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

我们评估了可能影响MRI信号强度模式的组织病理学因素，以阐明MRI t1加权图像上高分化肝癌和交界性病变（如腺瘤性增生）特征性高信号模式的原因。利用饱和脂肪图像证明了脂肪变态是造成这种现象的原因之一。与CT相比，MRI具有更高的灵敏度。结论铜堆积的顺磁效应不足以影响MRI。铁积累被认为是原因之一，额外的梯度回声序列可以提高边缘病变的可检出性，并可能有助于评估组织学分级。我们还认为细胞增多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学和组织学上的相似性支持了这一假设。对高分化肝癌的特征性低影及交界性病变在t2加权图像上的原因也进行了组织病理学检查。我们认为，这种病变的相对低信号模式是由慢性肝病相关炎症引起的周围实质信号强度增加引起的。

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.