Purpose
To evaluate the value of multiparametric quantitative ultrasound imaging (QUI) in assessing chronic kidney disease (CKD) using kidney biopsy pathology as the reference standard.
Methods
We prospectively measured multiparametric QUI markers with grayscale, spectral Doppler, and acoustic radiation force impulse imaging in 25 patients with CKD prior to their kidney biopsies and in 10 healthy volunteers. Based on all pathology (glomerulosclerosis, IF/TA, arteriosclerosis, and edema) scores, the 25 CKD patients were classified into mild (no grade 3 and < 2 of grade 2) and moderate to severe (at least 2 of grade 2 or 1 of grade 3) CKD groups. Multiparametric QUI in the study included kidney length, cortical thickness, pixel-intensity, parenchymal shear wave velocity (SWV), intrarenal artery peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI). We tested the difference in QUI parameters among mild CKD, moderate to severe CKD, and healthy controls using ANOVA, analyzed correlations of QUI parameters to kidney pathology scores and to eGFR using the Pearson correlation coefficient, and examined the diagnostic performance of QUI parameters in determining moderate CKD and eGFR <60 using ROC curve analysis.
Results
There were significant differences in cortical thickness, pixel-intensity, PSV, and EDV among the 3 groups (all p< 0.01). Among QUI parameters, the top AUROCs of PSV and EDV for determining pathologic moderate to severe CKD were 0.88 and 0.97, and for eGFR <60 were 0.76 and 0.86, respectively. Moderate to good correlations were found for PSV, EDV, and pixel-intensity to pathology score and eGFR.
Conclusion
PSV, EDV, and pixel-intensity are valuable in determining moderate to severe CKD. The value of SWV in assessing CKD needs further investigation.