Receiver operating characteristic curves (ROC) estimated the diagnostic performance of ARFI.

<p>For a cut-off value of 1.88 m/s, area under the ROC curve: 0.752 (95% CI: 0.704 to 0.797), Standard Error: 0.033, Significance level <i>P</i><0.001. For a cut-off value of 1.88 m/s, ARFI had 71.87% Sensitivity (95%CI: 59.2 to 82.4), 69.69% Specificity (95%CI: 64 to 75), +LR: 2.37,?−LR: 0.4, for predicting CKD.</p

Characteristics and laboratory data of the 64 CKD patients.

a<p>Variables are expressed as Mean ± SD.</p

Potential influencing factors of SWV in healthy volunteers (n = 30).

a<p>Correlation between SWV and variables are analyzed with Pearson’s correlation coefficients,</p>b<p>Unpaired <i>t</i>-test is used to analyze the differences in SWV between two different groups,</p>c<p>Influencing factors are expressed as Mean ± SD (Range).</p

Measurement of SWV in the middle third of the renal parenchyma.

<p>Measurement of SWV in the middle third of the renal parenchyma.</p

Definition and stages of CKD^*.

*<p>CKD is defined as either kidney damage or GFR less than 60 ml/min per 1.73 m² for 3 or more months. Kidney damage is defined as pathologic abnormalities or markers of damage, including abnormalities in blood or urine tests or imaging studies. In our study, CKD was defined as eGFR<60 ml/min/1.73 m² or albuminuria. Albuminuria was defied as a urinary albumin.</p

Correlation of SWV with different variables in the 64 CKD patients.

<p>Correlation of SWV with different variables in the 64 CKD patients.</p

Box and whiskers plot of SWV in different groups.

<p>The tops and bottoms of the boxes are the first and third quartiles, respectively. The line through the middle of each box represents the mean. The error bars show the minimum and maximum values (range).</p

Bland-Altman plot for interobserver SWV in 40 healthy volunteers.

<p>The difference of the observers is expressed as percentage deviation from the average of both observers (y axis), and the x axis represents the means of the two observers. The average interobserver difference is represented by the middle solid line, while the limit of agreement is represented by the two outer solid lines. The bias of the two observers is −4.7%, and the limit of agreement is between −48.9% and 39.5%. Two values lie outside the range.</p