Cronenweth Charlotte M, Shellock Frank G
Loyola Marymount University, 1 LMU Drive, Los Angeles, CA 90045, USA.
Keck School of Medicine, University of Southern California and Institute for Magnetic Resonance Safety, Education, and Research, 7751 Veragua Drive, Playa Del Rey, CA 90293, USA.
Int J Breast Cancer. 2015;2015:823759. doi: 10.1155/2015/823759. Epub 2015 Jul 22.
Purpose. To assess the MRI issues at 3 Tesla for a metallic tissue marker used to localize removal areas of tissue abnormalities. Materials and Methods. A newly designed, metallic tissue marker (Achieve Marker, CareFusion, Vernon Hills, IL) used to mark biopsy sites, particularly in breasts, was assessed for MRI issues which included standardized tests to determine magnetic field interactions (i.e., translational attraction and torque), MRI-related heating, and artifacts at 3 Tesla. Temperature changes were determined for the marker using a gelled-saline-filled phantom. MRI was performed at a relatively high specific absorption rate (whole body averaged SAR, 2.9-W/kg). MRI artifacts were evaluated using T1-weighted, spin echo and gradient echo pulse sequences. Results. The marker displayed minimal magnetic field interactions (2-degree deflection angle and no torque). MRI-related heating was only 0.1°C above background heating (i.e., the heating without the tissue marker present). Artifacts seen as localized signal loss were relatively small in relation to the size and shape of the marker. Conclusions. Based on the findings, the new metallic tissue marker is acceptable or "MR Conditional" (using current labeling terminology) for a patient undergoing an MRI procedure at 3 Tesla or less.
目的。评估用于定位组织异常切除区域的金属组织标记物在3特斯拉磁场下的磁共振成像(MRI)相关问题。材料与方法。对一种新设计的用于标记活检部位(尤其是乳房活检部位)的金属组织标记物(Achieve标记物,CareFusion公司,伊利诺伊州弗农山)进行MRI相关问题评估,包括确定磁场相互作用(即平移吸引力和扭矩)、MRI相关加热以及在3特斯拉磁场下的伪影的标准化测试。使用填充凝胶盐水的体模确定标记物的温度变化。MRI在相对较高的比吸收率(全身平均比吸收率,2.9瓦/千克)下进行。使用T1加权、自旋回波和梯度回波脉冲序列评估MRI伪影。结果。该标记物显示出最小的磁场相互作用(偏转角为2度且无扭矩)。MRI相关加热仅比背景加热(即不存在组织标记物时的加热)高0.1°C。与标记物的大小和形状相比,表现为局部信号丢失的伪影相对较小。结论。基于这些发现,对于在3特斯拉或更低磁场下接受MRI检查的患者,这种新型金属组织标记物是可接受的,或者按照当前的标签术语来说是“MR条件合格的”。