Multiparametric MRI in differentiating solitary brain metastasis from high-grade glioma: diagnostic value of the combined use of diffusion-weighted imaging, dynamic susceptibility contrast imaging, and magnetic resonance spectroscopy parameters

Objective. The purpose of this study was to determine whether the combined use of diffusion weighted imaging (DWI), magnetic resonance spectroscopy (MRS), and dynamic susceptibility contrast imaging (DSCI) parameters could provide a more accurate diagnosis in the differentiation of high-grade glioma (HGG) from solitary brain metastasis (SBM) in the enhancing tumour and in the peritumoural region.Materials and methods. Fifty-six patients who received DWI, DSCI, and MRS before surgery were assessed. In differentiating SBM from HGG, the cutoff values of the DWI-apparent diffusion coefficient (ADCmin, ADCmax, and ADCmean), DSCI-relative cerebral blood volume (rCBV), and MRS-Cho/Cr, Cho/NAA, and NAA/Cr parameters for the peritumoural region were determined with ROC. The combined ROC curve was used for the different combinations of the peritumoural region DWI, DSCI, and MRS parameters in differentiating between the two tumours, and the best model combination was formed. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki Declaration and its later amendments. This study was approved by the Institutional Review Board at our institutes.Results. In the enhancing tumour, all the parameters except NAA/Cr (P = 0.024) exhibited no statistical difference in differentiating between these two groups (P > 0.05). AUC values for ADCmin, ADCmax, ADCmean, rADCmin, rADCmax, rADCmean, rCBV, Cho/Cr, Cho/NAA, and NAA/Cr parameters in the peritumoural region in differentiating SBM from HGG were 0.860, 0.822, 0.848, 0.822, 0.801, 0.822, 0.906, 0.851, 0.903, and 0.784, respectively. In differentiating HGG from SBM, the best model consisted of thecombination of peritumoural ADCmin, rCBV, and Cho/NAA parameters. AUC values were 0.970.Conclusions. The combination of peritumoural region ADCmin, rCBV, and Cho/NAA parameters can help in differentiating SBM from HGG, with a diagnostic accuracy of 97%

The impact of high performance work systems on firm performance: An empirical study of lodging business

Bu çalışmanın amacı, konaklama işletmelerinde yüksek başarımlı çalışma sistemlerinin uygulanma veya benimsenme düzeyini saptamak ve konaklama işletmelerinde uygulanan yüksek başarımlı çalışma sistemlerinin işletme performansı üzerindeki etkisini ortaya koymaktır. Bu amaçla Nevşehir ilinde faaliyet gösteren 3, 4, 5 yıldızlı ve özel işletme belgeli konaklama işletmelerinde yüksek başarımlı çalışma sistemlerinin uygulanma düzeyleri, işgörenlerin ve insan kaynakları yöneticilerinin bakış açısıyla ortaya konulmuş ve yüksek başarımlı çalışma sistemlerinin işletme performansı üzerindeki etkisi incelenmiştir.Konaklama işletmelerinde uygulanan yüksek başarımlı çalışma sistemlerini ve konaklama işletmelerinin performanslarını ölçmek için daha önce geliştirilmiş, geçerliliği ve güvenilirliği sınanmış ve çeşitli araştırmalarda kullanılmış olan ölçeklerden yararlanılmıştır. Bu çalışmada örnekleme yöntemi olarak, tesadüfi olmayan örnekleme yöntemlerinden amaca göre (purposive) örnekleme yöntemi kullanılmış ve alan araştırması kapsamına Nevşehir ili sınırları içerisinde faaliyet gösteren 3, 4, 5 yıldızlı oteller ile özel işletme belgeli konaklama işletmeleri dahil edilmiştir. Araştırma verileri, konaklama işletmelerinin işgörenlerinden ve insan kaynakları yöneticilerinden anket tekniği kullanılarak elde edilmiştir.Araştırma sonuçlarına göre, Nevşehir ilindeki 3, 4, 5 yıldızlı ve özel işletme belgeli konaklama işletmelerinde yüksek başarımlı çalışma sistemlerinin uygulanma düzeyinin, özellikle performansa dayalı ücretlendirme, işletme içi terfi fırsatları, kariyer yönetimi, iş güvencesi, iletişim ve bilgi paylaşımı, sosyal haklar konularında düşük olduğu ve bu uygulamaların benimsenmediği saptanmıştır. Ayrıca yüksek başarımlı çalışma sistemlerinin konaklama işletmeleri performansının farklı boyutlarını önemli ölçüde etkilediği ve konaklama işletmeleri performansıyla en çok ilişkili olan yüksek başarımlı çalışma sistemleri uygulamalarının eğitim, güçlendirme, ekip çalışması, zengin(geniş) iş tasarımı olduğu ortaya çıkmıştır. Bu bulgular ışığında, Nevşehir ilindeki konaklama işletmeleri yöneticilerine işletme performanslarını iyileştirmelerini sağlayacak çeşitli önerilerde bulunulmuştur.The purpose of this study is to determine the implementation or adoption level of high performance work systems in lodging firms and to examine the impact of high performance work systems on lodging firms? performance. In line with the purpose of this study, using the self report data from employees and managers, the implementation levels of high performance work systems and the impact of high performance work systems on business performance in three, four and five star and S(special) Licence Lodging businesses were investigated in Nevşehir.In order to measure high performance work systems and lodging business performance, previously developed and used scales with proven reliability and validity in various studies were employed. In this study, purposive sampling technique, which is one of the nonprobability sampling methods, was used and three, four and five stars and S(special) Licence Lodging businesses in Nevşehir were included in the field research. Research data were gathered from the employees and managers of lodging businesses with the help of a questionnaire.According to the results of the study, the implementation level of high performance work systems in three, four and five star and S(special) Licence Lodging businesses in Nevşehir is low, especially in such issues as performance based pay, promotion from within, career management, job security, communication and information sharing, and social benefits. It is clear that these practices are not adopted by lodging businesses in Nevşehir. Also, the research findings indicate that high performance work systems have significant impacts on the different dimensions of lodging businesses performance and the most important high performance work systems dimensions that are associated with lodging businesses performance are training, empowerment, teamworking and job design. In the light of these findings, suggestions were made in order for managers to get better lodging business performance in Nevsehir

Imaging of unilateral adrenal hemorrhages in patients after blunt abdominal trauma: Report of two cases

Adrenal hemorrhage following blunt abdominal trauma is extremely rare. Most of the lesions are unilateral and right sided. Although often asymptomatic, life-threatening adrenal insufficiency may develop in the bilateral adrenal gland hemorrhage. Isolated adrenal injuries are very rare. They are often associated with other organ injuries. The mortality rates of patients range from 7% to 32%. In this report, we present the computed tomography and magnetic resonance imaging findings of unilateral adrenal hemorrhages in two patients with a history of fall from a height

Diffusion tensor imaging in hyperthyroidism: assessment of microstructural white matter abnormality with a tract-based spatial statistical analysis

Aslan, Kerim/0000-0001-6322-7163WOS: 000523911800001PubMed: 32202136Background Metabolic, morphological, and functional brain changes associated with a neurological deficit in hyperthyroidism have been observed. However, changes in microstructural white matter (WM), which can explain the underlying pathophysiology of brain dysfunctions, have not been researched. Purpose To assess microstructural WM abnormality in patients with untreated or newly diagnosed hyperthyroidism using tract-based spatial statistics (TBSS). Material and Methods Eighteen patients with hyperthyroidism and 14 age- and sex-matched healthy controls were included in this study. TBSS were used in this diffusion tensor imaging study for a whole-brain voxel-wise analysis of fractional anisotropy, mean diffusivity, axial diffusivity (AD), and radial diffusivity (RD) of WM. Results When compared to the control group, TBSS showed a significant increase in the RD of the corpus callosum, anterior and posterior corona radiata, posterior thalamic radiation, cingulum, superior longitudinal fasciculus, and the retrolenticular region of the internal capsule in patients with hyperthyroidism (P < 0.05), as well as a significant decrease in AD in the anterior corona radiata and the genu of corpus callosum (P < 0.05). Conclusion This study showed that more regions are affected by the RD increase than the AD decrease in the WM tracts of patients with hyperthyroidism. These preliminary results suggest that demyelination is the main mechanism of microstructural alterations in the WM of hyperthyroid patients.Ondokuz Mayis University Scientific Research ProjectOndokuz Mayis University [PYO.TIP.1901.15.008]The author(s) received the following financial support for the research, authorship, and/or publication of this article: This study was funded by Ondokuz Mayis University Scientific Research Project (grant no. PYO.TIP.1901.15.008)

Microstructural white matter abnormalities in hypothyroidism evaluation with diffusion tensor imaging tract-based spatial statistical analysis

WOS: 000539547800001PubMed: 32524282Purpose Hypothyroidism is presented in a wide range from neuropsychiatric problems including depression, memory and cognitive disorders to poor motor coordination. Against the background of morphologic, functional and molecular changes on the white and grey matter of the brain, we aimed to investigate the effects of hypothyroidism on white matter (WM) integrity using tract-based spatial statistics (TBSS). Methods Eighteen patients with hyperthyroidism and 14 age-sex-matched healthy control subjects were included in this study. TBSS was used in the diffusion tensor imaging study for whole-brain voxel wise analysis of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) of WM. Results When compared to the control group, the whole brain TBSS revealed extensive reductions of FA in the supratentorial WM including corticospinal tract, posterior limb of the internal capsule (PLIC), uncinate fasciculus, inferior longitudinal fasciculus (p < 0.005). the ROI analyses showed RD increment of superior longitudinal fasciculus, AD decrement of cingulum (CIN), external capsule, PLIC and corpus callosum (CC) in patients with hypothyroidism (p < 0.005). Autoimmune and non-autoimmune hypothyroidism patient subgroups showed a significant difference in terms of hippocampus FA, CIN MD, CC MD, CC AD, CIN RD, SLF RD, CC RD (p < 0.005). CIN FA values showed a negative correlation with the Beck Depression Inventory (p = 0.007,r = - 852). Conclusions These preliminary results of TBSS analyses represented FA and AD decrement, and RD increment in several WM tracts and indicates the demyelination process underlying pathophysiology of clinical aspects of hypothyroidism

Structural brain alterations of Down's syndrome in early childhood evaluation by DTI and volumetric analyses

To provide an initial assessment of white matter (WM) integrity with diffusion tensor imaging (DTI) and the accompanying volumetric changes in WM and grey matter (GM) through volumetric analyses of young children with Down's syndrome (DS). Ten children with DS and eight healthy control subjects were included in the study. Tract-based spatial statistics (TBSS) were used in the DTI study for whole-brain voxelwise analysis of fractional anisotropy (FA) and mean diffusivity (MD) of WM. Volumetric analyses were performed with an automated segmentation method to obtain regional measurements of cortical volumes. Children with DS showed significantly reduced FA in association tracts of the fronto-temporo-occipital regions as well as the corpus callosum (CC) and anterior limb of the internal capsule (p < 0.05). Volumetric reductions included total cortical GM, cerebellar GM and WM volume, basal ganglia, thalamus, brainstem and CC in DS compared with controls (p < 0.05). These preliminary results suggest that DTI and volumetric analyses may reflect the earliest complementary changes of the neurodevelopmental delay in children with DS and can serve as surrogate biomarkers of the specific elements of WM and GM integrity for cognitive development. aEuro cent DS is the most common genetic cause of intellectual disability. aEuro cent WM and GM structural alterations represent the neurological features of DS. aEuro cent DTI may identify the earliest aging process changes. aEuro cent DTI-volumetric analyses can serve as surrogate biomarkers of neurodevelopment in DS