Objective To analyze the hemodynamic changes with color Doppler flow imaging(CDFI) after liver transplantation. Methods One hundred fifty-six patients with transplanted livers were included. Hepatic morphology and parenehyma was investigated with B-mode ultrasound, and the patency of hepatic anastomosis was assessed with CDFI. Hemodynamic parameters were also measured. Results It showed increased parenchyma echogenicity during the early period after liver transplantation. Hepatic hemodynamies changed as follows: peak systolic velocity of portal vein was high in the first day after operation, and then it progressively decreased; the peak systolic velocity of hepatic artery was not changed during the follow-up period;the resistance index of hepatic artery was a little higher in the first day after liver transplantation, then it decreased ( P<0.05 ). Conclusions CDFI is valuable in evaluating hepatic hemodynamic changes after liver transplantation.

Objective To evaluate the feasibility of three-dimensional contrast-enhanced ultrasound (3D-CEUS) in showing vascular patterns of renal tumors.Methods The images of 3D-CEUS examination were retrospectively analyzed in one hundred and twenty one renal tumors which were confirmed sequentially by pathology.3D-CEUS was performed after conventional ultrasound and contrast-enhanced ultrasound (CEUS).The 3D-CEUS images were reconstructed by QLAB workstation and classified into 4 grades based on the blood supply characteristics.Results All the tumors were confirmed by pathology and operations,including clear cell renal cell carcinoma (CCRCC) (n=91),papillary renal cell carcinoma (PRCC) (n=5),chromophobe renal cell carcinoma (CRCC) (n=5),renal angiomyolipoma (RAML) (n=19),and cystic nephroma (n=1).Three-dimensional reconstruction could provide clear stereoscopic views of the interested structures and morphological characteristics of lesions.The three-dimensional ultrasonography of a particular renal tumor could be a mixture of different basic grades.There were significant differences between benign and malignant renal tumors in 3D-CEUS.The image quality was the best in early parenchymal phase comparing to other phases.In early parenchymal phase,84 RCCs (83.17%) were tortuous expansive reticular or irregular messy dendritic,61 cases (60.40%) with filling defect areas and 15 cases (14.85%) with pseudocapsules.Grade Ⅲ and Grade Ⅳ were the main vascular patterns in maglinant tumors.In early parenchymal phase,6 RAMLs (31.58%) were nebulous with dendritic in part,12 cases(63.16%) were reticular on the basis of nebulous with homogeneous internal structures.The vascular pattern was shown better in 3D-CEUS than CEUS.Conclusions 3D-CEUS can provide clear stereoscopic structures and morphological characteristics of the lesions,it is a useful adjuvant of CEUS for the diagnosis of renal tumors.

Objective To evaluate the value of contrast-enhanced ultrasound (CEUS) with high mechanical index(MI) in the diagnosis of renal artery stenosis(RAS). Methods Twenty-one patients with RAS including 3 patients after renal transplantation were studied. Ultrasound contrast agent SonoVue was used and MI was set at about 1 when the CEUS was performed. All patients were examined with conventional color Doppler sonography and CEUS. The diagnostic results of ultrasound were compared with those of intravenous digital subtraction angiography ( DSA), CT angiography(CTA) and MR angiography (MRA). Results The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of conventional color Doppler sonography were 85. 7%, 57. 1 % , 80. 0% , 66. 7% and 76. 2%, respectively, those of CEUS were 100%, 66.7%, 88.2%, 100% and 90.5%, respectively. Conclusions CEUS with high MI which improves the imaging of renal artery depicts the margin of the vascular lumen directly and clearly. It may be more helpful in the diagnosis of RAS.

Objective To evaluate the feasibility of virtual touch tissue quantification (VTQ) for the assessment of renal allograft.Methods A total of 72 kidney recipients were examined with conventional ultrasound and VTQ after transpantation.Biopsies were performed in 34 patients,20 patients were with acute rejection (AR),14 with chronic allograft nephropathy (CAN),38 patients as control group.The peak systolic velocity (PSV) and resistance index(RI) were measured on main,infrarenal and arcuate arteries with conventional ultrasound and shear wave velocity (SWV) of the renal cortex was obtained by VTQ.All the data were compared among three groups.Results There were no significant differences of PSV between two groups.An increased RI was presented in the CAN group(P ＜0.05).The mean SWV was (2.67 ± 0.27) m/s,(2.90 ± 0.31)m/s and (2.28 ± 0.24)m/s for AR,CAN and normal group,respectively.There were significant differences of SWV among the three groups (P ＜ 0.05).Conclusions VTQ technique could provide a new method for the assessment of transplanted kidney.

Objective To evaluate contrast-enhanced ultrasound imaging of carotid atherosclerosis with different stenostic degree as a clinical tool to study intraplaque neovascularization.Methods Fifty-eight patients suspected of carotid stenosis with 73 plaques were studied by standard and contrast-enhanced ultrasound.Plaque echogenicity at standard ultrasound were evaluated.Contrast enhancement within the plaques was categorized as 0 - 4 degree and compared to the stenosis degree and the plaque echogenicity.The degree of stenosis was determined by intravenous digital subtraction angiography.Results In the group with stenosis less than 90% ,stenosis degree was not associated with the grade of contrast enhancement (P =0.358),while the grade of enhancement was significantly higher in the group with sever stenosis(＞90%).The grades of enhancement were significantly different between plaques with different echogenicity (P =0.000).Conclusions Contrast-enhanced real-time ultrasound imaging can demonstrate the enhancement of carotid plaques non-invasively,which is helpful for assessing intraplaque neovascularization and provide valuable information for plaque risk stratification

Objective To evaluate the diagnostic value of virtual touch tissue quantification (VTQ) in the diagnosis of renal allograft fibrosis.Methods The renal allografts of 82 patients with biopsies or nephrectomy were assessed by virtual touch quantification.The renal allograft fibrosis was categorized according to the 2005 updated Banff criteria for a G0～G3 grade.All the results were compared among four groups.Results The mean SWV values in G0～G3 were (2.39 ± 0.31)m/s,(2.45 ± 0.34)m/s,(2.58 ± 0.18) m/s,(3.11 ± 0.40)m/s,respectively.There were no significant differences in the mean SWV value between G0 and G1 group,or between G1 and G2 group(P ＞0.05).There were significant differences in the mean SWV value between G0～G2 and G3 group,or between G0 and G2 group(P ＜0.05).Stiffness of renal allograft was significantly correlated to the mean SWV value (Spearman r =0.671,P ＜0.001).According to the area under the ROC curve,the sensitivity and specificity of SWV (area under ROC curve =0.847,cut-off=2.64 m/s) for grade ≥G2 was 78.9％ and 79.5％ respectively.Conclusions Stiffness measured by VTQ reflects the interstitial fibrosis in renal allograft.VTQ technique might be a new tool to identify patients with chronic allograft injury.

Objective To evaluate the value of quantitative analysis of contrast‐enhanced ultrasonography (CEUS) in differentiating acute rejection(AR) from acute tubular necrosis(ATN) of transplant kidney. Methods Total of 67 kidney recipients were examined with conventional US and CEUS. Biopsies were performed in 37 patients, 26 patients were with AR, 11 with ATN, 30 patients as control group. The hemodynamic parameters (PSV and RI) were measured on infrarenal artery with conventional US, while CEUS quantitative analysis was performed on the cortex, pyramid and interlobar artery by time‐intensity curve (TIC). TIC parameters including rise time (RT ), time to peak (TTP), mean transit time (mTT ) were compared among three groups. In addition, the reproducibility of TIC parameters was evaluated. Results The RI in AR group was significantly higher than that in control group, but there were no significant differences of RI between AR and ATN groups. TIC parameters including RT, TTP were with high reproducibility (ICC> 0 7.5). Compared to the other two groups, the RT and TTP of the pyramid, ΔRTm‐c, and ΔTTPm‐c were significantly longer in AR group, the receiver operating curves (ROC) analysis demonstrated that ΔRTm‐c had the highest accuracy and RI had the lowest accuracy for detecting AR(areas under the curve were 0 7.86, 0 7.56, 0 7.49, 0 7.36 and 0 4.98, respectively). High sensitivity and specificity(78 3.% and 73 5.%, respectively) were shown when using 4 6.2 s as a cutoff point of ΔRTm‐c to diagnose AR. Conclusions Quantitative analysis of CEUS could detected the changes of the microcirculation perfusion in kidney grafts with AR and ATN, which might be superior in the diagnosis of AR compared with conventional US.

Objective To study the value of quantitative analysis of contrast-enhanced ultrasound in diagnosing acute rejection of kidney graft.Methods Sixty-seven patients with normal kidney grafts and thirty-five patients with acute rejection were recruited.In conventional ultrasound,the peak systolic velocity (PSV) and resistance index (RI) of segmental artery and interlobar artery were measured.In quantitative analysis of contrast-enhanced ultrasound,four regions of interest including renal cortex,medulla,segmental artery and interlobar artery were drew and three parameters including rising time(RT),time to peak(TTP) and mean transit time(mTT) were obtained.In addition,the difference in RT,TTP and mTT between the renal cortex and interlobar artery,as well as medulla and interlobar artery were calculated.Results The differences of PSV in interlobar artery between the two groups were statistically significant (P ＜0.05).The time-intensity curves of the whole kidney grafts,and the difference in RT and TTP between the renal cortex and interlobar artery were statistically different between two groups (P ＜0.05).Conclasions Quantitative analysis of contrast-enhanced ultrasound proved a quantitative method for diagnosing kidney allograft acute rejection.

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.

Objective:To explore the feasibility of contrast-enhanced ultrasound in assessing the degree of transplant renal artery stenosis(TRAS)and evaluate its diagnostic efficacy of severe TRAS.Methods:From February 2013 to February 2022, clinical and follow-up data are retrospectively reviewed for 23 TRAS recipients.A definite diagnosis is made by magnetic resonance angiography (MRA, 2 cases)or digital subtraction angiography(DSA, 21 cases). They are assigned into two groups of mild-moderate stenosis(5 cases)and severe stenosis(18 cases)according to the diameter reduction rate of transplanted renal artery detected by DSA/MRA.Another 32 recipients of stable renal function are selected as controls.All contrast-enhanced ultrasonic images are quantitatively processed with SonoLiver.The following quantitative parameters are obtained, including rising time of interlobular artery(RTi), rising time of cortex(RTc), rising time of medulla(RTm), time to peak of interlobular artery(TTPi), time to peak of cortex(TTPc)and time to peak of medulla(TTPm). The differences of contrast-enhanced ultrasonic quantitative parameters are compared among three groups.And their diagnostic efficacies are calculated in the diagnosis of severe TRAS.Results:As compared with those in normal group, RTi, RTc, TTPi and TTPc are significantly longer in mild-moderate stenosis group(all P<0.05); Meanwhile, RTi, RTc, RTm, TTPi, TTPc and TTPm are significantly longer in severe stenosis group than those in normal group(all P<0.05); Comparing mild-moderate stenosis and severe stenosis groups, only RTm is significantly different between two groups( P<0.05). Among all the above parameters, RTc has the highest diagnostic efficacy in the diagnosis of severe TRAS(AUC=0.848)with a sensitivity of 72.22%, a specificity of 86.49% and an accuracy of 81.82%. Conclusions:The quantitative parameters of contrast-enhanced ultrasound offer aid in assessing the degree of TRAS.And RTc is the most valuable in the diagnosis of severe TRAS.