Research on MRI Contrast Agents for the Liver.

1.应用Gd-DTPA非特异性造影剂，评价其对肝肿瘤鉴别诊断的准确性，并探讨其对肝细胞癌（HCC）治疗的评价。在自旋回波延迟相，HCC与肝海绵状血管瘤（HCH）的鉴别准确率为94%。为了评价晚期时相细微增强的诊断作用，将Gd-DTPA的剂量从0.05 μ mol/kg增加到0.2 μ mol/kg。而具有典型HCH特征的HCC从7%上升到15%。动态MRI与动态CT比较，两者基本相同，仅3%的病变在不同扫描间隔、时间和成像方向下有不同的诊断。因此，MRI在检测微弱强化区域以及较少发生和严重不良反应方面优于CT，具有上级优势。然而，我们未能证实在早期发现治疗过的HCC复发方面优于CT， ...更多信息 d目前为止的治疗效果评价。MRI造影剂的效用也被评估在弥漫性肝病，如肝硬化和放射性肝炎。非铁存款型再生结节在平扫T1加权像上呈相对高信号，增强后由于Glisson鞘明显强化而变为等或低信号。然而，由于空间分辨率较低，MRI对CT所获得的结果没有任何增加。放射性肝炎表现为在肝癌的强化峰后逐渐明显强化。增强峰值出现的时间和程度不同，推测与照射剂量、照射后时间及肝炎的组织学状态有关.特异性造影剂我们首次报道了在土拨鼠高分化肝细胞癌中使用氧化铁的MRI发现网状内皮系统的存在，后来，在人类受试者中也观察到这种现象。我们用DAB诱发的大鼠肝肿瘤比较了氧化铁和Glutal在剂量和峰值时间方面的差异。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