Transmission imaging for integrated PET-MR systems.
Transmission imaging for integrated PET-MR systems.
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DOI：
10.1088/0031-9155/61/15/5547
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发表时间：
2016-08-07
影响因子：
3.5
通讯作者：
Catana C
中科院分区：
文献类型：
--
作者：
Bowen SL;Fuin N;Levine MA;Catana C
PET-MR系统的衰减校正仍然是一个具有挑战性的问题，特别是对于头部以外的身体区域。在集成的μ-MR系统上同时采集基于传输扫描的μ-MAP和MR图像可以显著提高基于MR的新的MAP算法的性能并为其提供验证。然而，对于Bioggraph MMR(西门子医疗保健)，使用传统的传输方案是不现实的，因为患者床和相对较小的直径扫描仪穿孔严重限制了放射源的运动和限制源的放置。我们提出了一种在Bioggraph MMR上实现无发射符合传输成像的方法。预期的应用不是用于常规的受试者成像，而是改进和验证基于MR的μ-MAP算法；特别是用于患者植入和扫描仪硬件衰减校正。在这项研究中，我们优化了震源几何结构，并通过蒙特卡罗模拟和体模扫描评估了该方法的性能。我们使用了贝叶斯重建算法，该算法直接从多个床位生成μ-MAP估计，并结合稳健的散射校正方法。对于骨盆体模的模拟，单个环面产生的峰值噪声等效计数率(34.8kcps)显着高于全轴长环(11.32kcps)和传统的旋转源配置。对于头部和骨盆模拟，重建的μ-MAP的偏差对于软组织是≤4%，对于骨ROI是≤11%。用18F-氟代脱氧葡萄糖填充单一环形源的实现，并将所提出的方法单独对几个测试案例进行量化，或与CT导出的μ-MAP进行比较。实验性均匀圆柱体体模扫描的平均体积为0.095 cm−1，而多间隔体模的皮质骨等效位置体的偏差为<；2%。与CT结果相比，髋关节植入体模的单环μ图显示明显更少的伪影和更好的动态范围，在患者床的情况下，高度衰减材料的差异很大。使用固定的环面几何结构，结合平移患者床面来执行完整的断层扫描采样，生成高定量的测量μ图，并有望在匹配的总采集时间产生比竞争的固定几何结构显著更高的信噪比图像。
Attenuation correction for PET-MR systems continues to be a challenging problem, particularly for body regions outside the head. The simultaneous acquisition of transmission scan based μ-maps and MR images on integrated PET-MR systems may significantly increase the performance of and offer validation for new MR-based μ-map algorithms. For the Biograph mMR (Siemens Healthcare), however, use of conventional transmission schemes is not practical as the patient table and relatively small diameter scanner bore significantly restrict radioactive source motion and limit source placement. We propose a method for emission-free coincidence transmission imaging on the Biograph mMR. The intended application is not for routine subject imaging, but rather to improve and validate MR-based μ-map algorithms; particularly for patient implant and scanner hardware attenuation correction. In this study we optimized source geometry and assessed the method's performance with Monte Carlo simulations and phantom scans. We utilized a Bayesian reconstruction algorithm, which directly generates μ-map estimates from multiple bed positions, combined with a robust scatter correction method. For simulations with a pelvis phantom a single torus produced peak noise equivalent count rates (34.8 kcps) dramatically larger than a full axial length ring (11.32 kcps) and conventional rotating source configurations. Bias in reconstructed μ-maps for head and pelvis simulations was ≤4% for soft tissue and ≤11% for bone ROIs. An implementation of the single torus source was filled with 18F-fluorodeoxyglucose and the proposed method quantified for several test cases alone or in comparison with CT-derived μ-maps. A volume average of 0.095 cm−1 was recorded for an experimental uniform cylinder phantom scan, while a bias of <2% was measured for the cortical bone equivalent insert of the multi-compartment phantom. Single torus μ-maps of a hip implant phantom showed significantly less artifacts and improved dynamic range, and differed greatly for highly attenuating materials in the case of the patient table, compared to CT results. Use of a fixed torus geometry, in combination with translation of the patient table to perform complete tomographic sampling, generated highly quantitative measured μ-maps and is expected to produce images with significantly higher SNR than competing fixed geometries at matched total acquisition time.
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DOI：
10.1056/nejmoa0901249
发表时间：
2009-08-27
期刊：
The New England journal of medicine
影响因子：
--
作者：
Fazel R;Krumholz HM;Wang Y;Ross JS;Chen J;Ting HH;Shah ND;Nasir K;Einstein AJ;Nallamothu BK
通讯作者：
Nallamothu BK
影响因子：
19.7
作者：
Goerres, GW;Ziegler, SI;Buck, A
通讯作者：
Buck, A
影响因子：
1.8
作者：
Dahlbom, M;Schiepers, C;Czernin, J
通讯作者：
Czernin, J
影响因子：
3.5
作者：
Delso, G.;Martinez-Moeller, A.;Ziegler, S. I.
通讯作者：
Ziegler, S. I.
影响因子：
3.3
作者：
Pace, Leonardo;Nicolai, Emanuele;Salvatore, Marco
通讯作者：
Salvatore, Marco