PET/CT图像采集时间对图像质量和病灶检出率的影响  

The influence of acquisition time on PET/CT imaging quality and lesion detectability

作　　者：陈香[1] 赵军[1] 管一晖[1] 薛方平[1] 左传涛[1] 华逢春[1] 

机构地区：[1]复旦大学附属华山医院核医学科PET中心,上海200235

出　　处：《中华核医学杂志》2007年第1期43-45,共3页Chinese Journal of Nuclear Medicine

摘　　要：目的探讨在不影响图像质量和病灶检出率前提下缩短 PET/CT 图像采集时间的可行性。方法 18例接受 PET/CT 检查的患者,在 CT 扫描后按1、2、3 min/床位依次进行3次 PET 扫描,共得到54帧图像。患者按体重分为以下3组:(1)45～60 kg(7例),(2)61～75 kg(7例),(3)76～90 kg(4例)。由2位有经验的医师共同阅片确定每例患者病变的位置和数目,图像质量由2位医师独立判断。结果 3 min/床位 PET/CT 图像上共检出127个病灶,其中最小的病灶直径约为3 mm,除1 min/床位图像漏检3个病灶外,其他所有病灶均能被1 min/床位、2 min/床位的图像识别。(1)～(3)组患者在3 min/床位采集图像上识别的病灶数分别为71、41、15个,第1组患者的所有病灶在3种不同采集时间图像上均能被识别,第2组患者1 min/床位采集图像遗漏了3个病灶,而2 min/床位图像识别出的病灶数与3 min/床位图像相同。第3组患者的所有病灶在3种采集图像上也均能被识别。1、2 min/床位的 PET 图像质量均较3 min/床位图像差,1 min/床位图像质量最差,主要表现为图像本底噪声高、对比度差。3组患者中,第3组患者图像质量最差。结论对体重低于60 kg 患者,1～3 min 的采集时间,病变的检出率无明显差异;而对体重60 kg 以上患者,建议选择2～3 min/床位的采集时间,对病情较重或不合作患者,根据需要可考虑选择1 min/床位的采集时间。Objective To explore the feasibility of shortening the acquisition time without influencing the image quality and detectability by analysing PET/CT imaging with different acquisition time. Methods PET emission scan of 18 patients was performed in sequence of 1 min/bed, 2 min/bed, 3 min/bed after CT scan. Fifty-four images were totally obtained. Patients were grouped according to body weight ： （ 1 ） 45 - 60 kg （ n = 7 ）, （ 2 ） 61 - 75 kg （ n = 7 ）, （ 3 ） 75 - 90 kg （ n = 4 ） o Lesion detectability were co-analyzed by two experienced doctors ; while image quality was judged separately by them. Results One hundred and twenty-seven lesions were identified in 3 min/bed PET images （n = 18） ; the smallest size was 3 mm. Only 3 were missed in 1 min/bed PET images, and all lesions were identified in the corresponding 2 min/bed PET images. All lesions from first group could be detected in the three kinds of acquisition time. Three lesions from second group were missed in the 1 rain/bed PET images. Image quality of 1 and 2 min/bed differed significantly from the 3 min/bed （P 〈 0.05 ） especially in high body weight patients; image quality of 1 min/bed was the worst. Conclusions For patients with body weight less than 60 kg, 1 - 3 min/bed acquisition protocols show no difference both with lesion detectability and image quality, while in patients with body weight over 60 kg, 2 - 3 min/bed acquisition is suggested. For patients with serious and uncooperated conditions, 1 min/bed acquisition protocol can be selected if necessary.

关 键 词：体层摄影术 发射型计算机 体层摄影术 X线计算机 时间 质量控制 

分 类 号：R817[医药卫生—影像医学与核医学] TP391.41[医药卫生—放射医学]