应用NEMA 2001标准测试Biograph 64/True V PET／CT性能

Biograph 64/True V performance measurements for a combined PET/CT scanner using the National Electrical Manufacturers Association 2001 standard

目的应用美国国家电器制造商协会（NEMA）2001标准对Biograph 64／True V（TV）PET／CT性能进行测试，以提供Biograph 64／TV测试数据并进行新老仪器测试结果对照。方法用NEMA 2001模型和测试方法测试Biograph 64／TV PET／CT空间分辨率、灵敏度、散射分数和计数丢失参数，测试中使用^18F。用空间分辨率模型测试空间分辨率。将放射性活度4．07 MBq的^18F注射到NEMA PET灵敏度模型，测试灵敏度，每300s采集1次数据。测散射分数和噪声等效计数：采用散射模型，且向模型内置入活度1．037MBq ^18F，采集35帧，每帧采集10min，间隔15min。使用体部模型图像评估图像质量，按照NEMA2001公式得到测试结果。结果离视野（FOV）中心1cm处径向和轴向空间分辨率分别为4．2和4．7min，10cm处分别为4．9和5．9mm。系统灵敏度为6．95×10^3计数·s^-1·MBq^-1。散射分数为32％，噪声等效计数率（NECR）为1．46×10^5计数／s和9．80×10^4计数／s。结论Biograph 64／TV PET／CT性能较好，空间分辨率小，灵敏度高，散射分数低，NECR较高。

Objective Biograph 64/True V performance measurements were performed using National Electrical Manufacturers Association （NEMA） 2001 standard. It could provide PET/CT NEMA 2001 data, and analyze the advantage of Biograph 64/True V PET/CT by comparing testing results with other PET/ CT data. Methods Performance measurements included spatial resolution, sensitivity, scatter fraction and count loss. ^18F was used through out the testing. Spatial resolution based on its model. About 4.07 MBq ^18F was injected into NEMA PET sensitivity model and the data was collected every 300 s. Scatter fraction and noise equivalent count were tested using scatter model with 1. 037 MBq ^18F injected in, and the data was collected every 15 min, every fragment for 10 min, totally 35 fragments. According to NEMA 2001 formula, image quality was evaluated based on body model. Results Average transverse and axial spatial resolution at 1 cm and at 10 cm off center was 4.2（4.7） mm and 4.6（5.9） mm respectively. System sensitivity was 6.95×10^3· s^-1 · MBq^-1 for the two radial positions（0 and 10 cm）. System scatter fraction was 32%. And noise equivalent count rate （NECR） was 1.46 × 10^5/s and 9.80 × 10^4/s. Conclusion The integrated PET/CT system Biograpb 64/True V has overall excellent performance, in particularly, good resolution, high sensitivity, low scatter fraction and good NECR response.