Bellin M F, Beigelman C, Precetti-Morel S
Department of Radiology, Hôpital Pitié-Salpêtière, 83 Boulevard de l'Hôpital, 75651 Cedex 13, Paris, France.
Eur J Radiol. 2000 Jun;34(3):257-64. doi: 10.1016/s0720-048x(00)00204-7.
The detection of nodal metastases is of utmost importance in oncologic imaging. Ultrasmall superparamagnetic iron oxide particles (USPIO) are novel contrast agents specifically developed for MR lymphography. After intravenous administration, they are taken up by the macrophages of the lymph nodes, where they accumulate. They reduce the signal intensity (SI) of normally functioning nodes on postcontrast T2-and T2*-weighted images through the magnetic susceptibility effects on iron oxide. Metastatic nodes, in which macrophages are replaced by tumor cells, show no significant change in SI on postcontrast T2-and T2*-weighted images. Early clinical experience suggests that USPIO-enhanced MR lymphography improves the sensitivity and specificity for the detection of nodal metastases. It also suggests that micrometastases could be detected in normal-sized nodes. This article reviews the physiochemical properties of USPIO contrast agents, their enhancement patterns, and early clinical experience.
在肿瘤成像中，检测淋巴结转移至关重要。超小超顺磁性氧化铁颗粒（USPIO）是专门为磁共振淋巴造影开发的新型造影剂。静脉注射后，它们被淋巴结的巨噬细胞摄取并在其中积聚。通过氧化铁的磁化率效应，它们降低了造影剂后T2加权和T2加权图像上正常功能淋巴结的信号强度（SI）。转移淋巴结中巨噬细胞被肿瘤细胞取代，在造影剂后T2加权和T2加权图像上SI无明显变化。早期临床经验表明，USPIO增强磁共振淋巴造影提高了检测淋巴结转移的敏感性和特异性。这也表明在正常大小的淋巴结中可以检测到微转移。本文综述了USPIO造影剂的理化性质、增强模式及早期临床经验。
