Ernstberger Thorsten, Heidrich Gabert, Buchhorn Gottfried
Department of Orthopedic Surgery, University of Gottingen, Robert-Koch-Strasse 40, 37075 Gottingen, Germany.
Spine J. 2007 May-Jun;7(3):353-9. doi: 10.1016/j.spinee.2006.03.016. Epub 2006 Nov 20.
Interbody spacers for anterior spine fusion are made of different materials, which can affect the postfusion magnetic resonance imaging (MRI) scans. Susceptibility artifacts specially for metallic implants can decrease the image quality.
This study focused on the influence of determined implant parameters like shape, implant volume, and implant material in MRI artifacting with regard to solid geometrical titanium and carbon test spacers.
STUDY DESIGN/SETTING: A comparative study on an in vitro spine model. The study was performed at a university research facility.
In this study we evaluated the postimplantation MRI scans of three determined cuboids and six cylinders, which were made of titanium alloy and carbon fiber reinforced polymer. MRI scans were carried out by using T1 turbo spin echo (TSE) sequences. The total artifact volume (TAV) as well as median artifact area (MAA) were calculated. Additionally the implant volume (IV)/TAV and cross-sectional area (CSA)/MAA relation were determined. Statistical analyses were calculated with the t test and Newman-Keuls test for multiple comparisons.
Considering all test implants with an increasing implant size, the TAV and the MAA became significantly larger (p<.001) with simultaneous reduction of the IV/TAV and CSA/MAA relation. In contrast to the carbon implant group, for titanium cylinders with an implant volume equivalent to the cuboids significant differences in MRI artifacting (p<.05) could be demonstrated.
Susceptibility artifacts were clearly affected by the implant material, shape, and implant volume. Independent of the implant material, with regard to a more advantageous IV/TAV and CSA/MAA relation, for larger implants the artifact rate was more limited to the implant's direct surroundings. On the basis of a high magnetizability for titanium implants with an equal IV, the range of implant-related susceptibility artifacts was influenced by the material as well as implant shape in favor of cylindric implants. According to the very low MRI artifact rate of carbon implants, the implant shape did not have any significant effect on the artifact behavior.
用于前路脊柱融合的椎间融合器由不同材料制成，这可能会影响融合后磁共振成像（MRI）扫描。特别是金属植入物的磁化伪影会降低图像质量。
本研究聚焦于特定植入物参数（如形状、植入物体积和植入物材料）对实心几何形状钛和碳测试融合器在MRI伪影方面的影响。
研究设计/地点：对体外脊柱模型进行的比较研究。该研究在大学研究机构进行。
在本研究中，我们评估了由钛合金和碳纤维增强聚合物制成的三个特定长方体和六个圆柱体植入后的MRI扫描。使用T1快速自旋回波（TSE）序列进行MRI扫描。计算总伪影体积（TAV）以及中位伪影面积（MAA）。此外，还确定了植入物体积（IV）/TAV和横截面积（CSA）/MAA的关系。使用t检验和Newman-Keuls检验进行多重比较的统计分析。
考虑所有测试植入物，随着植入物尺寸增加，TAV和MAA显著增大（p<0.001），同时IV/TAV和CSA/MAA关系降低。与碳植入物组相比，对于植入物体积与长方体相当的钛圆柱体，在MRI伪影方面存在显著差异（p<0.05）。
磁化伪影明显受植入物材料、形状和植入物体积影响。与植入物材料无关，就更有利的IV/TAV和CSA/MAA关系而言，对于较大的植入物，伪影率更多地局限于植入物的直接周围区域。基于相同IV的钛植入物具有高磁化率，与植入物相关的磁化伪影范围受材料以及植入物形状影响，有利于圆柱形植入物。根据碳植入物极低的MRI伪影率，植入物形状对伪影行为没有任何显著影响。
