Lord M L, McNeill F E, Gräfe J L, Galusha A L, Parsons P J, Noseworthy M D, Howard L, Chettle D R
Radiation Sciences Graduate Program, McMaster University, Hamilton, Canada L8S 4L8.
Department of Physics and Astronomy, McMaster University, Hamilton, Canada L8S 4L8.
Appl Radiat Isot. 2017 Feb;120:111-118. doi: 10.1016/j.apradiso.2016.12.011. Epub 2016 Dec 11.
The safety of using Gd in MRI contrast agents has recently been questioned, due to recent evidence of the retention of Gd in individuals with healthy renal function. Bone has proven to be a storage site for Gd, as unusually high concentrations have been measured in femoral heads of patients undergoing hip replacement surgery, as well as in autopsy samples. All previous measurements of Gd in bone have been invasive and required the bone to be removed from the body. X-ray fluorescence (XRF) offers a non-invasive and non-destructive method for carrying out in vivo measurements of Gd in humans. An updated XRF system provides improved detection limits in a short measurement time of 30-min. A new four-detector system and higher activity Cd-109 excitation source of 5GBq results in minimum detection limits (MDLs) of 1.64-1.72μgGd/g plaster for an average overlaying tissue thickness of the tibia. These levels are well within the range of previous in vitro Gd measurements. Additional validation through comparison with ICP-MS measurements has confirmed the ability of the XRF system for detecting Gd further, proving it is a feasible system to carry out human measurements.
由于最近有证据表明肾功能正常的个体体内存在钆（Gd）潴留，钆在磁共振成像（MRI）造影剂中的使用安全性最近受到了质疑。事实证明，骨骼是钆的储存部位，因为在接受髋关节置换手术的患者的股骨头以及尸检样本中测量到了异常高浓度的钆。此前所有对骨骼中钆的测量都是侵入性的，需要将骨骼从体内取出。X射线荧光（XRF）提供了一种用于在人体中进行钆的活体测量的非侵入性和非破坏性方法。一种更新的XRF系统在30分钟的短测量时间内提供了更低的检测限。一种新的四探测器系统和5GBq的更高活度Cd - 109激发源，对于胫骨平均覆盖组织厚度，最低检测限（MDL）为1.64 - 1.72μg Gd/g石膏。这些水平完全在之前体外钆测量的范围内。通过与电感耦合等离子体质谱（ICP - MS）测量结果进行比较的额外验证，进一步证实了XRF系统检测钆的能力，证明它是一种可行的用于人体测量的系统。
