[68Ga]Ga-FAPI-04（用镓-68标记的纤维母细胞激活蛋白抑制剂-04）PET/CT在诊断恶性肿瘤方面得到了广泛应用。全身PET/CT具有长轴向视野，并相比传统PET/CT具有更高的灵敏度。然而，降低注射剂量的[68Ga]Ga-FAPI-04是否能够获得合格的成像尚未评估。探究半剂量[68Ga]Ga-FAPI-04对肿瘤学患者影像质量和肿瘤可检测性的影响。共纳入27例肿瘤或临床疑似肿瘤的患者，所有患者在注射剂量为0.84-1.14 MBq/kg的[68Ga]Ga-FAPI-04后进行全身PET/CT扫描。所有患者在300 s的原始采集时间下获得了优越的图像质量。采用有序子集期望最大化算法对图像进行180 s、120 s、60 s、40 s、30 s和20 s的扫描时间的重建。采用5分制Likert量表对各时间组中所有患者的主观图像质量进行评分。以纵膈血池、肝脏、脾脏和肌肉为背景，使用半定量参数最大标准摄取值（SUVmax）、平均标准摄取值（SUVmean）、标准差（SD）和信噪比（SNR）进行分析。对经病理证实的肿瘤计算病变检出率、SUVmax和病灶与背景之间的比值（TBR）。随着扫描时间的缩短，主观图像质量评分下降；然而，180 s和120 s图像在整体质量、病变清晰度和图像噪声方面均满足诊断要求。背景的SUVmax随着扫描时间的缩短而增加，而SUVmean相对稳定。随着扫描时间的缩短，SD逐渐增加，SNR逐渐降低，这与主观图像质量评分一致。在180 s和120 s图像中，所有11个原发病灶和79个转移病灶均被检出。肿瘤病灶的SUVmax呈逐渐增加的趋势，与背景一致。与300 s相比，在180 s和120 s中，肌肉的TBR无统计学差异。半剂量的[68Ga]Ga-FAPI-04在全身PET/CT成像中可以将采集时间缩短至120 s，具有可接受的主观图像质量和100%的肿瘤检出率。半剂量的[68Ga]Ga-FAPI-04和缩短的采集时间的全身PET/CT成像可用于对辐射敏感和对水平位置和等待时间延长容忍度较差人群，如儿童和孕妇。 © 2023. 作者等独家授权给Springer-Verlag GmbH Germany，属于Springer Nature的一部分。

[68Ga]Ga-FAPI-04 (gallium-68-labeled fibroblast activation protein inhibitor-04) PET/CT has been widely used in diagnosing malignant tumors. Total-body PET/CT has a long axial field of view and provides higher sensitivity compared to traditional PET/CT. However, whether the reduced injected dose of [68Ga]Ga-FAPI-04 could obtain qualified imaging has not been evaluated.To explore the effect of half-dose [68Ga]Ga-FAPI-04 on image quality and tumor detectability in oncology patients.A total of twenty-seven patients with tumors or clinically suspected tumors were included, and all patients were scanned with total-body PET/CT after an injected dose of 0.84-1.14 MBq/kg [68Ga]Ga-FAPI-04. All patients obtained superior image quality with 300 s original acquisition time. Images were reconstructed using 180 s, 120 s, 60 s, 40 s, 30 s, 20 s scanning duration by ordered subset expectation maximization algorithm. The subjective image quality of all patients in each time group was scored using 5-point Likert scale. Mediastinal blood pool, liver, spleen, and muscle were analyzed as background using semi-quantitative parameters maximum standardized uptake values (SUVmax), mean standardized uptake values (SUVmean), standard deviation (SD), and signal to noise ratio (SNR). The lesion detection rate, SUVmax, and tumor-to-background ratio (TBR) were calculated for tumors confirmed by pathology.The subjective image quality score decreased with the shortening of scanning time; however, both 180 s and 120 s images met the diagnostic requirements in terms of overall quality, lesion conspicuity, and image noise. The SUVmax of background increased with the reduction of scanning time, while the SUVmean was relatively stable. With the shortening of scanning time, the SD gradually increased, and the SNR gradually decreased, which was consistent with subjective image quality scores. In 180 s and 120 s images, all 11 primary lesions and 79 metastatic lesions were detected. The SUVmax of tumor focus showed an increasing trend as same as the background. Compared with 300 s, the TBR muscle had no statistical difference in 180 s and 120 s.Half-dose [68Ga]Ga-FAPI-04 in total-body PET/CT imaging can shorten the acquisition time to 120 s with acceptable subjective image quality and 100% tumor detection rate. Total-body PET/CT imaging with a half-dose [68Ga]Ga-FAPI-04 and reduced acquisition time can be used in radiation-sensitive and poor tolerant to prolong horizontal positioning and waiting time populations such as children and gravidas.© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.