Objective. To investigate the usefulness of three-dimensional sonography in procedures of ablation for liver cancers. Methods. Two- and three-dimensional sonography were used in guiding 18 chemical ablation procedures (7 with boiling carboplatin ablation and 11 with ethanol ablation) and 21 radio frequency ablation procedures for treatment of liver cancers. The applicator conspicuity depicted by the 2 imaging modalities, the confidence level of the operator in determining the position relationship between the applicator and the tumor using the 2 imaging modalities, and the alteration of ablation procedures were evaluated. Results. Three-dimensional sonography was better than two-dimensional sonography in delineation of multitined, expandable electrode tips in radio frequency ablation procedures, whereas the 2 modalities were equal in depicting percutaneous transhepatic cholangiography needle tips in chemical ablation procedures. Three-dimensional sonography significantly enhanced the confidence level in defining the spatial relationship between applicator and tumor in comparison with two-dimensional sonography (P<0.01). Suboptimal applicator placement was detected in 6 (15%) of 39 ablation procedures on three-dimensional sonography: 3 chemical ablation procedures and 3 radio frequency ablation procedures. Applicator adjustment was required in 3 chemical ablation procedures. In 15 (38%) of 39 procedures, three-dimensional sonography allowed better visualization of the position relationship between the applicator and adjacent critical structures. Conclusions. Three-dimensional sonography was useful in delineation of expandable radio frequency electrodes, improvement of operator confidence level, determination of applicator placement, and visualization of the position relationship between the applicator and adjacent critical structures during procedures of liver cancer ablation under image guidance.

PURPOSE: To evaluate the use of percutaneous microwave coagulation therapy for hepatocellular carcinoma, particularly with tumor nodules larger than 2cm in diameter. MATERIALS AND METHODS: Fifty patients with 107 hepatocellular carcinoma nodules (mean diameter, 2.7cm 6 1.5 [SD]; range, 0.8-6.4 cm) were treated with percutaneous microwave coagulation therapy. Single electrode insertion was used in 46 nodules (43.0%) 2cm or smaller, whereas multiple electrode insertion was applied in 61 (57.0%) nodules larger than 2cm. RESULTS: At 1 month after therapy, technical success for tumors 2cm or smaller and those larger than 2cm was achieved in 45 (98%) and 56 (92%) nodules, respectively. After follow-up of 9 months or longer, local recurrence was found in one nodule (2%) sized 1.8cm and in five nodules (8%) larger than 2cm. At the end of the study, 26 (52%) of 50 patients were free of disease, and disease-free survival rates at 1 and 2 years were 55% and 41%, respectively. Overall survival rates at 1, 2, and 3 years were 96%, 83%, and 73%, respectively. CONCLUSION: Percutaneous microwave coagulation therapy is an effective and safe therapeutic modality for hepatocellular carcinoma. A multiple electrode insertion technique can enhance the effectiveness of this therapy in tumors 6cm or smaller.

Objective. To investigate the potential clinical usefulness of three-dimensional gray scale volume rendering in the liver. Methods. Sixty-two patients were enrolled in the study and categorized into 2 groups: group I with ascites and group II without. Two types of volume-rendering modes, i.e., surface and transparent, were used to obtain the three-dimensional images. The data were reviewed to identify the differences between two- and three-dimensional images of the liver in each subject. Results. In group I, three-dimensional sonography was superior to two-dimensional sonography in terms of surface features, edges, overall three-dimensional impression, image clarity, and structural relationships. However, it seemed that three-dimensional sonography in the surface mode was inferior to twodimensional sonography in showing intrahepatic structures, because it had decreased resolution. In group II, three-dimensional sonography was superior to two-dimensional sonography with respect to the continuity of intrahepatic vessels, overall three-dimensional impression of the vessels, image clarity, and the relationship between lesions and neighboring vessels. However, the resolution of the lesions was decreased in 7 cases of hepatocellular carcinoma. Conclusions. Our experience suggests that three-dimensional gray scale volume rendering of the liver provides more diagnostic information than two-dimensional sonography; however, further studies are needed to evaluate its clinical importance.

Objective. To compare three-dimensional sonography with two-dimensional sonography for diagnosis of gallbladder diseases. Methods. Sixty-three patients with gallbladder diseases were examined with two- and three-dimensional sonography. The morphologic features presented on both modalities were analyzed, and the diagnostic accuracies of both modalities were evaluated and compared. Results. Both two-and three-dimensional sonography facilitated correct diagnosis in all patients with gallstones. Three-dimensional sonography had no influence on the diagnosis of gallstones compared with two-dimensional sonography. Three-dimensional sonography showed the granular surfaces in 18 (81.8%) of 22 cases of polypoid lesions and the pedunculated fundus in 19 (86.4%) of 22, whereas two-dimensional sonography displayed them in 10 (45.5%) and 3 (13.6%) of 22, respectively (P<0.05 and. 001). Three- and two-dimensional sonography made correct differential diagnoses between nonneoplastic and neoplastic polyps in 20 (90.9%) and 12 (54.5%) of 22, respectively (P<0.05). In gallbladder carcinoma, both three- and two-dimensional sonography accurately showed all the associated gallstones and intrahepatic bile duct dilatation. Two-dimensional sonography could not correctly define the locations of the lesions in 2 (28.6%) and tumor extension in 1 (14.3%) of 7 cases with pathologically proved gallbladder cancer, whereas three-dimensional sonography improved the diagnosis in these cases. Conclusions. Three-dimensional sonography adds no advantages for diagnosis of gallstones compared with two-dimensional sonography, but it is better than two-dimensional sonography for differential diagnosis of gallbladder polyps and may improve the localization and staging for gallbladder carcinoma; however, additional studies are needed for further determination.

F ablation in the last 4 years. The applicators were introduced into the tumours under conscious analgesic sedation by intravenous administration of fentanyl citrate and droperidol and local anaesthesia in both thermal ablation procedures. The patients were then followed up with contrast-enhanced computed tomography (CT) to evaluate treatment response. Survival was analysed using the Kaplan-Meier method. RESULTS: Complete ablation was obtained in 92.6% (176/190) nodules. The complete ablation rates were 94.6% (106/112) in microwave ablation and 89.7% (70/78) in RF ablation. The complete ablation rates in tumours # 2.0, 2.1-3.9 and $ 4.0 cm were 93.1, 93.8 and 86.4%, respectively. Local recurrence was found in 9.5% nodules and the rates in tumours # 2.0, 2.1–3.9 and $ 4.0 cm in diameter were 3.4, 9.9 and 31.8%, respectively. In the follow-up period, 7.1% nodules ablated by microwave and 12.8% by RF presented local recurrence. The 1, 2 and 3-year distant recurrence-free survivals were 47.2, 34.9 and 31.0%, respectively. Estimated mean survival was 32 months, and 1, 2 and 3-year cumulative survivals were 75.6, 58.5, and 50.0%, respectively. One and 2 years survivals of Child–Pugh class A, B and C patients were 83.8 and 70.4%, 78.2 and 53.2%, 36.3 and 27.3%, respectively. CONCLUSION: Thermal ablation therapy by means of microwave and RF energy application is an effective and safe therapeutic technique for hepatocellular carcinoma. Large tumours can be completely ablated, but have a significantly higher risk of local recurrence at follow-up.

The usefulness of a new three-dimensional ultrasound (3DUS) volumetric system developed recently was validated in volume measurement of liver tumor in the present study. The system was used to estimate the volumes of 22 regular phantoms, 25 irregular phantoms and 37 liver tumors from 33 patients. The results showed that the consumed time of measurement with the system ranged from 1 to 15min, depending on different rotation angles. The measured volumes at different rotation angles all significantly correlated with the true volumes and there were no significant differences among measured volumes at different angles. The measurement error of 3DUS was 0.3%±3.3% in regular phantoms, －0.4%±3.7% in irregular phantoms and 0.9%±11.3% in liver tumors, respectively, as compared with－5.3±9.4%, 13.6±28.0% and 15.3±37.3% for two-dimensional ultrasound, respectively (all p<0.05). The volume estimation with 3DUS also had significant intraobserver and interobserver reproducibility both in vitro and in vivo. It can be concluded that the new system that we used can greatly reduce the consumed time and manual labor for volume measurement with high accuracy and reproducibility. 3DUS volumetry using the new system is more acceptable and valuable in clinical practice and is expected to be useful for evaluation of the efficacy of tumor therapy in situ in patients with hepatic tumors.