Heinrich Andreas, Reinhold Maximilian, Güttler Felix V, Matziolis Georg, Teichgräber Ulf K-M, Zippelius Timo, Strube Patrick
Department of Radiology, Jena University Hospital - Friedrich Schiller University, Am Klinikum 1, 07747, Jena, Germany.
Department of Orthopedics, Jena University Hospital, Campus Eisenberg, Klosterlausnitzer Straße 81, 07607, Eisenberg, Germany.
Eur Radiol. 2021 Jun;31(6):4298-4307. doi: 10.1007/s00330-020-07546-6. Epub 2020 Dec 4.
The implant constructs used in scoliosis surgery are often long with a high screw density. Therefore, it is generally believed that magnetic resonance imaging (MRI) should not be carried out after scoliosis surgery, with the result that computed tomography is often preferred despite the ionizing radiation involved. The objective of this study was to evaluate the MRI compatibility of long pedicle-screw-rod constructs at 1.5 T and 3 T using standardized methods of the American Society for Testing and Materials (ASTM).
Constructs between 130 and 430 mm long were systematically examined according to the ASTM standards F2182 (radio frequency-induced heating), F2119 (susceptibility artifacts), F2213 (magnetically induced torque), and F2052 (magnetically induced displacement force).
The maximum heating in the magnetic field was 1.3 K. Heating was significantly influenced by magnetic field strength (p < 0.001), implant length (p = 0.048), and presence of cross-links (p = 0.001). The maximum artifact width for different lengths of the anatomically bent titanium rods with CoCr alloy ranged between 14.77 ± 2.93 mm (TSE) and 17.49 ± 1.82 mm (GRE) for 1.5 T and between 23.67 ± 2.39 mm (TSE) and 27.77 ± 2.37 mm (GRE) for 3 T. TiCP and TiAl showed the smallest and CoCr and CoCr Plus the largest artifact widths. The magnetically induced torque and displacement force were negligible.
MRI following scoliosis surgery with long implant constructs is safe with the patient in supine position. Although susceptibility artifacts can severely limit the diagnostic value, the examination of other regions is possible.
• Large spinal implants are not necessarily a contraindication for MRI; MR conditional status can be examined according to the ASTM standards F2182, F2119, F2213, and F2052. • A metallic pedicle-screw-rod system could be reliably and safely examined in all combinations of length (130 to 430 mm), configuration, and material in a B at 1.5 T and 3 T. • According to ASTM F2503, the examined pedicle-screw-rod system is MR conditional and especially the young patients can benefit from a non-ionizing radiation MRI examination.
脊柱侧弯手术中使用的植入物结构通常较长且螺钉密度高。因此，人们普遍认为脊柱侧弯手术后不应进行磁共振成像（MRI）检查，结果是尽管涉及电离辐射，但计算机断层扫描通常更受青睐。本研究的目的是使用美国材料与试验协会（ASTM）的标准化方法评估1.5 T和3 T时长椎弓根螺钉棒结构的MRI兼容性。
根据ASTM标准F2182（射频感应加热）、F2119（磁化率伪影）、F2213（磁感应扭矩）和F2052（磁感应位移力），对长度在130至430 mm之间的结构进行系统检查。
磁场中的最大加热温度为1.3 K。加热受到磁场强度（p < 0.001）、植入物长度（p = 0.048）和交联的存在（p = 0.001）的显著影响。对于1.5 T，不同长度的解剖弯曲钴铬合金钛棒的最大伪影宽度在14.77±2.93 mm（快速自旋回波序列）和17.49±1.82 mm（梯度回波序列）之间；对于3 T，在23.67±2.39 mm（快速自旋回波序列）和27.77±2.37 mm（梯度回波序列）之间。钛磷灰石和钛铝显示的伪影宽度最小，钴铬合金和钴铬合金增强显示的伪影宽度最大。磁感应扭矩和位移力可忽略不计。
脊柱侧弯手术后使用长植入物结构进行MRI检查时，患者仰卧位是安全的。尽管磁化率伪影会严重限制诊断价值，但对其他区域进行检查是可行的。
• 大型脊柱植入物不一定是MRI检查的禁忌症；可根据ASTM标准F2182、F2119、F2213和F2052检查MR条件状态。• 在1.5 T和3 T的磁场中，对于长度（130至430 mm）、构型和材料的所有组合，金属椎弓根螺钉棒系统都可以可靠且安全地进行检查。• 根据ASTM F2503，所检查的椎弓根螺钉棒系统符合MR条件，尤其是年轻患者可以从非电离辐射的MRI检查中受益。
