Hepatectomy is a complicated operative procedure because of its anatomical complexity, vascular variability, and impaired hepatic function due to associated hepatitis or cirrhosis. Thus preoperative detailed topography and precise liver resection volume measurements should be obtained for a curative hepatectomy. The aim of this study was to assess the feasibility and accuracy of a novel three-dimensional (3D) virtual hepatectomy simulation software in patients who underwent liver resection or living donor liver transplantation. We developed the hepatectomy simulation software, which was programmed to analyze detailed 3D vascular structure and to predict liver resection volume and margins. In 72 patients receiving hepatectomy, the predicted liver resection volumes and margins revealed a significant correlation with the actual value with a mean difference of 9.3 mL (P < .0001) and 1.6 mm (P < .01), respectively. The drainage area by hepatic veins was quantified to achieve reconstruction of the corresponding venous branch. In conclusion, this hepatectomy simulation software reliably predicted an accurate liver resection volume, the cancer-free margin, and the drainage volume of hepatic vein branches. This software may promote curative hepatectomy and may be used for other interventional therapies in the treatment of liver disease. (HEPATOLOGY 2005;41:1297-1304

We developed a cone-beam computed tomography (CBCT) system equipped with a large flat-panel detector. Data obtained by 200 degree rotation imaging are reconstructed by means of CBCT to generate three-dimensional images. We report the use of CBCT angiography using CBCT in 10 patients with 8 liver malignancies and 2 hypersplenisms during abdominal interventional procedures. CBCT was very useful for interventional radiologists to confirm a perfusion area of the artery catheter wedged on CT by injection of contrast media through the catheter tip, although the image quality was slightly degraded, scoring as 2.60 on average by streak artifacts. CBCT is space-saving because it does not require a CT system with a gantry, and it is also time-saving because it does not require the transfer of patients.

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The efferent vessel of hepatocellular carcinoma (HCC) and the mechanism and pathogenesis of the high frequency of intrahepatic metastasis in HCC has not yet been clarified. Three hundred ninety-three resected specimens of HCC were examined for tumor thrombosis in the portal vein and the hepatic vein: 231 tumors <-5 cm in diameter were examined for the relationship between mode of tumor spread and tumor size. Efferent vessels in HCC were identified by direct injection of radiopaque material into the tumor in 23 resected liver specimens and by percutaneous infusion of radiopaque media into tumor nodules in 8 patients. The mode of tumor spread in HCC progressed from capsular invasion to extracapsular invasion, then to vascular invasion, and finally to intrahepatic metastasis. There was a strong statistical correlation between the presence of intrahepatic metastasis and portal vein thrombosis (p<0.05, R=0.998). Radiopaque material injected directly into 23 resected tumors entered only the portal vein in 17 tumors and into both the portal and hepatic veins in 6 tumors. In all 8 patients with unresectable lesions, radiopaque media injected percutaneously into tumor nodules flowed only into the portal vein. These findings suggest that intrahepatic invasion by HCC may occur through the portal vein as an efferent tumor vessel.

The RVS with novel automatic registration system can provide quick and easy registration and acceptable accuracy, which can promote the usage of IOUS.

A cone-beam lowers the X-ray exposure level and the contrast material dose used compared to those for the conventional angiography-computed tomography (angio-CT) technique. Herein we present a patient with a metastatic skull base bone tumor in which the subtraction image of cone-beam CT with a flat panel detector was useful for evaluating the vascular supply during superselective intraarterial chemotherapy. Although the image quality of cone-beam CT is poorer than that of conventional angio-CT, the cone-beam CT system is sufficient for clinical use.

We examined the low contrast resolution of cone beam CT (CBCT) equipped with an indirect-type flat panel detector and compared it with a commercial CT unit (Robusto) . In CBCT, the X-ray tube voltage of 110 kV was used, and in the Robusto, the usual 120 kV was used for examinations. The computed tomography dose index (CTDI) of the two systems was measured, and images scanned at about the same exposure to radiation were compared. The modulation transfer factors of the two systems were measured, and the convolution kernel that was the nearest to the characteristic of CBCT was chosen among kernels of the Robusto. A water phantom with a diameter of 200 mm was scanned, Wiener spectra were calculated, and signal-to-noise ratios were compared. The low contrast resolution phantom was scanned, and detectability and contrast-to-noise ratio (CNR) were measured. In addition, we placed diluted contrast medium into a phantom, scanned the phantom, and measured the detectability and CNR. When the X-ray irradiation condition of CBCT was 75 mAs at 110 kV, the equal dose of radioactivity in the Robusto was 50 mAs at 120 kV. In the low contrast resolution phantom, detectability was 8.7%mm in CBCT, and 9.4%mm in the Robusto. In the low contrast resolution evaluation phantom, CNR was 1.39 in CBCT, and 2.69 in the Robusto. With diluted contrast medium, CNR was 1.28 in CBCT, and 0.60 in the Robusto. CBCT was inferior to the Robusto in a low contrast resolution phantom, but CBCT was superior to the Robusto using diluted contrast medium. We found that CBCT was useful in examinations using contrast media.

No abstract