Acquisition settings for PET of 124I administered simultaneously with therapeutic amounts of 131I.
Acquisition settings for PET of 124I administered simultaneously with therapeutic amounts of 131I.
复制标题
124I PET 采集设置与治疗量的 131I 同时施用。
作者：
M. Lubberink;A. van Schie;H. de Jong;G. V. van Dongen;G. Teule
无标签
131I治疗甲状腺癌的放射剂量测定可以通过124I联合给药，然后进行几天的纵向PET扫描来进行。131I发射的光子可能会影响PET图像质量。本研究的目的是评估在不同的采集设置下，大量的~(131)I对PET图像质量和准确性的影响。
方法
用标准的临床PET扫描仪测量124I的噪声当量计数(NEC)率。除标准的350-650keV能量窗外，还使用425-650keV和460-562keV的能量窗，并在有(2维)和无(3维[3D])间隔的情况下采集数据。重复扫描包含6个热球的体模，其中填充有131I和124I的组合，球体与背景比为18：1，能量窗设置如图所示，发射和透射式扫描持续时间分别为7分钟和3分钟。计算NEC率，并与仅填充124I的体模测量的NEC率进行比较。确定重建图像中球体与背景的比率。1例已知的转移性甲状腺癌患者分别在注射5.5GBq的131I和75MBq的124I后，分别在第3天和第6天用能量窗设置和扫描时间进行扫描。
结果
在3D模式下，使用425到650 keV的能量窗获得了最高的124I-Only NEC率。在~(131)I存在的情况下，3D模式下给出最高NEC速率和对比度的设置为425-650keV和460-5262kev，临床扫描在相同设置下提供最高质量的图像。
结论
在425至650 keV或460至562 keV窗口的3D模式下进行采集，可在使用标准临床PET扫描仪在存在大量131I的情况下对124I进行成像时，获得最高的图像质量和对比度。
UNLABELLED
Radiation dosimetry of thyroid cancer therapy with 131I can be performed by coadministration of 124I followed by longitudinal PET scans over several days. The photons emitted by 131I may affect PET image quality. The aim of this study was to assess the influence of large amounts of 131I on PET image quality and accuracy with various acquisition settings.
METHODS
Noise equivalent count (NEC) rates of 124I only were measured with a standard clinical PET scanner. Apart from the standard 350- to 650-keV energy window, 425- to 650-keV and 460- to 562-keV windows were used and data were acquired both with (2-dimensional) and without (3-dimensional [3D]) septa. A phantom containing 6 hot spheres, filled with a combination of 131I and 124I and with a sphere-to-background ratio of 18:1, was scanned repeatedly with energy window settings as indicated and emission and transmission scan durations of 7 and 3 min, respectively. NEC rates were calculated and compared with those measured with the phantom filled with only 124I. Sphere-to-background ratios in the reconstructed images were determined. One patient with known metastatic thyroid cancer was scanned using energy window settings and scan times as indicated 3 and 6 d after administration of 5.5 GBq of 131I and 75 MBq of 124I.
RESULTS
The highest 124I-only NEC rates were obtained using a 425- to 650-keV energy window in 3D mode. In the presence of (131)I, the settings giving the highest NEC rate and contrast were 425-650 keV and 460-562 keV in 3D mode, with the clinical scans giving the highest quality images with the same settings.
CONCLUSION
Acquisition in 3D mode with a 425- to 650-keV or 460- to 562-keV window leads to the highest image quality and contrast when imaging 124I in the presence of large amounts of 131I using a standard clinical PET scanner.
DOI：
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发表时间：
2004-08
期刊：
Journal of nuclear medicine : official publication, Society of Nuclear Medicine
影响因子：
--
作者：
G. Sgouros;K. Kolbert;A. Sheikh;K. Pentlow;Edward Mun;A. Barth;R. Robbins;S. Larson
通讯作者：
G. Sgouros;K. Kolbert;A. Sheikh;K. Pentlow;Edward Mun;A. Barth;R. Robbins;S. Larson
影响因子：
158.5
作者：
MACH, JP;CARREL, S;ALBERTO, P
通讯作者：
ALBERTO, P
影响因子：
3.8
作者：
Beattie, BJ;Finn, RD;Pentlow, KS
通讯作者：
Pentlow, KS