Objective To investigate the role of new contrast agent and real time gray scale contrast tuned imaging in the evaluation of the perfusion and echogenicity of liver neoplasms and to discuss the diagnostic value.Methods Thirty five patients with unconfirmed liver neoplasms were enrolled in the study.Nine of them were diagnosed clinically,while the other 26 cases with pathological evidence through surgery or needle biopsy.Contrast agent SonoVue,Technos DU6 and CnTI technology were used.The contrast agents were delivered intravenously or through bolus injection.Results Timing of all phases following contrast injection in normal and cirrhotic liver was observed.And then the perfusion processs of liver neoplasms was recorded.Among the 23 cases of typical hepatocellular carcinoma(HCC),21 cases(91%) presented with early artery enhancement and immediate wash out,while the other 2 cases of small(

Objective To develop a protocol for ultrasound-guided percutaneous radiofrequency ablation (RFA) on hepatic tumors larger than 3.5 cm in diameter, and to evaluate its role in ablation treatment. Methods Mathematical analysis was performed to generate the preoperative protocol which included the least ablation (sphere) number and the optimal overlapping mode and procedure for adequately ablating a large and spherical target lesion. The target ablation volume consisted of a tumor plus a 0.5- 1.0 cm tumor-free margin. The operation method for electrode placement was also described. Based on this mathematical protocol, 113 patients with 124 hepatic tumors [( 4.75? 0.92)cm in diameter, ranging from 3.6- 7.0 cm] were enrolled and treated. Seventy-one patients had 76 primary and 42 had 48 metastatic hepatic tumors. Results Totally 554 ablations (electrode placements) were performed in 124 tumors. The tumor complete necrosis rate was 87.9% (109/124), the local recurrence rate 24.2% (30/124), the estimated mean time to local recurrence 17.3 months. Twenty-five patients had received 38 retreatments for the local recurrence (17 received one time, and 8 received two or three times). Major complications were found in 7 patients (6.2 %). Of them, only one patient who suffered from colon perforation one week after RFA treatment required surgical intervention. Conclusions A theoretic basis and clinical guidance in RFA of hepatic tumors larger than 3.5 cm might be provided. Treatment results indicated that the protocol might probably be used to improve complete necrosis rate and reduce local recurrence rate in ablation therapy. The protocol was firmed effective and feasible.

Objective To investigate the diagnostic value of determination of serum carcinoembryonic antigen (CEA) levels for primary liver carcinoma and metastatic liver cancer.Methods Serum CEA levels in 365 patients with liver cancer (273 with HCC and 92 with metastatic liver cancer accordingly) and 33 controls were determined with ELISA. Data were analysed with SPSS.Results Serum CEA levels were (7.52?18.04)?g/L in patients with liver cancer and (0.99?0.79)?g/L in controls. Taking 2.5 ?g/L as the cut-off level,the positive rate was 29.86% and 6.06% respectively. The values were significantly higher than those in controls (P

4 cm in diameter(Z=1.966,P=0.048).A positive relation was seen between HSP70 expression and CD8~+ T cell number at the border zone of RFA sphere(r=0.489,P=0.046).The HSP70 expression and the CD8~+ T cell number at the border zone of RFA sphere were higher in recurrence-free patients than in recurrent patients,respectively(Z=2.009,P=0.045;Z=2.007,P=0.045).Conclusions Following the RFA,the HSP70 expression and the CD8~+ T cell number at the border zone of RFA sphere will be elevated,indicating that RFA induces an immune response against tumor antigens and a tumor-specific T cell reaction.

ObjectiveTo evaluate the effect of ultrasound guided radiofrequency ablation (RFA) on malignant liver tumors.Methods82 patients of primary liver cancer and 49 patients of metastatic liver cancer with a total of 226 cancer foci underwent percutaneous ultrasound guided RFA.ResultsCT performed 1 day～1 month post treatment showed a complete ablation in 203(90%) nodules. One hundred and six patients were followed up for 3～26 months, the survival rate of 3, 6 months and 1 year was 98 1%(104/106), 85 7%(72/84) and 73 7%(42/57), respectively. The major post RFA complications occurred in 6 cases(4 6%) including hemorrhage, hepatic abscess, bile leak, and cholecystitis with no mortality.ConclusionUltrasound guided RFA for the treatment of malignant hepatic tumors has the advantage of good palliative results, easy compliance by the patients, and enabling repeated therapy.

Objective To investigate the clinical role of a combination therapy of percutaneous radiofrequency ablation(RFA) and transcatheter arterial chemoembolization(TACE) in large hepatic tumors. Methods Out of 62 patients with hepatocellular carcinomas confirmed by pathology, 21 patients received a combination therapy of TACE and RFA(combination group), 22 patients TACE therapy alone, and the rest 19 patients RFA therapy alone. A total of 106 tumors with a mean diameter of ( 5.9? 0.7) cm(ranged from 5.0 to 8.1 cm) were detected, and the largest tumor was selected for observation in a patient with multiple lesions. There was no significant difference in mean age, tumor size and liver function grade among the three groups.Results Tumor complete necrosis accounted for 80.9%in combination group, which was significantly higher than that of TACE group and RFA group ( 27.2%, 47.4%,P 0.05). Mean survival duration of combination group was 25.6 months, significantly higher than that of TACE group( 14.9 months)(P0.05). Conclusions Compared with TACE or RFA therapy alone, the combination therapy improves tumor complete necrosis rate and prolongs the patients′ survival duration.

University of Manchester who first introduced Problem based learning(PBL)to the UK medical education,and adopted this new curriculum in 1994.Notably,Cambridge and Oxford have always had a high proportion of student-centred and self-directed learning,and have therefore not introduced PBL.Other medical schools have followed the example of Manchester,now PBL has become the mainstream curriculum in British medical edacation.First,this article is going to introduce how PBL curriculum is structured at Manchester medical school,and then reflect and give some thoughts on its current practice.

ObjectiveTo evaluate prognostic factors affecting local tumor progression after radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC).MethodsA total of 246 HCC patients (343 lesions) underwent RFA treatment in our department and were enrolled into this study.The average tumor size was 3.7 cm ( range 0.9 ～ 3.7 cm).Regular follow-up with enhanced CT was performed to evalutate the treatment results.Kaplan-Meier model and log-rank test were used in univariate analysis and COX regression model was used in multivariate analysis to identify risk factors for local tumor progression.ResultsThe local tumor progression rate was 11.4％ (39/343 lesions),and the average time from initial RFA to local tumor progression was 12.0 months.Univariate analysis indicated tumor size ( P ＜0.001 ),close to intrahepatic vessels ( P ＜0.001),tumor boundary ( P =0.020),pathological grade( P =0.010) and CEUS before RFA ( P =0.001) as risk factors for local progression.The following factors were identified as independent prognostic factors for local tumor progression by multivariate model:tumor size (P ＜ 0.001),isolated or close to intrahepatic vessels( P ＜0.001) and CEUS before RFA(P =0.018).ConclusionsTumor size,CEUS before RFA and close to intrahepatic vessels are the most important factors for local progression after RFA.Being awaring of possible risk factors for local tumor progression may increase the treatment efficacy and help to promote the use of RFA technique.

Objective To evaluate the role of contrast-enhanced ultrasound (CEUS) for preoperative detection of colorectal liver metastases.Methods 42 consecutive patients with colorectal liver metastases confirmed by histopathology after surgery were recruited in the study.They all had undergone preoperative CEUS examination with contrast agent SonoVue.The number,location and size of the hepatic lesions found by CEUS were correlated with postoperatively histopathologic results on a lesion-by-lesion basis.Results 96 liver metastases in 42 patients with colorectal cancer had been resected and confirmed by histophathology.The size of the metastatic lesions ranged from 0.3～8.5 cm [average (2.6 ± 1.8)cm].From one to eight metastatic lesions were detected in one patient.21 (21.9％) metastatic lesions were equal to or less than 1.0 cm.86 of 96 metastatic lesions were correctly depicted by CEUS,with a sensitivity of 89.6％.And the sensitivity for metastatic lesions equal to or less than 1.0 cm was 71.4％ (15 of 21 tumors) by CEUS.35 metastatic lesions were found between the portal venous phase and late phase by CEUS and 19 (54.3％) metastatic lesions among them could not be detected at conventional ultrasound.The curative resection was performed in 37 (88.1％) of 42 patients.With 3 - 39 months follow-up,the intrahepatic recurrence rate within two years was 32.4％ (12 of 37 patients) and the one-year survival rate was 90.0％.Conclusions CEUS is highly sensitive for detecting liver metastases resulted from colorectal cancer,especially for small metastatic lesions.CEUS is helpful to choose reasonable therapeutic strategies and can be regarded as one of the most importantly and noninvasively preoperative imaging modalities.

Objective To analyze the findings of recurrent/residual caner after thyroidectomy for thyroid cancer in both ultrasonography (US) and contrast-enhanced CT (CECT),and to assess the diagnostic value of combination of these two modalities.Methods Forty-six patients with recurrence/ residue of thyroid cancer underwent both high-frequency US and CECT examinations and were enrolled in this study.The imaging features on US and CECT were reviewed and diagnostic accuracies for local residual lesions and cervical lymph node metastasis were evaluated according to pathological results.Results In 46 patients,the average period between thyroidectomy and diagnosis of recurrent/residual cancer was (14.6 ± 12.1) months(range,7 days-10 years).Twenty patients had local recurrent tumors at the surgical bed and the average size of tumors was 2.1 cm(range,0.5-4.6 cm).On US finding,the recurrent/residual tumors were hypoechoic in 60 ％ of cases,had microcalcification in 40 ％.Cervical lymph node metastasis were found in 40 patients,and 75％ of them were located in zone V[.The smallest size of abnormal lymph node which can be detected by US was 3 mm.In cases of lymph node metastasis,12 cases (30％) became cystic,10 (25 ％) presented microcalcifications,and 5 (12.5 ％) showed microcalcifications and cystic change within a lymph node.Microcalcifications,cystic change and hyperechoic appearance within a lymph node suggested malignant.The detection rate of US and CECT in the local recurrent/residual cancer were 90％ and 90％,respectively.The detection rate of cervical lymph nodes metastasis were 80 ％ and 72.5 ％,respectively.The diagnostic accuracy of US and CECT in local recurrence,cervical lymph node metastasis and both were 65％,67.5％ and 65.2％ vs 75％,55％ and 65.2％,respectively (P ＞ 0.05 for all comparisons).the diagnostic accuracy of combination of US and CECT were increased to 86.4％,77.5％ and 91.3％,respectively.US combined with CECT significantly improved the diagnostic capability compared with US or CECT alone(P ＜0.05).Conclusions US should be used as the first choice of imaging examination for post-thyroidectomy of thyroid cancer.US combined with CECT could further increase the diagnostic accuracy in recurrent/residual thyroid cancer.