目的·分析¹⁸F-氟代脱氧葡萄糖正电子发射断层扫描-计算机断层扫描技术（¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography，¹⁸F-FDG PET/CT）对于套细胞淋巴瘤（mantle cell lymphoma，MCL）的显像特点和诊断价值，并探索其在区分MCL经典型与侵袭性变型中的应用。方法·回顾性分析上海交通大学医学院附属瑞金医院116例经病理学确诊的初诊MCL患者的¹⁸F-FDG PET/CT显像及临床资料，分析淋巴结内外病灶的显像特点，评估¹⁸F-FDG PET/CT在诊断MCL骨髓和胃肠道浸润中的准确性，并分析经典型和侵袭性变型MCL的¹⁸F-FDG PET/CT特征及临床特征之间的差异。结果·116例患者中，100.0%的患者在¹⁸F-FDG PET/CT显像中有阳性表现，99.1%的患者有淋巴结异常，85.3%的患者有结外侵犯，其中脾脏、咽淋巴环、骨髓、胃肠道是最常见的结外侵犯部位。与骨髓穿刺结果比较，¹⁸F-FDG PET/CT对MCL骨髓侵犯的灵敏度、特异度以及准确率分别为43.4%、91.5%和66.0%。与胃镜、肠镜的活检结果比较，¹⁸F-FDG PET/CT对胃、肠道浸润的灵敏度分别为100.0%、94.1%，特异度分别为75.0%、100.0%，准确率分别为92.9%、94.7%。最大标准化摄取值（maximum standardized uptake value，SUV_max）和Ki-67指数在MCL经典型与侵袭性变型间差异显著，且SUV_max与Ki-67指数呈正相关。以SUV_max为10.4作为诊断阈值时，区分MCL经典型及侵袭性变型的灵敏度为73.9%，特异度为77.4%，AUC值为0.797。结论·¹⁸F-FDG PET/CT对MCL患者结内外病变具有较高的检出率，在骨髓浸润的诊断中具有较高的特异度，在胃肠道浸润的诊断中灵敏度和特异度均较高，可为MCL骨髓和胃肠道浸润提供非侵入性的、比较可靠的诊断信息，但仍不足以代替病理学检查。SUV_max与Ki-67指数呈正相关。应用SUV_max可以有效区分MCL经典型和侵袭性变型；当SUV_max>10.4时，侵袭性变型可能性更高，否则为经典型；SUV_max可为MCL的治疗策略的选择提供潜在帮助。

Objective ·To analyze the imaging characteristics and diagnostic value of ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET/CT) in mantle cell lymphoma (MCL) and explore its application to distinguishing between classic and aggressive variants of MCL. Methods ·A retrospective analysis was conducted on the ¹⁸F-FDG PET/CT images and clinical data of 116 pathologically confirmed, newly diagnosed MCL patients. The imaging features of intra- and extra-nodal lesions were summarized. The accuracy of ¹⁸F-FDG PET/CT in diagnosing bone marrow and gastrointestinal involvement in MCL was evaluated. Furthermore, differences in ¹⁸F-FDG PET/CT findings and clinical characteristics between the classic and aggressive variants of MCL were analyzed. Results ·Among the 116 patients, 100.0% showed positive findings on ¹⁸F-FDG PET/CT, with 99.1% exhibiting abnormal lymph nodes and 85.3% having extra-nodal involvement. The most common extra-nodal sites were the spleen, Waldeyer's ring, bone marrow, and gastrointestinal tract. Compared with bone marrow aspiration results, the sensitivity, specificity, and accuracy of ¹⁸F-FDG PET/CT for detecting bone marrow involvement in MCL were 43.4%, 91.5%, and 66.0%, respectively. When compared with endoscopic biopsy results, the sensitivity of ¹⁸F-FDG PET/CT for detecting gastric and intestinal involvement was 100.0% and 94.1%, respectively, with specificity of 75.0% and 100.0%, and accuracy of 92.9% and 94.7%, respectively. There were significant differences in the highest maximum standardized uptake value (SUV_max) and Ki-67 index between the classic and aggressive variants of MCL, with SUV_max positively correlated with Ki-67 index. By using SUV_max > 10.4 as the diagnostic threshold, the sensitivity and specificity for differentiating between the classic and aggressive variants of MCL were 73.9% and 77.4%, respectively, with an AUC value of 0.797. Conclusion ·¹⁸F-FDG PET/CT demonstrates a high detection rate for both intra- and extra-nodal lesions in MCL patients. It exhibits high specificity in diagnosing bone marrow involvement and high sensitivity and specificity in diagnosing gastrointestinal involvement, providing reliable non-invasive diagnostic information for MCL bone marrow and gastrointestinal involvement. However, it is not a substitute for pathological examination. Additionally, the positive correlation between SUV_max and Ki-67 index allows SUV_max to effectively differentiate between the classic and aggressive variants of MCL, with a higher SUV_max (>10.4) indicating a higher likelihood of the aggressive variant. These findings have clinical implications for treatment planning and prognosis assessment.