Objective:To compare the efficacy and prognostic evaluation of response evaluation criteria in lymphoma (RECIL) and Lugano classification in patients with 18F-FDG-avid Hodgkin′s lymphoma (HL) and non-HL (NHL) during mid-chemotherapy. Methods:From January 2015 to August 2021, 240 patients (149 males and 91 females, age 50.0(32.0, 62.0) years) with pathologically confirmed lymphoma in Shanxi Cancer Hospital were retrospectively analyzed. Pre-treatment and mid-treatment 18F-FDG PET/CT examinations were performed, and the differences of PET/CT imaging results among patients with different types of lymphoma were analyzed ( χ2 test or Kruskal-Wallis rank sum test). Efficacy evaluation was conducted during mid-chemotherapy, and the results were divided into complete remission (CR), partial remission (PR), stable disease (SD), progressive disease (PD) according to Lugano classification, which were divided into CR, PR, mild remission (MiR), SD, PD according to RECIL. For the better comparison with Lugano classification, MiR was included in PR group (recorded as RECIL-1) and SD group (recorded as RECIL-2) in this study. All patients were followed up, and the progression free survival (PFS) was analyzed. Kappa test, χ2 test or Fisher exact probability method were used to analyze the data, and ROC curve was used to compare the prediction efficiency of different standards. Results:Among 240 patients with different types of lymphoma (96 HL, 30 follicular lymphoma (FL), 114 diffuse large B-cell lymphoma (DLBCL)), there were statistically significant differences in baseline SUV max ( H=54.96, P<0.001) and the sum of longest diameters ( H=15.85, P<0.001). Patients were followed up for 12-89 months, and 26 patients (10.8%) were evaluated as MiR according to the RECIL. The consistency ( Kappa) was 0.84 between results of RECIL-1 and Lugano classification, which was 0.74 between RECIL-2 and Lugano classification (both P<0.001). According to Lugano classification, the PFS rates of patients evaluated as CR, PR, SD and PD were 91.4%(148/162), 57.1%(36/63), 1/3 and 3/12 respectively, which were 91.3%(136/149), 62.8%(49/78), 1/2 and 2/11 for RECIL-1, and 91.3%(136/149), 57.7%(30/52), 71.4%(20/28) and 2/11 for RECIL-2 respectively ( χ2 values: 46.64-52.44, all P<0.001). The AUC of Lugano classification for predicting PFS had a trend to be higher than AUCs of RECIL-1 and RECIL-2 (0.774, 0.758 and 0.746; z values: 1.28, 1.61, P values: 0.200, 0.107). Conclusion:RECIL and Lugano classification have similar efficacy and prognostic evaluation effect on patients with 18F-FDG-avid HL and NHL during mid-chemotherapy.

Drug-associated lung injury (DALI) is one of the important factors affecting the prognosis of patients with lymphoma, and early identification and timely intervention for DALI are essential. Currently, the commonly used imaging examinations, e. g. high-resolution computed tomography, and laboratory tests all have hysteresis, so that the lung injury may be irreversible. Nuclear medicine imaging provides functional and metabolic information for DALI before morphological changes, so that the opportunity for early clinical intervention can be obtained. This article reviews the application of nuclear medicine imaging in lymphoma DALI.

Objective:To explore the prognostic value of the maximum standardized uptake value reduction proportion (ΔSUVmax%) on 18F-fluorodeoxyglucose (FDG) positron emission tomography combined with computed tomography (PET/CT) imaging, Deauville scores and C-myc gene rearrangement for the prediction of diffuse large B-cell lymphoma (DLBCL) in early chemotherapy. Methods:A total of 83 primary patients with pathologically confirmed DLBCL admitted in Shanxi Provincial Cancer Hospital from September 2010 to December 2016 underwent 18F-FDG PET/CT 1 week before and after early chemotherapy. The patients underwent post-chemotherapy examinations between 17 to 21 days after one cycle ( n=34) or two cycles ( n=49). The region of interest (ROI) was drawn and the ΔSUVmax% was calculated. Deauville 5-point scale was used to score the PET/CT imaging in early chemotherapy. Fluorescence in situ hybridization (FISH) was used to detect C-myc gene rearrangement. The follow-up time was from 36 to 111 months. The primary end-point of the study was progression-free survival (PFS). Receiver operating characteristic (ROC) analysis, χ2 test, Spearman correlation analysis, Log rank test, and Cox regression analysis were used to analyze the data. Results:Of 83 DLBCL patients, 19 progressed during the follow-up period. The optimal cut-off value of ΔSUVmax% for predicting tumor progression in early chemotherapy was 62.59%, and the Deauville score was taken as 5. The differences in sensitivity, specificity, and accuracy between the two methods were not statistically significant ( P>0.05). The ΔSUVmax% were negatively correlated with C-myc gene rearrangement and the Deauville scores ( rs= -0.889, -0.862, P<0.001). However, the Deauville scores was positively correlated with the C-myc gene rearrangement ( rs=0.781, P<0.001). The median PFS were 59 months and 16 months in ΔSUVmax%≥62.59% ( n=57) and ΔSUVmax%<62.59% ( n=26), respectively, with significant difference ( P<0.001). The median PFS for the Deauville score <5 subgroup (61 cases) and =5 subgroup (22 cases) was 59.0 and 15.0 months, respectively, with statistically significant differences ( P<0.001). The median PFS for patients with C-myc rearrangement subgroup (62 cases) and without rearrangement subgroup (21 cases) was 59.0 and 15.0 months, respectively, with statistically significant differences ( P<0.001). The median PFS for ΔSUVmax%<62.59% and Deauville score=5 subgroup, ΔSUVmax%<62.59% and C-myc rearrangement subgroup, Deauville score=5 and C-myc rearrangement subgroup were 15.5 months, 15 months and 13.5 months, respectively, with statistically significant differences ( P<0.001). Conclusion:ΔSUVmax%, Deauville score and C-myc gene rearrangement in early chemotherapy are all associated with PFS in DLBCL patients, and the combination of the two has a good predictive value for the prognosis of DLBCL

Objective:To evaluate the value of 18F-FDG uptake features in differential diagnosis of benign and malignant solitary pulmonary lesions. Methods:A total of 274 patients (181 males, 93 females, age: (61.0±10.2) years) with solitary pulmonary lesions who underwent 18F-FDG PET/CT between September 2010 and March 2017 were retrospectively analyzed. The 18F-FDG uptake features of lesions were divided into 5 types: full uptake (Group A), circular uptake (Group B), multi-focus uptake (Group C), mild uptake (Group D) and no-uptake (Group E). According to the pathology or follow-up results, the incidences of benign and malignant lesions in each group were analyzed. The diagnostic efficiencies of 18F-FDG uptake feature classification(A+ B=malignancy, C+ D+ E=benign) and SUV method (lesions with SUV max≥2.5 was taken as the malignancy) were calculated. χ2 test and ROC curve were used to analyze the data. Results:The malignant incidences of Groups A-E were 86.25%(138/160), 71.05%(27/38), 31.25%(10/32), 43.48%(10/23) and 14.29%(3/21), respectively ( χ2=79.49, P<0.001), and the rate of Group A was the highest ( χ2 values: 5.11-55.84, all P<0.05). There were significant differences in the malignancy incidence between A+ B group and C+ D+ E group (83.33%(165/198) vs 30.26%(23/76)), and between SUV max≥2.5 group and SUV max<2.5 group (76.09%(175/230) vs 29.55%(13/44); χ2 values: 71.83 and 37.15, both P<0.001). The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the 18F-FDG uptake feature classification and the SUV method were 87.77%(165/188) vs 93.09%(175/188), 61.63%(53/86) vs 36.05%(31/86), 79.56%(218/274) vs 75.18%(206/274), 83.33%(165/198) vs 76.09%(175/230), 69.74%(53/76) vs 70.45%(31/44), respectively. ROC curve analysis showed that the diagnostic accuracy of the 18F-FDG uptake feature classification was higher than that of SUV method (AUCs: 0.747, 0.646; Z=4.05, P<0.001). Conclusions:18F-FDG uptake feature classification can improve the diagnostic specificity and accuracy of solitary pulmonary lesions. The multi-focus uptake feature maybe a sign of benign lesions, which still needs more researches to confirm.

目的 探讨18F脱氧葡萄糖(18F-FDG) PET/CT显像的代谢参数最大标准化摄取值(SUVmax)、肿瘤代谢体积(MTV)、病灶糖酵解总量(TLG)及临床指标对初诊弥漫性大B细胞淋巴瘤(DLBCL)的预后评估价值.方法 回顾性分析94例经病理确诊DLBCL患者临床资料及治疗前的18F-FDG PET/CT显像资料.以SUVmax.的41％作为阈值,得出病灶的MTV和TLG,采用受试者工作特征曲线(ROC)分析判断以上3个参数预测无进展生存期(PFS)的最佳阈值.采用Pearson卡方检验、Kaplan-Meier法、Log-rank检验、单因素和多因素Cox回归分析与预后相关的因素.结果 ROC曲线分析显示,SUVmaxMTV及TLG曲线下面积(AUC)分别为0.557(P =0.345)、0.871 (P＜0.001)和0.833(P ＜0.001).因SUVmax的AUC较小,不能通过ROC曲线分析获得界值.MTV和TLG的最佳界值分别为138.77 cm3、1998.62.将SUVmax、MTV和TLG分别以中位数及对应界值分为两组,Kaplan-Meier生存分析显示,MTV和TLG两组间PFS差异均有统计学意义(x2=35.887和30.435,P均＜0.001),而SUVmax两组间PFS差异无统计学意义(x2=0.782,P=0.376).高MTV和高TLG组,更易见大病灶直径、Ann Arbor分期晚、有B症状、乳酸脱氢酶(LDH)水平高、美国国家综合癌症网络IPI (NCCN-IPI)评分(4～8分)、美国东部肿瘤协作组(Ecog)评分(≥1分)、BCL-2蛋白表达阳性和MYC蛋白表达阳性的患者(x24.066～24.266,P均＜0.05).多因素分析中,Ecog评分、MTV和TLG均是影响患者PFS的独立危险因素[相对危险度(RR):6.444 ～8.811,P均＜0.05].结论 18F-FDG PET/CT的参数MTV和TLG可作为预测DLBCL患者PFS的重要指标,两者的预测价值优于SUVmax.

Objective:To investigate the value of 18F-prostate specific membrane antigen (PSMA)-1007 PET/CT in the detection of prostate cancer recurrence at low serum prostate specific antigen (PSA) level. Methods:From July 2018 to June 2019, 45 patients (age: 59-74 years) with suspected biochemical recurrence of prostate cancer with low PSA level (<2.0 μg/L) who underwent 18F-PSMA-1007 PET/CT examinations in Shanxi Tumor Hospital were retrospectively analyzed. Four patients with PSA<0.2 μg/L were not included in the statistical analysis due to the small sample. Among the remaining 41 patients with 0.2 μg/L≤PSA<2.0 μg/L, 10 were with 0.2 μg/L≤PSA<0.5 μg/L, 14 were with 0.5 μg/L≤PSA<1.0 μg/L, 17 were with 1.0 μg/L≤PSA<2.0 μg/L. PET/CT imaging were performed within 2 weeks after the examination of serum PSA. All patients were divided into low-moderate-risk group ( n=12) and high-risk group ( n=29) according to the National Comprehensive Cancer Network (NCCN) guidelines. χ2 test, Fisher′s exact test and Spearman rank correlation were used to analyze the data. Results:Patients were followed up for 7 (4-15) months, and all 45 patients were confirmed by pathology or follow-up. There were 31 patients with recurrence and 14 patients without recurrence. The sensitivity, specificity and accuracy were 100%(31/31), 13/14, 97.78%(44/45)respectively. One patient with PSA<0.2 μg/L presented retroperitoneal lymph node metastasis. Among 41 patients with 0.2 μg/L≤PSA<2.0 μg/L, 31(75.61%) were with at least one recurrent lesion by 18F-PSMA-1007 PET/CT. There were 20 cases of local recurrence, 13 cases of lymph node metastasis, 14 cases of bone metastasis. The detection efficacies of 18F-PSMA-1007 PET/CT were 5/10 for patients with 0.2 μg/L≤PSA<0.5 μg/L, 11/14 for those with 0.5 μg/L≤PSA<1.0 μg/L, and 15/17 for those with 1.0 μg/L≤PSA<2.0 μg/L ( χ2=4.641, P>0.05). The positive results of 18F-PSMA-1007 PET/CT were positively correlated with serum PSA value and risk group ( r values: 0.394, 0.384, both P<0.05). Conclusion:18F-PSMA-1007 PET/CT is a valuable tool for detecting biochemical recurrence of prostate cancer with low PSA level.

Objective To investigate the correlation between the maximum standardized uptake value(SUVm,) of colorectal cancer primary lesions and clinical pathological features,such as TNM staging and clinical staging.Methods Eighty-three patients diagnosed with colorectal cancer and without any previous treatment were retrospectively analyzed and underwent 18F-fluorodeoxyglucose PET/CT examinations within one week,in which the SUVmax of the primary lesions was measured.Data were compared using one-way ANOVA and two-sample t test.Spearman correlation analysis was used to evaluate the correlation of the SUVmax of colorectal cancer primary lesions with TNM staging and clinical staging.Results The SUVmax of colorectal cancer primary lesions correlated with the tumor diameter(t=2.497,P＜0.05),pathological type and differentiation degree(F=3.727,P＜0.05).Statistically significant differences were found in the SUVmax of different N stages,M stages,and clinical stages(t=2.081,t=2.168,F=2.839,all P＜0.05) but not in the SUVmax of different T stages.The SUVmax of colorectal cancer primary lesions positively correlated with N,M,and clinical stages(r=-0.248,0.273,0.324,all P＜0.05) but not with T stages (r=0.004,P＞0.05).Conclusions The SUVmax of colorectal cancer primary lesions correlated with the tumor diameter,pathological type,differentiation degree,N stages,M stages,and clinical stages.Hence,SUVmax can reflect the invasion and proliferation abilities of colorectal cancer.

在肺癌、乳腺癌及前列腺癌等恶性肿瘤的患者中,脊柱是骨转移最好发的部位[1].近年来,尽管脊柱转移瘤的治疗手段不断进步,但仍存在很多争议.因此如何根据患者的全身情况制定出有效的个体化治疗方案尤为重要. 2005年, Tokuhashi等[2]在原有评分系统的基础上制定出新的修正评分来指导脊柱转移瘤的治疗.

Objective To evaluate the prognostic value of the maximum standardized uptake value decrease proportion (△SUVmax％) on 18F-fluorodeoxyglucose (FDG) PET/CT imaging and C-MYC gene in diffuse large B cell lymphoma (DLBCL),and to find the optimal time of PET/CT imaging.Methods From September 2010 to February 2016,171 patients (87 males,84 females,average age:(50.66±2.56) years)with pathologically confirmed DLBCL were analyzed.18F-FDG PET/CT were performed before and after different courses of chemotherapy (60 patients in early phase which means 1 and 2 courses;55 patients in medium phase,3 and 4 courses;56 patients in late phase,5 and 6 courses).The region of interest (ROI) was drawn and the △SUVmax％ was calculated.Patients were evaluated with Deauville 5-point scale.Fluorescence in situ hybridization (FISH) was employed to detect C-MYC gene.Patients were followed up for 6-71 months,and progression-free survival (PFS) was calculated.x2 test,one-way analysis of variance,Kaplan-Meier analysis and Spearman correlation analysis were used to analyze the data.Results There were 42 C-MYC gene rearrangement of 171 DLBCL patients.Age,Ann Arbor stage,international prognostic index (IPI) score,serum lactate dehydrogenase (LDH) level and therapeutic response were different between patients with C-MYC gene rearrangement and those without rearrangement (x2:6.139-98.339,all P＜0.05).The optimum cutoff values of the △SUVmax％ were 62.5％,87.0％ and 92.0％ respectively in the early,medium and late phases of chemotherapy.Patients with △SUVmax％ ≥≥ 62.5％,≥ 87.0％ or ≥ 92.0％ and normal C-MYC gene showed longer PFS (x2 values:21.983-61.899,all P＜0.001).The △SUVmax％ was negatively correlated with C-MYC gene rearrangement (rs =-0.801,P ＜ 0.001).Significant differences were found in △SUVmax％ (F=6.509,P＜0.01) and Deauville 5-point scale (F=19.897,P＜0.001) among patients in early,medium and late phases.No Significant differences were shown between medium and late phases (P＞0.05).Conclusion △SUVmax％ in the different phases of chemotherapy and C-MYC gene rearrangemeut have better values for predicting the prognosis of DLBCL,and 18F-FDG PET/CT imaging should be performed between 1 course and 4 courses of chemotherapy.

Purpose To discuss the diagnostic value and the optimal diagnostic threshold of preoperative 18F-FDG PET/CT imaging on regional lymph node metastasis in colorectal cancer.Materials and Methods Seventy-six patients with newly diagnosed colorectal cancer underwent radical resection of colorectal cancer within one week after PET/CT examination.All lymph nodes matching PET/CT were divided into proximal and distal lymph nodes on the basis of their location relative to the primary tumor.Meanwhile,the receiver operating characteristic (ROC) curves of the lymph node short diameter and maximum standardized uptake value (SUVmax) were created according to the pathological findings which were considered as the gold standard,and the diagnostic efficacies were analyzed.Results The proximal and distal lymph node ROC curves showed that the optimum thresholds of lymph node short diameter,SUVmax were 6.5 mm,1.9 and 5.5 mm,1.81.The sensitivity,specificity and accuracy of the diagnosis of proximal lymph node metastasis under the optimum threshold of lymph node short diameter were 84.85％,73.02％ and 77.52％,respectively;and those of distal lymph node metastasis were 97.62％,65.45％ and 79.38％,respectively.The sensitivity,specificity and accuracy of the diagnosis of proximal lymph node metastasis under the optimum threshold of SUVmax were 84.85％,95.81％ and 91.64％,respectively;those of distal lymph node metastasis were 92.86％,94.55％ and 93.81％,respectively.The specificity and accuracy of the optimum threshold of SUVmax were higher than those of the optimum threshold of lymph node short diameter (P＜0.01).The homogeneity of optimum threshold of SUVmax was excellent in comparison with the pathological results (Kappa=0.813 and 0.874,P＜0.01).Conclusion Optimum threshold method improves the diagnostic efficacy of 18F-FDG PET/CT in regional lymph node metastasis of colorectal cancer.Moreover,the SUVmax standard is superior to lymph node short diameter standard.

Objective:The relationship between the effect of early metabolism in 18F-FDG PET/CT and conventional CT based on the RE-CIST standard to evaluate the best objective response after chemotherapy in patients with non-small cell lung cancer (NSCLC). Meth-ods:We studied 40 patients with unresectable locally advanced or advanced NSCLC that were confirmed pathologically. The patients were 35 years old to 78 years old and included 31 males and 9 females. Three patients have unresectable stageⅢA, 8 patients have stageⅢB, 29 patients have stageⅣ, 12 patients have squamous cell carcinoma, and 28 patients have adenocarcinoma. The PET/CT for the effect of chemotherapy was evaluated in NSCLC according to the SUV standard (SUVmax reduction>30%of primary lung can-cer after one cycle of chemotherapy), and the CT for the effect of chemotherapy was evaluated on the basis of NSCLC according to the RECIST standard. The objectives of the study are as follows:compare the differences and consistency between 18F-FDG PET/CT metabol-ic response after the first cycle of chemotherapy and the RECIST best objective response after the first or second cycle of chemothera-py with the paired chi-square test and kappa test;calculate the 18F-FDG PET/CT to predict the best objective response of two cycles of chemotherapy according to RECIST on the basis of NSCLC in terms of sensitivity, specificity, accuracy, positive predictive value, and neg-ative predictive value;compare the differences in SUVmax reduction between the metabolic remission group and metabolic no relief group with the two-sample t-test. All statistical methods were 0.05 for the inspection level, and P<0.05 was considered statistically sig-nificant difference (SPSS19.0). Results:Differences were found between the first cycle of chemotherapy for the RECIST best objective response and 18F-FDG PET/CT metabolic response (χ2=5.063, P=0.021), and the results had bad consistency (Kappa=0.240, P=0.085). No differences were observed between the second cycle of chemotherapy for the RECIST best objective response and 18F-FDG PET/CT metabolic response (χ2=2.083, P=0.146);the results had good consistency (Kappa=0.413, P=0.006). The sensitivity, specificity, accura-cy, positive predictive value, and negative predictive value were 82%, 61%, 70%, 61%, and 82%, respectively. The differences in SUV-max reduction between the metabolic remission group and metabolic no relief group with the two-sample t-test were statistically sig-nificant (P<0.001). Conclusion: 18F-FDG PET/CT may predict the best objective response to chemotherapy for NSCLC patients. Com-pared with conventional CT, 18F-FDG PET/CT can be an early and accurate way to evaluate the chemotherapy effect in NSCLC.

Objective To evaluate the value of 18F-FDG PET/CT in early in vivo monitoring of tumor response to cisplatin,and analyze the relationship between 18F-FDG uptake in tumor and the corresponding pathological changes.Methods Thirty VX2 rabbits were divided into 5 groups by random number table with 6 in each group,including 4 treatment groups and 1 control group.18F-FDG PET/CT were performed before and after (6,12,24 and 36 h post-injection respectively) intravenous administration of cisplatin (7 mg/kg) in the treatment groups,respectively.The control group was injected with physiological saline followed by 18F-FDG PET/CT.The ROI was drawn and the SUVmax and T/NT ratio were calculated.The tumor necrosis rate and apoptosis index were observed by histopathologic examination.Paired t test,GamesHowell test and arcuation correlation analysis were used to analyze the data.Results Significant differences were found in SUVmax and T/NT of the control group before and after injection of physiological saline (6.58±1.67 vs 9.77±2.45,52.93±3.90 vs 29.34±3.31;t=-5.480,17.593,both P＜0.05).18F-FDG uptake decreased after 6 h post-injection of cisplatin,with the mean SUVmax decrease rate of (11.83±8.89) ％ and the mean T/NT decrease rate of (59.00±8.22)％.In the 24 h treatment group,18F-FDG uptake decreased most,and the mean SUVmax decrease rate was (42.33±33.80)％,the mean T/NT decrease rate was (83.50± 7.69) ％.The SUVmax and T/NT of those 2 groups were significantly different from those of the control group,and no difference was found between the 2 treatment groups(all P＜0.05).The changes of SUVmax and T/NT were positively correlated with apoptosis index and tumor necrosis rate (r=0.750,0.794,0.804,0.874,all P＜0.05).Conclusion 18F-FDG PET/CT is a sensitive method for monitoring early response to tumor chemotherapy in VX2 tumor-bearing rabbits at 24 h after treatment.

Objective To assess the value of 18F-FDG PET-CT in monitoring early chemotherapy response in patients with diffuse large B-cell lymphoma (DLBCL).Methods 56 patients with DLBCL received 18F-FDG PET-CT before and after 2 cycles of chemotherapy (CHOP or R-CHOP protocol).The patients were divided into 3 groups,including complete response group (30 cases),partial response group (18 cases) and no response group (8 cases).The x2 test was performed on comparison of complete remission rate and the t test on SUVmax.Results Complete remission rate of complete response group,partial response group and no response group were 93.33 ％ (28/30),66.67 ％ (12/18),and 12.50 ％ (1/8),respectively (x2 =21.62,P ＜ 0.005).Complete remission rate of complete response group was higher than that of partial response group (x 2 =4.00,P ＜ 0.05).Complete remission rates of complete response group and partial response group were higher than that of no response group (x2 =18.58,P ＜ 0.005; x2 =4.51,P ＜ 0.05).A significant difference was observed in SUVmax of partial response group before and after chemotherapy (17.18±4.68 vs 5.20±3.35,t =14.32,P ＜ 0.001) and no obvious difference was showed in SUVmax of no response group between before and after chemotherapy (16.63±6.49 vs 13.81±5.95,t =2.073 2,P ＞ 0.05).Conclusion 18F-FDG PET-CT is very useful and helpful for predicting early chemotherapy response in DLBCL.

Objective Currently,pediatric 18F-FDG dose and acquisition durations are generally based on coarse extrapolation from adult guidelines.This study sought to determine whether shorter acquisition durations or a lower 18F-FDG injected activity could be used during pediatric 18F-FDG PET/CT examinations while maintaining diagnostic utility.Methods Thirty-six whole-body 18F-FDG PET/CT examinations were performed on 36 patients (weight,13-89 kg,(46.51±5.63) kg; age range,3-14 years old,(9.22±3.16) years old) with a weight-based injected activity (5.3 MBq/kg (0.144 mCi/kg)),fixed acquisition durations 180 S/FOV,VIP record acquisition mode using Discovery STE.For each examination,the Vip-mode data was truncated to form multiple datasets with shorter acquisition durations down to a minimum of 60 s/FOV (i.e.,60,80,100,120,140,160 s/FOV data were formed from single 180 s/FOV acquisition).168 image volumes were generated,randomized,and reviewed in a masked manner with corresponding CT image volumes by 6 radiologists.Overall,subjective adequacy and objective lesion detection accuracy by body region were evaluated.Results All examinations with maximum acquisition duration were graded as adequate and were used as the reference standard for detection accuracy.For patients more than 30 kg,when acquisition duration was more than 120 s/FOV,all PET/CT examinations were graded as adequate for clinical tasks,whereas,when acquisition duration was reduced to less than 120 s/FOV,lesion detection became less accurate.For patients less than 30 kg,lesion detection accuracy was perfect for acquisition times between 140 s/FOV and 180 s/FOV for all regions of the body.However,lesion detection became less accurate when imaging acquisition time was reduced less than 140 s/FOV.Conclusions When GE Discovery STE PET/CT was applied during pediatric PET/CT examination,using decreased acquisition times as a surrogate for 18F-FDG dose,18F-FDG dose can be reduced by approximately 33.33％ when patients weigh over 30 kg were scanned for 180 s/FOV.For patients less than 30 kg,18F-FDG dose can be reduced by approximately 22.22％ without losing diagnostic quality.Reduction of overall scan time potentially reduces motion artifacts,improves patient comfort,and decreases length of sedation.Alternatively,decreased 18F-FDG dose minimizes radiation risk.

目的评价低剂量^18F-氟代脱氧葡萄糖（^18F—FDG）PET／CT在体检中发现恶性肿瘤的意义。方法回顾分析2010年9月至2012年10月469例^18F-FDGPET／CT健康体检者的资料，并对照随访结果。结果^18F—FDGPET／CT显像共发现恶性肿瘤13例，其中肺癌8例，甲状腺癌、贲门癌、卵巢癌、升结肠癌、肾细胞癌各1例。2例支气管肺泡癌、1例神经内分泌癌及1例肾细胞癌为假阴性，其余。^18F-FDG代谢均增高。结论低剂量^18F-FDGPET／CT在体检中进行肿瘤筛查是安全的，具有重要意义。

Objective To evaluate the diagnosis value of spiral CT in leiomyosarcoma of abdomen.Methods Both plain and enhanced CT fingdings in 12 cases with pathologic-proved leiomyosarcoma of abdomen were respectively analyzed.Results In all of 12 cases,1 case occurred in colon,1 case in rectum,1 case in small intestine,5 cases in mesentery,4 cases in retroperitoneum,CT positioning accuracy rate was 91.7 ％ (11/12).The volume was comparatively large,the average diameter was 6 cm.The density were uneven,nodosity or lamellar necrosis were found.Delay enhacement were occurred in lower density part in most part of cases (9/12).Conclusion The localization of spiral CT is comparatively accurate to the leiomyosarcoma of abdomen,some characteristics are found in CT image,but the final diagnosis depends on immunohistochemistry.

Objective To evaluate the diagnostic value of multislice CT(MSCT)in multilocular cystic real cell carcinoma(MCRCC).Methods Imaging features of 22 patients with MCRCC proved by histopathologic examinations,these patients were underwent non-enhanced and dual-phase contrast-enhanced CT scans and evaluated CT signs.Results 22 tumors all appeared as well defined multilocular cystic mass.The cystic wall presented with irregular thicking in 14 cases and regular thicking in 8 cases.The tumors with thin coarse septum in 6 cases(the transverse diameter ≤2 mm),irregular thicking septum in 11cases(2mm ＜the transverse diameter ≤ 5 mm)and septum with nodule in 5 cases(the transverse diameter ≤ 5 mm).Cystic wall and septum enhancement were detected with dual-phase contrast-enhanced CT.Cystic ares and hemorrhagic areas and calcification were no enhanced.Calcification of cystic wall were found in 2 cases and cyst in 3 cases.Conclusion MSCT imaging appearances have typical features.It has great important value in the preoperative diagnosis of MCRCC with non-enhanced and dual-phase contrast-enhanced CT scans.

患者男,55岁,2010年10月无诱因出现左膝关节疼痛、肿胀,外院就诊,X线检查未见明显异常,临床考虑韧带撕裂,给予抗炎对症治疗,患者自觉疼痛减轻后出院.2010年12月患者因左膝关节疼痛加重于本院就诊,X线检查示髌骨骨密度减低(未予重视);MRI示髌骨信号减低且不均匀,关节腔见少量液体信号影(图1a),考虑滑膜炎,经休息、热敷、频谱治疗后好转.2011年5月患者扭伤后左膝关节疼痛再次加剧,局部软组织肿胀,行走困难,封闭治疗效果差,X线检查示髌骨局限性骨质破坏(图1b),遂再次于本院就诊.

18F-氟代脱氧葡萄糖（FDG）正电子发射断层扫描（PET）/CT是鉴别良恶性肿瘤、肿瘤分级、分期及预后判断较好的检查手段,但对肾脏肿瘤,由于部分肾细胞癌病理的特殊性,使18F-FDG PET/CT检查易出现假阴性,其灵敏度为40%～94%[1,2]。而CT双期增强扫描能明确提高肾脏肿瘤诊断的准确性。因此,本研究将评价18F-FDG PET/CT联合CT双期增强扫描在肾脏恶性肿瘤中的应用价值,现报告如下。