27 research outputs found

    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

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    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%

    Is cerebral edema effective in idiopathic intracranial hypertension pathogenesis?: Diffusion weighted MR imaging study

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    The aim of this study is to research whether cerebral edema is effective in the pathogenesis of patients with idiopathic intracranial hypertension (IIH) by using diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) measurements. Was changed into thirty-six IHH patients who received DWI and 36 age- and sex-matched healthy control group were assessed retrospectively. ADCmin, ADCmean, and ADCmax values were measured from different regions of the brain for both IHH patients and the control group. The Students t-test was used to compare the ADCmin, ADCmax, ADCmean values acquired from distinct parts of the brain parenchyma of IIH patients with the values of control group. No significant difference was found between ADCmin, ADCmax, and ADCmean values of IIH and control group in bilateral frontal, parietal temporal and occipital lobe cortical and subcortical white matter, caudate nucleus head, putamen, thalamus, corpus callosum splenium and genu (P>0.05). This study showed that cerebral edema cannot be a significant mechanism in the pathogenesis of IIH. [Med-Science 2019; 8(1.000): 48-52

    The value of apparent diffusion coefficient measurements in the differential diagnosis of vertebral bone marrow lesions

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    Aim: To be able to differentiate benign vertebral bone marrow lesions from malign lesions according to apparent diffusion coefficient (ADC) values, enabling quantitative assessment, and to determine the sensitivity and the specificity in differentiating benign and malign lesions according to the optimal cutoff ADC value. Materials and methods: In 99 patients, 133 lesions in total were included in the study, 59 of which were benign (acute vertebral compression fracture depending on osteoporosis or trauma, spondylitis, atypical hemangioma), and 74 malign (malign compression fracture, metastasis). Each of the benign lesions was compared to the malign lesions. In the statistical analysis, normality tests, variance analysis tests, and the Tukey HSD multi-discriminant analysis tests were performed for all measurable variables. The optimal cutoff ADC value was determined by ROC analysis in the differentiation of benign and malignant lesions. Results: The mean ADC value of the benign induced acute compression fractures was significantly higher than that of the malign induced compression fractures, and the mean ADC value of the spondylitis atypical hemangiomas was significantly higher than that of the malign lesions (P < 0.0001). According to the optimal cutoff value of 1.32 × 103 mm2/s, determined for the differentiation of benign and malignant vertebral bone-marrow lesions, sensitivity was 96.5%, specificity 95.2%, positive predictive value 96.5%, and negative predictive value 95.2%. Conclusion: Vertebral bone-marrow pathologies were differentiated as benign or malignant with high sensitivity and specificity with the aid of ADC values calculated from maps obtained by DWI

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

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    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

    NOVA: rendering virtual worlds with humans for computer vision tasks

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    Today, the cutting edge of computer vision research greatly depends on the availability of large datasets, which are critical for effectively training and testing new methods. Manually annotating visual data, however, is not only a labor-intensive process but also prone to errors. In this study, we present NOVA, a versatile framework to create realistic-looking 3D rendered worlds containing procedurally generated humans with rich pixel-level ground truth annotations. NOVA can simulate various environmental factors such as weather conditions or different times of day, and bring an exceptionally diverse set of humans to life, each having a distinct body shape, gender and age. To demonstrate NOVA's capabilities, we generate two synthetic datasets for person tracking. The first one includes 108 sequences, each with different levels of difficulty like tracking in crowded scenes or at nighttime and aims for testing the limits of current state-of-the-art trackers. A second dataset of 97 sequences with normal weather conditions is used to show how our synthetic sequences can be utilized to train and boost the performance of deep-learning based trackers. Our results indicate that the synthetic data generated by NOVA represents a good proxy of the real-world and can be exploited for computer vision tasks

    Lu-177-Labeled Macroaggregated Albumin Imaging and Treatment Effect in Patient with Cystic Thyroid Nodule

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    A number of different peptides or antibodies have been labeled with Lu-177 and used for clinical imaging and treatment. To our knowledge, Lu-177 had never before been used to label macroaggregated albumin, and our radiopharmacy laboratory at Istanbul University-Cerrahpasa made a special effort to do so. We present the case of a 43-y-old man whose cystic thyroid nodule was treated with an intranodular injection of Lu-177-macroaggregated albumin and imaged with SPECT/CT

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

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    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)
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