Nuclear Medicine Department, CHRU Brest, Boulevard Tanguy Prigent, Brest, France.
UMR Inserm GETBO 1304, University of Western Brittany, Brest, France.
Cancer Imaging. 2024 Aug 27;24(1):114. doi: 10.1186/s40644-024-00760-1.
The pulmonary Hot Clot artifact (HCa) on 18F-FDG PET/CT is a poorly understood phenomenon, corresponding to the presence of a focal tracer uptake without anatomical lesion on combined CTscan. The hypothesis proposed in the literature is of microembolic origin. Our objectives were to determine the incidence of HCa, to analyze its characteristics and to identify associated factors.
All 18F-FDG PET/CT retrieved reports containing the keywords (artifact/vascular adhesion/no morphological abnormality) during the period June 2021-2023 at Brest University Hospital were reviewed for HCa. Each case was associated with 2 control patients (same daily work-list). The anatomical and metabolic characteristics of HCa were analyzed. Factors related to FDG preparation/administration, patient and vascular history were investigated. Case-control differences between variables were tested using Chi-2 test and OR (qualitative) or Student's t-test (quantitative).
Of the 22,671 18F-FDG PET/CT performed over 2 years, 211 patients (0.94%) showed HCa. The focus was single in 97.6%, peripheral in 75.3%, and located independently in the right or left lung (51.1% vs. 48.9%). Mean ± SD values for SUVmax, SUVmean, MTV and TLG were 11.3 ± 16.5, 5.1 ± 5.0, 0.3 ± 0.3 ml and 1.5 ± 2.1 g respectively. The presence of vascular adhesion (p < 0.001), patient age (p = 0.002) and proximal venous access (p = 0.001) were statistically associated with the presence of HCa.
HCa is a real but rare phenomenon (incidence around 1%), mostly unique, intense, small in volume (< 1 ml), and associated with the presence of vascular FDG uptake, confirming the hypothesis of a microembolic origin due to probable vein wall trauma at the injection site.
18F-FDG PET/CT 上的肺部热点伪影（HCa）是一种尚未被充分了解的现象，其表现为在联合 CT 扫描上无解剖学病变的情况下存在局灶性示踪剂摄取。文献中提出的假设为微栓塞起源。我们的目标是确定 HCa 的发生率，分析其特征并确定相关因素。
回顾 2021 年 6 月至 2023 年期间在布雷斯特大学医院使用关键词（artifact/vascular adhesion/no morphological abnormality）检索到的所有 18F-FDG PET/CT 报告，以确定 HCa 的发生情况。每个病例均与 2 名对照患者（相同的日常工作列表）相关联。分析 HCa 的解剖学和代谢特征。调查与 FDG 准备/给药、患者和血管史相关的因素。使用卡方检验和 OR（定性）或学生 t 检验（定量）检验变量之间的病例对照差异。
在两年内进行的 22671 次 18F-FDG PET/CT 中，有 211 例（0.94%）患者出现 HCa。97.6%的焦点为单发，75.3%为外周，且位于右或左肺内（51.1%比 48.9%）。SUVmax、SUVmean、MTV 和 TLG 的平均值±标准差分别为 11.3±16.5、5.1±5.0、0.3±0.3ml 和 1.5±2.1g。血管黏附存在（p<0.001）、患者年龄（p=0.002）和近端静脉通路（p=0.001）与 HCa 的存在具有统计学相关性。
HCa 是一种真实但罕见的现象（发生率约为 1%），主要为单一、强烈、体积小（<1ml），与血管 FDG 摄取有关，证实了微栓塞起源的假说，可能是由于注射部位静脉壁创伤所致。
