双时相18F-FDG PET/CT显像在胰腺良恶性病变鉴别诊断中的应用

目的 探讨双时相18F-FDG PET/CT对胰腺良恶性病变鉴别诊断的价值.方法 回顾性分析2011年9月～2012年6月在我院行双时相18F-FDG PET/CT全身检查的胰腺病变患者41例,分别测定病灶早期及延迟标准摄取值（SUVmax）,计算18F-FDG的滞留指数（retention index,RI）;以病理及临床随访结果作为诊断标准,绘制SUVmax早期及RI的ROC曲线,寻找最佳诊断界值,分别计算SUVmax早期、RI为标准诊断胰腺癌敏感性、特异性及准确性.结果 41例胰腺病变患者中,恶性组（26例）SUVmax早期、SUVmax延迟、RI分别为8.2±2.7、10.5±4.1、（24.1±22.6）％,良性组（15例）SUVmax早期、SUVmax延迟、RI分别为4.0±3.7、4.3±3.8、（8.5±14.1）％;胰腺恶性病变SUVmax延迟较SUVmax早期明显升高（P＜0.001）,胰腺良性病灶延迟显像前后SUVmax差异无统计学意义（P=0.068）,胰腺良恶性组间RI差异有统计学意义（P=0.004）.本试验根据ROC曲线观察发现以SUV max=3.4为界值,诊断胰腺癌的敏感性、特异性及准确性分别为92.3％、66.7％、82.9％;以RI=9.1％为界值,诊断胰腺癌的敏感性、特异性及准确性分别为76.9％、73.3％及73.2％;SUVmax≥3.4结合RI≥9.1％诊断胰腺癌敏感性、特异性及准确性分别为88.5％、86.7％及87.8％.结论 应用双时相18F-FDG PET/CT显像能提高胰腺癌诊断特异性及准确性,但炎性（包括肿块型胰腺炎、自身免疫性胰腺炎、结核）延迟显像也可明显升高.

Value of dual-time-point 18 F-FDG PET/CT in differential diagnose of pancreatic disease

Objective To explore the value of dual time-point lSF_FDG PET/CT in differential diagnosis of pancreatic disease. Methods We retrospectively analyzed dual-time point PET/CT imaging of pancreatic disease in the hospital from September 2011 to June 2012, the maximum standard uptake value （SUV） were measured in early and delayed imaging, retention index （RI） was calculated; Pathological findings and clinical following-up longer than 6 months were served as the gold standard, the ROC curves of the SUV maxearly and RI were drawn to find the best cutoff point value for differ- ential diagnosis, the sensitivity,specificity and accuracy of SUVmaxearly, and RI were compared. Results In malignant cases, the SUVmax, SUVmaxdelayed and RI value were 8.24-2.7, 10.54. 1, （24.1 ! 22.6）0/00, respectively. In be- nign cases, the corresponding values were 4.0 ＋ 3.7, 4.3 ＋ 3.8, （8.5±14.1） %, respectively. In malignant cases, the SUVmax in delayed imaging were significantly higher than those early imaging （ P d0. 001）. In benign cases, there were no significant differences between SUVmaxearly and SUVmaxdelayed （ P --0. 068）. The RI of the malignant lesions was significantly higher than that of the benign ones. When the optimal cutoff value of SUVmax was 3.4, the sensitivity, spe cificity and accuracy for diagnosing pancreatic malignant lesions were 92.3G, 66.7%0, 82.9 %. When the optimal cutoff value of RI was 9. 1, the sensitivity, specificity and accuracy for diagnosing pancreatic malignant lesions were 76. 9%, 73.3%, 73.2%. The sensitivity,specificity and accuracy of SUVmax~3.4 combined with RI9.1% in diagnosing pan- creatic malignant lesions were 88. 5G, 86.7%0, 87.8G. Conclusion Dual-time-point ~SF_FDG PET/CT imaging could improve the specificity and accuracy of differentiating malignant from benign pancreatic diease, but tuberculosis, autoimmune pancreatitis and granulomatous diease also have increased SUV in delay imaging.