OBJECT-SPECIFIC ATTENUATION CORRECTION OF SPECT WITH CORRELATED DUAL-ENERGY X-RAY CT
OBJECT-SPECIFIC ATTENUATION CORRECTION OF SPECT WITH CORRELATED DUAL-ENERGY X-RAY CT
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DOI：
10.1109/23.256618
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发表时间：
1993-08-01
影响因子：
1.8
通讯作者：
RAMANATHAN, C
中科院分区：
文献类型：
--
作者：
HASEGAWA, BH;LANG, TF;RAMANATHAN, C
我们已经开发了一个原型发射透射计算机断层扫描（ETCT）系统，它可以获得放射性核素发射和双能X射线透射数据。双能量X射线数据用于合成对象和能量特异性衰减图，该衰减图被并入ML-EM算法以重建衰减校正的SPECT图像。该技术被应用到一个类似胸部的体模与区域模拟肺，背景和心脏区域，和骨。与体模中所含的放射性浓度相比，未进行衰减校正或使用均匀水当量标测图重建的SPECT图像中，肺区域的计数水平增加，心脏区域的计数水平降低。使用对象特定的衰减图提高了重建的准确性，但高估了约10%的心腔中的活动。当衰减系数被修改以包括散射辐射的影响时，该误差减小到约5%。
We have developed a prototype emission-transmission computed tomographic (ETCT) system, which can acquire both radionuclide-emission and dual-energy X-ray transmission data. The dual-energy X-ray data are used to synthesize an object- and energy-specific attenuation map which is incorporated into an ML-EM algorithm to reconstruct an attenuation-corrected SPECT image. The technique was applied to a thorax-like phantom with regions simulating lung, background and cardiac regions, and bone. SPECT images reconstructed with no attenuation correction, or with a uniform water-equivalent map, contained increased count levels in the lung region and reduced count levels in the cardiac region as compared with the radioactivity concentrations contained in the phantom. Use of an object-specific attenuation map improved the accuracy of the reconstruction, but overestimated the activity in the cardiac chamber by about 10%. This error was reduced to about 5% when the attenuation coefficients were modified to include the effects of scattered radiation.