Objective To investigate the influencing factors of quality of shear wave elastography (SWE) image and the reproducibility of using SWE for focal liver lesions .Methods A total number of 289 consecutive patients with 305 lesions (the lesions could be detected on baseline ultrasound with intercostals approach ,and the depth of lesion was less than 10 cm) were undergone SWE examination .The SWE values of both lesion and adjacent liver parenchyma were measured .The quality of images was classified into three grades:“Good” ,“Common” ,and “Poor” .The depth of lesion ,the distance from body surface to liver capsule ,diameter and location of lesion were compared among three groups .Twenty consecutive patients with 20 lesions were performed SWE by two operators and another 20 consecutive patients with 20 lesions were performed SWE by one operator at different time .Intra‐class correlation coefficient was used to evaluate the reproducibility of inter‐ and intra‐ observer .Results A total number of 179 lesions were“Good” ,107“Common” and 19 “Poor” .The distance from body surface to liver capsule was significantly different among three groups [(Good (1 3.4 ± 0 3.5)cm ,Common (1 6.3 ± 0 3.6)cm ,Poor (1 8.7 ± 0 3.9)cm , P < 0 0.01] .No significant difference was found for the depth ,diameter and location of lesions among three groups .For all parameters of SWE both lesion and adjacent parenchyma ,intra‐class correlation coefficient of inter‐and intra‐observer were higher than 0 7.5 .The reproducibility of max SWE value was best of four elasticity parameters for lesion ,which intra‐class correlation coefficient of inter‐and intra‐observer was 0 9.0 and 0 9.6 ,respectively .Conclusions For focal liver lesions which could be detected on baseline ultrasound and the depth of lesions was less than 10 cm ,SWE could be used to evaluate elasticity characteristics with good feasibility and reproducibility .

Objective To investigate the value of shear wave elastography (SWE) and quasi-static elastography in the evaluation of radiofrequency ablation of pork.Methods Twelve pieces of fresh pork were underwent radiofrequency ablation (RFA) with different target temperatures.Before and after RFA,conventional ultrasound (US),SWE and quasi-static elastography were conducted to visualize the boundaries of RFA zones.The size of ablation zones obtained from conventional ultrasound,SWE and quasi-static elastography measurement were observed and detected the correlativity with pathology findings.Moreover,the Young's modulus and stain ratio of ablated zone were recorded.Results Most ablated boundaries were clearly delineated by both elastography techniques,except one with a low target temperature of 70 ℃.The sizes of ablated zones measured by SWE and quasi-static elastography were closely correlated with pathological findings.However,no ablated zones could be visualized by conventional US.Before and after RFA,the mean,minimum and maximum values of Young's modulus were (24.2 ± 3.8) kPa vs (97.6 ± 29.1) kPa,(9.2 ± 0.7)kPa vs (44.5 ± 7.7)kPa and (29.9 ± 3.8)kPa vs (181.5 ± 36.7)kPa,respectively (all P ＜0.001).With the increase of target temperature of RFA,the Young's modulus values and the mean strain ratio were significantly increased (all P ＜ 0.01).Conclusions Both SWE and quasi-static elastography are useful tools for evaluating the ablation,which are superior to conventional US.Moreover,SWE can be used to monitor the procedure of ablation.

Objective To evaluate the effective and safety of ultrasound-guided percutaneous portal vein guide wire placement adjunct to thrombolytic catheter,which treating portal vein thrombosis after liver transplantation.Methods From Jan 2012 to Dec 2015,a total of 6 patients (5 male,1 female,average age 50.6 years old,age range 41-65 years old) with portal vein thrombosis after liver transplantation were retrospectively studied.The diagnosis was confirmed by contrast enhanced ultrasound (CEUS) with hypoechonic and no enhancement in portal vein.With ultrasound-guided a 18-guage guide wire was placed in right branch of portal vein,and a guidewire was placement.After exchanging the catheter,the thrombosis was confirmed again by venography.A thrombolytic catheter was placed and local thrombolysis therapy was performed.Results The guidewires were successfully placed in 6 patients.The thrombolytic catheters were successfully placed in 5 patients (day 2-60 after operation),and failed in 1 patient (9 years after operation).With 5-11 days urokinase injection,the patency of portal vein was found in 5 patients,of which 4 patients was treated by angioplasty and stent placement.With 16-31 months follow-up,the patency of portal vein was maintained.Neither server complication nor related-death was occurred.Conclusions Ultrasound-guided percutaneous portal vein guide wire placement adjuncts thrombolytic catheter is effective and safety for treating portal vein thrombosis after liver transplantation.

Objective To evaluate the value of intra-cavitary contrast-enhanced ultrasound (IC-CEUS) via abdomen in fistulas difficult to diagnose before operation.Methods Clinical data of 12 patients with preoperative clinical suspicion of Crohn's Disease (CD) complications of fistula were enrolled in the study.Colonoscopy,cystoscope,or CT/MR has not confirmed the diagnosis of intra abdominal fistulas.IC-CEUS were performed by locally-injection of contrast agent in abdominal abscess,observing fistula and the relationship with the adjacent organs in CEUS mode.Diagnostic criteria were surgical findings.Results Fistulas in 10 patients were detected by IC-CEUS,including 7 cases of Ileo-mesenteric fistuls,2 cases of il eo-vesical fistulas,and 1 case of colo-vesical fistula.The accuracy rate of IC-CEUS in diagnosis of fistulas difficult to diagnose before operation in Crohn's disease was 83.3％ (10/12).No severe adverse events occurred during and after IC-CEUS procedure.Conclusions Our preliminary study shows that IC-CEUS is feasible in detecting abdominal fistula with high accuracy.It might be used as the alternative imaging tech nique for detecting fistulas when CT and MR are insufficient.

Objective To investigate the correlation between the elastographic characteristics of liver and postoperative function of liver allografts.Methods Forty-eight cases of liver transplantation from The First Affiliated Hospital of Sun Yat-sen University were analyzed,Shear wave elastography (SWE) was performed before operation or at one week or one month post-operation.Liver function was evaluated by measuring alanine aminotransferase (ALT),aspartate transaminase (AST),total bilirubin (TBIL),γ-glutamine transferase (GGT),albumin (ALB),alkaline phosphatase (ALP),prothrombin time (PT),activated partial thromboplastin time (APTT),and international normalized ratio (INR).Early allograft dysfunction (EAD) was also analyzed with reference to SWE among liver transplant recipients.Results SWE at one week after transplantation was significantly correlated with TBIL (r=0.525 6,P<0.01),APTT (r=0.668 3,P<0.000 1),PT (r=0.593 7,P=0.000 1),INR (r=0.609 6,P<0.000 1) and prealbumin (r=-0.464 1,P<0.01).However,no significant correlation was observed between pre-operative SWE and parameters of post-operative liver function.SWE in EAD patients was higher than that of patients without EAD (17.60±1.09 kPa vs.13.38±0.99 kPa,P<0.01).The optimal cut-off value of SWE at one week post-operation was 14.85 kPa.Conclusion Postoperative SWE is significantly correlated with postoperative liver function tests and EAD,suggesting SWE is a potential test for evaluating the quality of liver allografts.

Objective To investigate the influencing factors of quality in contrast-enhanced ultrasound (CEUS) perfusion analysis for hepatocellular carcinoma (HCC) and the reproducibility of using CEUS perfusion analysis on HCC.Methods A total of 136 HCC lesions were undergone CEUS perfusion analysis.Maximum intensity (Imax),rise time (RT),time to peak (TTP),mean transit time (mTF) and quality of fit (QOF) of HCC lesion,top-enhanced region inside HCC lesion and adjacent liver parenchyma were measured.The quality of perfusion analysis was classified into three grades " Good" (QOF ＞ 75％),"Common" [QOF (50％-75％)],and " Poor" (QOF ＜ 75％).Ultrasound machine,patients' age,tumor depth,tumor size and tumor location were recorded and compared among the three groups.20 consecutive patients with 20 HCC lesions were received CEUS perfusion analysis by two operators and another 20 consecutive HCC lesions were received CEUS perfusion analysis by one operator at different time.Intra-class correlation coefficient (ICC) was used to evaluate the reproducibility of inter-and intra-observer.Results Fifty-six HCC lesions were classified as " Good",39 as " Common" and 39 as " Poor",respectively.Tumor size (P =0.015) and tumor location (P =0.041) were significantly different among the three groups.Tumor size ＞ 3.0 cm and tumor located in S3,S4b,S5,S6 were apt to gain a better QOF.No significant difference was found for the different ultrasound machine,tumor depth and patients' age.For all CEUS perfusion analysis parameters of both lesion and adjacent parenchyma,intra-class correlation coefficient of inter-and intra-observer were higher than 0.90,the reproducibility of CEUS perfusion analysis was good.For Imax,RT and TTP in top-enhanced region inside HCC lesion,ICC of inter-and intra-observer was all higher than 0.90 (good).For mITT in highest enhanced area inside HCC lesion,ICC of inter-and intra-observer were 0.459 (poor),0.609 (common),respectively.Conclusions The parameters of HCC quantitative perfusion analysis were reproducible in peripheral liver parenchyma and tumor,but the mTT repeatability was poor in the highest enhancement area of the tumor.The size and location of the lesion were the factors affecting quantitative analysis.The quantitative analysis of ＞ 3.0 cm and the tumor located in S3,S4b,S5,S6 in the liver were satisfactory.

Objective:To qualitatively analyze the elasticity characteristics of boundaries and surrounding liver tissue of focal liver lesions (FLL) by real-time shear wave elastography (SWE), and to analyze the relating influencing factors.Methods:One hundred and fifty-two patients with FLLs (152 lesions) from February 2012 to October 2013 in the First Affiliated Hospital of Sun Yat-Sen University were collected. SWE of FLLs and the surrounding liver tissue was performed and baseline clinical data were collected. The elastic boundary (clear or not clear) of FLLs and elasticity distributions of surrounding liver tissue and their influencing factors were analyzed.Results:A total of 26 benign lesions and 126 malignant lesions were included in this study. Twenty-five cases (96.2%) of benign lesions showed clear elastic boundaries and 1 case (3.8%) showed unclear elastic boundary while 82 cases (65.1%) of malignant lesions showed clear elastic boundaries and 44 cases (34.9%) showed unclear elastic boundaries. Multivariate analysis showed benign/malignant lesion was an independent influencing factor for elastic boundary ( P<0.05). Twenty cases (76.9%), 6 cases (23.1%) and 0 case of liver tissue around benign lesions showed type A, B and C elastic distribution respectively while 17 cases (13.5%), 60 cases (47.6%), and 49 cases (38.9%) of liver tissue around malignant lesions showed type A, B, and C elastic distribution. There were statistically significant differences of benign and malignant lesions, different viral hepatitis backgrounds, different gender, and different ALB, TBIL, ALT levels in elasticity distributions of surrounding liver tissue of FLLs among type A, B and C (all P<0.05) while there was no significant difference in different lesion size( P=0.036). Conclusions:The elasticity characteristics of boundaries and surrounding liver tissue of FLLs on SWE images can provide a reference for differential diagnosis of benign and malignant FLLs. The elastic characteristics of surrounding liver tissue of FLLs are influenced by the nature of lesions and the background of liver disease, but are not influenced by lesion size. Further quantitative studies of elasticity characteristics of boundaries and surrounding liver tissue are needed for the differential diagnosis of different types of FLLs.