BACKGROUND: Multirow-detector helical CT (MDCT) allows faster Z-axis coverage and improves longitudinal re- solution to scan the entire liver. This study was to evaluate the value of multiphase hepatic CT scans using ...BACKGROUND: Multirow-detector helical CT (MDCT) allows faster Z-axis coverage and improves longitudinal re- solution to scan the entire liver. This study was to evaluate the value of multiphase hepatic CT scans using MDCT in diagnosing hypervascular hepatocellular carcinoma (HCC). METHODS: Multiphase hepatic CT scans in 40 patients were carried out with a Marconi Mx8000 MDCT scanner. The scans of early arterial phase (EAP), late arterial phase (LAP) and portal venous phase (PVP) were started at 21, 34 and 85 seconds after injection of contrast medium, re- spectively. The number of detected lesions was calculated in each phase. The density of the liver and tumor was great- er than 1 cm for HCC, and the density of the liver and tumor in each phase was statistically calculated. RESULTS: A total of 61 lesions were found in the 40 pa- tients , and lesions greater than 1 cm were seen in 47 cases. The density differences between the liver and tumor were statistically significant (P<0.05) at the LAP and EAP and between the LAP, EAP and PVP. In the 61 lesions, the de- tectability in the EAP, LAP and the double arterial phases (DAP) was 32%, 87%, and 94%, respectively. Significant difference was found between the LAP plus PVP and the EAP plus PVP; but no significant difference was observed between the DAP plus PVP and the LAP plus PVP. CONCLUSIONS: The utility of MDCT scan in the liver has optimized the protocol of arterial phase scan. MDCT is possible to scan the entire liver in a real arterial phase and it is very valuable in the detection of small HCC.展开更多
At the limited roof north-south （N-S） width of a building, for the array with multirow collectors based on no shading at winter solstice noon and sloped at latitude, this paper studied the shading and the radiant en...At the limited roof north-south （N-S） width of a building, for the array with multirow collectors based on no shading at winter solstice noon and sloped at latitude, this paper studied the shading and the radiant energy striking on solar collector array. Based on Kunming solar radiation data, the annual and monthly solar radiant energy striking on multi-array collectors was analyzed and estimated, from no shading to partial shading by adding 1-3 collector row, at the slopes of 10°, 15°, 20°, 25°, 30°, 35° and 40°, respectively. The results showed that properly increasing the row number by reducing the slope of collectors was reasonable in order to get more annual radiant energy. Adding 1 row at 10° of slope was economical for Kunming, based on the 5-row array at 25°. And adding collector row by 20% at 10° of slope could increase the radiant energy striking on the array by 19%.展开更多
目的比较3.0 T磁共振(MRI)动态增强与64层螺旋CT(64-MDCT)多期扫描对肝硬化背景下小肝癌的诊断价值。方法选择肝硬化合并小肝癌患者55例(66个癌性小结节),分别进行3.0 T MRI动态增强与64-MDCT多期扫描,由两位专家对检查结果进行判定,比...目的比较3.0 T磁共振(MRI)动态增强与64层螺旋CT(64-MDCT)多期扫描对肝硬化背景下小肝癌的诊断价值。方法选择肝硬化合并小肝癌患者55例(66个癌性小结节),分别进行3.0 T MRI动态增强与64-MDCT多期扫描,由两位专家对检查结果进行判定,比较两种检查方法的诊断价值。结果两位观察者通过3.0 T MRI动态增强得到的ROC曲线下面积(AUC)分别为0.893±0.013、0.859±0.027,通过64-MDCT得到的AUC分别为0.657±0.034、0.679±0.026;两位观察者对两种检查方法的诊断价值比较,P均<0.01。两位观察者采用3.0T MRI动态增强诊断肝硬化背景下小肝癌的敏感度、特异度、阴性预测值均高于64-MDCT,P均<0.01。结论 3.0T MRI动态增强对肝硬化背景下小肝癌的诊断价值高于64-MDCT。展开更多
文摘BACKGROUND: Multirow-detector helical CT (MDCT) allows faster Z-axis coverage and improves longitudinal re- solution to scan the entire liver. This study was to evaluate the value of multiphase hepatic CT scans using MDCT in diagnosing hypervascular hepatocellular carcinoma (HCC). METHODS: Multiphase hepatic CT scans in 40 patients were carried out with a Marconi Mx8000 MDCT scanner. The scans of early arterial phase (EAP), late arterial phase (LAP) and portal venous phase (PVP) were started at 21, 34 and 85 seconds after injection of contrast medium, re- spectively. The number of detected lesions was calculated in each phase. The density of the liver and tumor was great- er than 1 cm for HCC, and the density of the liver and tumor in each phase was statistically calculated. RESULTS: A total of 61 lesions were found in the 40 pa- tients , and lesions greater than 1 cm were seen in 47 cases. The density differences between the liver and tumor were statistically significant (P<0.05) at the LAP and EAP and between the LAP, EAP and PVP. In the 61 lesions, the de- tectability in the EAP, LAP and the double arterial phases (DAP) was 32%, 87%, and 94%, respectively. Significant difference was found between the LAP plus PVP and the EAP plus PVP; but no significant difference was observed between the DAP plus PVP and the LAP plus PVP. CONCLUSIONS: The utility of MDCT scan in the liver has optimized the protocol of arterial phase scan. MDCT is possible to scan the entire liver in a real arterial phase and it is very valuable in the detection of small HCC.
文摘At the limited roof north-south （N-S） width of a building, for the array with multirow collectors based on no shading at winter solstice noon and sloped at latitude, this paper studied the shading and the radiant energy striking on solar collector array. Based on Kunming solar radiation data, the annual and monthly solar radiant energy striking on multi-array collectors was analyzed and estimated, from no shading to partial shading by adding 1-3 collector row, at the slopes of 10°, 15°, 20°, 25°, 30°, 35° and 40°, respectively. The results showed that properly increasing the row number by reducing the slope of collectors was reasonable in order to get more annual radiant energy. Adding 1 row at 10° of slope was economical for Kunming, based on the 5-row array at 25°. And adding collector row by 20% at 10° of slope could increase the radiant energy striking on the array by 19%.
文摘目的比较3.0 T磁共振(MRI)动态增强与64层螺旋CT(64-MDCT)多期扫描对肝硬化背景下小肝癌的诊断价值。方法选择肝硬化合并小肝癌患者55例(66个癌性小结节),分别进行3.0 T MRI动态增强与64-MDCT多期扫描,由两位专家对检查结果进行判定,比较两种检查方法的诊断价值。结果两位观察者通过3.0 T MRI动态增强得到的ROC曲线下面积(AUC)分别为0.893±0.013、0.859±0.027,通过64-MDCT得到的AUC分别为0.657±0.034、0.679±0.026;两位观察者对两种检查方法的诊断价值比较,P均<0.01。两位观察者采用3.0T MRI动态增强诊断肝硬化背景下小肝癌的敏感度、特异度、阴性预测值均高于64-MDCT,P均<0.01。结论 3.0T MRI动态增强对肝硬化背景下小肝癌的诊断价值高于64-MDCT。
