; P = .063; P = 1.000). There was a significant difference in grading TRAS between CEUS and DSA (P = .031). CEUS had a good performance in distinguishing stenosis ≥50% with a sensitivity of 91.4%, specificity of 100%, accuracy of 91.9%, PPV of 100%, and NPV of 40%. The sensitivity, specificity, accuracy, PPV, and NPV for the identification of stenosis ≥70% by CEUS were 87.1%, 100%, 89.2%, 100%, and 60%, respectively.

CEUS demonstrates a great depiction of the degree and location in the TRAS compared with DSA. CEUS has the potential to be a noninvasive method to support the diagnosis and follow-up of TRAS.