Factors Affecting the Application of Virtual Touch Tissue Quantification Technique in Chronic Kidney Disease: a Spleen-kidney Comparative Study

  Objective  To study the methodological factors that influence the application of virtual touch tissue quantification (VTQ) technique in chronic kidney disease (CKD).

  Methods  A total of 62 CKD patients who underwent kidney biopsy in Peking Union Medical College Hospital between September 2011 and April 2012 were enrolled in this study. Under the same positions, the tissue shear wave velocity (SWV) of left kidney cortex and spleen parenchyma at the same depth were measured with VTQ technique for 15 times, respectively. The coefficient of variation (CV) was calculated to identify the variability of measurements. With regard to repetition number, measuring depth, pathologic etiology, and CKD stage, their impacts on CV were analyzed and compared between kidney and spleen.

  Results  The CV level did not reduce when the number of measurements increased (P > 0.05), while the stability of mean value of SWV was improved (P=0.000). Kidney CV had a significantly positive correlation with the depth of measurement (r=0.370, P=0.003), while such a tendency was not observed in spleen (P > 0.05). Spearman analysis indicated that neither CKD stage nor pathologic etiology showed a significant correlation with kidney CV level (P > 0.05).

  Conclusion  When VTQ technique is applied to measure the renal tissue elasticity, more standardized methodologies should be developed to improve the stability of measurement results.