Goethals Ingeborg, D'Asseler Yves, Dobbeleir André, Deblaere Karel, Ham Hamphrey
Department of Nuclear Medicine, Ghent University Hospital, B-9000 Ghent, Belgium.
Nucl Med Commun. 2010 Mar;31(3):227-31. doi: 10.1097/MNM.0b013e328334fbfd.
To evaluate the impact of acquisition time on F-18 fluorodeoxyglucose positron emission tomography (PET) image quality, lesion detection rate, standard uptake and lesion volume measures.
In 17 consecutively referred head and neck cancer patients, a 10-min acquisition of the head and neck was performed in list mode after completion of a whole-body PET-computed tomography scan. For each patient, 0.5, 1, 2, 3, 5, 7 and 10-min PET images were reconstructed. Image quality was scored on a 5-point scale. Lesions were visually identified and lesion locations were compared between scans with various acquisition times. Standard uptake values (SUVs) and lesion volumes were automatically obtained and compared.
Image quality was scored excellent/good for 10 and 7-min scans; moderate for 5 and 3-min scans and poor/very poor for 2, 1 and 0.5-min scans. Lesion detection rate did not differ between scans with shorter acquisition times and the reference. Similarly, SUVmax was not significantly different between images with various scan times and the reference, except for the 0.5-min PET image (Wilcoxon, P = 0.04). Overall, lesion volume increased significantly with longer scan time (Friedman, P<0.0001). For individual lesions, however, the effect of scan time on volume was quite variable. The variability was significantly larger for images with scan times below 3 min than for images with scan times of > or = 3 min.
Despite poor image quality for scans with short acquisition times, the lesion detection rate was not adversely affected. Increased scan time resulted in an increase in lesion volumes. This finding is of particular interest if PET images are implemented in radiation oncology treatment planning.
评估采集时间对F-18氟脱氧葡萄糖正电子发射断层扫描（PET）图像质量、病变检测率、标准摄取值及病变体积测量的影响。
对17例连续转诊的头颈癌患者，在完成全身PET-计算机断层扫描后，以列表模式对头颈部进行10分钟的采集。对每位患者，重建0.5、1、2、3、5、7和10分钟的PET图像。图像质量按5分制评分。目视识别病变，并比较不同采集时间扫描之间的病变位置。自动获取并比较标准摄取值（SUV）和病变体积。
10分钟和7分钟扫描的图像质量评分为优秀/良好；5分钟和3分钟扫描为中等；2分钟、1分钟和0.5分钟扫描为差/非常差。较短采集时间的扫描与参考扫描之间的病变检测率无差异。同样，除0.5分钟PET图像外，不同扫描时间的图像与参考图像之间的SUVmax无显著差异（Wilcoxon检验，P = 0.04）。总体而言，病变体积随扫描时间延长而显著增加（Friedman检验，P<0.0001）。然而，对于单个病变，扫描时间对体积的影响差异很大。扫描时间低于3分钟的图像的变异性明显大于扫描时间≥3分钟的图像。
尽管采集时间短的扫描图像质量较差，但病变检测率未受到不利影响。扫描时间增加导致病变体积增大。如果在放射肿瘤治疗计划中应用PET图像，这一发现尤其值得关注。
