Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, 8091, Zurich, Switzerland.
Eur Radiol. 2012 Nov;22(11):2357-64. doi: 10.1007/s00330-012-2501-7. Epub 2012 May 30.
To evaluate optimal monoenergetic dual-energy computed tomography (DECT) settings for artefact reduction of posterior spinal fusion implants of various vendors and spine levels.
Posterior spinal fusion implants of five vendors for cervical, thoracic and lumbar spine were examined ex vivo with single-energy (SE) CT (120 kVp) and DECT (140/100 kVp). Extrapolated monoenergetic DECT images at 64, 69, 88, 105 keV and individually adjusted monoenergy for optimised image quality (OPTkeV) were generated. Two independent radiologists assessed quantitative and qualitative image parameters for each device and spine level.
Inter-reader agreements of quantitative and qualitative parameters were high (ICC = 0.81-1.00, κ = 0.54-0.77). HU values of spinal fusion implants were significantly different among vendors (P < 0.001), spine levels (P < 0.01) and among SECT, monoenergetic DECT of 64, 69, 88, 105 keV and OPTkeV (P < 0.01). Image quality was significantly (P < 0.001) different between datasets and improved with higher monoenergies of DECT compared with SECT (V = 0.58, P < 0.001). Artefacts decreased significantly (V = 0.51, P < 0.001) at higher monoenergies. OPTkeV values ranged from 123-141 keV. OPTkeV according to vendor and spine level are presented herein.
Monoenergetic DECT provides significantly better image quality and less metallic artefacts from implants than SECT. Use of individual keV values for vendor and spine level is recommended.
• Artefacts pose problems for CT following posterior spinal fusion implants. • CT images are interpreted better with monoenergetic extrapolation using dual-energy (DE) CT. • DECT extrapolation improves image quality and reduces metallic artefacts over SECT. • There were considerable differences in monoenergy values among vendors and spine levels. • Use of individualised monoenergy values is indicated for different metallic hardware devices.
评估不同供应商和脊柱水平的后路脊柱融合植入物的最佳单能量双能 CT（DECT）设置，以减少伪影。
对 5 家供应商的颈椎、胸椎和腰椎后路脊柱融合植入物进行离体单能 CT（120 kVp）和 DECT（140/100 kVp）检查。生成 64、69、88、105 keV 的外推单能量 DECT 图像和为优化图像质量而单独调整的单能量（OPTkeV）。两位独立的放射科医生评估了每个设备和脊柱水平的定量和定性图像参数。
定量和定性参数的读者间一致性很高（ICC=0.81-1.00，κ=0.54-0.77）。不同供应商（P<0.001）、脊柱水平（P<0.01）、 SECT、64、69、88、105 keV 的单能量 DECT 和 OPTkeV 之间（P<0.01），脊柱融合植入物的 HU 值存在显著差异。与 SECT 相比，数据集之间的图像质量差异显著（P<0.001），DECT 的单能量越高，图像质量越好（V=0.58，P<0.001）。与 SECT 相比，较高的单能量显著降低了伪影（V=0.51，P<0.001）。 OPTkeV 值范围为 123-141 keV。本文提供了根据供应商和脊柱水平的 OPTkeV 值。
与 SECT 相比，单能量 DECT 可显著提高脊柱融合植入物后的图像质量并减少金属伪影。建议根据供应商和脊柱水平使用单个 keV 值。
后路脊柱融合术后的 CT 会出现伪影问题。
使用双能 CT（DECT）的单能量外推可更好地解释 CT 图像。
DECT 外推可提高图像质量并减少 SECT 的金属伪影。
不同供应商和脊柱水平之间的单能量值存在较大差异。
不同的金属硬件设备需要使用个体化的单能量值。
