Respiratory average CT for attenuation correction in myocardial perfusion SPECT/CT
Respiratory average CT for attenuation correction in myocardial perfusion SPECT/CT
复制标题
用于心肌灌注 SPECT/CT 衰减校正的呼吸平均 CT
DOI：
10.1007/s12149-016-1144-1
复制
发表时间：
2017-02-01
影响因子：
2.6
通讯作者：
Mok, Greta Seng Peng
中科院分区：
文献类型：
--
作者：
Zhang, Duo;Yang, Bang-Hung;Mok, Greta Seng Peng
已经提出了连续电影平均CT（CACT）和插值平均CT（IACT），以改善肿瘤和心脏研究中PET/CT的衰减校正（AC）。本研究旨在评估其有效性心肌灌注SPECT/CT使用计算机模拟和物理phantom experiments.MethodsWe第一次模拟正常男性与99 mTc-sestamibi分布使用数字XCAT体模与呼吸运动幅度为2，3，和4厘米。平均活动和衰减图代表静态SPECT和CACT，而吸气末和呼气末的衰减图分别代表两个螺旋CT（HCT）。使用分析平行孔投影仪在180°范围内模拟了60个无噪声和有噪声投影。然后，我们将673 MBq 99 mTc填充到具有正常心脏或具有缺陷的心脏的拟人躯干体模中，该体模放置在可编程呼吸平台上以模拟各种呼吸幅度。使用临床SPECT/CT扫描仪在180°范围内采集60个投影。采集CACT、标准HCT和极端相位的2个HCT。使用仿射加b样条配准在它们之间生成内插CT相位，并且通过对模拟和体模实验的内插相位和2个原始极端相位进行平均来获得IACT。分别使用CACT、IACT和HCT用AC重建投影。通过摄取的相对差（RD）分析极坐标图和17段图。在缺损区和背景区分别绘制感兴趣区域（ROI），得到强度比（IR）。结果不同AC方法生成的极坐标图无明显差异，而定量RD测量结果显示SPECTCACT与原始体模最相似，其次是SPECTIACT，模拟研究中RDmax<8，<10%。SPECTHCT的RD在不同段偏离了原始体模和SPECTCACT，模拟和体模实验的RD max分别为19.76%和16.68%。IR的SPECTHCTsfluctuated从真理更高的运动amplitude.ConclusionsBoth CACT-AC和IACT-AC减少呼吸伪影和改善定量心肌灌注SPECT相比，HCT-AC。IACT的使用进一步降低了辐射剂量。
ObjectiveCine average CT (CACT) and interpolated average CT (IACT) have been proposed to improve attenuation correction (AC) for PET/CT in oncologic and cardiac studies. This study aims to evaluate their effectiveness on myocardial perfusion SPECT/CT using computer simulation and physical phantom experiments.MethodsWe first simulated normal male with99mTc-sestamibi distribution using digital XCAT phantom with respiratory motion amplitudes of 2, 3, and 4 cm. Average activity and attenuation maps represented static SPECT and CACT, while the attenuation maps of end-inspiration and end-expiration represented two helical CTs (HCTs), respectively. Sixty noise-free and noisy projections were simulated over 180° using an analytical parallel-hole projector. We then filled 673 MBq99mTc into an anthropomorphic torso phantom with normal heart or heart with a defect which placed on a programmable respiratory platform to model various respiratory amplitudes. Sixty projections were acquired over 180° using a clinical SPECT/CT scanner. The CACT, standard HCT, and 2 HCTs at extreme phases were acquired. Interpolated CT phases were generated between them using affine plus b-spline registration, and IACT was obtained by averaging the interpolated phases and the 2 original extreme phases for both simulation and phantom experiments. Projections were reconstructed with AC using CACT, IACT, and HCTs, respectively. Polar and 17-segment plots were analyzed by relative difference (RD) of the uptake. Two regions-of-interest (ROI) were drawn on the defect and background area to obtain the intensity ratio (IR).ResultsNo substantial difference was observed on the polar plots generated from different AC methods, while the quantitative RD measurements showed that SPECTCACTwere most similar to the original phantom, followed by SPECTIACT, with RDmax<8 and <10% in the simulation study. The RD of SPECTHCTsdeviated from the original phantom and SPECTCACTin various segments, with RDmaxof 19.76 and 16.68% in the simulation and phantom experiment, respectively. The IR of SPECTHCTsfluctuated more from the truth for higher motion amplitude.ConclusionsBoth CACT-AC and IACT-AC reduced respiratory artifacts and improved quantitation in myocardial perfusion SPECT as compared to HCT-AC. The use of IACT further reduced the radiation dose.