Accurate hybrid template-based and MR-based attenuation correction using UTE images for simultaneous PET/MR brain imaging applications.
Accurate hybrid template-based and MR-based attenuation correction using UTE images for simultaneous PET/MR brain imaging applications.
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DOI：
10.1186/s12880-018-0283-3
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发表时间：
2018-11-06
影响因子：
2.7
通讯作者：
Egan GF
中科院分区：
文献类型：
--
作者：
Baran J;Chen Z;Sforazzini F;Ferris N;Jamadar S;Schmitt B;Faul D;Shah NJ;Cholewa M;Egan GF
衰减校正是混合PET/MR扫描仪中精确PET数据定量的最关键校正因素之一，并且从MR脑采集计算精确衰减系数图具有挑战性。在这里，我们开发了一种使用MR超短回波时间（UTE）图像进行精确骨和空气分割的方法。来自5名健康志愿者的同时MR和PET成像的MR UTE图像用于生成整个头部、骨骼和空气模板图像，以包含在改进的MR导出的衰减校正图中，并应用于PET图像数据以进行定量分析。以概率组织图为先验信息，基于高斯混合模型对骨骼、空气和软组织进行分割。我们提出了两种方法的骨衰减系数分配的结果：一个使用恒定的衰减校正值;和另一个使用基于校准拟合的估计连续衰减值。进行定量比较，以评价重建的PET图像的准确性，相对于手动分割的衰减图重建的参考图像。与UTE方法和其他最先进的技术相比，图像中空气和骨区域的DICE系数分析显示出改进。使用恒定的骨衰减系数值获得最准确的全脑和局部脑分析。提出了一种新的PET数据重建衰减校正方法。分析表明，与同步PET/MR扫描仪的其他最先进的AC方法相比，重建PET图像的定量准确性有所提高。需要对FDG以外的放射性药物进行进一步评估，并在更大的参与者队列中进行评估。
Attenuation correction is one of the most crucial correction factors for accurate PET data quantitation in hybrid PET/MR scanners, and computing accurate attenuation coefficient maps from MR brain acquisitions is challenging. Here, we develop a method for accurate bone and air segmentation using MR ultrashort echo time (UTE) images. MR UTE images from simultaneous MR and PET imaging of five healthy volunteers was used to generate a whole head, bone and air template image for inclusion into an improved MR derived attenuation correction map, and applied to PET image data for quantitative analysis. Bone, air and soft tissue were segmented based on Gaussian Mixture Models with probabilistic tissue maps as a priori information. We present results for two approaches for bone attenuation coefficient assignments: one using a constant attenuation correction value; and another using an estimated continuous attenuation value based on a calibration fit. Quantitative comparisons were performed to evaluate the accuracy of the reconstructed PET images, with respect to a reference image reconstructed with manually segmented attenuation maps. The DICE coefficient analysis for the air and bone regions in the images demonstrated improvements compared to the UTE approach, and other state-of-the-art techniques. The most accurate whole brain and regional brain analyses were obtained using constant bone attenuation coefficient values. A novel attenuation correction method for PET data reconstruction is proposed. Analyses show improvements in the quantitative accuracy of the reconstructed PET images compared to other state-of-the-art AC methods for simultaneous PET/MR scanners. Further evaluation is needed with radiopharmaceuticals other than FDG, and in larger cohorts of participants.
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影响因子：
10.6
作者：
Burgos, Ninon;Cardoso, M. Jorge;Ourselin, Sebastien
通讯作者：
Ourselin, Sebastien
影响因子：
4.3
作者：
Aiello M;Cavaliere C;Salvatore M
通讯作者：
Salvatore M
DOI：
10.1007/s00259-002-0796-3
发表时间：
2002-07-01
影响因子：
9.1
作者：
Burger, C;Goerres, G;von Schulthess, GK
通讯作者：
von Schulthess, GK
影响因子：
9.3
作者：
Cabello, Jorge;Lukas, Mathias;Ziegler, Sibylle I.
通讯作者：
Ziegler, Sibylle I.
影响因子：
2.6
作者：
Izquierdo-Garcia D;Catana C
通讯作者：
Catana C