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Urban development causes serious changes to watershed conditions by decreasing storage area, introducing pavement and channeling. As a result, the peak discharge has been increasing and the arrival time of peak becomes shorter. The purpose of this study is to estimate the change of flood discharge by transition of landuse in the Mikasa River watershed with the effect of the existing storage facilities such an irrigation ponds. To estimate that we applied the distributed runoff model considering the landuse in 1900, 1950, 1976 and 1997 of the Mikasa River watershed about flood disaster in July 19, 2003. The result of calculation showed that the peak discharge at Sanno Bridge has been increased 27% for the last 100 years result from transition of landuse in the Mikasa River watershed.

Transcatheter arterial embolization (TAE) is considered to be relatively ineffective in the treatment of portal and/or hepatic vein tumor thrombi associated with hepatocellular carcinoma (HCC). However, we have seen patients with a positively enhanced tumor thrombus on angioechography where necrosis has occurred after TAE. In this study, we compared the angioechographic enhancement of tumor thrombi with the effect of TAE to assess the use of this method in predicting the efficacy of TAE, and in predicting survival.Angioechography, using a small amount of CO2 gas injected into the hepatic artery, was performed before TAE in 41 HCC patients with tumor thrombi of the portal vein (PVTT; n = 35) or hepatic vein (HVTT; n = 6). The relationship between the enhancement of the thrombi and the efficacy of TAE was investigated by follow-up ultrasonography.All 13 PVTT that decreased in size had shown positive enhancement (PE) before treatment (P0.001), while 6 of the 7 cases (86%) in which the lesions increased in size had shown negative enhancement (NE). The survival of patients with PE was significantly longer than that of patients with NE (P0.005). Multivariate analysis identified two clinical variables associated with survival, angioechographic findings of PVTT, and age. There were no correlations between enhancement and HVTT.Determination of enhancement of PVTT on angioechography was useful in predicting the efficacy of TAE treatment of HCC and the survival time. Angioechography may be valuable in treatment decisions for HCC patients with PVTT, especially as a guide to the effectiveness of TAE.

Color Doppler energy (CDE) offers a marked improvement in sensitivity over existing color Doppler systems. We report here the use of this system in the diagnosis of small hepatocellular carcinoma (HCC). CDE was used in the clinical investigation of 13 nodules in 12 suspected cases of HCC less than 2 cm in diameter. Findings were compared with those on color Doppler imaging (CDI), angiography, angioechography and histological examination. The apparatus consisted of an Acuson 128XP 10 (ART) with 4- and 5-MHz transducers. Comparison of angiography, angioechography and CDE findings: CDE showed pulsatile flow in 8 of the 9 nodules (88.9%) in which angiography showed tumor stain or angioechography showed positive enhancement. In the 3 nodules in which staining was negative and angioechography showed negative or non-enhancement, CDE showed no pulsatile flow. Comparison between pathological and CDE findings: All 7 nodules which showed moderate or poor differentiation in pathology showed continuous pulsatile flow on CDE. Among 5 well-differentiated HCC, 4 showed no pulsatile flow and 1 showed intermittent pulsatile flow. The remaining non-malignant nodules showed no pulsatile flow. Comparison between CDI and CDE findings: Both CDI and CDE showed pulsatile flow in 8 nodules but with marked differences in sensitivity. Flow was intermittent or spotty with CDI, but mostly showed a continuous branched pattern with CDE. Thus, CDE images correlated well with angiography, angioechography and pathological findings. CDE is an effective and non-invasive means of determining the hemodynamics of small nodules and is useful in the diagnosis of small HCC.

アンジオエコーにて腫瘍とともに腫瘍栓もエンハンスされた肝細胞癌切除例で,TAEにより腫瘍栓の壊死が認められた2症例を報告する.症例1は69歳男性.肝S4に2.5cmの肝細胞癌とそれに連続する中肝静脈内の腫瘍栓を認めた.アンジオエコーにて肝細胞癌と腫瘍栓がエンハンスされた.TAE施行後切除し,腫瘍と共に腫瘍栓も壊死に陥っていることを確認した.症例2は73歳女性,小肝細胞癌切除後の再発例.6.5cmの腫瘍がS3にありS3門脈枝から臍部にかけて腫瘍栓を認める.アンジオエコーにて腫瘍栓は淡くエンハンスされ,TAE後切除にて腫瘍栓の壊死を確認した.アンジオエコー法は肝細胞癌結節のみでなく腫瘍栓に関してもその血流動態を反映し,エンハンスの状態から簡単にTAEの効果が推測できると考えられた.