Correlation of virtual touch tissue quantification and liver biopsy in a rat liver fibrosis model.

Liver fibrosis assessment is very important to the treatment of chronic liver disease. In the present study, Virtual Touch Tissue Quantification (VTQ) and eSie Touch™ elasticity imaging techniques were used to examine the rat liver fibrosis model. Rat liver fibrosis was induced with thioacetamide and the degree of liver fibrosis was determined using pathological diagnosis as a gold standard. The right lobe of the liver was also examined with the VTQ and eSie Touch™ techniques. The VTQ and serological results were correlated and analyzed. The results were compared with those obtained from liver biopsies to investigate the accuracy and diagnostic value of eSie Touch™ and VTQ on the classification of liver fibrosis in rats. A total of 30 successful modeling cases were obtained, with a success rate of 86%. The mean acoustic radiation force impulse (ARFI) elastography­VTQ values were 1.08, 1.51, 1.88 and 2.50 m/sec for the normal and F1/F2, F3 and F4 fibrosis groups, respectively. A significant correlation (r = 0.969) was identified between the ARFI measurements and the degree of fibrosis assessed by pathological examination (P<0.001). The histological staging results correlated with those of the eSie Touch™ elasticity imaging of the biopsy site (r = 0.913, P<0.001). The predictive values of ARFI for various stages of fibrosis were as follows: F≥1 and 2 ­ cut­off >1.250 m/sec (when Vs >1.250 m/sec, the pathological grading was ≥F1/F2) [Area under receiver operating characteristic (AUROC) = 1.00], F≥3 ­ cut­off >1.685 m/sec (when Vs >1.685 m/sec, the pathological grading was ≥F3; AUROC = 1.00) and F≥4 ­ cut­off >2.166 m/sec (when Vs >2.166 m/sec, the pathological grading is cirrhosis; AUROC = 1.00). In conclusion, the eSie Touch™ elasticity imaging and VTQ techniques may be successfully adopted to assess the extent of liver stiffness. These techniques are expected to replace liver biopsy.

Disruption of splenic circulation using microbubble-enhanced ultrasound and prothrombin: a preliminary study.

The spleen is a solid organ in which splenomegaly frequently develops and to which abdominal blunt trauma occurs. In this study, we demonstrated the potential therapeutic effect of microbubble-enhanced ultrasound (MEUS) combined with prothrombin to disrupt splenic circulation. A high-pressure-amplitude therapeutic ultrasound (TUS) device was used to treat 36 surgically exposed spleens in healthy New Zealand rabbits. Eighteen spleens were treated with either MEUS (n = 9) or MEUS combined with prothrombin (n = 9). The other 18 spleens were treated with TUS only or sham ultrasound exposure and served as the controls. The TUS was operated at a frequency of 831 kHz and a peak negative pressure of 4.8 MPa. Prothrombin was administered intravenously at 20 IU/kg. Contrast-enhanced ultrasound (CEUS) and acoustic quantification were performed to assess splenic blood perfusion. We found significant blood perfusion slowdown and drop-off in the MEUS-treated spleens. The peak intensity dropped from 20.2 ± 2.70 dB to 11.6 ± 4.58 dB immediately after treatment. The spleens treated with the combination of MEUS and prothrombin showed consistently poor perfusion within 1 h. In histologic examination of the MEUS-treated spleens, we found significant dilatation of splenic sinuses, hemorrhage, interstitial edema and thrombosis. This study demonstrated that the vascular effects induced by microbubble-enhanced, high-pressure ultrasound can slow down or block blood perfusion in the rabbit spleen. Prothrombin helps to enhance and extend the effects for up to 1 h.