Objective  To explore the clinical value of virtual touch tissue quantification (VTQ) technique in the diagnosis of acute rejection of transplant kidney at different stages.

  Methods  Clinical data of 170 renal transplant recipients were retrospectively analyzed. According to the time of VTQ examination and the occurrence of acute rejection after renal transplantation, the recipients within 4 weeks and after 4 weeks post-renal transplantation were assigned into the normal renal function group (n=41, 51) and acute rejection group (n=22, 56). Clinical ultrasound parameters at different stages after renal transplantation were compared between two groups. The diagnostic value of ultrasound parameters in acute rejection at different stages after renal transplantation was evaluated.

  Results  Within 4 weeks post-renal transplantation, the resistance index (RI) and shear wave velocity (SWV) in the acute rejection group were significantly higher than those in the normal renal function group (both P < 0.001). After 4 weeks post-renal transplantation, the SWV in the acute rejection group was significantly higher than that in the normal renal function group (P < 0.001). The area under curve (AUC) of RI and SWV in the diagnosis of acute rejection were 0.729 and 0.803 respectively within 4 weeks post-renal transplantation, which were 0.478 and 0.794 respectively after 4 weeks post-renal transplantation. The diagnostic value of SWV was higher than RI (P < 0.05). The cutoff value of SWV in the diagnosis of acute rejection within 4 weeks post-renal transplantation was considerably higher than that after 4 weeks post-renal transplantation.

  Conclusions  VTQ technique can effectively assist in diagnosing acute rejection of transplant kidney at different stages.