Kaneta Tomohiro, Ogawa Matsuyoshi, Motomura Nobutoku, Iizuka Hitoshi, Arisawa Tetsu, Hino-Shishikura Ayako, Yoshida Keisuke, Inoue Tomio
Department of Radiology, Yokohama City University, Yokohama, Japan.
Nuclear Medicine System Development Department, Toshiba Medical Systems Corporation, Tochigi, Japan.
EJNMMI Res. 2017 Oct 11;7(1):83. doi: 10.1186/s13550-017-0331-y.
The goal of this study was to evaluate the performance of the Celesteion positron emission tomography/computed tomography (PET/CT) scanner, which is characterized by a large-bore and time-of-flight (TOF) function, in accordance with the NEMA NU-2 2012 standard and version 2.0 of the Japanese guideline for oncology fluorodeoxyglucose PET/CT data acquisition protocol. Spatial resolution, sensitivity, count rate characteristic, scatter fraction, energy resolution, TOF timing resolution, and image quality were evaluated according to the NEMA NU-2 2012 standard. Phantom experiments were performed using F-solution and an IEC body phantom of the type described in the NEMA NU-2 2012 standard. The minimum scanning time required for the detection of a 10-mm hot sphere with a 4:1 target-to-background ratio, the phantom noise equivalent count (NEC), % background variability (N ), % contrast (Q ), and recovery coefficient (RC) were calculated according to the Japanese guideline.
The measured spatial resolution ranged from 4.5- to 5-mm full width at half maximum (FWHM). The sensitivity and scatter fraction were 3.8 cps/kBq and 37.3%, respectively. The peak noise-equivalent count rate was 70 kcps in the presence of 29.6 kBq mL in the phantom. The system energy resolution was 12.4% and the TOF timing resolution was 411 ps at FWHM. Minimum scanning times of 2, 7, 6, and 2 min per bed position, respectively, are recommended for visual score, noise-equivalent count (NEC), N , and the Q to N ratio (QNR) by the Japanese guideline. The RC of a 10-mm-diameter sphere was 0.49, which exceeded the minimum recommended value.
The Celesteion large-bore PET/CT system had low sensitivity and NEC, but good spatial and time resolution when compared to other PET/CT scanners. The QNR met the recommended values of the Japanese guideline even at 2 min. The Celesteion is therefore thought to provide acceptable image quality with 2 min/bed position acquisition, which is the most common scan protocol in Japan.
本研究的目的是根据NEMA NU - 2 2012标准以及日本肿瘤学氟脱氧葡萄糖PET/CT数据采集协议2.0版，评估具有大孔径和飞行时间（TOF）功能的Celesteion正电子发射断层扫描/计算机断层扫描（PET/CT）扫描仪的性能。根据NEMA NU - 2 2012标准对空间分辨率、灵敏度、计数率特性、散射分数、能量分辨率、TOF定时分辨率和图像质量进行评估。使用F溶液和NEMA NU - 2 2012标准中描述的类型的IEC体模进行体模实验。根据日本指南计算检测具有4:1靶本底比的10毫米热球所需的最短扫描时间、体模噪声等效计数（NEC）、本底变化百分比（N ）、对比度百分比（Q ）和恢复系数（RC）。
测得的空间分辨率在半高宽（FWHM）为4.5至5毫米范围内。灵敏度和散射分数分别为3.8 cps/kBq和37.3%。在体模中存在29.6 kBq/mL时，峰值噪声等效计数率为70 kcps。系统能量分辨率为12.4%，TOF定时分辨率在FWHM时为411 ps。根据日本指南，每个床位位置的视觉评分、噪声等效计数（NEC）、N 和Q 与N 之比（QNR）的推荐最短扫描时间分别为2、7、6和2分钟。直径10毫米球体的RC为0.49，超过了推荐的最小值。
与其他PET/CT扫描仪相比，Celesteion大孔径PET/CT系统灵敏度和NEC较低，但具有良好的空间和时间分辨率。即使在2分钟时，QNR也符合日本指南的推荐值。因此，Celesteion被认为在每个床位位置采集2分钟时可提供可接受的图像质量，这是日本最常见的扫描方案。
