Objective To evaluate the ablation zone and temperature changes in the liver caused by laser ablation in vitro and in vivo.Methods Single needle single point laser ablation was performed in vitro with porcine liver using 5 W and 7 W-power and in vivo with rabbit liver using 5 W-power.All energy outputs were 1 800 J.The ablation zone and temperature changes were evaluated.Results Coagulation caused by laser ablation was divided into a black carbonized area and a brown white necrotic area from inside to out,respectively.The mean in vitro ablation range obtained by 5 W and 7 W-power laser ablation was 1.9 cm × 1.2 cm × 1.2 cm and 2.5 cm × 1.5 cm × 1.5 cm,respectively.The mean in vitro black carbonized range obtained by 5 W and 7 W-power laser ablation was 1.1 cm × 0.5 cm × 0.5 cm and 1.4 cm × 0.7 cm ×0.7 cm,respectively.The average maximum temperature using 5 W-power was 243.57 ℃,62.47 ℃ and 34.27 ℃ in the ablation center,5 mm from the center,and 10 mm from the center,respectively.For in vivo liver experimentation,the average maximum temperature using 5 W-power was 62.26 ℃ and 44.35 ℃5 mm and 10 mm from the center,respectively.Conclusion Laser ablation can cause coagulation necrosis of the liver tissue in vitro and in vivo,and the ablation range increased with increasing power.Laser ablation may have potential use in the ablation of tumor localized in critical sites.

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 retrospectively compare the safety and local efficacy of multiple-electrode switching based radiofrequency ablation (RFA) and the conventional RFA in treating single early-stage hepatocellular carcinoma (HCC).Methods A total of 82 patients with single early-stage HCC received either RFA with a multiple-electrode switching system (n =43) or conventional RFA (n =39) as the first-line treatment.The rate of initial local complete response,major complications and local tumor progression (LTP) were compared between two groups.Results The total ablation time was significantly shorter in the switching-RFA group [(16.7 ± 3.4) mins] than in the conventional RFA group [(29.8 ± 10.4) mins] (P ＜ 0.05).The rate of initial local complete response was 100％ (43/43) in the switching-RFA group and 94.9％ (37/39) in the conventional RFA group (P ＞0.05).After a mean follow-up period of (26.4 ± 21.8)months (ranging 3.0-91.6 months),the rates of LTP in the switching-RFA group and conventional RFA group were 16.3％ (7/43) and 17.9％ (7/39),respectively.The LTP rates in two groups were 16.1％ versus 11.2％ atyear1,and20.5％ versus 20.6％ at year2 (P=0.666).Conclusions The multiple-electrode switching based RFA is safe and effective with shorter ablation time in treating single early-stage hepatocellular carcinoma.

Objective To evaluate the safety and effective of ultrasound-guide percutaneous radio frequency ablation (RFA).Methods Retrospectively analyze the incident,management and influence factors of complication of ultrasound-guide percutaneous RFA.Results From 2001 to 2011,536 patients with 762 lesions underwent RFA were enrolled in this study.Incident of RFA complication was 2.03％ (11/536),including 5 (0.92％) major complication.The complication covered fever (1 case),massive hydrothorax (2 cases),hydrothorax accompany with ascites (1 case),massive ascites (1 case),liver abscess (1 case),liver capsule hemorrhage (1 case) and hemothrorax (1 case).No RFA relate mortality was observed.According to logistics regression analysis,the liver function Child-Pugh grading was associated with the RFA complication (P =0.005).Conclusions Ultrasound-guide percutaneous RFA is a safe and effective local treatment approach for hepatocellular carcinoma.It's necessary to comprehensively think over the basic condition of patients and the characters of tumor such as tumor location,size and abutting organs.Nevertheless,an appropriate treatment plan and closely monitor during and after RFA are crucial.

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 usefulness of parametric imaging of contrast-enhanced ultrasound(CEUS) in imaging hepatocellular carcinoma (HCC) using dynamic vascular patterns (DVP). Methods Thirty clinically or pathologically proven HCCs that had undergone CEUS were randomly included. SonoLiver CAP sofeware was used to analyze the CEUS images and reconstruct DVP parametric images. Results The rise time, time to peak and mean transit time were (16. 72±11. 07) s, (29. 92±14. 13) s,(115. 03±90. 91)s in HCC versus (26. 59±9. 60) s, (41.67±12. 59) s, (159.26±123. 74) s in the surrounding liver parenchyma (all P <0. 05). The perfusion index was (90. 41±102. 49) % in HCC versus (54. 10±24. 99)% in surrounding liver parenchyma( P = 0.044). DVP curve and DVP parametric image could both be divided into three types:washout,non-washout and cystic type. The percentages of which were 76.7% (23/30), 20.0% (6/30) and 3.3% (1/30) in DVP curves, respectively, and 66.7% (20/30), 30.0% (9/30) and 3.3% (1/30) in DVP parametric images,respectively. Conclusions Parametric image of CEUS could demonstrates the difference of flow perfusion static between HCC and surrounding liver parenchyma dynamically and directly.

Objective To compare the features of different heating modes cauterization mode and standard ablation mode of Cool-tip on coagulation zone and thermal field distribution in order to provide references for focused and accurate vascular occlusion and explore the primary efficacy of Cool-tip applied to intrahepatic vascular occlusion in living dogs Methods Ex-vivo porcine livers were ablated for 2 4 6 8 minites with cauterization mode and standard ablation mode respectively and the long- and short-axis diameters in the greatest dimension were compared The tissue temperature around the tip midpoint and end of the exposed part of radiofrequency electrode were measured under the circumstance of 4 min ablation by the two modes respectively Animal experiment the intrahepatic vessels of 2 Beagles were ablated with cauterization mode one procedure for each animal and contrast-enhanced ultrasound was used to evaluate the perfusion change of liver tissue Gross anatomy and pathological examination of the liver was performed after 1 week Results In the 2 min 4 min 6 min and 8 min ablation the coagulation volume of cauterization mode and standard ablation mode were 1 01 ± 0 41 cm 3 vs 2 95 ± 0 74 cm 3 1 47 ± 0 33 cm 3 vs 5 03±1 06 cm 3 2 29±0 49 cm 3 vs 9 23±2 53 cm 3 2 70±0 24 cm 3 vs 1 5 89±0 77 cm 3 The coagulation volume was significant smaller in cauterization mode than in standard ablation mode P <0 05 for all The peak temperature of cauterization mode presented on the tip of electrode which averaged 94 4℃ in maximum and maintain around 70 ℃ in the equilibrium phase The peak temperature of standard mode presented on the midpoint of the electrode which periodically variated between 70 ℃- 100 ℃ The result of the animal experiment showed that cauterization mode could be used to occlude the intrahepatic vessel in vivo which induced the ischemia and necrosis in the corresponding area Conclusions Cauterization mode and standard alation mode of Cool-tip have different characteristic in terms of coagulation zone and thermal distribution and carterization mode may have a promising application in intrahepatic vascular occlusion.

Objective: To compare the diagnostic performance of contrast-enhanced ultrasound (CEUS) with contrast-enhanced computed tomography (CECT) for the maximum diameter ≤2 cm metastatic liver cancer (MLC). Methods: Sixty-nine pathologically diagnosed MLC patients (maximum diameter ≤2 cm) were retrospectively recruited. The lesion detection rate, diagnostic confidence and enhancement pattern of CEUS and CECT for MLC were analyzed. Diagnostic value of CEUS and CECT for MLC were evaluated and compared by using diagnostic test. Results: The cases of 0, 1, 2, multiple lesions detected by CEUS and CECT in these 69 patients with ≤2 cm MLC were 0 case (0%), 41 cases(59.42%), 13 cases(18.84%), 15 cases(21.74%) and 9 cases(13.04%), 29 cases(42.03%), 13 cases(18.84%), 18 cases(26.09%), respectively. The positive cases detected by CEUS and CECT were 69 cases(100%) and 60 cases(86.96%) respectively, with a statistically significant difference between the two groups (P=0.006). However, for the detection rate of non-single-lesion cases, there was no statistical difference between CEUS and CECT (P=0.409). The cases showed typical manifestation in CEUS and CECT were 56 cases(81.16%)and 29 cases(42.03%)(P<0.001). The cases with diagnostic confidence level of 3, 4, 5 in CEUS were 3 cases(0.04%), 11 cases(15.94%), 55 cases(79.71%), and those of CECT were 19 cases(27.54%), 20 cases(28.99%), 20 cases(28.99%), respectively. The diagnostic sensitivity of CEUS and CECT for ≤2 cm MLC were 100% (69/69) and 85.51% (59/69), with statistically significant difference(P=0.001). Conclusions The lesion detection rate and diagnostic value of CEUS for the maximum diameter ≤2 cm MLC might be superior to that of CECT, but the detection rate shows no significant difference in the non-single-lesion cases. CEUS has important clinical value in the diagnosis of ≤2 cm MLC.

As the incidence of chronic kidney disease (CKD) increases year by year, the number of patients with CKD is increasing year by year before or during pregnancy. Pregnancy management is increasingly important for patients with kidney disease, and women with CKD face a number of challenges during pregnancy, such as the risk of kidney disease progression, fetal growth restriction, the potential teratogenicity of medications, and an increased risk of complications such as preeclampsia and preterm birth. In order to ensure a good outcome for pregnant women and the fetus, it is necessary for multidisciplinary physicians in the department of nephrology, obstetrics, reproductive health and other departments to assess the risk of pregnancy in patients with CKD in a standardized manner, adjust medication in a timely manner, and closely monitor to detect maternal and fetal complications early, stabilize the patient′s condition, and determine the safest time for pregnancy and delivery.

"Early clinical practice, multiple clinical practice and repeated clinical practice" is the mainstream of the reform of higher medical education in the 21st century. Based on the shortages of the current medical education model, a university started to reform from both theoretical teaching and practical teaching, and constructed a teaching model of "early clinical practice, multiple clinical practice and repeated clinical practice" that fits China's reality. And the teaching effect was evaluated questionnaire survey and OSCE tests. The results showed that this teaching model could promote the all-round development of medical students' knowledge, ability and quality.