Objective To varify contrast-enhanced ultrasound (CEUS) quantitative analysis plaque enhancement is able to assess the intraplaque neovascularization.Methods The abdominal aortas were examined with CEUS in 9 atherosclerosis rabbits established by feeding high-fat diet.Sonographic examinations were performed with ultrasound instruments equipped with low mechanical index contrast imaging software.Contrast agent SonoVue was used with a dose of 0.2 ml,The enhanced intensity (EI) with the plaque and the ratio of EI within the plaque to that in the lumen of the carotid artery was calculated with QLab software,Each aorta specimen was stained with F8 (von willebrand factor) for mierovessel.The quantitative parameters EI and ratio were compared with the immunohistochemical study results.Results The mean value of EI and ratio were (3.91 ± 0.87)dB and 0.30 ± 0.06,respectively.Five specimens showed positive F8 staining and 4 showed negative.EI and ratio were significantly greater in positive group than in negative group [(4.47 ± 0.60) dB vs (3.22 ± 0.62) dB,0.34 ± 0.05 vs 0.25 ± 0.05].CEUS quantitative parameters EI ( r =0.779,P =0.013) and ratio ( r =0.693,P =0.019) were correlated to microvessels marked with F8,respectively.Conclusions It is histologically validated that CEUS quantifies the neovascularization in atherosclerosis plaques.CEUS provides a window for plaque risk stratification.

Objective To investigate the effect of gene transfection to mice's muscle combining polyethyleneimine (PEI) with ultrasound (US)-targeted microbubble (MB) destruction (UTMD).Methods Twenty-five female Balb/c mice were divided into 5 groups (5 mice per group) randomly.Plasmid DNA (20 μg) encoding green fluorescent protein (GFP) was used as expresion vector.The transfection materials were injected into the bilateral tibialis anterior muscles of mice respectively and delivered as follows:(a) untreated control,(b) plasmid + US,(c) plasmid + US + MB,(d) plasmid + PEI,(e) plasmid + PEI + US,(f) plasmid + PEI + MB+ US.SonoVue MB was used at a final concentration of 30％ (v/v).The acoustic intensity and duty cycle were optimized before the study and set at 2.0 W/cm2 and 50％ respectively.Transfection efficiency was assessed by counting the number of GFP-positive fibers under fluorescence microscopy 10 days after gene delivery.Hematoxylin-Eosin staining was performed on separate specimen and examined with light microscopy for tissue damage.Results No GFP-positive fiber was found in the untreated control group.There were 14 ± 3,58 ± 6,96 ± 7,119 ± 11 and 158 ± 18 GFP-positive fibers respectively found in plasmid+ US,plasmid + MB + US,plasmid + PEI,plasmid + PEI + US,and plasmid + PEI + MB + US groups.The plasmid + PEI + MB + US group had the maximal GFP-positive fibers,the differences were significant compared with other groups (P ＜0.05).No evidence of inflammation or necrosis was revealed in histological examination with hematoxylin-eosin staining.Conclusions PEI combining with UTMD can significantly improve efficiency of gene transfection in vivo and has great potential in gene therapy.

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 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 probe the correlation between the short-axis diameter(SD) of microwave coagulation and the time(T) and/or power(P) using a new type of internally cooled microwave antenna. Methods A MTC-3 microwave apparatus with a new type of internally-cooled microwave antenna was used to coagulate a fresh porcine liver in vitro. The correlation was analyzed between the SD of coagulation necrosis and the time and/or power. Results ①Under the same power, there was high linear relationship(r= 0.94- 0.98,P

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 probe the correlation between the short-axis diameter(SD) of coagulation necosis and the microwave power(P) using a new type of internally cooled microwave antenna in ex vivo and in vivo liver model.Methods Fourteen microwave ablations were performed in swine livers ex vivo and canine livers in vivo under the microwave powers of 30-90W and the durations of 10 min and 20 min, respectively.The short-axis diameter(SD) and the long-axis diameter(LD) of the coagulation were measured.The difference of SD, LD and SD/LD in swine liver ex vivo and canine liver in vivo were compared.The relationship between the SD and microwave power was analysised using linear regression model.Results Under the same conditions,the SDs and LDs of the coagulations of canine livers in vivo were smaller than those of swine livers in ex vivo (P <0.01).There was such a higher linear relationship(r = 0.96-0.99, P <0.01) between the SD of coagulation and the power in vivo liver model as the results acquired in ex vivo.Conclusions Although the blood flow decreased the SDs of the coagulation of microwave ablation in liver in vivo, but there was still a higher linear relationship between SD and microwave power.

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 diagnosis value of contrast-enhanced real-time harmonic gray scale imaging in the diagnosis of renal artery stenosis.Methods Sixteen patients with renal artery stenosis including 4 patients after stent placement were enrolled.Ultrasound contrast agent SonoVue was used.All patients were examined with conventional color Doppler sonography and real-time harmonic gray scale imaging.The diagnostic results were divided into three scales:①no diagnosis result;②doubted diagnosis;③unequivocal diagnosis. The results were compared with those of digital subtraction angiography,CT and MRI.Results Unequivocal diagnosis were achieved in 50.0% (8/16) patients,doubted diagnosis in 31.3% (5/16),no diagnostic result in 18.7% (3/16) on conventional color Doppler sonography;the ratio was 81.3% (13/16), 12.5% (2/16), 6.2% (1/16),respectively on contrast-enhanced real-time harmonic gray scale imaging.The sensitivity,specificity and accuracy of conventional color Doppler scanning were 63.6% (7/11), 40.0% (2/5) and 56.3% (9/16),respectively;those of real-time harmonic gray scale imaging were 83.3% (10/12),100%(4/4) and 87.5% (14/16),respectively.Conclusions Contrast-enhanced real-time harmonic gray scale imaging depicts the margin of the vascular lumen and outer wall directly.Therefore real-time harmonic gray scale imaging may be more helpful in the diagnosis of renal artery stenosis.

2, but precise estimation of stenoses was impossible on CDUS. The stenosis degree and the length of stenosis measured by contrast-enhanced harmonic gray scale imaging were correlated well with those of DSA(r= 0.94 and 0.63 , respectively). Conclusions Microbubbles fill the arterial lumen with echoes at contrast-enhanced harmonic gray scale imaging. The ability to visualize the inner and outer surfaces of the vascular wall improved the evaluation of luminal abnormalities.