Histopathologic Analysis of Signal Intensity Patterns of Well Differentiated Hepatocellular Carcinoma and Borderline Lesions on Magnetic Resonance Imaging

对可能影响MRI信号强度模式的组织病理学因素进行评价，以明确高分化肝细胞癌和交界性病变(如腺瘤性增生)T1加权像上典型高信号模式的原因，脂肪变形是原因之一，并通过脂肪饱和图像证实。与CT相比，MRI的敏感性也更高。铜沉积的顺磁效应不足以影响MRI。铁沉积是原因之一，附加梯度回波序列可以提高交界性病变的显示率，有助于组织学分级。我们还提出细胞密度增加可能会增加信号强度，并指出交界性病变与良性增生性病变在影像和组织学上的相似性，这支持了这一假说。我们还从组织病理学角度探讨了高分化性肝癌和T2加权图像交界性低信号的原因。我们认为，这些病变的相对低信号模式是由于慢性肝病相关的炎症导致周围实质信号强度增加所致。

The histopathologic factors which may influence the signal intensity patterns of MRI were evaluated to clarify the causes of characteristic hyperintense pattern of well differentiated hepatocellular carcinoma and borderline lesions such as adenomatous hyperplasia on T1-weighted images of MRI.Fatty metamorphosis was proved to be one of the causes and demonstrated by using the fat saturated images. Higher sensitivity of MRI compared to CT was also demonstrated.The paramagnetic effect of copper accumulation was concluded to be insufficient to influence the MRI.Iron accumulation was suggested to be one of the causes and additional gradient echo sequences may improve the detectability of borderline lesions and may be helpful for the evaluation of histological grades.We also suggested that the increased cellularity might increase the signal intensity and pointed out the similarity between borderline lesions and benign hyperplastic lesions on both imaging and histology which supported this hypothesis.The causes of characteristic hypointence pottern of well differentiated hepatocellular carcinoma and borderline lesions on T2-weighted images were also examined histopathologically. We suggested the relative hypointense pattern of such lesions resulted from increased signal intensity of surrounding parenchyma caused by the inflammation associated with chronic hepatic disease.