RESUMO
Objective:To establish and validate a malignant risk prediction model of solitary pulmonary nodules (SPNs) with pulmonary fibrosis in long-term smokers based on 18F-flurodeoxyglucose (FDG) PET/CT. Methods:PET/CT images of 222 SPNs combined with pulmonary fibrosis which were shown in integrated CT scan in 169 patients (all males; age 68(63, 75) years) were analyzed retrospectively. All patients were examined in PET/CT Center of the Affiliated Hospital of Qingdao University from January 2011 to December 2019 and all had definite smoking history. The benign and malignant nodules were judged according to the pathological diagnosis or follow-up imaging data of lung lesions (follow-up≥2 years). The clinical characteristics (age, smoking index), morphological characteristics (longest diameter of lesion, density, location, distribution, relative position of fibrosis, spiculation, lobulation, calcification, vacuole, vascular convergence, pleural indentation, emphysema and severity of bilateral pulmonary fibrosis) and metabolic characteristics (maximum standardized uptake value (SUV max)) of the benign and malignant lesions were analyzed by χ2 test and Mann-Whitney U test. Then multivariate logistic regression analysis was applied to select independent risk factors of malignant nodules, and a risk prediction model was established and verified by the area under the receiver operating characteristic (ROC) curve and k-fold cross validation ( k=10) respectively. Results:Among 169 patients, 222 SPNs were detected (157 malignant nodules, 65 benign nodules). Univariate analysis showed that smoking index, speculation, lobulation, vascular convergence sign, calcification, emphysema, nodule size, relative position of nodule and fibrosis, SUV max and severity of bilateral pulmonary fibrosis were significantly different between the benign and malignant nodules ( z values: 2.514-9.858, χ2 values: 4.353-18.442, all P<0.05). Result of multivariate logistic regression analysis showed that calcification, vascular convergence and SUV max were the independent risk factors of malignant nodules combined with pulmonary fibrosis (odds ratio ( OR): 0.048-2.534, all P<0.05). The risk prediction model was as follow: P=1/(1+ e - x), x=-1.839-3.033×calcification+ 0.930×vascular convergence+ 0.754×SUV max(with calcification/vascular convergence=1, without calcification/vascular convergence=0). The area under ROC curve was 0.932(95% CI: 0.895-0.969), and the sensitivity and specificity of the model were 87.9% and 86.2%, respectively. Results of k-fold cross validation showed that the prediction accuracy of 10 test sets was 0.847±0.075, and was 0.862±0.010 in training sets. Conclusions:Calcification, vascular convergence and SUV max are independent risk factors of malignant SPNs combined with pulmonary fibrosis in long-term asymptomatic smokers. The model based on the above variables presents high diagnostic efficiency in diagnosing malignant SPNs.
RESUMO
Objective To develop a model of malignant risk prediction of solitary pulmonary nodules(SPN) with the metabolic characteristics of the lesion.Methods A total of 362 patients (291 malignant cases and 71 benign cases;194 males,168 females;median age:61 years) who underwent PET/CT imaging from January 2013 to July 2017 were analyzed.The diagnosis of malignant SPN was based on pathological results,and that of benign SPN was based on pathological or follow-up results.Differences of clinical/imaging characteristics in patients with benign and those with malignant SPN were analyzed.Risk factors were screened by multivariate non-conditional logistic regression analysis.The self-verification of the model was done by the receiver operating characteristic (ROC) curve analysis,out-of-group verification was performed by k-fold cross-validation.Results There were statistically significant differences in age,maximum standardized uptake value (SUVmax),size,lobulation,spiculation,pleural traction,vessel connection,calcification,vacuole,and emphysema between patients with benign and malignant nodules (all P＜0.05).The risk factors for malignant nodules included age,SUVmax,size,lobulation,calcification and vacuole.The odds ratio (OR) values (95％ CI) were 1.040(1.007-1.075),1.612(1.287-2.017),1.149(1.074-1.230),4.650(2.138-10.115),0.216(0.085-0.548),and 3.043(1.302-7.111),respectively.The logistic regression model was as follows:P=1/(1+e-x),x=-5.583+0.039×age+0.477×SUVmaxx+0.139×size+1.537×lobulation-1.532×calcification+ 1.1 13×vacuole.The estimated area under the curve (AUC) for the model was 0.915(95％ CI:0.883-0.947),sensitivity was 89.7％,specificity was 78.9％.K-fold cross-validation showed that the training accuracy was 0.899±0.011,the predictive accuracy was 0.873±0.053.Conclusions The risk factors for malignant nodules included age,SUVmax,size,lobulation,calcification and vacuole.After verification,the model has a satisfactory accuracy.It may help clinics make accurate decisions.
RESUMO
Objective To compare the 18F-FDG PET metabolic characteristics and VHRCT morphological characteristics between invasive and non-invasive adenocarcinoma presenting as pure ground-glass nodules(pGGN).Methods Fifty-one patients with pGGN from October 2010 to June 2016 were retrospectively enrolled in this study.There were totally 52 lesions with sizes of no more than 30 mm and were grouped depending on pathological and follow-up diagnosis (31 lesions in the invasive adenocarcinoma group and 21 lesions in the non-invasive group).Clinical and imaging features were analyzed including age,gender,lesion location,size,density,SUVmax T/N,spiculation,lobulation,pleural indentation,vascular connection signs,vacuole sign and the air bronchogram.T test or x2-test was used in the comparison of different manifestations between the two groups.Logistic regression analysis on clinical parameters was applied.The ROC curve was used to find the cutoff of T/N.Results In the invasive adenocarcinoma group,T/N,SUV density and size were 1.97±0.71,1.16±0.54,-(431±104)HU,(18.48±5.65)mm,respectively.In the non-invasive group,T/N,SUVmax density,size were 1.20±0.28,0.64±0.20,-(533± 109)HU,(12.05±5.04)mm,respectively.The differences of T/N,SUVmax density and size had statistical significance between the two groups (t=-5.40,-4.87,-3.39,-4.21,P＜0.05).Lobulation and vascular connection signs in the invasive adenocarcinoma group were found in 21 and 13 cases respectively,while in the non-invasive group,they were present in 2 and 1 case,respectively,which showed significant differences between the two groups(x2=17.85,7.01,P＜0.05).T/N,lobulation,and vascular connection signs were the independent factors for the differentiation of benign and malignant lesions.The ORs were 52.547,8.375,72.206,respectively.When T/N=l.62,the area under the ROC curve was 0.885.The sensitivity,specificity and accuracy were 77.42％,90.48％,82.69％,respectively.Conclusions Pulmonary pGGNwith T/N no less than 1.62,lobulation and vascular connection sign indicates an invasive adenocarcinoma.
RESUMO
Objective To compare the characteristics of lymph nodes on 18F-FDG imaging in patients with NHL and widespread lymph node metastases carcinoma (WLNMC) for helping the differential diagnosis.Methods A total of 40 NHL patients(22 males,18 females,average age 51 years) and 42 WLNMC patients (19 males,23 females,average age 61 years) confirmed by histopathology from November 2010 to May 2015 were included in this retrospective study.The regions and the metabolism features of the lesions on PET/CT images were observed and recorded with routine visual method.Two-sample t test and x2 test were used for statistical analysis.Results Lymph nodes of NHL were kidney-shaped (47.2％,142/301),which was significantly different from that of WLNMC with circular form (47.6％,140/294;x2 =36.261,P＜0.05).Lymph nodes of NHL mostly showed homogeneous density with no necrosis (51.8％,156/301);however,that of WLNMC showed uneven density (20.4％,60/294) or with necrosis (32.3％,95/294;x2 =26.266,P＜0.05).Both of the two kinds of lymph nodes showed the characteristic of fusion (30.6％ (92/301) vs 36.1％ (106/294);x2 =2.019,P＞0.05).The ratios of lymph nodes with clear boundary in NHL and WLNMC were significantly different:28.2％(85/301) vs 19.4％(57/294);x2 =6.413,P＜0.05.Lymph nodes with symmetric distribution were more in NHL patients (52.5％,158/301)than that in WLNMC patients (42.2％,124/294;X2=6.347,P＜0.05).Sizes of lymph nodes in NHL patients and WLNMC patients were not significantly different:(2.08±0.65) cm vs (1.97±0.81) cm;t=0.316,P＞0.05.SUVmax of lymph nodes in NHL patients (9.02±3.97) was much higher than that in WLNMC patients (6.92± 1.34;t=0.370,P＜0.05).Conclusions Some characteristics of lymph nodes on 18F-FDG PET/CT imaging,such as the distribution,morphology,density and glucose metabolism features,are different in patients with NHL and WLNMC.Those differences may be helpful for the differential diagnosis.
RESUMO
Objective To compare 18F-FDG、11C-MET and 11C-CHO PET/CT in rat C6 glioma and inflammation models and observe their correlations with HIF-1α and VEGF expressions.Methods Thirtytwo male Wistar rats were included to bear both C6 glioma and turpentine oil-induced acute inflammation (AI).18F-FDG,11C-MET and 11C-CHO PET/CT were performed on rats.The SUVmax ratios of tumor-tomuscle (T/M),AI-to-muscle (AI/M) and tumor selectivity index (SI) were calculated.One-way analysis of variance and two-sample t test were used for statistical analyses.HIF-1α and VEGF expression was detected by immunohistochemical staining.Spearman correlation analysis was performed to evaluate the relationship between T/M ratios and the expressions of HIF-1α or VEGF.Results T/M ratios of 18F-FDG,11 C-MET and 11C-CHO in C6 glioma were 6.89±2.53,2.75±0.87,2.73±1.01,and the AI/M were 4.77±2.21,1.75±0.66,2.23±0.90 respectively.The 18F-FDG and 11C-MET uptake between C6 glioma and AI were significantly different(tFDG =2.133,tMET =3.267,both P＜0.05).The SIMET was significantly higher than SIFDG(t =2.600,P＜0.05).The 11C-CHO uptake between tumor and inflammation showed no significant difference(t=1.537,P＞0.05).T/M ratios of 18F-FDG and 11C-MET were positively related to HIF-1α and VEGF expressions(rs =0.725,0.637,0.621,0.764,all P＜0.05).The T/M ratio of 11C-CHO related only to VEGF (rs =0.682,P＜0.05).Conclusions 18F-FDG and 11 C-MET PET/CT may differentiate C6 glioma from AI,and 11 C-MET PET/CT seems more tumor-selective.11C-CHO PET is less valuable for the differential diagnosis.The 18F-FDG and 11 C-MET uptake of C6 glioma may be related to tumor hypoxia.All the three tracers could reflect tumor angiogenesis,but with different sensitiveness.
RESUMO
Objective To study the regional cerebral glucose utilization with 18 F-fluorodeoxyglucose (FDG) PET and to investigate the correlation between cerebral glucose metabolism and the clinical characteristic of progressive supranuclear palsy (PSP).Methods A total of 13 patients with PSP and 30 matched healthy controls were performed 18F-FDG PET imaging at rest state.Visual inspection and statistical parametric mapping (SPM) were used to investigate regional cerebral metabolic rate of glucose (rCMRglc).Results Based on the visual inspection,PET imaging in the PSP patients showed that the focal hypometabolic areas mainly included the bilateral frontal cortex,midbrain and subcortical structures.Compared to the controls,voxel-based analysis showed that the regional glucose metabolism decreased in bilateral superior,middle frontal gyrus,cingulate gyrus,midbrain and subcortical structures including basal ganglion and thalamus,which were consisted with the clinical characteristics,such as vertical gaze palsy,pseudobulbar palsy,postural instability,axial rigidity,dementia and so on.Conclusion 18 F-FDG PET imaging is helpful for the early diagnosis of PSP.
RESUMO
Objective To evaluate the value of three dimensional CT angiography in the diagnosis of intracranial aneurysms by the comparison with DSA.Methods CTA and DSA were performed in 30 patients(aged 34~76 years) who were highly suspected with intracranial aneurysms.Feasible endovascular treatment were performed simultaneously.The sensitivity,specificity,accuracy in detecting the aneurysms,in demonstrating the neck of the aneurysms and the relationship of parent artery were compared between CTA and DSA.Results 26 intracranial aneurysms were detected by CTA,the sensitivity,sepcificity and accuracy were 95.5%,87.5% and 93.3% respectively.There were no statistical differences among the sensitivity,specificity,accuracy between CT and DSA(?
