Focal hypoechoic tumors of Fatty liver: characterization of conventional and contrast-enhanced ultrasonography.

OBJECTIVE: The purpose of this study was to investigate the characteristics of focal hypoechoic tumors of fatty liver using conventional ultrasonography and contrast-enhanced ultrasonography (CEUS). METHODS: Sixty-four hypoechoic tumors of fatty liver in 52 patients were examined by both conventional ultrasonography and CEUS. Contrast pulse sequencing and a sulfur hexafluoride contrast agent were used for CEUS. The enhancement patterns were evaluated in real time. Results. Hypoechoic tumors of fatty liver showed posterior echo enhancement, including 71.4% (25 of 35) of hemangiomas, 73.3% (11 of 15) of metastases, and 50.0% (3 of 6) of hepatocellular carcinomas (HCCs) on conventional ultrasonography. During the early arterial phase, 62.5% (5 of 8) of focal nodular hyperplasia lesions showed a central spoked wheel enhancement pattern, whereas the remaining 37.5% (3 of 8) showed eccentric spoked wheel enhancement. During the arterial phase, 97.1% (34 of 35) of hemangiomas showed peripheral enhancement and centripetal fill-in, including ringlike peripheral enhancement (12 of 35), small nodular peripheral enhancement (19 of 35), and massive irregular peripheral enhancement (3 of 35). In total, 76.5% (26 of 34) of hemangiomas were completely filled in. All HCCs showed complete enhancement from 9 to 24 seconds during the arterial phase and began to wash out from 21 to 114 seconds. During the arterial phase, 40.0% (6 of 15) of metastases showed ringlike enhancement; 26.7% (4 of 15) showed slight hyperenhancement; 13.3% (2 of 15) showed hyperenhancement quickly; and the remaining 20.0% (3 of 15) showed heterogeneous hyperenhancement. All metastatic tumors began to wash out from 25 to 40 seconds. In total, 92.2% (59 of 64) of focal hypoechoic tumors of fatty liver were diagnosed as the correct pathologic type with CEUS. CONCLUSIONS: With CEUS, characterization of hypoechoic tumors of fatty liver is greatly improved.

[Local cellular immune response induced by ultrasound-guided tumor bed superantigen injection after percutaneous microwave coagulation therapy for liver cancer].

OBJECTIVE: To investigate the local cellular immune response after injection of superantigen, the highly agglutinative staphylococin (HAS), into the tumor bed after ultrasound-guided percutaneous microwave coagulation therapy (PMCT) in the liver cancer patients. METHODS: Ninety-two patients with pathologically proven primary liver cancer were divided into two groups: 45 in group A were treated by PMCT alone and 47 in the group B by combined with ultrasound-guided percutaneous injection of highly agglutinative staphylococin (HAS). Before and after PMCT and HAS treatment, the patients underwent ultrasound-guided percutaneous biopsy from the tumor bed and the samples were examined by pathology and immunohistochemistry. The infiltration of CD3+, CD4+, CD57+ and CD68+ lymphocytes in treatment zone was compared between the two groups. Moreover, the infiltrating immunocytes were observed by transmission electron microscopy. RESULTS: One week after HAS injection, the densities of CD3+, CD4+, CD57+ and CD68+ cells in the group B were 54.50 +/- 18.44, 38.14 +/- 12.44, 33.38 +/- 10.79 and 45.56 +/- 16.53, respectively. All the above mentioned parameters increased significantly in varying degrees compared with that before PMCT or HAS injection (P < 0.05). Four weeks after HAS injection, the density of CD3+, CD4+, CD57+ and CD68+ cells in the group B were 32.67 +/- 10.42, 23.43 +/- 6.99, 18.63 +/- 7.89 and 30.01 +/- 11.05, respectively, still significantly higher than those before PMCT (P < 0.05). Five weeks after PMCT and HAS injection, the densities of CD3+, CD4+, CD57+ and CD68+ cells in the group B were 54.50 +/- 18.44, 38.14 +/- 12.44, 33.38 +/- 10.79 and 45.56 +/- 16.53, versus 32.03 +/- 8.11, 15.67 +/- 8.32, 15.23 +/- 8.26 and 29.67 +/- 11.98 in the group A, respectively, still with a significant difference between the two groups (P < 0.05). A lot of lysosomes, endoplasmic reticulum and mitochondria in the immune cells after injection of HAS were observed by transmission electron microscopy. CONCLUSION: The local cellular immunity in liver cancer treatment area can be significantly improved by ultrasound-guided injection of highly agglutinative staphylococin after percutaneous microwave coagulation therapy.

Prognostic factors and recurrence of small hepatocellular carcinoma after hepatic resection or microwave ablation: a retrospective study.

PURPOSE: This study aims to analyze the long-term therapeutic results of small HCC less than 5 cm in diameter after microwave ablation (MA) or hepatic resection (HR) and choose factors that could predict metastasis and recurrence of small HCC. MATERIALS AND METHODS: The metastasis and recurrence of 194 patients with one HCC less than 5 cm in diameter who underwent curative HR or MA between January 1995 and December 2004 were reviewed retrospectively; immunohistochemistry was used to analyze the expressions of VEGF, bFGF, and c-Met in HCC tissues. Posttreatment prognostic factors were evaluated by multivariate analysis using Cox's proportional hazards model. The variables included the expressions of these three proteins in HCC tissues, the clinical and pathologic characteristics of the patients. RESULTS: The retrospective study showed that 1-, 3-, and 5-year disease-free survival rates of patients with single HCC of diameter <5 cm were 71.3, 57.0 and 32.5%, respectively. Furthermore, 1-, 3-, and 5-year disease-free survival rates of the patients in MA group and resection group were 72.8, 54.0 and 33.0%; 68.5, 60.0, and 25.6%, respectively. There was no significant difference in disease-free survival rates between these two groups. The result of multivariate analysis showed that differentiation degree of HCC and the expressions of VEGF and c-Met in HCC tissues could be as the independent prognostic factors affecting metastasis and recurrence in patients with small HCC, whereas the methods of therapy had no impact on prognosis. CONCLUSIONS: The metastasis and recurrence rate after MA is similar to that after HR, and the methods of therapy do not affect the prognosis of small HCC. The metastasis and recurrence of patients with small HCC will differ depending on tumor differentiation, expressions of VEGF and c-Met in HCC tissues.

Evaluation of focal fatty infiltration of the liver using color Doppler and contrast-enhanced sonography.

PURPOSE: To investigate the vascular characteristics of focal fatty infiltration (FFI) in the liver using color Doppler sonography (CDUS) and contrast-enhanced sonography (CEUS). METHODS: We prospectively examined 25 areas of FFI of the liver in 20 patients via conventional gray-scale sonography, CDUS, and CEUS. Cadence contrast pulse sequencing and the contrast agent SonoVue were used for CEUS examination. CEUS criteria for diagnosis of FFI were isoenhancement or hypoenhancement in the arterial phase and homogeneous isoenhancement in the portal and late phases. RESULTS: CDUS revealed a draining vein in 4 of 9 (44%) lesions in the hepatic hilum, whereas CEUS revealed a draining vein in 8 (89%) lesions. A vein was associated with the 2 lesions located at the edge of segment II on both CDUS and CEUS. Blood flow was seen on both CDUS and CEUS in the 2 lesions adjacent to the falciform ligament. In one patient, CDUS and CEUS revealed the mid-hepatic vein coursing between 2 FFIs. In the arterial phase of CEUS, the lesions were hypoenhancing in 44% (11/25), iso-enhancing in 44% (11/25), and hyperenhancing in 12% (3/25). In the portal phase and in the late vascular phase, all 25 lesions (100%) were iso-enhancing. Sensitivity of combined sonography and CDUS in the diagnosis of FFI was 44%, and overall accuracy was 81%. The sensitivity of CEUS in the diagnosis of FFI was 88%, and its overall accuracy was 96%. CONCLUSION: FFI in the porta hepatis is correlated with aberrant venous drainage. FFI around the falciform ligament may be related to divergence of the portal vein or unusual blood supply. In the arterial phase of CEUS, FFI lesions were iso-enhancing as often as they were hypoenhancing.

[Influence of microwave ablation and surgical resection of small primary hepatocellular carcinoma on hematogenous dissemination of tumor cells].

OBJECTIVE: To study the influence of percutaneous microwave ablation (PMA) and surgical resection for patients with small primary hepatocellular carcinoma (PHC) on dissemination of tumor cells in peripheral blood determined by AFP mRNA. METHODS: Forty patients with small PHC (The maximal diameter < or = 5 cm) confirmed histologically were included in this study. All the patients had single tumor nodule only without metastasis. Of the 40 patients, 19 were treated by PMA and 21 by surgical resection. Blood samples were collected and tested immediately before treatment, 30 min after the mass ablated/resected, 1 d and 7 d later by RTD-Nested-RT-PCR for AFP mRNA. The CD3, CD4, CD8 and CD4/CD8 in blood, and hepatic function were tested at the same time points as well. RESULTS: After treatment, ALT and AST in peripheral blood increased in both groups, but more intensely in the surgical group. The CD3, CD4 and CD4/CD8 in peripheral blood decreased at 30 min, 1 day and 7 days after surgical resection, and the lowest value was at 30 min after surgery. The immune function was kept at the same level as pre-treatment in the PMA group. AFP mRNA copies in blood could be detected in 27 of 40 patients (67.5%) in two groups before treatment, and the copy number was increased after treatment. There was no significant difference between the two groups. The patients were followed up for 1 - 16 months. AFP mRNA copies in blood could be detected persistently in the 4 patients with extrahepatic metastasis or liver recurrence. CONCLUSION: Surgical resection and microwave ablation may cause PHC cells dissemination into the blood circulation in patients with small PHC, and there was no difference between the two treatment groups. The cellular immune function in peripheral blood is decreased after surgical resection, but is maintained at the same level as pre-treatment in the PMA group. The impairment of liver function is less severe after PMA treatment than surgical resection. PMA may provide certain value for clinical management of small hepatocellular carcinoma.

[Long-term results of percutaneous sonographically-guided microwave ablation therapy of early-stage hepatocellular carcinoma].

OBJECTIVE: To evaluate the long-term results of percutaneous microwave coagulation therapy in the treatment of early hepatocellular carcinoma. METHODS: From May 1994 to June 2004, a total of 216 patients with 275 nodules of hepatocellular carcinoma whose diameter

[Evaluation of long-term therapeutic effects of ultrasound-guided percutaneous microwave ablation of liver metastases].

OBJECTIVE: To explore therapeutic results of local microwave ablation for hepatic metastasis and the factors influencing the survival after percutaneous microwave ablation therapy. METHODS: From July 1995 to June 2005 128 patients with 282 hepatic metastases nodules with the primary diseases of upper gastrointestinal tumor (n = 26), colorectal tumor (n = 44), breast carcinoma (n = 19), pulmonary carcinoma (n = 15), and malignant tumor in other part of the body (n = 24), underwent percutaneous microwave ablation therapy and were followed up for 29.7 +/- 19.9 months (1 - 103 months). The largest diameter of the metastatic nodules was 3.5 +/- 1.6 cm (0.7 - 8.6 cm). Sixty-four cases had 140 nodules 3.0 cm in diameter. Forty-seven patients had single nodule, 44 patients had 2 nodules, and 93 patients had 3 or more nodules. Fifty-seven patients had tumor of low differentiation, 53 had tumor of middle differentiation, and 18 had highly differentiated tumors. Kaplan-Meier method was used to calculate the cumulative survival rate. Statistical comparison of the effects of potential predictive factors on survival rate was performed using log-rank analysis. Multivariate analysis of the survival rates was performed by using Cox's proportional hazard model. RESULTS: The 1, 2, 3, 4, and 5-year cumulative survival rates of all 128 patients were 90.88%, 73.84%, 51.09%, 36.14%, and 31.89% respectively. Univariate analysis showed that tumor size (P = 0.028), tumor differentiation (P = 0.026) and local recurrence or new metastases (P < 0.001) significantly affected the survival. Multivariate analysis revealed that tumor size (P = 0.035), recurrence or new metastases (P = 0.001) and tumor differentiation (P = 0.038) each had a significant effect on survival. CONCLUSION: There is a significantly higher probability of long-term survival for patients with well-differentiated tumors 3.0 cm or less in diameter and without recurrence or new metastasis after percutaneous microwave ablation.

Construction and clinical significance of a predictive system for prognosis of hepatocellular carcinoma.

AIM: The aims of this study were to explore individualized treatment method for hepatocellular carcinoma (HCC) patients whose maximum tumor size was less than 5 cm to improve prognosis and survival quality. METHODS: Thirty cases of primary HCC patients undergoing tumor resection were retrospectively analyzed (resection group). All the tumors were proved as primary HCC with pathologic examination. The patients were divided into two groups according to follow-up results: group A, with tumor recurrence within 1 year after resection; group B, without tumor recurrence within 1 year. Immunohistochemical stainings were performed using 11 kinds of monoclonal antibodies (AFP, c-erbB2, c-met, c-myc, HBsAg, HCV, Ki-67, MMP-2, nm23-H1, P53, and VEGF), and expressing intensities were quantitatively analyzed. Regression equation using factors affecting prognosis of HCC was constructed with binary logistic method. HCC patients undergoing percutaneous microwave coagulation therapy (PMCT) were also retrospectively analyzed (PMCT group). Immunohistochemical stainings of tumor biopsy samples were performed with molecules related to HCC prognosis, staining intensities were quantitatively analyzed, coincidence rate of prediction was calculated. RESULTS: In resection group, the expressing intensities of c-myc, Ki-67, MMP-2 and VEGF in cancer tissue in group A were significantly higher than those in group B (t = 2.97, P = 0.01; t = 2.42, P = 0.03<0.05; t = 2.57, P = 0.02<0.05; t = 3.43, P = 0.004<0.01, respectively); the expressing intensities of 11 kinds of detected molecules in para-cancer tissue in groups A and B were not significantly different (P>0.05). The regression equation predicting prognosis of HCC is as follows: P(1) = 1/[1+e(-(3.663-0.412mycc-2.187Ki-67c-0.397vegfc))]. It demonstrates that prognosis of HCC in resection group was related with c-myc, Ki-67 and VEGF expressing intensity in cancer tissue. In PMCT group, the expressing intensities of c-myc, Ki-67 and VEGF in cancer tissue in group A were significantly higher than those in group B (t = 4.57, P = 0.000<0.01; t = 2.08, P = 0.04<0.05; t = 2.38, P = 0.02<0.05, respectively); the expressing intensities of c-myc, Ki-67 and VEGF in para-cancer tissue in groups A and B were not significantly different (P>0.05). The coincidence rate of patients undergoing PMCT in group A was 88.00% (22/25), in group B 68.75% (11/16), the total coincidence rate was 80.49% (33/41). CONCLUSION: The regression equation is accurate and feasible and could be used for predicting prognosis of HCC, it helps to select treatment method (resection or PMCT) for HCC patients to realize individualized treatment to improve prognosis.

Effect of c-myc, Ki-67, MMP-2 and VEGF expression on prognosis of hepatocellular carcinoma patients undergoing tumor resection.

AIM: To explore the effect of c-myc, Ki-67, MMP-2 and VEGF expression on prognosis of hepatocellular carcinoma (HCC) patients undergoing tumor resection. METHODS: Primary HCC patients underwent tumor resection were retrospectively analysed. The maximum size of the tumor was less than 5 cm, there was only one nodule in each patient. No chemoembolization was performed before resection. They were followed up after resection, and the time of recurrence was recorded. They were divided into 2 groups: group A (15 cases): tumor recurrence within 1 year after tumor resection, and group B (15 cases): with or without tumor recurrence 2 years after tumor resection. Pathological slices were made with tumor wax-sample. Immunohistochemistry staining was performed with c-myc, Ki-67, MMP-2 and VEGF monoclonal antibodies. Staining intensity was quantitatively analysed with a pathological diagram-writing analyzing system. The expressing intensity differences of stained molecules in cancer tissue and para-cancer were analysed. RESULTS: c-myc, Ki-67, MMP-2 and VEGF expressing intensities in cancer tissue in group A were higher than those in group B (P values were 0.010, 0.030, 0.022 and 0.004, respectively), but they were not significantly different in para-cancer tissue in groups A and B (P values were 0.334, 0.343, 0.334 and 0.334, respectively). CONCLUSION: The expression of c-myc, Ki-67, MMP-2 and VEGF in cancer tissue is related to the recurrence of HCC after tumor resection.

[Effect of hepatic artery embolization on the microwave coagulated area].

OBJECTIVE: To study the effect of hepatic artery embolization on the microwave coagulated area, an in vivo animal experiment. METHODS: Twenty-four suitable hepatic lobes of ten dogs were divided into two groups: microwave coagulation alone 12 lobes (control group) and hepatic artery occlusion with iodized oil and gelatin sponge particles followed by microwave coagulation 12 (experiment group). Microwave coagulation was delivered with an output of 50 W for 300 or 400 seconds with thermal needles introduced parallel to and 5 approximately 20 mm from the puncture needle. After sacrifice of the dogs, their hepatic lobes were sectioned along the puncture line. Then, the appearance and size of the coagulated area were recorded. The tissue specimens were fixed in formalin for light microscopic evaluation. RESULTS: A decline in temperature gradient was detected from the center to the periphery of the affected tissue after the application of microwave coagulation, which was sharper in the control group than in the experimental group. Single polar microwave coagulation at 50 W for 300 seconds produced a necrotic volume of 25 approximately 33 mm in longitudinal diameter and 13 approximately 22 mm in transverse diameter in control group, 33 approximately 44 mm and 24 approximately 32 mm in the experimental group. The coagulation area was slightly bigger when the duration of coagulation was 400 seconds than 300 seconds, without significant difference. CONCLUSION: Hepatic artery occlusion, inhibiting the heat loss caused by hepatic arterial blood flow, is able to significantly enlarge the necrotic volume of microwave coagulation.

[Ultrasound-guided percutaneous microwave coagulation therapy for hepatic metastases].

OBJECTIVE: To analyze the therapeutic results and prognostic factors of hepatic metastases treated by ultrasound-guided percutaneous microwave coagulation. METHODS: Seventy-four patients with 149 nodules of hepatic metastases were given percutaneous microwave coagulation therapy. The longest diameter of the metastatic nodule ranged from 0.7 - 6.8 cm (mean, 3.1 +/- 1.8 cm). The cumulative survival rate was analyzed by Kaplan-Meier method and the difference between groups was compared with log-rank test. Cox proportional hazard model was used to determine potential prognostic variables. RESULTS: The follow-up period for the 74 patients was 5 - 83 months (mean, 25.1 +/- 11.4 months). The overall 1-, 3-, and 5-year cumulative survival rates were 91.4%, 46.4% and 29.0%, respectively. The log-rank test showed that number of metastases, tumor size, tumor cell differentiation and local recurrence or new metastases were statistically significant prognostic factors; while age, sex and site of primary tumors were not significant prognostic factors. Multivariate analysis revealed that tumor differentiation, number of metastases and recurrence or new metastases were statistically significant prognostic factors. CONCLUSION: Ultrasound-guided percutaneous microwave coagulation therapy for hepatic metastases in patients with single metastasis, well-differentiated tumor, and without recurrence and new metastases could achieve long-term survival.

[The influence of c-Myc, Ki-67, MMP-2 and VEGF expression on the prognosis of hepatocellular carcinoma patients with tumor resection].

OBJECTIVES: To explore the effect of c-Myc, Ki-67, MMP-2 and VEGF expression on prognosis of hepatocellular carcinoma (HCC) patients who had tumor resection. METHODS: Primary HCC patients who underwent tumor resection were retrospectively analyzed. The maximum size of their mononodular tumors was less than 5 cm, and no intrahepatic arterial chemotherapy was performed before the resections. They were followed up after resection and the time of recurrence was recorded. They were divided into 2 groups: group A (15 cases): tumor recurred within 1 year after tumor resection; group B (15 cases): with tumor recurrence after 2 years or without it. Paraffin sections of the tumors were remade from their old blocks. Immunohistochemistry stainings were performed with c-Myc, Ki-67, MMP-2 and VEGF monoclonal antibodies. Staining intensity of the tumor and paracancer tissues was quantitatively analyzed. RESULTS: c-Myc, Ki-67, MMP-2 and VEGF expressing intensities in cancer tissues in group A were higher than those in group B, and their expressed intensities in paracancer tissue in group A and B were not significantly different. CONCLUSION: The expressions of c-Myc, Ki-67, MMP-2 and VEGF in cancer tissues of the patients are related to the recurrence of their HCC after tumor resection.

Characterization of primary hepatic carcinosarcoma by contrast-enhanced ultrasonography: a case report.

Primary hepatic carcinosarcoma is a rare tumor and is comprised of a mixture of carcinomatous and sarcomatous elements. We present a case of primary carcinosarcoma of the liver in a 59-year-old woman, which was confirmed by pathology following surgical resection. Using contrast-enhanced ultrasonography, the tumor showed peripheral nodular hyperenhancement in the arterial phase with two feeding arterial vessels and a large internal non-enhancing portion in the center. The peripheral nodular portion of the tumor showed hypoenhancement in the later phase.

Predicting early intrahepatic recurrence of hepatocellular carcinoma after microwave ablation using SELDI-TOF proteomic signature.

BACKGROUND/AIMS: Despite great progress in the treatment of hepatocellular carcinoma (HCC) over the last-decade, intrahepatic recurrence is still the most frequent serious adverse event after all the treatments including microwave ablation. This study aimed to predict early recurrence of HCC after microwave ablation using serum proteomic signature. METHODS: After curative microwave ablation of HCC, 86 patients were followed-up for 1 year. Serum samples were collected before microwave ablation. The mass spectra of proteins were generated using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). Serum samples from 50 patients were randomly selected as a training set and for biomarkers discovery and model development. The remaining serum samples were categorized for validation of the algorithm. RESULTS: According to preablation serum protein profiling obtained from the 50 HCC samples in the training set, nine significant differentially-expressed proteins were detected in the serum samples between recurrent and non-recurrent patients. Decision classification tree combined with three candidate proteins with m/z values of 7787, 6858 and 6646 was produced using Biomarker Patterns Software with sensitivity of 85.7% and specificity of 88.9% in the training set. When the SELDI marker pattern was tested with the blinded testing set, it yielded a sensitivity of 80.0%, a specificity of 88.5% and a positive predictive value of 86.1%. CONCLUSIONS: Differentially-expressed protein peaks in preablation serum screened by SELDI are associated with prognosis of HCC. The decision classification tree is a potential tool in predicting early intrahepatic recurrence in HCC patients after microwave ablation.

Practice guidelines for ultrasound-guided percutaneous microwave ablation for hepatic malignancy.

Primary liver cancer and liver metastases are among the most frequent malignancies worldwide, with an increasing number of new cases and deaths every year. Traditional surgery is only suitable for a limited proportion of patients and imaging-guided percutaneous thermal ablation has achieved optimistic results for management of hepatic malignancy. This synopsis outlines the first clinical practice guidelines for ultrasound-guided percutaneous microwave ablation therapy for hepatic malignancy, which was created by a joint task force of the Society of Chinese Interventional Ultrasound. The guidelines aim at standardizing the microwave ablation procedure and therapeutic efficacy assessment, as well as proposing the criteria for the treatment candidates.

Microwave ablation assisted by a real-time virtual navigation system for hepatocellular carcinoma undetectable by conventional ultrasonography.

OBJECTIVES: To evaluate the efficiency and feasibility of microwave (MW) ablation assisted by a real-time virtual navigation system for hepatocellular carcinoma (HCC) undetectable by conventional ultrasonography. METHODS: 18 patients with 18 HCC nodules (undetectable on conventional US but detectable by intravenous contrast-enhanced CT or MRI) were enrolled in this study. Before MW ablation, US images and MRI or CT images were synchronized using the internal markers at the best timing of the inspiration. Thereafter, MW ablation was performed under real-time virtual navigation system guidance. Therapeutic efficacy was assessed by the result of contrast-enhanced imagings after the treatment. RESULTS: The target HCC nodules could be detected with fusion images in all patients. The time required for image fusion was 8-30 min (mean, 13.3 ± 5.7 min). 17 nodules were successfully ablated according to the contrast enhanced imagings 1 month after ablation. The technique effectiveness rate was 94.44% (17/18). The follow-up time was 3-12 months (median, 6 months) in our study. No severe complications occurred. No local recurrence was observed in any patients. CONCLUSIONS: MW ablation assisted by a real-time virtual navigation system is a feasible and efficient treatment of patients with HCC undetectable by conventional ultrasonography.

Needle track seeding after percutaneous microwave ablation of malignant liver tumors under ultrasound guidance: analysis of 14-year experience with 1462 patients at a single center.

OBJECTIVE: To determine the incidence and risk factors associated with needle tract seeding after percutaneous microwave ablation (MWA) of liver cancer under ultrasound guidance. MATERIALS AND METHODS: Over a 14-year period, a total of 1462 patients with 2530 malignant nodules were treated by MWA. The influence of age, sex, Child-pugh classification, tumor size, tumor position, previous biopsy, insertion number and antenna type on the risk of neoplastic seeding was assessed. The survival of seeding patients after the MWA was analyzed. RESULTS: Eleven patients with 12 nodules (0.47% per tumor, 0.75% per patient) were identified with needle tract seeding with an interval time of 6-37 (median 10) months after MWA. The mean size of the seeding nodule was 2.3 ± 0.7 cm (from 1.3 to 3.9 cm). Only previous biopsy was significantly associated with neoplastic seeding (P=0.02). All the seeding lesions were successfully treated by resection, MWA, radiation or high intensity focus ultrasound. The median survival period of the 11 patients after the MWA was 36.0 months. The cumulative survival rates of the 11 patients after the MWA at 1-, 2-, 3-, 4- and 5-year were 90.9%, 72.7%, 62.3%, 31.2% and 15.6%, respectively. CONCLUSION: The results showed that the neoplastic seeding was a low risk complication of percutaneous MWA of liver cancer and was considered acceptable in general.

Analysis of focal spared areas in fatty liver using color Doppler imaging and contrast-enhanced microvessel display sonography.

OBJECTIVE: The purpose of this study was to investigate whether focal fatty sparing (FFS) formation in the liver relates to aberrant blood flow. METHODS: Sixty-three FFSs of the liver in 52 patients were examined by color Doppler flow imaging and contrast-enhanced microvessel display sonography. The 63 FFSs included 16 FFSs in the porta hepatis, 14 FFSs around the gallbladder fossa, and 33 other FFSs. The control group included patients with a diagnosis of fatty liver but no FFSs or focal lesions near the porta hepatis. RESULTS: Fourteen of 16 FFSs in the porta hepatis showed venous blood toward those areas that were differentiated from the portal and hepatic veins. Focal fatty sparings in the hilus hepatis correlated with aberrant veins, having a statistical significance compared with the control group (P < .0001). Seven of 14 FFSs around the gallbladder fossa contained blood vessels, 5 of them veins and the remaining 2 arteries. Two FFSs were located around hemangiomas. Three FFSs were located around maldeveloped vessels. CONCLUSIONS: The blood supply to an FFS in the porta hepatis may be correlated with aberrant veins. Focal fatty sparings around the gallbladder fossa may be associated with aberrant blood flow.

Gray scale contrast enhancement and quantification in different positions of rabbit liver.

OBJECTIVE: The purpose of this study was to evaluate the difference between central and ventral peripheral positions and the difference between left and right lobes in rabbit liver with gray scale contrast enhancement. METHODS: An in vivo model of perfusion was studied with a sulfur hexafluoride contrast agent and low-mechanical-index, real-time, gray scale harmonic imaging. The contrast agent (0.1 mL/kg body weight) was applied respectively in 10 rabbits by intravenous bolus injection. The time-intensity curve was used to obtain flow-related parameters such as time to enhancement (ET), time to peak intensity (PIT), peak signal intensity (PSI), enhancement duration (ED), and area under the curve (AUC). RESULTS: There was a significant difference in parameters of the time-intensity curve between central and peripheral ventral positions of liver parenchyma (P < .05), except for the ED in the left liver. The ET and PIT were earlier, the PSI higher, the ED longer, and the AUC larger in the central position of parenchyma than in the peripheral position. In addition, the ET and PIT were earlier, the PSI higher, the ED longer, and the AUC larger in the right lobe of liver parenchyma than in the left lobe. There was a significant difference in parameters of the time-intensity curve between the left and right lobes of liver parenchyma (P < .05), except for the ET of the peripheral position. CONCLUSIONS: Flow parameters are different between central and ventral peripheral positions and between left and right lobes of hepatic parenchyma.