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Background Although methotrexate has been widely used as a second-line therapy for cardiac sarcoidosis (CS), it is not clear if it has a direct anti-inflammatory effect. Case summary A 65-year-old man presented to our hospital with symptomatic ventricular tachycardia (VT). After cardioversion, electrocardiography showed a first-degree atrioventricular block with a right bundle branch block, and transthoracic echocardiography revealed left ventricular dilatation. After extensive investigations, including fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET), the patient was diagnosed with CS according to the Japanese Circulation Society guidelines. After the implantation of a transvenous implantable cardioverter defibrillator, corticosteroid therapy was introduced at a starting dose of 30 mg/day. After corticosteroid therapy was tapered to a maintenance dose of 10 mg/day, he had an uneventful clinical course without symptoms for the 1st year after hospital discharge. However, symptomatic VT recurred and 18F-FDG PET showed abnormal patterns of cardiac FDG uptake. Although he was treated with corticosteroid therapy once more, which was gradually up-titrated to a dose of 20 mg/day over a 1-month period, myocardial uptake of 18F-FDG PET remained unchanged. As the patient was considered steroid refractory, second-line treatment with 6 mg/week of methotrexate was introduced, whereas maintaining the dose of corticosteroid therapy at 20 mg/day. After 1 month, 18F-FDG PET showed remarkable reduction in FDG uptake, and the patient had a good clinical course without further episodes of arrhythmia or other symptoms during an 8-month follow-up. Discussion Methotrexate may have a direct anti-inflammatory effect in patients with CS refractory to regular corticosteroid therapy. [ABSTRACT FROM AUTHOR]

As a prevalent disease all over the world, changed functional activities and/or structures in many brain regions have been found in depression. In this study, 5-week chronic restraint stress (CRS) was performed to establish depression rat models, and 18 F-fluorodeoxyglucose positron emission tomography ( 18 F-FDG PET) was used to detect brain functional activities. Our study found that CRS induced depressive behaviors and increased the expression of serum IL-6. After exposure to CRS, rats showed decreased glucose metabolism in the whole-brain and brain regions including left medial prefrontal and auditory cortices; right amygdala, cingulate cortex, olfactory and AcbCore/Shell; bilateral caudate putamen, dorsal hippocampi, insular and entorhinal cortices. Expression of serum IL-6 and glucose metabolism in most of the above brain regions were significantly correlated with the severity of some CRS-induced depressive behaviors. In conclusion, the increased peripheral inflammatory response and decreased brain functional activities might be the important pathogenesis of experimental depression induced by CRS, and could reflect the severity of depression to some extent. [ABSTRACT FROM AUTHOR]

Objectives: To achieve multicentre external validation of the Herder and Bayesian Inference Malignancy Calculator (BIMC) models.Methods: Two hundred and fifty-nine solitary pulmonary nodules (SPNs) collected from four major hospitals which underwent 18-FDG-PET characterization were included in this multicentre retrospective study. The Herder model was tested on all available lesions (group A). A subgroup of 180 SPNs (group B) was used to provide unbiased comparison between the Herder and BIMC models. Receiver operating characteristic (ROC) area under the curve (AUC) analysis was performed to assess diagnostic accuracy. Decision analysis was performed by adopting the risk threshold stated in British Thoracic Society (BTS) guidelines.Results: Unbiased comparison performed In Group B showed a ROC AUC for the Herder model of 0.807 (95 % CI 0.742-0.862) and for the BIMC model of 0.822 (95 % CI 0.758-0.875).Conclusions: Both the Herder and the BIMC models were proven to accurately predict the risk of malignancy when tested on a large multicentre external case series. The BIMC model seems advantageous on the basis of a more favourable decision analysis.Key Points: • The Herder model showed a ROC AUC of 0.807 on 180 SPNs. • The BIMC model showed a ROC AUC of 0.822 on 180 SPNs. • Decision analysis is more favourable to the BIMC model. [ABSTRACT FROM AUTHOR]

Background The choice of biomarkers for early detection of Alzheimer's disease (AD) is important for improving the accuracy of imaging-based prediction of conversion from mild cognitive impairment (MCI) to AD. The primary goal of this study was to assess the effects of imaging modalities and brain atlases on prediction. We also investigated the influence of support vector machine recursive feature elimination (SVM-RFE) on predictive performance. Methods Eighty individuals with amnestic MCI [40 developed AD within 3 years] underwent structural magnetic resonance imaging (MRI) and 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans at baseline. Using Automated Anatomical Labeling (AAL) and LONI Probabilistic Brain Atlas (LPBA40), we extracted features representing gray matter density and relative cerebral metabolic rate for glucose in each region of interest from the baseline MRI and FDG-PET data, respectively. We used linear SVM ensemble with bagging and computed the area under the receiver operating characteristic curve (AUC) as a measure of classification performance. We performed multiple SVM-RFE to compute feature ranking. We performed analysis of variance on the mean AUCs for eight feature sets. Results The interactions between atlas and modality choices were significant. The main effect of SVM-RFE was significant, but the interactions with the other factors were not significant. Comparison with existing method Multimodal features were found to be better than unimodal features to predict AD. FDG-PET was found to be better than MRI. Conclusions Imaging modalities and brain atlases interact with each other and affect prediction. SVM-RFE can improve the predictive accuracy when using atlas-based features. [ABSTRACT FROM AUTHOR]

Summary Aim To assess the interest of 18 F-fluorodeoxyglucose positron emission tomography ( 18 F-FDG PET/CT) to evaluate the tumor response after radiotherapy (RT) in anaplastic thyroid cancer (ATC) patients. Methods and Materials 92 patients were treated for ATC at our institution from 1987 to 2012, out of which 64 (70%) received an aggressive multimodal treatment and 28 (30%) a palliative treatment. In the multimodal treatment group, curative-intended surgery, chemotherapy, and RT were delivered in 35 (55%), 59 (92%), and 56 (88%) patients. The maximum standardized uptake value (SUVmax) was determined in tumor (T), nodes (N) and metastases (M) in each available 18 F-FDG PET/CT. Results The median follow-up was 3.2 years. The 1-year actuarial overall survival (OS) was 18% (median: 5.2 months) in the entire population and 27% (median: 7 months) in the multimodal treatment group. In the multivariate analysis, RT, surgery, and pre-RT chemotherapy independently predicted for OS, with HRs respectively of 0.1, 0.3, and 0.5. Quantification of FDG uptake with SUVmax was assessable in 26 (40%), 19 (30%), and 25 (39%) of 18 F-FDG PET/CT performed initially (prior to any treatment), prior to RT, and after RT, respectively. Mean SUVmax significantly decreased in T ( p < 0.001), but not in N ( p = 0.1) and M ( p = 0.3) during the assessment period, which might be related to the local effect of RT. Comparing pre- and post-RT 18 F-FDG PET/CT, the T mean relative SUVmax decrease was lower (23 ± 54%) in the 4 patients that had a local relapse (LR) as compared with others in the 12 others patients (62 ± 33%; p = 0.3). A relative SUVmax decrease inferior to 20% significantly predicted for LR ( p = 0.02). Conclusion The prognosis of ATC patients remains dismal despite an aggressive multimodal treatment. Although our results were not significant, 18 F-FDG PET/CT could potentially serve as a surrogate marker of treatment response in ATC. [ABSTRACT FROM AUTHOR]

Aim The role of 18 F-fluorodeoxyglucose positron emission tomography ( FDG-PET) in the diagnosis and staging of primary liver cancer has been demonstrated in several reports. However, no preoperative evaluations of sarcomatous hepatocellular carcinoma ( HCC) and combined hepatocellular and cholangiocarcinoma (c HCC- CC) with FDG-PET have been reported so far. Methods Fifty-three HCC patients and three c HCC- CC patients who received liver resection or living-donor liver transplantation were enrolled in this study. All 56 patients had undergone preoperative FDG-PET, and a total of 67 HCC and three c HCC- CC were analyzed histologically. The relationship between clinicopathological features and the maximum standardized uptake value ( SUVmax) of tumors were evaluated. Results The detection rate of HCC by FDG-PET was 43.3 %, and the sensitivity of FDG-PET for the detection of HCC was significantly associated with tumor differentiation, tumor size and microvascular invasion. All three c HCC- CC were detected by FDG-PET. The SUVmax values of the three sarcomatous HCC ( SUVmax 14.1, 18.6 and 25.0) and the three c HCC- CC ( SUVmax 9.9, 12.0 and 13.0) were higher than that of the poorly differentiated HCC (mean SUVmax 5.7 ± 2.3). Conclusion SUVmax may be a useful diagnostic tool for the preoperative evaluation of the aggressiveness of primary liver cancers such as sarcomatous HCC and c HCC- CC. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the use of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) for detection of high-fat and high-salt diet-induced inflammatory lesions of the arterial vessel walls in Wistar rats. A total of 20 healthy, 8-week-old, male Wistar rats were randomly assigned to the high-fat diet group and the normal diet group. After 16 and 24 weeks of feeding, Wistar rats in the normal diet group and the high-fat diet group (five rats in each group) were injected with 18F-FDG through the tail vein at a dose of 1 mCi/kg after fasting for 12 h. After 1 h, the rats were anesthetized with 2% isoflurane, followed by micro-PET imaging with a 10-min image capture duration and immunohistochemical staining. The standardized uptake values (SUVs) of 18F-FDG were significantly higher in the iliac artery in the high-fat diet group compared with those in the normal diet group at 16 weeks (1.53±0.08 vs. 1.04±0.03; P<0.05) and at 24 weeks (1.96±0.17 vs. 1.12±0.07; P<0.05). The SUVs of 18F-FDG were also significantly greater in the abdominal aorta in the high-fat diet group compared with those in the normal diet group at 16 weeks (1.35±0.08 vs. 1.02±0.02; P<0.05) and at 24 weeks (1.54±0.09 vs. 1.04±0.02; P<0.05). In addition, the SUVs of 18F-FDG in the iliac artery and abdominal aorta were significantly higher at 24 weeks compared with those at 16 weeks in the high-fat diet group (P<0.05). As determined by immunohistochemistry, the percentage of CD68-positive cells in the total number of cells per unit area in each group was 3.20±1.80% in the 24-week normal diet group, 4.70±2.02% in the 16-week high-fat diet group and 6.94±2.02% in the 24-week high-fat diet group; the percentage of CD68-positive cells in the high-fat diet group at 24 weeks was significantly higher than that in the high-fat diet group at 16 weeks and in the normal diet group at 24 weeks (P<0.05). In conclusion, 18F-FDG PET is a noninvasive imaging tool that can continuously monitor inflammatory lesions of the arterial vessel walls in Wistar rats. Further improvement of the Wistar rat atherosclerosis model may provide data to support the early assessment of and intervention in atherosclerosis. [ABSTRACT FROM AUTHOR]