Yamamoto H, Yamashita Y, Takahashi M
Department of Radiology, Kumamoto University School of Medicine, Japan.
Acad Radiol. 1996 Apr;3(4):330-5. doi: 10.1016/s1076-6332(96)80253-4.
Hyperplastic nodules developed in cirrhotic livers reportedly show accumulations of superparamagnetic iron oxide (SPIO) on magnetic resonance (MR) images, whereas hepatocellular carcinomas do not. We examined whether SPIO-enhanced MR imaging would detect cancerous liver lesions within hyperplastic nodules.
The study included 40 rats with N-2-fluorenyldiacetamide (FAA)-induced liver tumors. Spin-echo T1-, T2-, and proton density-weighted images were obtained at 1.5 T before and after the administration of SPIO. We evaluated 47 tumors accumulating iron particles on SPIO-enhanced MR images. Among the 47 tumors, 33 were observed on MR images obtained 10-26 weeks after the initiation of the carcinogenic diet. The signal intensity changes within the tumors were observed at 2 weeks and were compared with histologic findings. As a control study, 30 hyperintense (non-SPIO-enhanced) tumors also received pathologic examination.
Hyperintense (non-SPIO-enhanced) foci within hypointense (SPIO-enhanced) tumors were observed in seven of the 33 tumors on all pulse sequences, and hyperintense (non-SPIO-enhanced), enlarged foci were observed in three of the seven lesions. In the remaining 26 lesions, the signal intensity of the tumor was totally hypointense on all pulse sequences at initial and follow-up MR imaging. During the 2-week follow-up period, 15 hypointense (SPIO-enhanced) tumors were replaced by hyperintense (non-SPIO-enhanced) tumors. Histologically, SPIO-accumulating tumors were hyperplastic nodules; the lesions that did not accumulate SPIO were hepatocellular carcinomas or hyperplastic nodules with atypical cells.
MR imaging using SPIO detects the development of hepatocellular carcinoma at an early stage in our animal model.
据报道，肝硬化肝脏中形成的增生性结节在磁共振（MR）图像上显示超顺磁性氧化铁（SPIO）积聚，而肝细胞癌则无此表现。我们研究了SPIO增强MR成像能否检测增生性结节内的肝脏癌性病变。
本研究纳入40只经N - 2 - 芴基二乙酰胺（FAA）诱导产生肝肿瘤的大鼠。在注射SPIO前后，于1.5 T场强下获取自旋回波T1加权、T2加权和质子密度加权图像。我们评估了47个在SPIO增强MR图像上积聚铁颗粒的肿瘤。在这47个肿瘤中，33个是在致癌饮食开始后10 - 26周获得的MR图像上观察到的。在2周时观察肿瘤内的信号强度变化，并与组织学结果进行比较。作为对照研究，30个高信号（非SPIO增强）肿瘤也接受了病理检查。
在33个肿瘤中的7个肿瘤的所有脉冲序列上，均观察到低信号（SPIO增强）肿瘤内有高信号（非SPIO增强）灶，在这7个病变中的3个观察到高信号（非SPIO增强）、增大的灶。在其余26个病变中，在初始和随访MR成像时，肿瘤的信号强度在所有脉冲序列上均完全为低信号。在2周的随访期内，15个低信号（SPIO增强）肿瘤被高信号（非SPIO增强）肿瘤取代。组织学上，积聚SPIO的肿瘤为增生性结节；未积聚SPIO的病变为肝细胞癌或伴有非典型细胞的增生性结节。
在我们的动物模型中，使用SPIO的MR成像可早期检测肝细胞癌的发生。
