A pilot trial to evaluate the clinical usefulness of contrast-enhanced ultrasound in predicting renal outcomes in patients with acute kidney injury.

Hye Eun Yoon,Yaeni Kim,Dongryul Kim,Seok Joon Shin,Da Won Kim,Yu Ri Shin,Tatsuo Shimosawa

doi:10.1371/journal.pone.0235130

Abstract

Contrast-enhanced ultrasound (CEUS) enables the assessment of real-time renal microcirculation. This study investigated CEUS-driven parameters as hemodynamic predictors for renal outcomes in patients with acute kidney injury (AKI). Forty-eight patients who were diagnosed with AKI were prospectively enrolled and underwent CEUS at the occurrence of AKI. Parameters measured were the wash-in slope (WIS), time to peak intensity, peak intensity (PI), area under the time-intensity curve (AUC), mean transit time (MTT), time for full width at half maximum, and rise time (RT). The predictive performance of the CEUS-driven parameters for Kidney Disease Improving Global Outcomes (KDIGO) AKI stage, initiation of renal replacement therapy (RRT), AKI recovery, and chronic kidney disease (CKD) progression was assessed. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance of CEUS. Cortical RT (Odds ratio [OR] = 1.21) predicted the KDIGO stage 3 AKI. Cortical MTT (OR = 1.07) and RT (OR = 1.20) predicted the initiation of RRT. Cortical WIS (OR = 76.23) and medullary PI (OR = 1.25) predicted AKI recovery. Medullary PI (OR = 0.78) and AUC (OR = 1.00) predicted CKD progression. The areas under the ROC curves showed reasonable performance for predicting the initiation of RRT and AKI recovery. The sensitivity and specificity of the quantitative CEUS parameters were 60-83% and 62-77%, respectively, with an area under the curve of 0.69-0.75. CEUS may be a supplemental tool in diagnosing the severity of AKI and predicting renal prognosis in patients with AKI.

Highlights

Acute kidney injury (AKI) is characterized by a rapid decline in kidney function within a few hours to a few days
Forty-eight patients who were diagnosed with AKI were prospectively enrolled and underwent Contrast-enhanced ultrasound (CEUS) at the occurrence of AKI
CEUS may be a supplemental tool in diagnosing the severity of AKI and predicting renal prognosis in patients with AKI

Summary

Introduction

Acute kidney injury (AKI) is characterized by a rapid decline in kidney function within a few hours to a few days. Alterations in renal perfusion are thought to play a central role in its pathogenesis [2], diagnostic tools for assessing renal perfusion are lacking. Different imaging modalities, such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography, are limited in clinical applications due to their high cost, reduced availability, long examination duration, and toxicities associated with the contrast agents used. Evaluation of cortical perfusion by US is challenging, when the cortical blood flow is reduced In these situations, US contrast agents can improve the diagnostic capabilities of conventional US, and allow the development of semi-quantitative and functional assessment of renal microvascular perfusion [3]. Few studies have assessed the utility of noninvasive evaluation of AKI using the CEUS technique

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