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。     

18F-FDG PET/CT结合高分辨率CT对孤立性肺结节的

 目的 探讨18F-FDG PET/CT显像结合高分辨率CT(high resolution CT,HRCT)对孤立性肺结节(solitary pulmonary nodule,SPN)的诊断价值。方法 回顾性分析124例SPN患者的18F-FDG PET/CT检查资料,其中76例加做HRCT扫描,所有病例经病理或临床随访证实。18F-FDG PET/CT通过目测法和半定量法判断病灶的代谢情况,结合CT或HRCT病灶的形态学特征判断良、恶性。结果 48例仅行18F-FDG PET/CT检查的SPN患者,正确诊断32例为恶性,8例为良性,假阳性与假阴性各4例。76例加做HRCT的患者,正确诊断62例恶性与8例良性,假阳性与假阴性分别为2例和4例。18F-FDG PET/CT 结合HRCT与单纯18F-FDG PET/CT诊断SPN的灵敏度、特异性及准确率分别为94%、80%、90%与89%、67%、83%。结论 18F-FDG PET/CT协同HRCT可提高对SPN性质判断的灵敏度、特异性及准确率。     

Clinical significance of small pulmonary nodules with little or no 18F-FDG uptake on PET/CT images of patients with nonthoracic malignancies.

Small pulmonary nodules with little or no perceptible (18)F-FDG uptake are relatively common findings on combined PET/CT images of patients with nonthoracic malignancies. Interpreting such nodules is often a diagnostic challenge, and this study aimed to evaluate the clinical significance of the nodules. METHODS: Patients with pulmonary nodules < or =1 cm in diameter showing no (18)F-FDG uptake or uptake less than the mediastinal background were included. Nodules with clearly benign or metastatic findings on CT were excluded. One hundred twenty-one patients had either tissue confirmation or clinical follow-up with additional chest images. The subjects were studied by 3 variables: (i) solitary versus multiple nodules, (ii) presence of accompanying benign lung lesion versus absence, and (iii) imperceptible (18)F-FDG uptake versus faint (18)F-FDG uptake. The malignancy rates were calculated for each variable. RESULTS: Of the 121 patients, 24 had malignancy, with a strong possibility of pulmonary metastasis (19.8%). Six of the 44 patients with solitary nodules (13.6%) and 18 of the 77 patients with multiple nodules (23.4%) had malignancies, though there was no statistically significant difference in the incidences of malignancy between the solitary and multiple groups. On the other hand, there was a statistically significant difference (P = 0.040) between the accompanying lung lesion present (8.3%) and absent (24.7%) groups. No statistically significant difference was noted between the (18)F-FDG uptake imperceptible group and faint (18)F-FDG uptake group (20.7% vs. 17.2%). CONCLUSION: For patients with incidental lung nodules of indeterminate nature with no (18)F-FDG uptake or uptake less than that of the mediastinum on PET/CT images, >19% of the cases turned out to be malignant. The nodule was more likely to be malignant when no other benign pulmonary lesions could be identified elsewhere in the lung field. Thus, regardless of the number of nodules and (18)F-FDG uptake, tissue confirmation or close imaging follow-up is necessary when small nodules with imperceptible or faint (18)F-FDG activity are present on the PET/CT images, especially in the absence of accompanying benign lung lesions.     

Accuracy of PET for diagnosis of solid pulmonary lesions with 18F-FDG uptake below the standardized uptake value of 2.5.

Benign and malignant pulmonary lesions usually are differentiated by 18F-FDG PET with a semiquantitative 18F-FDG standardized uptake value (SUV) of 2.5. However, the frequency of malignancies with an SUV of <2.5 is significant, and pulmonary nodules with low 18F-FDG uptake often present diagnostic challenges. METHODS: Among 360 consecutive patients who underwent 18F-FDG PET to evaluate pulmonary nodules found on CT, we retrospectively analyzed 43 who had solid pulmonary lesions (excluding lesions with ground-glass opacity, infiltration, or benign calcification) with an SUV of <2.5. The uptake of 18F-FDG was graded by a visual method (absent, faint, moderate, or intense) and 2 semiquantitative methods (SUV and contrast ratio [CR]). Final classification was based on histopathologic findings or at least 6 mo of clinical follow-up. RESULTS: We found 16 malignant (diameter, 8-32 mm) and 27 benign (7-36 mm) lesions. When faint visual uptake was the cutoff for positive 18F-FDG PET results, the receiver-operating-characteristic (ROC) analysis correctly identified all 16 malignancies and yielded false-positive results for 10 of 27 benign lesions. Sensitivity was 100%, specificity was 63%, and the positive and negative predictive values were 62% and 100%, respectively. When an SUV of 1.59 was the cutoff for positive 18F-FDG PET results, the ROC analysis revealed 81% sensitivity, 85% specificity, and positive and negative predictive values of 77% and 89%, respectively. At a cutoff for positive 18F-FDG PET results of a CR of 0.29, the ROC analysis revealed 75% sensitivity, 82% specificity, and positive and negative predictive values of 71% and 85%, respectively. The areas under the curve in ROC analyses did not differ significantly among the 3 analyses (visual, 0.84; SUV, 0.81; and CR, 0.82). Analyses of intra- and interobserver variabilities indicated that visual and SUV analyses were quite reproducible, whereas CR analysis was poorly reproducible. CONCLUSION: These results suggested that for solid pulmonary lesions with low 18F-FDG uptake, semiquantitative approaches do not improve the accuracy of 18F-FDG PET over that obtained with visual analysis. Pulmonary lesions with visually absent uptake indicate that the probability of malignancies is very low. In contrast, the probability of malignancy in any visually evident lesion is about 60%.     

11C-胆碱与18F-FDG双时相PET/CT显像结合高分辨率CT在孤立性肺结节鉴别诊断中的应用

目的比较11C-胆碱（11C-CHO）PET/CT、18F-FDG双时相PET/CT、常规18F-FDG PET/CT、11C-CHO+18F-FDG双时相PET/CT显像结合高分辨率CT（HRCT）4种方法对鉴别诊断孤立性肺结节（SPN）良恶性的价值。方法对28例SPN患者进行18F-FDG PET/CT显像（注药后l h显像,2 h行延迟显像）和11C-CHO PET/CT显像（于注药10 min后进行）。PET图像判断以SPN最大截面勾画ROI,计算SUV_max作为半定量指标,SUV_max ≥ 2.5为阳性,18F-FDG PET/CT延迟显像SUV_max上升10%为恶性病变（阳性）,下降或升高 < 10%为良性病变（阴性）。HRCT以是否有分叶征、短细毛刺、胸膜尾征、支气管充气征、血管集束征、空泡征为分析良恶性的指征。所有病例进行临床综合分析及随访,以影像诊断是否符合临床随访及病理结果作为判断标准。组间SUV_max的比较采用t检验;计数资料的比较采用χ2检验。结果 28例SPN患者中,病理或临床随访诊断发现肺癌17例,结核7例,结节病4例。常规18F-FDG PET/CT显像确诊21例,18F-FDG双时相PET/CT显像确诊24例,11C-CHO PET/CT显像确诊23例,11C-CHO +18F-FDG双时相PET/CT+HRCT确诊27例。28例患者良恶性结节的18F-FDG及11C-CHO PET/CT的SUV_max比较,差异有统计学意义（t=10.57和13.19,均P < 0.05）。良恶性结节分叶、毛刺、胸膜尾征、血管集束征之间的差异有统计学意义（χ2=9.27、10.36、14.31和17.52,均P < 0.05）。11C-CHO+18F-FDG双时相PET/CT+HRCT联合显像的灵敏度为81.8%,特异度为94.1%,准确率为96.4%,明显高于非联合显像。结论 11C-CHO+18F-FDG双时相PET/CT+HRCT能较好地鉴别SPN的良恶性,三者联合能提高对SPN的诊断率。     

Rapidly destructive osteoarthritis of the hip: MR imaging findings

OBJECTIVE: The purpose of our study was to use an artificial neural network to differentiate benign from malignant pulmonary nodules on high-resolution CT findings and to evaluate the effect of artificial neural network output on the performance of radiologists using receiver operating characteristic analysis. MATERIALS AND METHODS: We selected 155 cases with pulmonary nodules less than 3 cm (99 malignant nodules and 56 benign nodules). An artificial neural network was used to distinguish benign from malignant nodules on the basis of seven clinical parameters and 16 radiologic findings that were extracted by attending radiologists using subjective rating scales. In the observer test, 12 radiologists (four attending radiologists, four radiology fellows, and four radiology residents) were presented with high-resolution CT images, first without and then with the artificial neural network output. Observer performance was evaluated by means of receiver operating characteristic analysis using a continuous rating scale. RESULTS: The artificial neural network showed a high performance in differentiating benign from malignant pulmonary nodules (A(z) = 0.951). The average A(z) value for all radiologists increased by a statistically significant level, from 0.831 to 0.959, with the use of the artificial neural network output. CONCLUSION: Our computerized scheme using the artificial neural network can improve the diagnostic accuracy of radiologists who are differentiating benign from malignant pulmonary nodules on high-resolution CT.     

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.     

A multicenter clinical trial on the diagnostic value of dual-tracer PET/CT in pulmonary lesions using 3'-deoxy-3'-18F-fluorothymidine and 18F-FDG.

Some new radiotracers might add useful information and improve diagnostic confidence of (18)F-FDG imaging in tumors. A multicenter clinical trial was designed to investigate the diagnostic performance of dual-tracer ((18)F-FDG and 3'-deoxy-3'-(18)F-fluorothymidine [(18)F-FLT]) PET/CT in pulmonary nodules. METHODS: Fifty-five patients underwent dual-tracer imaging in 6 imaging centers using the same models of equipment and standardized protocols. The images were interpreted by a collective group of readers who were unaware of the clinical data. The diagnostic performance using either tracer alone or dual-tracers together, with or without CT, was compared. The histological diagnosis or clinical findings in a 12-mo follow-up period served as the standard of truth. RESULTS: In 16 patients with malignant tumor, 16 with tuberculosis, and 23 with other benign lesions, the sensitivity and specificity of (18)F-FDG and (18)F-FLT were 87.5% and 58.97% and 68.75% and 76.92%, respectively. The combination of dual-tracer PET/CT improved the sensitivity and specificity up to 100% and 89.74%. The 3 subgroups of patients could be best separated when the (18)F-FLT/(18)F-FDG standardized uptake value ratio of 0.4-0.90 was used as the threshold. CONCLUSION: By reflecting different biologic features, the dual-tracer PET/CT using (18)F-FDG and (18)F-FLT favorably affected the diagnosis of lung nodules.     

~(18)F-FDG和~(18)F-FLT PET显像SUV在肺结块诊断中的价值

目的:探讨18F-氟氏脱氧葡萄糖(18F-FDG)和18F-氟氏胸腺嘧啶(18F-FLT)PET显像诊断肺结块的影响因素,以提高PET/CT对肺结块的诊断价值。方法:选择肺结块患者55例为研究对象,其中28例为肺内孤立结块,其余为2～3个结块,结块大小0.6～11.0cm。所有患者均行肺部18 F-FDG和18 F-FLT PET/CT检查,检查结果按不同性别、年龄、结块大小及病理类型进行分组,以各组18F-FDG和18F-FLT显像标准摄取值(SUV)的均数为界定标准,分析SUV与肺结块患者的性别、年龄、结块大小及病理类型等相互关系。结果:55例肺结块患者,不同性别、年龄、结块大小患者的18 F-FDG和18F-FLT显像SUV差异均无统计学意义(P>0.05),不同病理类型患者的18 F-FDG显像SUV差异无统计学意义(P>0.05),而不同病理类型患者的18F-FLT显像SUV差异有统计学意义(P<0.05)。结论:肺结块患者结块的病理类型是影响18F-FLT显像SUV的重要因素,18F-FLT PET/CT显像SUV鉴别诊断肺结块良恶性具有重要的价值和意义。     

Focal thyroid lesions incidentally identified by integrated 18F-FDG PET/CT: clinical significance and improved characterization.

In this retrospective study, we investigated whether the (18)F-FDG uptake pattern and CT findings improved the accuracy over the standardized uptake value (SUV) for differentiating benign from malignant focal thyroid lesions incidentally found on (18)F-FDG PET/CT. We also defined the prevalence of these lesions and their risk for cancer. METHODS: (18)F-FDG PET/CT was performed on 1,763 subjects without a previous history of thyroid cancer from May 2003 to June 2004. Two nuclear medicine physicians and 1 radiologist interpreted PET/CT images, concentrating on the presence of focal thyroid lesions, the maximum SUV of the thyroid lesion, the pattern of background thyroid (18)F-FDG uptake, and the CT attenuation pattern of the thyroid lesion. RESULTS: The prevalence of focal thyroid lesions on PET/CT was 4.0% (70/1,763). Diagnostic confirmation was done on 44 subjects by ultrasonography (US)-guided fine-needle aspiration (n = 29) or US with clinical follow-up (n = 15). Among 49 focal thyroid lesions in these 44 subjects, 18 focal thyroid lesions of 17 subjects were histologically proven to be malignant (papillary cancer in 16, metastasis from esophageal cancer in 1, non-Hodgkin's lymphoma in 1). Therefore, the cancer risk of focal thyroid lesions was 36.7% on a lesion-by-lesion basis or 38.6% on a subject-by-subject basis. The maximum SUV of malignant thyroid lesions was significantly higher than that of benign lesions (6.7 +/- 5.5 vs. 10.7 +/- 7.8; P < 0.05). When only the maximum SUV was applied to differentiate benign from malignant focal thyroid lesions for the receiver-operating-characteristic curve analysis, the area under the curve (AUC) of PET was 0.701. All 16 focal thyroid lesions with very low attenuation or nonlocalization on CT images, or with accompanying diffusely increased thyroid (18)F-FDG uptake, were benign. When those lesions were regarded as benign lesions, irrespective of the maximum SUV, the AUC of PET/CT was significantly improved to 0.878 (P < 0.01). CONCLUSION: Focal thyroid lesions incidentally found on (18)F-FDG PET/CT have a high risk of thyroid malignancy. Image interpretation that includes (18)F-FDG uptake and the CT attenuation pattern, along with the SUV, significantly improves the accuracy of PET/CT for differentiating benign from malignant focal thyroid lesions.     

~(18)F-FDG PET-CT和双源CT的LungCare软件在评估孤立性肺结节中的比较研究

目的 探讨18-氟-脱氧葡萄糖(~(18)F-FDG)PET/CT显像及Siemens双源CT的LungCare软件对孤立性肺结节(SPN)的辅助诊断能力及适用范围.方法 回顾分析经病理证实的24例SPN患者的PET-CT图像资料,并与利用双源CT的LungCare软件分析SPN进行比较研究.用χ~2检验对2种检查方法的评价结果进行统计学分析,以P<0.05作为差异有显著意义.结果 在24例SPN中,恶性结节15例,良性结节9例.LungCare软件评估其良恶性的准确性、敏感性、特异性、阳性预测值、阴性预测值分别为83.3%、80.0%、88.8%、92.3%、72.7%,PET-CT评估其良恶性的准确性、敏感性、特异性、阳性预测值、阴性预测值分别为87.5%、93.3%、77.7%,87.5%、87.5%.LungCare软件和PET/CT定性SPN的准确性相当,两者之间并不存在明显的差异(P>0.05).PET/CT的敏感性、阴性预测值明显高于LungCare软件,但其特异性、阳性预测值明显低于LungCare软件(P<0.05).结论 ~(18)F-FDG PET-CT对肺结节的诊断有一定辅助作用,适用于对孤立性肺结节的良恶性鉴别诊断.PET/CT密切结合LungCare软件,可进一步提高诊断正确率.     

18F-FDG PET/CT结合高分辨率CT对孤立性肺结节的诊断价值

目的探讨^18F-脱氧葡萄糖（FDG）PET／CT结合高分辨率CT（HRCT）对孤立性肺结节（SPN）的鉴别诊断价值。方法25例经手术病理检查或治疗随访证实的SPN（共27个）患者，同期行^18F—FDGPET／CT显像和病灶部位HRCT检查。^18F—FDGPET／CT用目测法结合半定量法判断良恶性。HRCT则根据病灶形态学特征判断良恶性。所得^18F—FDGPET／CT结果和^18F—FDGPET／CT与HRCT相结合结果分别与病理检查结果对照比较。结果27个SPN中15个恶性，12个良性。PET／CT正确诊断14个恶性和9个良性SPN。3个良性SPNPET／CT显像为阳性，其中2个经PET／CT和HRCT联合诊断为良性。联合诊断灵敏度和单纯PET／CT相同（93．3％），但特异性、阳性预测值、阴性预测值、准确性分别高于PET／CT（91．7％、93．3％、91．7％和93．7％对75．0％、82．4％、90．0％和85．2％）。结论^18F—FDGPET／CT结合HRCT是有效的无创性鉴别SPN良恶性的方法。     

18F-FDG和18F-FLT PET/CT在肺部良恶性肿瘤鉴别诊断中的价值

目的:分析18F-FDG(18F-脱氧葡萄糖)和18F-FLT(18F-胸腺嘧啶)两种显像剂的PET/CT检查在肺部肿瘤中的不同影像学表现,提高PET/CT在肺部良恶性肿瘤鉴别诊断中价值,从而为临床治疗方案的选择提供可靠依据。方法:收集肺肿瘤患者55例为研究对象,其中男性33例,女性22例,年龄17～82岁,28例为肺内孤立肿块,其余为2～3个肿块,肿块大小0.6～11.0cm,所有患者均行肺部18 F-FDG和18 F-FLT PET/CT检查,分析18 F-FDG和18 F-FLT标准摄取值(SUV)与肺肿瘤患者的年龄、肿块大小及病理类型等相互关系和统计学意义。结果:18 F-FDG和18 F-FLT PET/CT的SUV与肺肿瘤患者的年龄、肿块大小均无统计学差异(P>0.05),18 F-FDG PET/CT的SUV与患者的病理类型亦无统计学差异(P>0.05),而18F-FLT PET/CT的SUV与患者的病理类型有统计学差异(P<0.05)。结论:肺肿瘤患者的肿块病理类型是影响18F-FLT PET/CT的SUV的重要因素,18F-FLT PET/CT的SUV在肺部良恶性肿瘤鉴别诊断中具有重要的价值。     

基于PET/CT、HRCT特征的评分系统鉴别诊断孤立性肺部病变的临床研究

目的 探讨基于PET/CT、HRCT影像学特征的评分系统对孤立性肺部良恶性病变的诊断价值。方法 回顾性分析行PET/CT检查的孤立性占位性肺病变112例,其中良性病变44例,恶性病变68例。对孤立性肺病变的12项PET/CT及HRCT影像特征进行评估,初步建立量化分级系统,采用受试者工作特征（ROC）曲线分析良恶性病变的最佳诊断评分临界值。结果 PET/CT及HRCT预测孤立性肺部病变的指标包括年龄≥60岁（2分）、病灶大小≥1.0 cm（2分）、密度不均匀（2分）、边界清楚（1分）、SUV_max≥2.5（2分）、ΔSUV_max≥1.0（2分）、滞留指数≥15%（2分）、分叶征（3分）、毛刺征（3分）、胸膜牵拉征（3分）、空泡征（3分）。根据各项指标建立评分系统,随着评分增加,恶性率逐渐增高,通过ROC曲线得出12分为区分良、恶性病变的最佳临界点,灵敏度为92.6%,特异度为81.8%。结论 基于PET/CT、HRCT影像学特征的量化分级系统有助于鉴别孤立性肺部良恶性病变。     

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.     

Comparison of lesion-to-cerebellum uptake ratios and standardized uptake values in the evaluation of lung nodules with 18F-FDG PET

OBJECTIVE: To evaluate the clinical performance of the lesion-to-cerebellum uptake ratio (LCR), a semiquantitative index for differentiating malignant from benign lung nodules with [F]fluorodeoxyglucose positron emission tomography (F-FDG PET). METHODS: Thirty-six patients (16 females, 20 males; median age, 73 years; range, 41-87 years) with 42 known or suspected malignant lung nodules underwent whole-body PET imaging after an intravenous injection of a mean dose of 543+/-69 MBq (14.7+/-1.9 mCi) of F-FDG. The standardized uptake value (SUV) and the LCR were calculated for each nodule and receiver operating characteristic (ROC) curves were analysed using the ROCKIT 0.9B software package. RESULTS: Surgical pathology and follow-up with serial computed tomography scans for at least 24 months revealed 18 malignant lung lesions and 24 benign lesions less than 3.0 cm in size. The mean LCR was 0.70+/-0.40 for malignant nodules and 0.23+/-0.12 for benign nodules (P<0.001, two-tailed test). The area under the estimated ROC curve was 0.8660 for SUV data and 0.9197 for LCR data (P=0.2408, two-tailed test). CONCLUSIONS: The LCR method appears to be a valuable semiquantitative index for the evaluation of malignancy in pulmonary nodules with F-FDG PET, which is simple to perform clinically and does not require accurate measurements of body weight or the residual activity in the syringe utilized for F-FDG injection.     

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.     

Impact of dual-time-point <Superscript>18</Superscript>F-FDG PET imaging and partial volume correction in the assessment of solitary pulmonary nodules

Purpose Our aim was to assess the diagnostic potential of ¹⁸F-FDG PET using partial volume correction and dual-time-point imaging in the assessment of solitary pulmonary nodules. Methods We included 265 patients in this retrospective study (171 men; 94 women; age range, 41–92 years). All had pulmonary nodules on CT, and diagnosis was confirmed by biopsy or follow-up CT. All underwent whole body FDG PET, 60 min after FDG injection. Of the 265 patients, 255 underwent second FDG PET for chest 100 min after injection. Maximum SUVs for nodules were calculated from both scans. Partial volume correction for first time SUVs was applied, using coefficient factor. Malignancy was defined using the following criteria: (1) Visual assessment; (2) First time SUV ≥ 2.5; (3) Partial volume corrected first time SUV ≥ 2.5; (4) second time SUV ≥ 2.5; (5) Increase in SUV over time; (6) Increase or no change in SUV; (7) First time SUV ≥ 2.5 and/or increase or no change in SUV. Results Biopsy and follow-up revealed 72 malignant lung nodules and 193 benign nodules. Sensitivity, specificity and accuracy for the five criteria were as follows: (1) 97, 58 and 68%; (2) 65, 92 and 85%; (3) 84, 91 and 89%; (4) 90, 80 and 83%; (5) 84, 95 and 92%; (6) 92, 92, and 92%; (7) 95, 90 and 91%, respectively. Conclusion Dual-time-point ¹⁸F-FDG PET has potential impact on improving the diagnostic accuracy for malignant lung nodules. Dual-time-point ¹⁸F-FDG PET imaging should be included in the clinical work-up of patients with pulmonary nodule.     

Prospective evaluation of solitary thyroid nodule on 18F-FDG PET/CT and high-resolution ultrasonography

Purpose

The utility of 18F-FDG PET/CT in the assessment of thyroid nodules is unclear as there are several conflicting reports on the usefulness of SUV as an indicator to distinguish benign from malignant thyroid lesions. This study incorporated an additional parameter, namely dual time point imaging, to determine the diagnostic accuracy of PET/CT imaging. The performance of 18F-FDG PET/CT was compared to that of high-resolution ultrasound which is routinely used for the evaluation of thyroid nodules.

Methods

Two hundred patients with incidentally detected solitary thyroid nodules were included in the study. Each patient underwent ultrasound and PET/CT evaluation within 7 days of each other, reported by an experienced radiologist and nuclear medicine specialist, respectively, in a blinded manner. The PET/CT criteria employed were maximum SUV (SUV_max) at 60 min and change in SUV_max at delayed (120 min) imaging. Final diagnosis was based on pathological evaluation and follow-up.

Results

Of the 200 patients, 26 had malignant and 174 had benign nodules. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of ultrasound were 80.8, 81.6, 39.6, 96.6 and 81.5%, respectively. Using SUV_max at 60 min as the diagnostic criterion, the above indices were 80.8, 84.5, 43.8, 96.7 and 84%, respectively, for PET/CT. The SUV_max of malignant thyroid lesions was significantly higher than benign lesions (16.2 ± 10.6 vs. 4.5 ± 3.1, respectively; p = 0.0001). Incorporation of percentage change in SUV_max at delayed imaging as the diagnostic criterion yielded a slightly improved sensitivity, specificity, PPV, NPV and accuracy of 84.6, 85.6, 46.8, 97.4 and 85.5%, respectively. There was a significant difference in percentage change in SUV_max between malignant and benign thyroid lesions (14.9 ± 11.4 vs. ?1.6 ± 13.7, respectively; p = 0.0001). However, there was no statistically significant difference (95% confidence interval) between the diagnostic performance of PET/CT and ultrasound.

Conclusions

Routine use of 18F-FDG PET/CT with SUV_max at 60 min as the sole diagnostic criterion does not appear to have a significant advantage over high-resolution ultrasound in the evaluation of thyroid nodules. Incorporation of dual time point imaging enhances image interpretation, and yields a higher diagnostic performance, yet it is not statistically significant. Bearing in mind the cost, limited availability and radiation exposure, routine use of 18F-FDG PET/CT for distinguishing benign from malignant thyroid nodules cannot be recommended.