Objective: To investigate the value of 18F-FDG PET/CT in diagnosing pancreatic lesions, and compare it with CA19-9, contrast-enhanced CT (CECT), and contrast-enhanced MRI (CEMR).Methods: Cases of patients with suspected pancreatic lesions examined between January 1, 2011 and June 30, 2017 were retrospectively analyzed. CA19-9, CECT and CEMR within 2 weeks of PET/CT were evaluated. We compared the diagnostic efficacy of PET/CT with CA19-9, CECT and CEMR as well as combined tests.Results: A total of 467 cases were examined in this study, including 293 males and 174 females, with an average age of 57.79 ± 12.68 y (16–95 y). Cases in the malignant group (n = 248) had significantly higher SUVmax (7.34 ± 4.17 vs. 1.70 ± 2.68, P < 0.001) and CA19-9 (663.21 ± 531.98 vs. 87.80 ± 218.47, P < 0.001) than those in the benign group (n = 219). The sensitivity, specificity and accuracy of PET/CT were 91.9, 96.3, and 94.0%, respectively. Those for CECT were 83.6, 77.8, 81.2%, respectively; and 91.2, 75.0, 81.7% were for CEMR. PET/CT corrected 14.7% (28/191) CECT diagnoses and 12.2% (10/82) CEMR diagnoses. Although the diagnostic efficiency of CA19-9 was acceptable (80.0, 69.0, 74.9% respectively), the joint application of PET/CT and CA19-9 could significantly enhance the diagnostic efficiency compared with PET/CT alone (sen 97.4 vs. 90.5%, P = 0.0003; spe 100.0 vs. 95.2%, P = 0.0047).Conclusions: PET/CT has sensitivity similar to CECT, CEMR and significantly higher specificity and accuracy, helping reduce false diagnoses of morphological images. Combining PET/CT with CA19-9 could enhance diagnostic efficiency.

Abstract Background: Pancreatic cancer is one of the most fatal tumors in the world, which incidence and mortality have continued to rise in the past decade. The main challenge in clinical practice for patients with pancreatic cancer is to accurately distinguish malignant lesions from benign ones in early evaluation. This research aims to investigate the value of 18F-FDG PET/CT in diagnosing pancreatic lesions, and compare it with CA19-9, contrast-enhanced CT (CECT), and contrast-enhanced MRI (CEMR).Methods: Cases of patients with suspected pancreatic lesions examined between Jan 1st, 2011 and June 30th, 2017 were retrospectively analyzed. CA19-9, CECT and CEMR within 2 weeks of PET/CT were evaluated. We compared the diagnostic efficacy of PET/CT with CA19-9, CECT and CEMR as well as combined tests.Results: A total of 467 cases were examined in this study, including 293 males and 174 females, with an average age of 57.79 ± 12.68 y (16–95 y). Cases in the malignant group (n=248) had significantly higher SUVmax (7.34 ± 4.17 vs. 1.70 ± 2.68, P < 0.001) and CA19-9 (663.21 ± 531.98 vs. 87.80 ± 218.47, P < 0.001) than those in the benign group (n=219). The sensitivity, specificity and accuracy of PET/CT were 91.9%, 96.3% and 94.0% respectively. Those for CECT were 83.6%, 77.8%, 81.2% respectively; and 91.2%, 75.0%, 81.7% were for CEMR. PET/CT corrected 14.7% (28/191) CECT diagnoses and 12.2% (10/82) CEMR diagnoses. Although the diagnostic efficiency of CA19-9 was acceptable (80.0%, 69.0%, 74.9% respectively), the joint application of PET/CT and CA19-9 could significantly enhance the diagnostic efficiency compared with PET/CT alone (sen 97.4% vs. 90.5%, P =0.0003; spe 100.0% vs. 95.2%, P = 0.0047). Conclusions: PET/CT has sensitivity similar to CECT, CEMR and significantly higher specificity and accuracy, helping reduce false diagnoses of morphological images. Combining PET/CT with CA19-9 could enhance diagnostic efficiency.

Abstract Background : Pancreatic cancer is one of the most fatal tumors in the world, which incidence and mortality have continued to rise in the past decade. The main challenge in clinical practice for patients with pancreatic cancer is to accurately distinguish malignant lesions from benign ones in early evaluation. This research aims to investigate the value of 18 F-FDG PET/CT in diagnosing pancreatic lesions, and compare it with CA19-9, contrast-enhanced CT (CECT), and contrast-enhanced MRI (CEMR). Methods : Cases of patients with suspected pancreatic lesions examined between Jan 1st, 2011 and June 30th, 2017 were retrospectively analyzed. CA19-9, CECT and CEMR within 2 weeks of PET/CT were evaluated. We compared the diagnostic efficacy of PET/CT with CA19-9, CECT and CEMR as well as combined tests. Results : A total of 467 cases were examined in this study, including 293 males and 174 females, with an average age of 57.79 ± 12.68 y (16–95 y). Cases in the malignant group (n=248) had significantly higher SUVmax (7.34 ± 4.17 vs . 1.70 ± 2.68, P < 0.001) and CA19-9 (663.21 ± 531.98 vs. 87.80 ± 218.47, P < 0.001) than those in the benign group (n=219). The sensitivity, specificity and accuracy of PET/CT were 91.9%, 96.3% and 94.0% respectively. Those for CECT were 83.6%, 77.8%, 81.2% respectively; and 91.2%, 75.0%, 81.7% were for CEMR. PET/CT corrected 14.7% (28/191) CECT diagnoses and 12.2% (10/82) CEMR diagnoses. Although the diagnostic efficiency of CA19-9 was acceptable (80.0%, 69.0%, 74.9% respectively), the joint application of PET/CT and CA19-9 could significantly enhance the diagnostic efficiency compared with PET/CT alone (sen 97.4% vs. 90.5%, P =0.0003; spe 100.0% vs. 95.2%, P = 0.0047). Conclusions : PET/CT has sensitivity similar to CECT, CEMR and significantly higher specificity and accuracy, helping reduce false diagnoses of morphological images. Combining PET/CT with CA19-9 could enhance diagnostic efficiency.

OBJECTIVE:The purpose of this study is to investigate the value of 18F-FDG PET/CT combined with assessment of tumor markers in serum or ascites for the diagnosing and determining the prognosis of benign and malignant ascites.MATERIALS AND METHODS:Patients with ascites of unknown cause who underwent evaluation with FDG PET/CT were included in this retrospective study. The maximum standardized uptake value (SUVmax) and levels of the tumor markers carbohydrate antigen-125 (CA-125) and carcinoembryonic antigen (CEA) in serum and ascites were recorded. The diagnostic values of FDG PET/CT, CEA and CA-125 levels in serum or ascites, and the combination of imaging plus tumor marker assessment were evaluated. Factors that were predictive of survival were also analyzed.RESULTS:A total of 177 patients were included. Malignant ascites was eventually diagnosed in 104 patients, and benign ascites was diagnosed in the remaining 73 patients. With the use of FDG PET/CT, 44 patients (42.3%) were found to have primary tumors. The sensitivity, specificity, and accuracy of FDG PET/CT were 92.3%, 83.6%, and 88.7%, respectively. CA-125 levels in serum and ascites showed much better sensitivity than did CEA levels, but they showed significantly lower specificity. If the combination of tumor markers and FDG PET/CT was analyzed, the sensitivity, specificity, and accuracy of tumor markers in serum were 96.6%, 78.1%, and 88.7%, and those of tumor markers in ascites were 97.7%, 80.0%, and 90.4%, respectively. Sex may be an important factor affecting survival time (hazard ratio, 0.471; p = 0.004), but age, CEA level, and FDG PET/CT findings could not predict survival.CONCLUSION:FDG PET/CT combined with assessment of tumor markers, especially CEA, increased the efficacy of diagnosis of ascites of unknown causes. Male sex conferred a poorer prognosis, whereas age, CEA level, and FDG uptake had no predictive significance in patients with malignant ascites.

A 26-year-old man had unilateral facial numbness. A brain MRI suggested possible brain metastases. F-FDG and C-choline PET/CT revealed multiple sites of abnormal activity in the body. However, C-choline PET/CT was more impressive than FDG PET/CT. Especially, the brain lesions revealed by MRI had only elevated C-choline uptake but had FDG uptake levels similar to adjacent brain. Acute myeloid leukemia was diagnosed after bone marrow biopsy.

A 26-year-old man had unilateral facial numbness. A brain MRI suggested possible brain metastases. F-18-FDG and C-11-choline PET/CT revealed multiple sites of abnormal activity in the body. However, C-11-choline PET/CT was more impressive than FDG PET/CT. Especially, the brain lesions revealed by MRI had only elevated C-11-choline uptake but had FDG uptake levels similar to adjacent brain. Acute myeloid leukemia was diagnosed after bone marrow biopsy.

目的 研究18F-FDG PET/CT显像对胃癌患者肺转移诊断与鉴别诊断的临床价值.方法 回顾性分析2011年9月至2015年3月间通过手术切除或胃肠镜活检病理诊断为胃癌(gastric carcinoma,GC)且在该中心进行18F-FDG PET/CT显像的患者,选取91例术前怀疑肺转移的患者,其中男性72例,女性19例,中位年龄(60.6±14.2)岁(年龄范围17～86岁),统计肺转移灶的直径,勾画感兴趣区ROI并记录胃原发灶及肺部转移灶的SUVmax值.91例患者中原发灶为腺癌70例,其中管状腺癌29例、黏液腺癌6例、乳头状腺癌22例、低分化腺癌13例;原发灶为印戒细胞癌21例.所有患者在检查后都经过了6～36个月随访,随访至2015年7月,随访包括穿刺或手术活检、监测血浆CEA水平及影像学检查.结果 91例GC术前怀疑肺转移的患者中,通过病理活检或临床/影像学随访证实63例为恶性,其中2例PET/CT显示为阳性患者纤维支气管镜活检证实为原发性肺鳞癌,在61例肺转移患者中55例PET/CT显示为阳性,6例为假阴性;28例肺部良性病灶患者中,23例PET/CT显示为阴性,5例为假阳性.PET/CT对于胃癌患者肺转移的诊断敏感性、特异性、准确性、阳性预测值及阴性预测值分别为90.16％、82.14％、87.64％、91.67％和79.31％.转移病灶的平均直径为(13.21±9.15)mm,而转移病灶的SUVmax平均值为(5.53±3.78),二者相关性有统计学意义(P＜0.01).胃原发灶为腺癌SUVmax平均值为(6.25±3.67),印戒细胞癌SUVmax平均值为(3.14±3.19),两组间差异有统计学意义(P=0.006).肺转移病灶的SUVmax平均值为(5.53±3.78),胃原发病灶的SUVmax平均值为(6.19±3.18),两组间Spearman秩相关系数为0.658,呈正相关.而肺转移病灶的SUVmax平均值低于胃原发灶,差异无统计学意义(P＞0.05).结论 18F-FDG PET/CT显像对于胃癌患者肺转移病灶的发现及良恶性判断具有很高的敏感性、特异性和准确性,病灶大小和SUVmax值正相关,病灶越大SUVmax值越高,肺转移病灶的SUVmax值和原发病灶的病理类型及SUVmax值正相关.

Objective To evaluate the efficacy 18 F-FDG PET/CT in diagnosis and prognosis for nasopharyngeal carcinoma(NPC) patients during follow-up after comprehensive therapy.Methods A total of 89NPC patients after comprehensive therapy were included,and the diagnostic results of 18 F-FDG PET/CT and traditional imaging were analyzed and compared with histopathological diagnosis or clinical follow-up data retrospectively.The diagnostic sensitivity,specificity,accuracy rate,positive predictive value(PPV) and negative predictive value(NPV) of residual,recurrent or metastasis were calculated,respectively.The qualitative diagnosis using the maximal standard uptake value(SUV max) was determined.ROC curves were determined to assess the optimal cutoff value for evaluating diagnostic value of 18 F-FDG PET/CT and predicting survival,while qualitative diagnosis was predicted survival.COX proportional hazards regression model analysis was performed to identify the prognostic factors which impact overall survival(OS) and disease-free survival(DFS).Results In all 89patients,five-year OS of all patients was 73.00%,and the mean survival time was(69.22±4.46) months.The diagnostic sensitivity,specificity,accuracy rate,PPV and NPV of 18 F-FDG PET/CT and conventional imaging was 100%(59/59),90.20%(46/51),95.45%(105/110),92.19%(59/64),100%(46/46) and 75.86%(44/58),78.85%(41/52),77.27%(85/110),80.00%(44/55),72.73%(40/55),respectively.The sensitivity and accuracy rate of 18 F-FDG PET/CT were high than those of traditional imaging(both P0.01).From ROC curve,the cut off value of SUV max was 2.5,which might be the best diagnostic value in the follow-up of NPC.Patients with SUVmaxbelow 2.5had significantly better 5-year OS than those with SUV max ≥ 2.5(81.90% vs 62.00%,P=0.036).18 F-FDG PET negative patients had long 5-year OS than positive ones(59.90% vs 100%,P=0.006).COX proportional hazards regression model analysis showed both SUV max(relative risk [ RR ] =1.205,P=0.014) and number of lesions(RR=2.734,P=0.005) could be used to predict OS.For DFS,number of lesions(RR=2.105,P=0.008) might have predictive relevance.Conclusion 18 F-FDG PET/CT imaging has significantly higher sensitivity and accuracy rate than conventional imaging in detection of the residual,recurrent and metastasis of NPC after comprehensive therapy.SUV max being 2.5may be a relatively good diagnostic value in the following-up,and may also have great valuable for predicting long-term survival.SUVmaxand number of lesions may be predictors for OS and DFS,and number of lesions may be an important factor for DFS.

Objective To assess the diagnostic value of PET/CT in detection of recurrence and metastasis in patients with postoperative colon cancer.Methods A total of 78 patients were suspected with recurrence and metastasis of postoperative colon cancer,including 46 males and 32 females.The diagnostic results of PET/CT and traditional imaging were analyzed and compared with histopathological diagnosis or clinical follow-up data.Results In all 78 patients,recurrence and metastasis were confirmed in 54 patients with histopathological diagnosis or clinical follow-up data.The sensitivity and accuracy of PET/CT were higher than those of traditional imaging in diagnosis of all recurrence and metastasis of postoperative colon cancer,and the sensitivity and accuracy of PET/CT and traditional imaging was 90.74% and 51.85%(P0.01),89.74% and 58.97%(P0.01),respectively.The sensitivity and accuracy of PET/CT were also higher than those of traditional imaging in diagnosis of local recurrence and metastasis of postoperative colon cancer(90.91% vs.42.42%,P0.01;96.15% vs.75.64%,P0.01),respectively.Conclusion PET/CT imaging has significantly higher sensitivity and accuracy than traditional imaging in detection of recurrence and metastasis of postoperative colon cancer.It is an ideal method to monitor the recurrence and metastasis of postoperative colon cancer.

OBJECTIVE:To investigate the effects of extract of Bulbus Allii Caespitosi on cardiocyte viability of swines with myocardial reperfusion injury by analyzing the 18F-fluorodeoxyglucose ((18)F-FDG) position emission tomography (PET) imaging. METHODS:Twenty-four swines were randomly divided into sham-operated group, untreated group, trimethazine group and extract of Bulbus Allii Caespitosi group. Myocardial reperfusion injury was induced by plugging the anterior descending coronary artery of swine with sacculus. Bulbus Allii Caespitosi or trimetazidine was given twice daily for 28 days. Then myocardial perfusion was detected with (18)F-FDG PET/CT and the radioactivity distribution was evaluated. RESULTS:Compared with the untreated group, Bulbus Allii Caespitosi and trimetazidine could improve the activity of myocardial cells after myocardial infarction (P<0.01), and there were no significant differences between Bulbus Allii Caespitosi and trimetazidine (P>0.05). CONCLUSION:Bulbus Allii Caespitosi can improve myocardial metabolism after ischemia and reperfusion in swines.

643 Objectives To assess the value of 18F-FDG PET/CT in diagnostic and therapeutic evaluation of malignant lymphoma. Methods The results of 136 18F-FDG PET/CT scans were retrospectively reviewed in 112 patients with pathological diagnosis of malignant lymphoma. All 28 PET/CT scans in 23 cases with Hodgkin’s Disease (HD) were performed after therapy. Among108 PET/CT scans in 89 patients with Non-Hodgkin Lymphoma (NHL), 39 scans were performed before therapy, and 69 scans after therapy. All the patients had corresponding CT, MRI, and/or ultrasound (conventional) images. Results (1) From the 28 PET/CT scans in patients with HD, 7 cases showed normal after chemotherapy and/or radiotherapy, and 8 cases showed improved or partly improved. The other 13 cases were in progresses or recurred after relief. Of 21 cases shown abnormal in PET/CT scans, only 14 cases (66.7%) could reflect the pathogenetic condition on conventional images. (2) From 39 NHL cases performed PET/CT scanning before therapy, 37 cases showed positive, and the accuracy rate was 94.9%. The positive rate was 83.3% from conventional images, but there were 14 cases (46.7%) from positive scans underestimated. (3) From the 69 PET/CT scans of NHL cases after therapy, 30 cases (43.5%) showed normal, and 16 cases (23.2%) improved or partly improved. The other 23 cases (33.3%) were in progresses or recurred after relief. There are only 41 cases (59.4%) could reflect the true situation from conventional images. Conclusions 18F-FDG PET/CT is a sensitive and accurate imaging method in clinical diagnosis, therapy and recurrence evaluation of malignant lymphoma, much more sensitive than conventional imaging methods. Research Support Supported by China National 863 Project 2008AA02Z426

本研究通过回顾性分析37例乳腺癌患者治疗后的18F-脱氧葡萄糖(FDG)PET/CT检查资料,探讨其诊断乳腺癌复发和转移的应用价值,现报道如下.

OBJECTIVE:To study the changes of hypothalamus metabolism in patients with psychogenic erectile dysfunction (ED) so as to get some clues to the possible pathogenic factors and pathophysiological mechanism of the problem. METHODS:Six cases of psychogenic ED and 4 normal volunteers were studied by positron emission tomography (PET) for the characteristics of hypothalamus glucose metabolism. Following audiovisual sexual stimulation, the concentration of fluorine-18-fluorodeoxyglucose (18 F-FDG) was determined and the ratio of the left (right) hypothalamus count to the cerebrum count was calculated. RESULTS:Audiovisual sexual stimulation significantly increased 18F-FDG in the volunteers (left: 1.026 +/- 0.115 vs 2.400 +/- 0.210; right: 1.003 +/- 0.187 vs 2.389 +0.196, P < 0.05) as compared with the psychogenic ED patients (left: 2.781 +/- 0.156 vs 2.769 +/- 0.223; right: 2.809 +/- 0.129 vs 2.793 +/- 0.217, P > 0.05). CONCLUSION:Psychogenic ED may not be simply a functional disease; the hypothalamus may be involved in the pathophysiology of the problem.

In recent years, the clinical status of positron emission tomography(PET)/computed tomography(CT) in achieving more accurate staging of lung cancer has been established and the technology has been enthusiastically accepted by the medical community. However, its capability in chest imaging is still limited by several physical factors. As a result of typical PET/CT imaging protocol, respiration-averaged PET data and free of respiration-averaged CT data are collected in a PET/CT scanning. In this work, we investigate the effects of respiration motion. We employ mathematical and Monte-Carlo simulations for generating PET/CT data. We scale a Zubal phantom to generate 30 phantoms having various sizes in order to represent different torso anatomic states during respiration. Images reconstructed from selected scaling PET data using the respective scaling PET attenuation maps serve as baseline results. PET/CT imaging protocol is simulated by reconstruction from respiration-averaged PET data with the selected PET attenuation maps. We also reconstruct PET images from respiratory-averaged PET data with respiration-averaged PET attenuation maps, which simulates conventional PET imaging protocol. We will compare the resulting images reconstructed from the above-mentioned approaches to evaluate the effects of respiration motion in PET/CT.

The accurate determination of biological target volume in non-small cell lung cancer (NSCLC)is essential for the three-dimensional and intensity modulated radiation therapy.Functional im- aging(PET or SPECT)and image fusion technologies is useful to dehneate accurately biological target volume in NSCLC.This article reviews the application of functional imaging techniques in NSCLC and in- troduces the current derelopment of various functional imaging.

Objective:To evaluate the use of 18F-fluorodeoxyglucose(FDG) PET/CT in recurrence and metastasis of breast cancer. Methods: Thirty-seven patients after operation underwent 18F-FDG PET/CT whole body imaging for evaluation of recurrent breast cancer and metastasis. Visual and semiquantitative methods(standard uptake value, SUV) were used to analyze the images. The results of PET/CT imaging were compared with those of pathology or CT. Results: Twenty-seven malignant recurrent breast lesions in thirty-seven resected breast cancers detected by this modality were proven histopathology, biopsy, cytological examination, and clinical follow-up. Among the twenty-seven malignant breast lesions, the diagnostic sensitivity of PET/CT and CT imaging were 96.30% and 62.96% respectively. There were statistical differences in sensitivity between PET/CT and CT(χ2=9.247, P<0.05). Fourteen patients with breast cancer underwent PET/CT at 2 time points. Recurrence and metastasis were diagnosed in 9 patients, and all of their SUVs increased at time 2. Conclusions: 18F-FDG PET/CT makes the location and characterization of the lesions more accurate, and it is a useful diagnostic modality in the diagnosis of recurrent and metastatic breast cancer.

OBJECTIVE:To assess the role of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) in the management of unknown primary primary (CUP) with metastatic loci.METHODS:Thirty-four patients of CUP with metastatic loci who had undergone unsuccessful conventional diagnostic work-up underwent (18)F-FDG PET/CT. The images thus obtained were analyzed with visual and semi-quantitative methods. Histopathology, cytology, and/or follow-up were used to evaluate the PET/CT results.RESULTS:In 20 of the 34 patients (18)F-FDG PET/CT showed focal tracer accumulations corresponding to potential primary tumor sites located in the lung (n = 9), colon (n = 3), rectum (n = 2), pancreas (n = 1), right aryepiglottic wall (n = 1), esophagus (n = 1), breast (n = 1), and ovary (n = 2). The detection rate of primary tumor by (18)F-FDG PET/CT was 50.0% (17/34), the primary tumors were identified in the lung (n = 8), colon (n = 2), rectum (n = 1), pancreas (n = 1), right aryepiglottic wall (n = 1), esophagus (n = 1), ovary (n = 2), and breast (n = 1). The false positive rate was 8.8% (3/34) with the diagnosis of primary tumor in the lung (n = 1), colon (n = 1), and rectum (n = 1) to be identified as false. In 14 of the 34 patients, (18)F-FDG PET/CT did not reveal lesions suspected to be the primary tumor sites in 13 patients, and it was impossible to identify one lesion as the most likely primary tumor in one patient due to the presence of multiple hot spots in several organs. The (18)F-FDG PET/CT findings affected the medical management in 17 of the 34 (50.0%) patients due to the finding of primary sites and/or additional metastases.CONCLUSION:(18)F-FDG PET/CT has relevant impact on the therapeutic management of patients with unknown primary tumor. It is recommended that (18)F-FDG PET/CT be performed in the patient with unknown primary tumor after unsuccessful conventional diagnostic workup.

AIM: To assess the clinical value of dual time point 2-[F-18]-fluoro-2-deoxy-D-glucose positron emission tomography (F-18-FDG PET) imaging for the differentiation between malignant and benign lesions.MATERIALS AND METHODS: Ninety-six patients (28 patients with primary lung cancer, 18 patients with digestive system carcinoma, 13 patients with other malignant tumours, and 37 patients with benign lesions) underwent FDG-PET/CT at two time points: examination 1 at 45-55 min and examination 2 at 160 +/- 24 (150-180) min after the intravenous injection of 233 +/- 52 (185-370) MBq F-18-FDG. Reconstructed images were evaluated qualitatively and quantitatively. The maximum standardized uptake values (SUVmax) of the lesions were calculated for both time points. An increase was considered to have occurred if the SUVs at examination 2 had increased by >10% as compared with those at the examination 1.RESULTS: The lesions in 24 of 28 (86%) patients with primary lung cancer had an SUVmax >= 2.5 at examination 1. Of these, SUVmax values increased in 23 patients, but had not changed in one patient, at examination 2. The lesions in the other four patients with primary Lung tumour had SUVmax values between 1.5 and 2.5 at examination 1, which were considered as suspected positive, increased SUVmax values were observed in three of these patients at examination 2. The malignant lesions in 17 of 18 patients with digestive system carcinoma showed SUVmax values >= 2.5 and only one patient had an SUVmax value <1.5 at examination 1; all lesions showed an increase in SUVmax values at examination 2. In 13 patients with other malignant tumours, all lesions had SUVmax values >= 2.5 at examination 1 and the SUVmax values were further increased at examination 2. Therefore, the malignant lesions in 54/59 (92%) of patients had SUVmax values >= 2.5 at examination 1 and showed a further increase in SUVmax value at examination 2. Only 12 of 37 (32%) patients with benign lesions showed SUVmax values >= 2.5 at examination 1 and nine patients with benign lesions had SUVmax values >= 2.5 in examination 2. The sensitivity, specificity, accuracy, positive and negative predictive values for the early and delayed imaging were 91.5, 67.6, 82.3, 81.8, and 83.3%, and 98.3, 75.7, 89.6, 86.6, and 96.6%, respectively.CONCLUSION: The results of the present study provide further evidence that dual time point F-18-FDG PET imaging is an important noninvasive method for the differentiation of malignant and nonmalignant lesions. (C) 2008 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.