Department of Radiology, University of Yamanashi, Yamanshi, Japan.
J Magn Reson Imaging. 2009 Nov;30(5):1005-11. doi: 10.1002/jmri.21931.
To evaluate the effectiveness of diffusion-weighted magnetic resonance imaging (DWI) in estimating the grade of malignancy of hepatocellular carcinoma.
Dynamic contrast-enhanced computed tomography (CE-CT) and DWI (b value, 1000 s/mm(2)) were performed on 73 patients. Using DW images, the lesions were classified as "visible" or "invisible." The apparent diffusion coefficient (ADC) of the lesions was measured. Furthermore, the lesions were classified as hypervascular or iso-hypovascular using arterial phase CE-CT images. The image findings for each lesion type were compared.
The 73 patients had 98 hepatocellular lesions, of which 12 were histologically diagnosed as dysplastic nodules; 39, well-differentiated HCCs; 33, moderately differentiated HCCs; and 14, poorly differentiated HCCs. The mean ADC values of moderately poorly-differentiated HCCs were significantly lower than well-differentiated HCCs and dysplastic nodules (P < 0.01). On DW images, >90% of moderately (30/33) and poorly differentiated HCCs (13/14) were visible, while 51% of well-differentiated HCCs (20/39) and all dysplastic nodules were invisible. Of 22 iso-hypovascular lesions, 4 were visible on DW images and were poorly differentiated HCCs, whereas 18 were invisible and were dysplastic nodules (12/18) or well-differentiated HCCs (6/18).
A combination of hypovascularity and visibility on DW images can help distinguish poorly differentiated HCCs from low-grade hepatocellular lesions (dysplastic nodules and well-differentiated HCCs).
评估弥散加权磁共振成像（DWI）在估计肝细胞癌恶性程度中的作用。
对 73 例患者进行了动态对比增强 CT（CE-CT）和 DWI（b 值为 1000 s/mm²）检查。在 DW 图像上，将病变分为“可见”或“不可见”。测量病变的表观弥散系数（ADC）。此外，使用动脉期 CE-CT 图像将病变分为富血管性或等血管性。比较了每种病变类型的图像表现。
73 例患者共有 98 个肝细胞病变，其中 12 个组织学诊断为不典型增生结节；39 个为高分化 HCC；33 个为中分化 HCC；14 个为低分化 HCC。中低分化 HCC 的平均 ADC 值明显低于高分化 HCC 和不典型增生结节（P < 0.01）。在 DW 图像上，33 个中分化 HCC（30/33）和 14 个低分化 HCC（13/14）中超过 90%可见，而 39 个高分化 HCC（20/39）中仅有 51%可见，且均为不典型增生结节。在 22 个等血管性病变中，有 4 个在 DW 图像上可见，为低分化 HCC，而 18 个不可见，为不典型增生结节（18/18）或高分化 HCC（6/18）。
低分化 HCC 具有低灌注和 DW 图像可见性的特征，有助于与低级别肝细胞病变（不典型增生结节和高分化 HCC）相鉴别。
