Korpics Mark, Johnson Paul, Patel Rakesh, Surucu Murat, Choi Mehee, Emami Bahman, Roeske John C
Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL, USA.
Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL, USA
Technol Cancer Res Treat. 2016 Dec;15(6):NP88-NP94. doi: 10.1177/1533034615618319. Epub 2015 Nov 26.
To evaluate a method for reducing metal artifacts, arising from dental fillings, on cone-beam computed tomography images.
A projection interpolation algorithm is applied to cone-beam computed tomography images containing metal artifacts from dental fillings. This technique involves identifying metal regions in individual cone-beam computed tomography projections and interpolating the surrounding values to remove the metal from the projection data. Axial cone-beam computed tomography images are then reconstructed, resulting in a reduction in the streak artifacts produced by the metal. Both phantom and patient imaging data are used to evaluate this technique.
The interpolation substitution technique successfully reduced metal artifacts in all cases. Corrected images had fewer or no streak artifacts compared to their noncorrected counterparts. Quantitatively, regions of interest containing the artifacts showed reduced variance in the corrected images versus the uncorrected images. Average pixel values in regions of interest around the metal object were also closer in value to nonmetal regions after artifact reduction. Artifact correction tended to perform better on patient images with less complex metal objects versus those with multiple large dental fillings.
The interpolation substitution is potentially an efficient and effective technique for reducing metal artifacts caused by dental fillings on cone-beam computed tomography image. This technique may be effective in reducing such artifacts in patients with head and neck cancer receiving daily image-guided radiotherapy.
评估一种减少锥形束计算机断层扫描（CBCT）图像上由牙科填充物引起的金属伪影的方法。
将投影插值算法应用于包含牙科填充物金属伪影的CBCT图像。该技术包括识别各个CBCT投影中的金属区域，并对周围值进行插值以从投影数据中去除金属。然后重建轴向CBCT图像，从而减少由金属产生的条纹伪影。使用体模和患者成像数据来评估该技术。
插值替换技术在所有情况下均成功减少了金属伪影。与未校正的图像相比，校正后的图像条纹伪影更少或没有。从定量角度看，包含伪影的感兴趣区域在校正图像中的方差相对于未校正图像有所降低。在减少伪影后，金属物体周围感兴趣区域的平均像素值在数值上也更接近非金属区域。对于金属物体不太复杂的患者图像，伪影校正往往比具有多个大牙科填充物的患者图像表现更好。
插值替换可能是一种有效减少CBCT图像上由牙科填充物引起的金属伪影的技术。该技术可能对接受每日图像引导放射治疗的头颈癌患者减少此类伪影有效。
