Department of Radiology, Weill Medical College of Cornell University, New York, NY 10022, USA.
J Xray Sci Technol. 2003 Jan 1;11(4):231-40.
To evaluate the imaging potential of ferumoxytol, a new superparamagnetic iron oxide colloidal blood pool contrast agent.
Magnetic resonance (MR) imaging at 1.5 Tesla was performed before and after intravenous injection of ferumoxytol using escalating doses of 0.4, 0.8, 1.2 and 1.6 mg Fe/kg for a total of 4 mg Fe/kg in five subjects imaged with 3D MR Angiography (MRA) of the trifurcation after each dose. In five subjects cardiac cine MRI was performed pre and post 4.0 mg Fe/kg. Image quality was assessed by measuring signal to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in the vascular structures. Pre- and post-dose urine and blood tests as well as EKG/vital sign monitoring were performed to evaluate safety and blood samples were collected for T1 relaxivity measurements.
Cumulative doses of 0, 0.4, 1.2, 2.4 and 4 mg Fe/kg yielded mean SNR in the arteries of 10, 16, 39, 57 and 69 respectively indicating that the higher doses produced higher SNR on 3D vascular images. Similarly aorta SNR on 2D time-of-flight increased from 11.8 without Fe to 15.4 post Fe (p = 0.004) indicating improved image quality on MRA sequences optimized for use without contrast. At 4 mg Fe/kg there was a substantial T1 shortening measured in the blood from 1990 ± 573 ms to 80 ± 42 ms (p < 0.0001), corresponding to the increased SNR. Images of large vascular structures including cardiac chambers, aorta, and pulmonary arteries were excellent post ferumoxytol but images of smaller arteries of the trifurcation were difficult to evaluate due to enhancement of the overlapping veins. No serious adverse events occurred.
The new superparamagnetic iron oxide colloid ferumoxytol is a promising blood pool agent especially for cardiac, aorta and pulmonary imaging.
评估新型超顺磁性氧化铁胶体血池对比剂 ferumoxytol 的成像潜力。
在 1.5T 磁共振（MR）下，对 5 名受试者进行静脉注射 ferumoxytol，剂量分别为 0.4、0.8、1.2 和 1.6mgFe/kg，总剂量为 4mgFe/kg，在每次注射后使用 3D 磁共振血管造影（MRA）对三分叉进行成像。在 5 名受试者中，在注射 4.0mgFe/kg 前后进行心脏电影磁共振成像。通过测量血管结构中的信噪比（SNR）和对比噪声比（CNR）来评估图像质量。进行了预注射和注射后尿液和血液检查以及心电图/生命体征监测，以评估安全性，并采集血样进行 T1 弛豫率测量。
累积剂量为 0、0.4、1.2、2.4 和 4mgFe/kg 的受试者，其动脉的平均 SNR 分别为 10、16、39、57 和 69，这表明较高剂量的 ferumoxytol 在 3D 血管图像上产生了更高的 SNR。同样，在没有铁的情况下，主动脉的 SNR 从 2D 时间飞跃序列的 11.8 增加到注射铁后的 15.4（p = 0.004），这表明在优化的不使用对比剂的 MRA 序列上，图像质量得到了改善。在 4mgFe/kg 时，血液中的 T1 明显缩短，从 1990 ± 573ms 缩短至 80 ± 42ms（p < 0.0001），这与 SNR 的增加相对应。心脏腔室、主动脉和肺动脉等大血管结构的图像在注射 ferumoxytol 后非常清晰，但由于重叠静脉的增强，三分叉较小动脉的图像难以评估。未发生严重不良事件。
新型超顺磁性氧化铁胶体 ferumoxytol 是一种很有前途的血池造影剂，特别适用于心脏、主动脉和肺动脉成像。
