18F-FDG PET显像对胰腺良恶性病变鉴别诊断的作用

目的探讨18F-脱氧葡萄糖(FDG) PET显像对胰腺良恶性病变鉴别诊断的价值.方法临床疑胰腺病变患者30例,其中胰腺恶性肿瘤20例胰腺癌15例,胰腺癌切除术后复发3例,低恶性胰岛细胞瘤、癌肉瘤各1例;胰腺良性病变10例,均为慢性胰腺炎,其中3例并假性囊肿形成.除8例慢性胰腺炎为临床、放射学随访3～12个月外,余均由组织病理学检查证实.静脉注射18F-FDG 222～296 MBq 1 h后行PET显像.测定肿瘤体积和标准摄取值(SUV),并与PET检查前2周内CT(25例)、MRI(8例)结果对照.结果 20例胰腺恶性肿瘤中19例肿瘤明显摄取18F-FDG,平均SUV 4.91±3.65.10例慢性胰腺炎中9例病灶轻度或无摄取18F-FDG,平均SUV 1.70±1.12(t=2.69,P=0.012).4例肿瘤病灶直径≤3 cm,SUV 2.75±0.63;6例3.1～5 cm,SUV 4.59±3.06;10例>5 cm,SUV 5.46±2.29(χ2=9.02,P=0.011).1例PET假阳性为慢性胰腺炎并假性囊肿,SUV 4.82;1例PET假阴性为胰头癌术后复发,病灶SUV 2.1.以SUV 2.5为胰腺良恶性病变的判断阈值,18F-FDG PET显像诊断胰腺癌灵敏度、特异性和准确性分别为95.0%、90.0%、93.3%,明显高于CT(75.0%、55.6%、68.0%,χ2=5.89,P=0.015).结论 18F-FDG PET显像诊断胰腺癌灵敏度、特异性较高,尤其适于胰腺癌术前分期和术后复发、转移的探查.     

^18F-FDG PET／CT在胰腺癌诊断中的价值

目的评价^18F-脱氧葡萄糖（FDG）PET／CT鉴别诊断胰腺良恶性病变及检测淋巴结和（或）远处转移的价值。方法回顾性分析上海交通大学医学院附属仁济医院行^18F—FDGPET／CT检查的46例临床疑胰腺肿瘤患者的影像学检查资料和临床资料,其中胰腺癌患者26例,良性病变者20例,比较分析PET和CT的特征。结果当选择最大标准摄取值（SUVmax）=2．95为判断良恶性的界值时,对胰腺癌诊断的灵敏度是88．5％（23／26）,特异性是85．0％（17／20）。^18F—FDGPET／CT显像假阳性3例,假阴性3例。同时发现16例检查前未确定的肝、肺、骨及淋巴结转移患者。根据显像结果,11例患者治疗方案得以修正。结论根据现有资料分析,^18F—FDGPET／CT是鉴别诊断胰腺良恶性病变及检测胰腺癌患者淋巴结和（或）远处转移一种较好的方法。     

11C-胆碱与18F-FDG双时相PET显像在孤立性肺结节鉴别诊断中的应用

目的 比较^11C-胆碱、18F-脱氧葡萄糖（FDG）和^18F-FDG双时相PET显像对鉴别肺部孤立性结节良恶性的价值。方法16例临床疑为肺肿瘤的患者进行^18F-FDGPET显像（注药后1h显像，2h后行延迟显像）、^11C-胆碱PET显像（3d内，于注药后10min进行）。图像判断以标准摄取值（SUV）作为半定量指标，异常放射性浓聚灶以SUV〉2．5为葡萄糖代谢增高，^18F-FDG延迟显像SUV上升≥10％为恶性病变（阳性），如下降或升高〈10％为良性病变（阴性）；^11C-胆碱异常摄取灶以SUV〉2．0为阳性。所有病例进行随访，以显像诊断是否符合病理检查结果作为判断标准。结果病理检查结果证实12例肺癌，3例结核，1例结节病。^11C-胆碱PET显像确诊了12例肿瘤中的ll例，而^18F-FDG PET显像确诊10例（10／12例），双时相^18F-FDG PET显像确诊11例。4例良性病变者，^11C-胆碱PET显像能较好鉴别；而^18F-FDG PET显像2例假阳性，结合延迟显像仅1例假阳性。结论 ^11C-胆碱和^18F-FDG PET显像均能较好地鉴别肺部良恶性肿瘤。但^11C-胆碱和双时相^18F-FDGPET显像优于常规^18F-FDGPET显像，三者联合能提高对肺部病变的诊断效率。     

11 C-胆碱PET/CT显像在PSA升高的前列腺病变中的应用价值

目的：探讨11C-胆碱PET/CT显像在PSA升高的前列腺良恶性病变中鉴别诊断及术前分期的应用价值。方法：PSA升高的前列腺病变患者40例,静脉注射0.2mli/kg11C-胆碱5min后行仰卧位盆腔PET/CT显像,必要时加做全身显像。测量病变组织与对照组织的最高SUV（SUVmax）,并计算其比值（P/M）,通过半定量法分析显像结果。结果：病理证实前列腺增生及炎症共17例,前列腺癌23例。前列腺良恶性病变的P/M值之间的差异具有显著性。以P/M＆gt;2.14为标准,11C-胆碱PET/CT显像诊断前列腺癌的灵敏度为86.96%,特异性为88.24%,阳性预测值为90.91%。PET/CT同时发现了6例患者的盆腔淋巴结转移,4例骨转移,1例肺转移。结论：对于PSA升高的前列腺病变,11C-胆碱PET/CT显像不仅是一种鉴别良恶性的较好的无创性检查方法,而且可以有助于准确术前分期。     

~(18)F-FDG-PET/CT显像在胰腺炎和胰腺癌鉴别诊断中的应用

目的探讨~(18)F-FDG-PET/CT显像在鉴别诊断胰腺癌良恶性病变中的价值。方法选取我院2014年1月～2017年1月确诊的胰腺癌患者53例(恶性组)、慢性胰腺炎患者22(良性组),两组患者均接受了~(18)F-FDG-PET/CT显像检测,对比两组患者病灶早期、延迟期的最大标准摄取值(SUV),滞留指数(RI),并绘制受试者工作曲线(ROC)求取早期SUV、RI鉴别诊断胰腺癌的最佳临界值及对应的诊断学指标。结果恶性组的~(18)F-FDG-PET/CT显像早期SUV测定值、延迟期SUV测定值、RI值均显著的高于良性组患者,差异具有统计学意义(P 0. 05);当选取早期SUV的临界值为3. 07时,~(18)F-FDG-PET/CT显像诊断灵敏度为78. 82%、特异度为86. 14%、漏诊率为21. 18%、误诊率为13. 86%、AUC值为0. 846;当选取RI的临界值为14. 46时,~(18)F-FDG-PET/CT显像诊断灵敏度为87. 64%、特异度为95. 20%、漏诊率为12. 36%、误诊率为4. 80%、AUC值为0. 911。结论~(18)F-FDG-PET/CT显像在鉴别诊断胰腺癌良恶性病变中具有较高的临床实用价值。     

18F-FDG PET/CT对不同大小孤立性肺结节的诊断价值

目的 评价18F-脱氧葡萄糖(FDG) PET/CT对不同大小范围孤立性肺结节(SPN)良恶性鉴别诊断的价值.方法 从全国拥有PET/CT的10家医院筛选出已经获得病理学检查结果的SPN病例,收集诊断CT、PET/CT和病理检查结果以及标准摄取值(SUV)、结节大小等资料.诊断CT、PET/CT结果为肺癌、肺癌可能性大、肺癌可能者为阳性;结果为良性病变、良性可能性大、良性可能者为阴性;难以确定阳性和阴性者为不确定.采用SPSS 10.0软件对资料进行分析.结果 120个(120例)SPN中良性结节28个,恶性结节92个.直径或(长径+短径)/2≤1.0cm的结节17个,恶性病变9个;1.1～2.0cm 57个,恶性病变占75.44%;2.1～3.0cm 46个,恶性病变占86.96%.28个良性结节SUV最大值(SUVmax)的平均值为4.5±4.9, SUV平均值(SUVmean)的平均值为2.9±3.6;92个恶性结节SUVmax平均值为6.7±4.2, SUVmean平均值为4.9±3.6;良性结节的SUV显著低于恶性结节的SUV.无论良性还是恶性结节,随着结节的增大,SUV升高.诊断CT对结节良恶性鉴别的灵敏度为78.26%,特异性3/8,准确性72.22%; PET/CT灵敏度为94.51%,特异性64.00%,准确性87.93%.结论 18F-FDG PET/CT在SPN鉴别诊断中具有较高的灵敏度、特异性和准确性,优于诊断CT;结节大小是判断SPN良恶性的重要指标,直径或(长径+短径)/2＞2.0cm的结节,恶性可能性约为87%; SUV可以作为鉴别诊断的依据,但鉴于良性结节SUVmean的平均值为2.9±3.6,界值2.5仅供参考,尤其是对于≤1.0cm的结节.     

18F-FDG PET/CT显像诊断心包恶性病变的价值

目的 评价18F-脱氧葡萄糖（FDG）PET/CT对心包恶性病变的诊断价值.方法 对23例心包积液患者进行18F-FDG PET/CT显像,并采用两独立样本非参数检验分析良恶性病灶最大标准摄取值（SUVmax）差异有无统计学意义.结果 经病理检查证实恶性心包积液14例,良性心包积液9例.1例PET/CT假阴性,2例PET/CT假阳性.18F-FDG PET/CT鉴别诊断良恶性心包积液的灵敏度、特异性、准确性、阳性预测值、阴性预测值分别为92.9%（13/14）、7/9、87.0%（20/23）、86.7%（13/15）和7/8.良、恶性病变的SUVmax中位值分别为2.2和6.0,两者间比较差异有统计学意义（z=-3.279,P=0.001）.结论 18F-FDG PET/CT是评价心包恶性病变较好的无创性手段,对良恶性心包积液的诊断与鉴别诊断有一定临床价值.     

肺内病灶18F-FDG PET/CT显像与手术病理结果之对比研究

目的：评价^18F-脱氧葡萄糖（FGD）PET／CT显像在非小细胞肺癌（NSCLC）诊断中的价值及显像特征。方法：回顾性分析53例手术病例的碍F-FDGPET／CT显像诊断结果。PET／CT用目测法结合半定量法判断病灶良恶性，所得诊断结果与病理结果进行对照。结果：53个肺内病灶，49个恶性、4个良性，PET／CT正确诊断45个恶性病灶；灵敏度为91．8％，准确性为84．9％；4个良性病灶，其中炎性假瘤1例、结核3例。53例肺内病变，纵隔淋巴结病理诊断转移阳性者16例（45个淋巴结），PET／CT正确诊断10例，灵敏度为62．5％，纵隔淋巴结病理诊断阴性者37例（32个淋巴结），PET／CT正确诊断30例，特异性为81．1％，准确性为75．5％。结论：^18F-FDGPET／CF显像是评价肺内病灶良恶性的一种有效、无创性检查方法，有重要临床应用价值。     

18F-FDG PET对肺结节良恶性鉴别诊断的研究

 目的探讨18F-FDG PET(氟代脱氧葡萄糖正电子发射断层显像)对肺结节良、恶性鉴别诊断的价值.方法对80例肺结节行18F脱氧葡萄糖(FDG)正电子发射断层显像(PET).以病理组织学诊断为依据,结合临床,分析18F-FDG放射性摄取灶及最大标准摄取值(SUVmax)对肺结节良恶性鉴别诊断的意义.结果18F-FDG PET鉴别肺结节良恶性的灵敏度为98.6%,特异度为81.8%,准确度为96.4%,阳性预测值97.14%,阴性预测值90.0%.结论根据18F-FDGPET代谢显像特征,可以对肺内结节的良恶性作出进一步鉴别诊断.     

11C-胆碱PET/CT显像在前列腺良恶性病变鉴别诊断中的应用

目的 探讨11C-胆碱PET/CT显像在前列腺良恶性病变鉴别诊断中的作用.方法 前列腺病变患者45例,按体重静脉注射7.4 MBq/kg 11C-胆碱5 min后行仰卧位盆腔PET/CT显像,可疑转移患者行全身显像.测量前列腺病灶(靶)及肌肉(非靶)组织的最高标准摄取值(SUVmax),并计算其比值(P/M).结果 病理检查证实前列腺良性病变27例,前列腺癌18例.前列腺良恶性病变的P/M比值间差异有显著性(1.87±1.21与4.02±1.88,t=2.07,P＜0.01).以P/M比值＞2.32为标准,11C-胆碱PET/CT显像诊断前列腺癌的灵敏度为88.89%,特异性为88.89%,阴性预测值为92.31%.结论 11C-胆碱PET/CT显像是一种诊断前列腺癌较好的无创性检查方法;P/M比值比SUV能更好鉴别前列腺良恶性病变.     

18F-FDG PET/CT与3.0T MRI联合显像在乳腺癌原发病灶诊断中的价值

目的 探讨18F-FDG PET/CT与3.0T MRI联合显像在乳腺癌原发病灶诊断中的价值。 方法 对38例临床怀疑为乳腺癌的女性患者于一周内分别行18F-FDG PET/CT、3.0T MRI和病理学检查。 结果 组织病理学检查结果证实,全部患者中,24例为乳腺癌患者,14例为乳腺良性肿瘤患者。3.0T MRI诊断乳腺癌的灵敏度、特异度、准确率分别为91.7%、78.6%、86.8%;PET/CT诊断乳腺癌的灵敏度、特异度、准确率分别为87.5%、92.9%、89.5%;PET/CT和3.0T MR联合显像诊断乳腺癌的灵敏度、特异度、准确率分别为100.0%、92.9%、97.4%;3种显像方法间灵敏度、特异度、准确率差异无统计学意义（χ2=2.987、1.612和2.955,P均＞0.05）。 结论 18F-FDG PET/CT和3.0T MRI联合显像在乳腺癌原发病灶诊断中具有重要价值;但与单独18F-FDG PET/CT和3.0T MRI显像比较,3种显像方法在乳腺癌原发病灶的诊断效能上差异无统计学意义。     

孤立性肺病变18F-FDG PET/CT显像诊断价值及误诊原因分析

目的 探讨18F-FDG PET/CT显像对孤立性肺病变的诊断价值及误诊原因.方法 回顾分析32例孤立性肺部病变患者18F-FDG PET/CT显像结果.将PET/CT结果与病理检查结果进行对比,评价18F-FDG PET/CT显像在孤立性肺部病变诊断中的价值,并分析其误诊原因.应用SPSS 16.0软件行统计学分析,SUVmax及SUVmax变化率(△SUVmax)与病灶直径大小关系采用Pearson相关分析.结果 32例孤立性肺部病变中,恶性病变22例,良性病变10例.18F-FDG PET/CT对68.75％( 22/32)患者进行了准确定性诊断.18F-FDG PET/CT显像假阴性5例,假阳性5例.22例肺部恶性病变中,6例恶性病变早期SUVmax ＜2.5,5例恶性病变△SUVmax＜15％.10例肺部良性病变中,2例良性病变早期SUVmax≥2.5,4例良性病变△SUVmax≥15％.良恶性病变SUVmax及△SUVmax有交叉.32例肺部病变中,孤立性肺部病变最大直径≤3 cm共26例,最大直径＞3 cm共6例,平均(1.98±1.08) cm.SUV max与病变直径大小呈正相关(r=0.690,P＜0.01),△SUVmax与病灶直径大小无相关性(r=-0.081,P＞0.05).结论 18F-FDG PET/CT在肺部孤立性病变定性诊断中有重要临床价值,但单纯依靠SUV max存在不足,应将PET与CT综合分析.     

18F-FDG PET/CT in the evaluation of adrenal masses.

Our purpose was to evaluate the performance of (18)F-FDG PET/CT, using data from both the PET and the unenhanced CT portions of the study, in characterizing adrenal masses in oncology patients. METHODS: One hundred seventy-five adrenal masses in 150 patients referred for (18)F-FDG PET/CT were assessed. Final diagnosis was based on histology (n = 6), imaging follow-up (n = 118) of 6-29 mo (mean, 14 mo), or morphologic imaging criteria (n = 51). Each adrenal mass was characterized by its size; its attenuation on CT, expressed by Hounsfield units (HU); and the intensity of (18)F-FDG uptake, expressed as standardized uptake value (SUV). Receiver operating characteristic curves were drawn to determine the optimal cutoff values of HU and SUV that would best discriminate between benign and malignant masses. RESULTS: When malignant lesions were compared with adenomas, PET data alone using an SUV cutoff of 3.1 yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 98.5%, 92%, 89.3%, 98.9%, respectively. For combined PET/CT data, the sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 98%, 97%, 100%, respectively. Specificity was significantly higher for PET/CT (P < 0.01). Fifty-one of the 175 masses were 1.5 cm or less in diameter. When a cutoff SUV of 3.1 was used for this group, (18)F-FDG PET/CT correctly classified all lesions. CONCLUSION: (18)F-FDG PET/CT improves the performance of (18)F-FDG PET alone in discriminating benign from malignant adrenal lesions in oncology patients.     

PET/CT联合高分辨超声对甲状腺偶发病灶良恶性鉴别诊断的价值

目的 探讨PET/CT联合高分辨超声(US)对甲状腺偶发病灶良、恶性的鉴别诊断价值.方法 对73个PET/CT检出的甲状腺偶发病灶病理确诊前PET/CT和US诊断意见按3分法(0分,良性可能;1分,无明确定性;2分,恶性可疑)分类,并测定病灶长径和SUVmax.以病理诊断为“金标准”,评价SUVmax、PET/CT、US、PET/CT联合US( PET/CT+US)对恶性病灶的检出效能.统计学检验包括t检验、Z检验、x2检验和Kappa一致性检验.结果 73个甲状腺偶发病灶病理确诊恶性病灶占59％(43/73),良性病灶占41％(30/73).恶性病灶SUVmax (7.0±8.1)高于良性病灶(4.1±3.8;t=2.062,P=0.043),长径小于良性病灶[(2.0±1.1) cm比(2.7±1.4) cm;t=2.628,P=0.011].SUVmax、PET/CT、US及PET/CT+ US诊断恶性病灶的ROC AUC(95％CI)分别为0.580(0.448-0.713)、0.763 (0.647～0.878)、0.905(0.826～0.983)和0.909(0.840～0.979),PET/CT AUC明显大于SUVmax(Z=2.033,P=0.042),US、PET/CT+US也明显大于PET/CT(Z值分别为1.992和2.112,P均＜0.05)和SUVmax(Z值分别为4.120和4.276,P均＜0.001).最佳阈值下,SUVmax、PET/CT、US、PET/CT+US诊断的灵敏度、特异性、准确性、阳性预测值、阴性预测值分别为42％(18/43)、83％(25/30)、59％(43/73)、78％(18/23)、50％(25/50),79％(34/43)、80％(24/30)、79％(58/73)、85％(34/40)、73％(24/33),84％(36/43)、90％(27/30)、86％(63/73)、92％(36/39)、79％(27/34)和98％(42/43)、67％(20/30)、85％(62/73)、81％(42/52)、95％(20/21).与病理诊断比较,SUV.诊断的一致性较差(Kappa=0.229,P=0.023),PET/CT的一致性中等(Kappa=0.582,P＜0.001),US和PET/CT+US的一致性好(Kappa值分别为0.668和0.674,P均＜0.001).PET/CT+US与PET/CT比较,灵敏度从79％(34/43)提高到98％(42/43),差异有统计学意义(x2=6.125,P=0.008),而特异性差异无统计学意义(从80％降低到67％;x2=2.250,P＞0.05).结论 联合高分辨US能明显提高18F-FDG PET/CT对甲状腺偶发病灶良、恶性的鉴别诊断效能.     

18F-FDG PET/CT联合肺动脉灌注成像指数在单发肺结节中的应用价值

目的探讨18F-FDG PET/CT联合320容积CT双入口灌注成像(DI-CTP)肺动脉灌注指数(PPI)对单发性肺结节的鉴别诊断价值。方法搜集经病理证实40例单发性肺结节患者的18F-FDG PET/CT及320排CT灌注成像影像资料(恶性结节24例、良性结节16例),PET/CT以结节18F-FDG摄取值SUV≥2.5为诊断恶性结节阈值,18F-FDG PET/CT联合PPI则在SUV≥2.5诊断阈值的基础上综合PPI<50%判定,并分析SUV与PP均值在良恶性结节间差异性及相关性。结果PET/CT联合PPI正确诊断38例,其中恶性结节22例、良性结节16例,误诊2例。18F-FDG PET/CT联合PPI诊断肺单发结节的敏感性91.6%,特异性100%,准确性95.0%;18F-PDG摄取值SUV在良、恶性结间差异无统计学意义(t=1.66,P>0.05),而PPI均值在良、恶性结节间差异有统计学意义(t=-3.14,P<0.01);SUV与PPI间相关性无统计学意义(r=0.20,P>0.05)。结论18F-FDG PET/CT联合PPI可以提高诊断肺单发肺结节敏感性、特异性和准确性,减少误诊率。     

The Clinical Role of Dual-Time-Point 18F-FDG PET/CT in Differential Diagnosis of the Thyroid Incidentaloma

Thyroid incidentalomas are common findings during imaging studies including ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) for cancer evaluation. Although the overall incidence of incidental thyroid uptake detected on PET imaging is low, clinical attention should be warranted owing to the high incidence of harboring primary thyroid malignancy. We retrospectively reviewed 2,368 dual-time-point ¹⁸F-FDG PET/CT cases that were undertaken for cancer evaluation from November 2007 to February 2009, to determine the clinical impact of dual-time-point imaging in the differential diagnosis of thyroid incidentalomas. Focal thyroid uptake was identified in 64 PET cases and final diagnosis was clarified with cytology/histology in a total of 27 patients with ¹⁸F-FDG-avid incidental thyroid lesion. The maximum standardized uptake value (SUVmax) of the initial image (SUV1) and SUVmax of the delayed image (SUV2) were determined, and the retention index (RI) was calculated by dividing the difference between SUV2 and SUV1 by SUV1 (i.e., RI = [SUV2 - SUV1]/SUV1 × 100). These indices were compared between patient groups that were proven to have pathologically benign or malignant thyroid lesions. There was no statistically significant difference in SUV1 between benign and malignant lesions. SUV2 and RI of the malignant lesions were significantly higher than the benign lesions. The areas under the ROC curves showed that SUV2 and RI have the ability to discriminate between benign and malignant thyroid lesions. The predictability of dual-time-point PET parameters for thyroid malignancy was assessed by ROC curve analyses. When SUV2 of 3.9 was used as cut-off threshold, malignancy on the pathology could be predicted with a sensitivity of 87.5 % and specificity of 75 %. A thyroid lesion that shows RI greater than 12.5 % could be expected to be malignant (sensitivity 88.9 %, specificity 66.3 %). All malignant lesions showed an increase in SUVmax on the delayed images compared with the initial images. But in the group of benign lesions, 37.5 % (6/16) showed a decrease or no change in SUVmax. Dual-time-point ¹⁸F-FDG PET/CT, obtaining additional images 2 h after injection, seems to be a complementary method for the differentiation between malignancy and benignity of incidental thyroid lesions.     

双时相18F-FDG PET显像用于肿瘤良恶性鉴别诊断

目的探讨双时相^18F-FDG PET显像在肿瘤良恶性鉴别中的临床价值。方法52例单次显像难以鉴别病变性质的患者行双时相全身^18 F-FDG PET／CT显像，将显像结果与病理学检查结果对照。结果43例延迟显像SUV升高的患者中有39例经病理检查证实为恶性病变，4例为良性病变；9例延迟显像SUV降低的患者中有7例经病理检查证实为良性病变，2例为恶性病变。灵敏度为95．1％，准确性为88．5％，特异性为63．6％，阳性预测值为90．7％，阴性预测值为7／9例。结论双时相^18F—FDG PET对良恶性病变的鉴别具有较高的灵敏度和准确性。     

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.     

正电子发射计算机体层摄影-CT诊断骨转移瘤的临床价值

目的 应用^18氟-脱氧葡萄糖（^18F-FDG）正电子发射计算机体层摄影（PET）-CT全身显像，探讨PET、同机CT和PET—CT融合图像在骨转移瘤诊断中的价值。方法 共332例^18F-FDG PET—CT受检者中有35例发现骨异常病变。分别阅读和记录^18FDG PET图像、同机CT图像和PET-CT融合图像判断的良、恶性病变，比较3种方法在诊断骨转移瘤上的差异。结果 35例中共检出89个病灶，其中68个病灶最后确诊为恶性肿瘤骨转移，21个为良性病变。PET诊断骨转移病灶62个，诊断良性病变17个，诊断骨转移瘤的敏感性为91．2％（62／68个），特异性为81．0％（17／21个），准确性为88．8％（79／89个）；同机CT诊断骨转移病灶55个，良性病变16个。诊断骨转移瘤的敏感性、特异性和准确性分别为80．9％（55／68个），76．2％（16／21个）和79．8％（71／89个）；PET．CT融合图像诊断骨转移病灶64个，良性病变19个，诊断骨转移瘤的敏感性、特异性和准确性分别为94．1％（64／68个），90．5％（19／21个）和93．2％（83／89个）。结论 PET-CT融合图像在诊断骨转移瘤方面，可减少单用PET或单用CT诊断时的假阴性和假阳性，提高了鉴别骨良、恶性病变的能力。     

Dual-time-point 18F-FDG PET for the evaluation of gallbladder carcinoma.

Conventional imaging techniques such as ultrasonography, CT, and MRI are able to detect gallbladder abnormalities but are not always able to differentiate a malignancy from other disease processes such as cholecystitis. The purpose of the present study was to evaluate the efficacy of dual-time-point (18)F-FDG PET for differentiating malignant from benign gallbladder disease. METHODS: The study evaluated 32 patients who were suspected of having gallbladder tumors. (18)F-FDG PET (whole body) was performed at 62 +/- 8 min (early) after (18)F-FDG injection and was repeated 146 +/- 14 min (delayed) after injection only in the abdominal region. We evaluated the (18)F-FDG uptake both visually and semiquantitatively. Semiquantitative analysis using the standardized uptake value (SUV) was performed for both early and delayed images (SUV(early) and SUV(delayed), respectively). The retention index (RI) was calculated according to the equation (SUV(delayed) - SUV(early)) x 100/SUV(early). The tumor-to-liver ratio was also calculated. Results: The final diagnosis was gallbladder carcinoma in 23 patients and benign disease in 9 patients. For visual analysis of gallbladder carcinoma, delayed (18)F-FDG PET images improved the specificity of diagnosis in 2 patients. When an SUV(early) of 4.5, SUV(delayed) of 2.9, and RI of -8 were chosen as arbitrary cutoffs for differentiating between malignant and benign conditions, sensitivity increased from 82.6% to 95.7% and 100% for delayed imaging and combined early and delayed imaging (i.e., RI), respectively. With the same criteria, specificity decreased from 55.6% to 44.4% for delayed imaging and combined early and delayed imaging, respectively. The specificity of (18)F-FDG PET improved to 80% in the group with a normal level of C-reactive protein (CRP) and decreased to 0% in the group with an elevated CRP level. For gallbladder carcinoma, both SUV and tumor-to-liver ratios derived from delayed images were significantly higher than the ratios derived from early images (P < 0.0001). CONCLUSION: Delayed (18)F-FDG PET is more helpful than early (18)F-FDG PET for evaluating malignant lesions because of increased lesion uptake and increased lesion-to-background contrast. However, the diagnostic performance of (18)F-FDG PET depends on CRP levels.