Research on MRI Contrast Agents for the Liver.

1.应用非特异性对比剂Gd-DTPA，评价其在肝肿瘤鉴别诊断中的准确性，并探讨其在肝细胞癌治疗中的应用价值。在自旋回波延迟期，肝细胞癌与肝海绵状血管瘤的鉴别准确率为94%。为评价Gd-DTPA对晚期微小强化的诊断价值，将Gd-DTPA剂量从0.05增加到0.2mmoL/kg。然而，表现出典型六氯环己烷模式的肝癌从7%增加到15%。动态MRI与动态CT比较，两者基本一致，尽管扫描间隔、扫描时间不同、成像方向不同，但仅有3%的病变有不同诊断。因此，MRI在发现微弱强化区域以及较少出现和严重的不良反应方面优于CT。然而，我们未能证实在治疗的肝细胞癌和…中早期发现复发方面优于CT的优势。到目前为止对治疗效果的评价较多。并对MRI对比剂在肝硬变、放射性肝炎等弥漫性肝病中的应用进行了评价。非铁沉积型再生结节在平扫T1加权像上表现为相对高信号，增强后因Glisson鞘明显强化而变为等信号或低信号。然而，由于空间分辨率较低，MRI没有任何补充CT所见的内容。放射性肝炎在肝细胞癌增强峰值后呈渐进性、显著强化。结果：1.增强峰出现的时间和程度不同，可能与照射剂量、照射后时间和肝组织学状态有关。我们首先报道了氧化铁在土拨鼠高分化肝细胞癌中网状内皮系统的存在，后来在人体中也发现了这一现象。在DAB诱发的大鼠肝肿瘤模型上，比较了氧化铁和谷氨酸甘油在剂量和峰值时间上的差异。较少

1. Nonspecific Contrast Agents Using Gd-DTPA, we evaluted its differential diagnostic accuracy among liver tumors and investigated the evaluation of treatment in hepatocellular carcinoma (HCC). In delayed phase of spin echo, differentiation of HCC from hepatic cavernous hemangioma (HCH) was achieved with accuracy of 94%. In order to evaluate the diagnostic role of subtle ehancement noted in the late phase, the dose of Gd-DTPA administered was increased from 0.05 to 0.2m mol/kg. However, HCC revealing the typical HCH pattern was in creased from 7% to 15%. Comparing dynamic MRI with dynamic CT, both studies were essentially same and only 3% of lesions had different diagnoses despite different scanning interval and time as well as different direction of imaging used. Thus MRI was superior to CT in the detection of feebly enhanced areas and in less frequent and severe adverse effects. However, we failed to confirm the advantage over CT in the early detection of recurrence in treated HCC an … More d the evaluation of treatment effect so far. The utility of MRI contrast agent was also evaluated in diffuse liver diseases such as liver cirrhosis and radiation hepatitis. Regenerating nodules of non-iron deposit type appeared as relatively hyperintense on plain Tl-weighted image and became isointense or hypoinse after contrast enhancement because of prominent enhancement of Glisson's sheath. However, due to inferior spatial resolution, MRI did not have anything adding to findings obtained with CT. Radiation hepatitis showed gradual, prominent enhancement behind the enhancement peak of HCC. The time and degree of enhancement peak were varying and were inferred to be related with radiation dose, period after irradiation and histological state of hapatitis.2. Specific Contrast Agents We first reported the presence of reticulo-endothelisl system in well-differentiated HCC of woodchuck with MRI using iron oxide, and later, this phenomenon was also noted in human subjects, Iron oxide and Glutal were compared in terms of dose and peak time using rat having hepatic tumors induced by DAB. Less