Although it is known that health is not merely the absence of disease, the positive aspects of mental health have been less comprehensively researched compared with its negative aspects. Subjective well-being is one of the indicators of positive psychology, and high subjective well-being is considered to benefit individuals in multiple ways. However, the neural mechanisms underlying individual differences in subjective well-being remain unclear, particularly in terms of brain microstructural properties as detected by diffusion tensor imaging. The present study aimed to investigate the relationship between measurements of diffusion tensor imaging (mean diffusivity and fractional anisotropy) and the degree of subjective well-being as measured using a questionnaire. Voxel-based analysis was used to investigate the association between mean diffusivity and subjective well-being scores in healthy young adults (age, 20.7 ± 1.8 years; 695 males and 514 females). Higher levels of subjective well-being were found to be associated with lower mean diffusivity in areas surrounding the right putamen, insula, globus pallidus, thalamus, and caudate. These results indicated that individual subjective well-being is associated with variability in brain microstructural properties.

Objectives: Metabolic tumor volume (MTV) on 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) is a promising prognostic predictor in pancreatic ductal adenocarcinoma (PDAC). However, the optimal segmentation method and threshold value to determine MTV for PDAC are still unclear. We explored the optimal method and threshold value for the prognostic value of MTV measured on pre-treatment 18F-FDG-PET/CT. Methods: Seventy-three patients with resected PDAC who underwent 18F FDG-PET/CT before surgical resection were enrolled. MTV values of the tumor were measured on FDG-PET/CT by the two fixed-threshold methods using threshold values as 2.0, 2.5, 3.0, and 3.5 for the absolute method and 35%, 40%, 42%, 45%, and 50% for the relative method. Receiver operating characteristic curve analysis for prediction of 1-year survival rates was conducted for determining the optimal threshold values, and we selected the optimal method and threshold value considering area under the curve. The prognostic values of each FDG-PET/CT parameter for disease-specific survival and recurrence-free survival were assessed with Kaplan-Meier method and Cox proportional hazard models. Results: In receiver operating characteristic curve analysis, MTV by the fixed-absolute threshold method based on a threshold value of 3.5 (MTV3.5) performed best in our study with area under the curve 0.724, sensitivity of 65%, and specificity of 75%. In univariate and multivariate analyses, MTV3.5 was significantly associated with disease-specific and recurrence-free survival. Conclusions: MTV3.5 by absolute threshold on pre-treatment FDG-PET/CT was the best independent prognostic predictor in resectable PDAC compared with other absolute threshold values and relative threshold values.

Intelligence is among the key determinants of power and social status in modern societies. In this functional magnetic resonance imaging study, we examined the neural correlates of intelligence evaluation from faces. Participants underwent scans while they evaluated the perceived intelligence and friendliness of faces. We found that medial orbitofrontal cortex activity increased linearly with friendliness ratings. The relationship between perceived intelligence and brain activity was positively linear in the right caudate nucleus and U-shaped (i.e., strong responses to unintelligent-looking or intelligent-looking faces) in the right anterior insula/inferior frontal gyrus. Perceived intelligence was also significantly positively correlated with both friendliness and attractiveness. Furthermore, intelligence rating scores had a positive linear effect on reaction times in the friendliness rating task, suggesting that participants had greater conflicts when making friendliness judgments for faces that appeared to belong to intelligent individuals. In addition, the degree of this effect predicted individual differences in the positive linear modulatory effect of intelligence scores in the right caudate nucleus. Our interpretation was that the activity in the caudate nucleus revealed an approach-avoidance conflict with regard to highly intelligent people, that is, they were perceived as attractive but also potentially threatening. Although our interpretations are merely suggestive because we did not measure the approach-avoidance behaviors directly, our findings have important implications for understanding the dynamics of human interaction in modern societies that increasingly allocate power and status based on intelligence.

BACKGROUND Primary cardiac lymphoma is rare and can be an aggressive disease, depending on the grade. A case is reported of low-grade primary cardiac lymphoma associated with a pericardial effusion. 18F-fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) imaging was useful in the diagnosis and in evaluating the disease activity in this case. CASE REPORT A 72-year-old Japanese woman visited a general practitioner, complaining of dyspnea associated with cardiac tamponade. Pericardiocentesis was performed, and Group V malignant cells were identified by cytology, suspicious for malignant lymphoma. Whole-body FDG-PET/CT scans showed no pleural effusion or lymph node metastasis supporting the diagnosis of primary cardiac lymphoma diagnosed on pericardial effusion. The laboratory investigations showed that levels of serum soluble interleukin-2 (IL-2) receptor (sIL-2R), a diagnostic and prognostic marker for malignant lymphoma, were not elevated (258 U/ml). A six-month follow-up FDG-PET/CT scan showed an increased volume of the pericardial effusion and mild but abnormal uptake diffusely in the pericardial space, and the sIL-2R was slightly elevated (860 U/ml). No abnormal FDG accumulation outside the retained pericardial effusion was noted, which was compatible with a clinical picture of low-grade primary cardiac lymphoma, and in a period of watchful waiting during the first two years later, the sIL-2R had reduced to 195 U/ml. CONCLUSIONS This is a rare case of low-grade primary cardiac lymphoma detected in a pericardial effusion, and highlights the utility of the FDG-PET/CT scan as a valuable diagnostic and follow-up modality.

BACKGROUND: We aimed to determine whether treatment should be stratified according to 18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) maximum standardized uptake values (SUVmax) in pancreatic ductal adenocarcinoma. METHODS: Patients who underwent preoperative 18F-FDG PET/CT between 2006 and 2014 (n = 138) were stratified into high (≥ 4.85) and low (< 4.85) PET groups. The clinicopathological characteristics and prognostic outcomes were analyzed retrospectively. RESULTS: The primary tumor SUVmax was positively correlated with preoperative CA19-9 levels (P < 0.001). The high PET group failed to achieve postoperative CA19-9 normalization (P = 0.014). Disease-specific (P < 0.001), recurrence-free (P < 0.001), liver recurrence-free (P < 0.001), and peritoneal recurrence-free (P = 0.020) survivals were significantly shorter in the high PET group. The primary tumor SUVmax was an independent predictive risk factor for liver metastasis (hazard ratio 3.46, 95% confidence interval 1.61-7.87; P = 0.001) and peritoneal recurrence (hazard ratio 3.36, 95% confidence interval 1.18-10.89; P = 0.023). CONCLUSIONS: Surgical resection failed to achieve CA19-9 normalization in the high PET group and distant recurrence was frequent. This suggests the potential for residual cancer at distant sites, even after curative resection. Stronger preoperative systemic chemotherapy is preferred for the high PET group patients.