Efficacy of Virtual Touch Quantification Technique for Differentiating Patients with Immunoglobulin A Nephropathy (IgAN) from Healthy Controls

Abstract

Background: The virtual touch quantification (VTQ) using acoustic radiation force impulse (ARFI) is a type of ARFI technology, which has been widely used against many diseases. The sensitivity and specificity of VTQ in differentiating immunoglobulin A nephropathy (IgAN) patients from healthy controls remain unestablished. Objectives: The present study aimed to measure the VTQ values of renal parenchyma in patients with IgAN and to evaluate the efficacy of these values in distinguishing IgAN patients from healthy individuals. Patients and Methods: Ultrasound examinations were performed for the experimental and control groups. All routine ultrasound data, including the renal parenchymal thickness, renal volume, resistive index (RI) of interlobar renal arteries, and peak velocity of interlobar renal arteries, were collected. The VTQ values were measured in the middle and lower renal parenchyma using the VTQ technique. A receiver operating characteristic (ROC) curve was plotted to evaluate the efficacy of VTQ in differentiating IgAN patients from healthy individuals. Results: The VTQ values, RI values of interlobar arteries, and peak velocity of interlobar arteries were significantly different between patients with IgAN and the controls (2.14 ± 0.31 vs. 2.62 ± 0.24 m/s, 0.68 ± 0.05 vs. 0.63 ± 0.03 m/s, and 0.56 ± 0.59 vs. 0.60 ± 0.58 m/s; P < 0.05 for all). The VTQ values were associated with the renal parenchymal thickness, peak flow velocity of interlobular arteries, and Lee’s grade (P < 0.05 for all). The ROC curve analysis revealed that VTQ values might be used as a diagnostic method for differentiating IgAN patients (area under the curve [AUC] = 0.909) from healthy controls. Conclusion: The VTQ values significantly decreased in patients with IgAN and might play an important role in distinguishing IgAN patients from healthy individuals, with high sensitivity and specificity.