Quantification of cerebral blood flow and oxygen metabolism with 3-dimensional PET and 15O:: Validation by comparison with 2-dimensional PET
Quantification of cerebral blood flow and oxygen metabolism with 3-dimensional PET and 15O:: Validation by comparison with 2-dimensional PET
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DOI：
10.2967/jnumed.107.044008
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发表时间：
2008-01-01
影响因子：
9.3
通讯作者：
Amano, Masaharu
中科院分区：
文献类型：
--
作者：
Ibaraki, Masanobu;Miura, Shuichi;Amano, Masaharu
O-15 定量 PET 提供脑血流量 (CBF)、脑血容量 (CBV)、脑氧代谢率 (CMRO2) 和氧提取分数 (OEF) 的绝对值，用于评估脑病理生理学。绝对定量依赖于物理上的精确测量，迄今为止，这已通过二维PET（2D PET）实现，这是当前CBF和氧代谢测量的金标准。我们调查了使用 3 维 PET (3D PET) 进行的定量 O-15 研究是否具有与 2D PET 相同的准确度。方法：同一天对 8 名健康男性（年龄，21-24 岁）进行 2D PET 和 3D PET 测量。 2D PET 使用配备锗酸铋 (BGO) 探测器和 150 毫米轴向视场 (FOV) 的 PET 扫描仪进行。对于 3D PET，使用带有氧原硅酸钆 (GSO) 探测器和 156 毫米轴向 FOV 的纯 3D 断层扫描仪。 3D PET 研究中应用了基于双能量窗口采集的混合散射校正方法（混合双能量窗口 [HDE] 方法）。每项 PET 研究均包括 (CO)-O-15、O-15(2) 和 (H2O)-O-15 的 3 次连续 PET 扫描（三步法）。 3D PET 的吸入（或注射）剂量约为 2D PET 的四分之一。结果：在 2D PET 研究中，CBF、CBV、CMRO2 和 OEF 的平均灰质值（平均值 +/- SD）分别为 53 +/- 12 (mL/100 mL/min)、3.6 +/- 0.3 (mL/100 mL)、3.5 +/- 0.5 (mL/100 mL/min) 和 0.35 +/- 0.06。在 3D PET 研究中，散射校正对结果影响很大。未经散射校正，平均值分别为 44 +/- 6 (mL/1100 mL/min)、5.2 +/- 0.6 (mL/100 mL)、3.3+/- 0.4 (mL/100 mL/min) 和 0.39 +/- 0.05。除 OEF 外，2D PET 和 3D PET 之间的值有所不同。然而，散射校正 3D PET 的平均灰质值与 2D PET 的平均灰质值相当：分别为 55 +/- 11 (mL/100 mL/min)、3.7 +/- 0.5 (mL/100 mL)、3.8 +/- 0.7 (mL/100 mL/min) 和 0.36 +/- 0.06。尽管使用了具有不同晶体材料、数据采集系统、空间分辨率和衰减校正方法的2 PET扫描仪，2D PET和散射校正3D PET之间的结果的一致性非常好。结论：散射重合是 3D PET 定量 150 研究中的一个问题。本发明的 PET/CT 设备和 HDE 散射校正的组合允许定量 3D PET，其精度与 2D PET 相同，并且辐射剂量更低。如果适当调整吸入剂量，本扫描仪也适用于常规稳态150气体吸入。
Quantitative PET with O-15 provides absolute values for cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral metabolic rate of oxygen (CMRO2), and oxygen extraction fraction (OEF), which are used for assessment of brain pathophysiology. Absolute quantification relies on physically accurate measurement, which, thus far, has been achieved by 2-dimensional PET (2D PET), the current gold standard for measurement of CBF and oxygen metabolism. We investigated whether quantitative O-15 study with 3-dimensional PET (3D PET) shows the same degree of accuracy as 2D PET. Methods: 2D PET and 3D PET measurements were obtained on the same day on 8 healthy men (age, 21-24 y). 2D PET was performed using a PET scanner with bismuth germanate (BGO) detectors and a 150-mm axial field of view (FOV). For 3D PET, a 3D-only tomograph with gadolinium oxyorthosilicate (GSO) detectors and a 156-mm axial FOV was used. A hybrid scatter-correction method based on acquisition in the dual-energy window (hybrid dual-energy window [HDE] method) was applied in the 3D PET study. Each PET study included 3 sequential PET scans for (CO)-O-15, O-15(2), and (H2O)-O-15 (3-step method). The inhaled (or injected) dose for 3D PET was approximately one fourth of that for 2D PET. Results: In the 2D PET study, average gray matter values (mean +/- SD) of CBF, CBV, CMRO2, and OEF were 53 +/- 12 (mL/100 mL/min), 3.6 +/- 0.3 (mL/100 mL), 3.5 +/- 0.5 (mL/100 mL/min), and 0.35 +/- 0.06, respectively. In the 3D PET study, scatter correction strongly affected the results. Without scatter correction, average values were 44 +/- 6 (mL/1100 mL/min), 5.2 +/- 0.6 (mL/100 mL), 3.3+/- 0.4 (mL/100 mL/min), and 0.39 +/- 0.05, respectively. With the exception of OEF, values differed between 2D PET and 3D PET. However, average gray matter values of scatter-corrected 3D PET were comparable to those of 2D PET: 55 +/- 11 (mL/100 mL/min), 3.7 +/- 0.5 (mL/100 mL), 3.8 +/- 0.7 (mL/100 mL/min), and 0.36 +/- 0.06, respectively. Even though the 2 PET scanners with different crystal materials, data acquisition systems, spatial resolution, and attenuation-correction methods were used, the agreement of the results between 2D PET and scatter-corrected 3D PET was excellent. Conclusion: Scatter coincidence is a problem in 3D PET for quantitative 150 study. The combination of both the present PET/CT device and the HDE scatter correction permits quantitative 3D PET with the same degree of accuracy as 2D PET and with a lower radiation dose. The present scanner is also applicable to conventional steady-state 150 gas inhalation if inhaled doses are adjusted appropriately.