Opposing effects of thyroid hormones on hypothalamic subunits and limbic structures in hyperthyroidism patients: A comprehensive volumetric study.

Thyroid hormones play a critical role in brain development, but paradoxically, patients with hyperthyroidism often exhibit cognitive decline and irritability. This study aims to explore the pattern of atrophy in hyperthyroid patients, changes in specific areas of the brain, including hypothalamic subfields and limbic structures, and their relationships with hormonal levels and psychometric tests. This prospective cross-sectional study involves 19 newly diagnosed, untreated hyperthyroid patients, and 15 age and gender-matched control subjects. The participants underwent psychometric and cognitive tests and volumetric MRI. The hypothalamic subfield (anterior-inferior, anterior-superior, superior-tubular, inferior-tubular, and posterior hypothalamus) and limbic structures (fornix, basal forebrain, nucleus accumbens, and septal nucleus) were segmented using voxel-based morphometry, surface-based morphometry, and deep learning algorithms. The groups were compared using the t-test, and correlation analyses were performed between clinical parameters and volumetric measurements. The correlation between hormonal parameters and volumetric measurements in patient and control groups was assessed with the Meng test. Hyperthyroid patients displayed widespread grey matter loss and sulcal shallowing in the left hemisphere. However, no local gyrification index changes or cortical thickness variations were detected. The limbic structures and hypothalamic subunits did not show any volume discrepancies. Free thyroxine in the patient group negatively correlated with bilateral anterior-inferior and right septal nucleus, but positively correlated with left anterior-inferior in the control group. Thyroid stimulating hormone in the patient group showed a positive correlation with bilateral fornix volume, a correlation absent in the control group. Disease duration negatively correlated with right anterior-inferior, right tubular inferior, and right septal nucleus. Changes in cognitive and psychometric test scores in the patient group correlated with the bilateral septal nucleus volume. Hyperthyroidism primarily leads to a reduction in grey matter volume and sulcal shallowing. Thyroid hormones have differing volumetric effects in limbic structures and hypothalamic subunits under physiological and hyperthyroid conditions.

Paediatric supratentorial tumours do not cause microstructural alterations in contralateral white matter: a preliminary study.

BACKGROUND AND PURPOSE: Intracranial tumours in children can exhibit different characteristics compared to those in adults. Understanding the microstructural changes in the contralateral normal-appearing white matter (NAWM) in children with primary intracranial masses is essential for optimizing treatment strategies. This study aimed to investigate the apparent diffusion coefficient (ADC) changes in contralateral NAWM using fully automated methods and deep learning algorithms. METHODS: We included 22 paediatric patients with primary supratentorial intracranial masses (23% high-grade) in the study. ADC values of the contralateral NAWM in the patient group were compared to those of a control group. Deep learning algorithms were utilized to analyse diffusion changes in NAWM. RESULTS: The mean ADC values of contralateral NAWM in the patient group were 0.80 ± 0.03 × 10-3 mm2/s, while the control group had a mean ADC value of 0.81 ± 0.03 × 10-3 mm2/s. There was no statistically significant difference between the groups (p = 0.39). Our findings indicate that there are no significant diffusion changes in the contralateral white matter of children with supratentorial intracranial masses. CONCLUSION: Primary supratentorial intracranial masses in children do not cause microstructural changes in contralateral normal-appearing white matter. This could be attributed to the less infiltrative nature and different biochemical profile of these tumour groups in the paediatric population. Further studies using advanced imaging techniques could provide additional insights into the distinct characteristics of paediatric intracranial tumours and improve patient management.

Microstructural Abnormalities in the Contralateral Normal-appearing White Matter of Glioblastoma Patients Evaluated with Advanced Diffusion Imaging.

PURPOSE: Glioblastoma patients develop recurrence in the opposite hemisphere far from the primary tumor site even after complete resection. This is one of the main reasons for short disease survival. Our aim in this study is to detect microstructural changes in the contralateral hemisphere of glioblastoma patients using different diffusion models with the fully automated tract-based spatial statistics (TBSS) method. METHODS: Fourteen right-sided and eleven left-sided glioblastoma patients without any treatment and eighteen age- and gender-matched controls were included in the study. Multi-shell diffusion weighted images were created with a 3T MRI device. After various preprocessing steps, images of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), axial kurtosis (AK), mean kurtosis (MK), radial kurtosis (RK), intracellular volume fraction (ICVF), orientation dispersion index (ODI), and isotropic water fraction (ISO) were obtained. TBSS was used to compare diffusion tensor imaging, diffusion kurtosis imaging, and neurite orientation dispersion and density imaging parameters of right- and left-sided glioblastoma patients with the control group for the contralateral hemisphere. RESULTS: Both right-sided and left-sided glioblastoma patients have shown an increase in MD and ODI in the contralateral hemisphere. While right-sided glioblastoma patients showed an increase in RD, AD, and ISO in a more limited area in the contralateral hemisphere, left-sided glioblastoma patients showed an increase in MK and AK. FA, ICVF, and RK did not show any difference in both groups. CONCLUSION: There are microstructural changes in the contralateral hemisphere in glioblastoma patients, and these changes differ between right-sided and left-sided glioblastoma patients.

Cortical morphological changes in multiple sclerosis patients: a study of cortical thickness, sulcal depth, and local gyrification index.

PURPOSE: Multiple sclerosis (MS) is a disease that progresses not only with demyelination but also with neurodegeneration. One of the goals of drug treatment in MS is to prevent neurodegeneration. Cortical thickness (CT), sulcal depth (SD), and local gyrification index (LGI) are indicators related to neurodegeneration. The aim of this study is to investigate changes in CT, SD, and LGI in patients with relapsing-remitting MS (RRMS). METHODS: T1 images of 74 RRMS patients and 65 healthy controls were used. T1 hypointense areas in RRMS patients were corrected using fully automated methods. CT, SD, and LGI were calculated for each patient. RESULTS: RRMS patients showed widespread cortical thinning, especially in bilateral temporoparietal areas, decreased SD in bilateral supramarginal gyrus, superior temporal gyrus, postcentral gyrus, and transverse temporal gyrus, and decreased LGI, especially in the left posterior cingulate gyrus and insula. The decrease in cortical thickness was associated with the number of attacks and lesion volume. EDSS was related to CT in the right lingual, inferior temporal, and fusiform gyrus. The LGI was correlated with T2 lesion volume in bilateral insula, with EDSS in the right insula and transverse and superior temporal gyri, and with the number of attacks in the right paracentral gyrus and pre-cuneus. However, SD did not show any correlation with EDSS, T2 lesion volume, or the number of attacks. CONCLUSION: Our results demonstrate widespread cortical thinning, decreased sulcal depth in local areas, and decreased gyrification in folds in RRMS patients, which are related to clinical parameters.

The role of MR diffusion kurtosis and neurite orientation dispersion and density imaging in evaluating gliomas.

BACKGROUND AND PURPOSE: Conventional MRI sequences in neuro-oncology are insufficient for glioma grading. However, newly developed diffusion-weighted imaging techniques have been shown to have a great potential for glioma grading. This study examined the diagnostic performance of diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), neurite orientation dispersion and density imaging (NODDI), and their combinations in glioma grading. METHODS: Multishell diffusion tensor images were obtained with 3T MRI in 38 glioma patients (22 high-grade glioma [HGG], 16 low-grade glioma [LGG]). DTI (fractional anisotropy [FA], mean diffusivity [MD], axial diffusivity [AD], radial diffusivity [RD]), DKI (Axial kurtosis [AK], mean kurtosis [MK], radial kurtosis [RK]), and NODDI (intracellular volume fraction [ICVF], orientation distribution index, isotropic water fraction [ISO]) images were obtained after preprocessing. The average value of these parameters was calculated in the solid components of the tumors. The receiver operating characteristic curve analyses were performed to investigate the diagnostic performance and the curves were compared with the Delong test. RESULTS: FA shows an increase in HGG, while MD, RD, and AD exhibit a decrease. AK, MK, and RK were higher in HGG than LGG. ICVF increased in HGG, while ISO decreased. AK demonstrated the best diagnostic performance among all parameters, and kurtosis outperformed NODDI but not DTI. Combining these parameters did not yield a statistically significant improvement in diagnostic performance. CONCLUSION: DTI, DKI, and NODDI approaches can differentiate between HGG and LGG; however, kurtosis parameters perform better and adding NODDI parameters does not improve diagnostic performance. Using multishell b-value has not led to an increase in diagnostic performance.

Volumetric changes in hypothalamic subunits in patients with relapsing remitting multiple sclerosis.

PURPOSE: Studies on hypothalamic changes in patients with relapsing remitting multiple sclerosis (RRMS) are very scarce, despite the fact that the relationship with the hypothalamus is frequently reported. The aim of the study was to determine the volume of the hypothalamic subunits and the total hypothalamus and its relationship with the total demyelinating lesion volume (TLV) and expanded disability status scale (EDSS) in RRMS patients. METHODS: In this cross-sectional study, anterior-superior, superior tubular, posterior hypothalamus, anterior-inferior, inferior tubular subunits of hypothalamus, and total hypothalamus volume were calculated, with fully automatic analysis methods using volumetric T1 images of 65 relapsed RRMS patients and 68 healthy controls (HC). Volume changes in the hypothalamus and its subunits in RRMS patients were examined using multivariate analysis of covariance (MANCOVA). The relationship of these volumes with EDSS and TLV was investigated by partial correlation analysis. RESULTS: There is volume reduction in total hypothalamus (F = 13.87, p < 0.001), anterior-superior (F = 19.2, p < 0.001), superior tubular (F = 10.1, p = 0.002) subunits, and posterior hypothalamus (F = 19.2, p < 0.001) volume in RRMS patients. EDSS correlates negatively with anterior-superior (p = 0.017, r = - 0.333), superior tubular subunits (p = 0.023, r = - 0.439), posterior hypothalamus (p < 0.001, r = - 0.511), and whole hypothalamus volume (p = 0.001, r = - 0.439). TLV correlates negatively with anterior superior (p < 0.001, r = - 0.565), anterior inferior (p = 0.002, r = - 0.431), superior tubular subunits (p = 0.002, r = - 0.432), posterior hypothalamus (p < 0.001, r = - 0.703), and whole hypothalamus (p < 0.001, r = - 0.627) volumes. CONCLUSION: This study demonstrates a reduction in total hypothalamus volume, anterior-superior, superior tubular, and posterior hypothalamus in patients with RRMS. Anterior-superior and superior tubular subunit, posterior hypothalamus, and total hypothalamus volume were negatively correlated with TLV and EDSS scores.

Quantitative evaluation of cortical thickness in 3T in Behçet's patients without neurological involvement and parenchymal neuro-Behçet's disease.

PURPOSE: To evaluate the spatial distribution of cortical damage in Behcet's Disease (BD) with or without neurological involvement using a cortical thickness measurement approach using three-dimensional T1-weighted imaging. MATERIAL AND METHODS: Fifty-eight BD patients without neurological involvement, twenty-two Parenchymal Neuro-Behçets disease (PNBD) patients, and fifty healthy controls were included in the prospective study. Anatomical 3D T1 images were obtained from all participants using 3T MRI. Using a computational anatomy toolbox (CAT12), we calculated and compared group differences in cortical thickness. RESULTS: Patients with BD without neurological involvement showed cortical thickness reduction in bilateral frontal, bilateral parietal, and right precuneus compared with the healthy controls (HCs) (p < 0.05 FWE corrected [FWEc]). PNBD patients showed frontoparietal cortical thickness reduction when compared with BD patients without neurological involvement (p < 0.05 FWEc). The PNBD patients showed widespread cortical thickness reduction compared with the HC patients (p < 0.05 FWEc). Disease duration was correlated with cortical thickness in the right pericalcarine (p = 0.012 false discovery rate [FDR], r = -0.40), left pericalcarine (p = 0.013 FDR, r = -0.44), and left transverse temporal (p = 0.007 FDR, r = -0.41) regions. CONCLUSION: There is a decrease in cortical thickness in BD patients without neurological involvement. Cortical thickness reduction is more prominent in parenchymal neurobehçet's patients. Cortical thickness shows a negative correlation with disease duration in some regions.

Role of apparent diffusion coefficient measurement in differentiating histological subtypes of brain metastasis of lung cancer.

OBJECTIVE: The aim of this study was to investigate the role of apparent diffusion coefficient of diffusion-weighted imaging in differentiating histological subtypes of brain metastasis of lung cancer. METHODS: Diffusion-weighted imaging of 158 patients (mean age: 61.2±10.68 years) with brain metastasis of lung cancer (36 small cell lung cancer and 122 non-small cell lung cancer) were retrospectively evaluated. The minimum and mean apparent diffusion coefficient values of the metastasis, apparent diffusion coefficient of edema around the metastasis, and apparent diffusion coefficient of contralateral brain parenchyma were measured. Normalized apparent diffusion coefficient was calculated by proportioning the mean apparent diffusion coefficient of the metastasis to the apparent diffusion coefficient of the contralateral brain parenchyma. Minimum and mean apparent diffusion coefficient of the metastasis, apparent diffusion coefficient of edema around metastasis, and normalized apparent diffusion coefficient were compared between small cell lung cancer and non-small cell lung cancer metastases. RESULTS: Minimum apparent diffusion coefficient, mean apparent diffusion coefficient, and normalized apparent diffusion coefficient values of small cell lung cancer metastases (0.43±0.19×10-3mm2/s, 0.63±0.20×10-3mm2/s, and 0.81 [0.55-1.44], respectively) were significantly lower than those of non-small cell lung cancer metastases (0.71±0.26×10-3mm2/s, 0.93±0.29×10-3mm2/s, and 1.30 [0.60-3.20], respectively; p<0.001). Mean apparent diffusion coefficient of edema of small cell lung cancer metastases (1.21±0.28×10-3mm2/s) was significantly lower than that of non-small cell lung cancer metastases (1.39±0.26×10-3mm2/s, p=0.020). The best cutoff values of minimum apparent diffusion coefficient, mean apparent diffusion coefficient, normalized apparent diffusion coefficient, and apparent diffusion coefficient of edema for the differentiation of small cell lung cancer and non-small cell lung cancer were found to be 0.56×10-3mm2/s, 0.82×10-3mm2/s, 1.085, and 1.21×10-3mm2/s, respectively. The area under the receiver operating characteristic curve, sensitivity, and specificity values were, respectively, 0.812, 80.6, and 73.8% for minimum apparent diffusion coefficient; 0.825, 91.7, and 61.5% for mean apparent diffusion coefficient; 0.845, 80.6, and 73.8% for normalized apparent diffusion coefficient; and 0.698, 75.0, and 67.7% for apparent diffusion coefficient of edema. CONCLUSIONS: Minimum apparent diffusion coefficient, mean apparent diffusion coefficient, normalized apparent diffusion coefficient, and apparent diffusion coefficient of edema around metastasis can differentiate histological subtypes of brain metastasis of lung cancer.

Age, GH/IGF-1 levels, tumor volume, T2 hypointensity, and tumor subtype rather than proliferation and invasion are all reliable predictors of biochemical response to somatostatin analogue therapy in patients with acromegaly: A clinicopathological study.

PURPOSE: To determine whether biochemical responses to long-acting forms of first-generation somatostatin analogue (SSA) therapy in patients with acromegaly could be predicted from baseline and postoperative hormone concentrations, and tumor radiological and histopathological characteristics. METHODS: A total of 68 patients with acromegaly for whom postoperative SSA therapy was started were categorized according to their responses to treatment (SSA-responders vs. non-responders). The patients were compared based on their demographic characteristics, hormone levels, magnetic resonance imaging (MRI), and histopathological findings. Receiver-operating-characteristic (ROC) curves were constructed using the predictive factors that were significant in the univariate analysis to determinate the optimal cut-off values. RESULTS: The SSA-responders were significantly older (p = 0.041). Lower GH at diagnosis (p = 0.036), the postoperative 1st-week GH level (p = 0.027), baseline GH, insulin-like growth factor-1 (IGF-1) and IGF-1% upper limit of normal (ULN) (p = 0.001, p = 0.006, p = 0.023, respectively) were associated with biochemical response. T2-hypointensity and lower tumor volume were more common in the SSA-responders (p = 0.018, p = 0.03, respectively). Compared to sparsely granulated somatotroph tumors, densely granulated somatotroph tumors and other PitNETs causing GH excess including mammosomatotroph and mixed somatotroph and lactotroph tumors were more likely to respond to SSA therapy (p = 0.026, p = 0.03, respectively). The cut-off values generated by ROC curve analysis were GH at diagnosis of ≤8.8 ng/mL, GH at baseline of ≤2.69 ng/mL, IGF-1 at baseline ≤461.5 ng/mL, IGF-1% ULN at baseline ≤180.4%, and tumor volume of ≤1.11 cm3 (all p < 0.05). There were no differences between the groups in terms of tumor invasiveness, proliferative activity (mitotic count per 2 mm2 and Ki-67 labeling index) and quantitative analyses of T2-weighted MRI. CONCLUSION: This study underscores that advanced age, low baseline GH and IGF-1 at diagnosis, low tumor volume, densely granulated tumor subtype, and T2 hypointensity may help predict biochemical response to SSA therapy in cases of acromegaly. These variables should be assessed with utmost attention for all patients prior to SSA treatment. In cases of possible resistance to SSA therapy, therapeutic activity should be monitored more closely and other therapies should be administered immediately in the event of poor response.

Role of apparent diffusion coefficient measurement in differentiating histological subtypes of brain metastasis of lung cancer

SUMMARY OBJECTIVE: The aim of this study was to investigate the role of apparent diffusion coefficient of diffusion-weighted imaging in differentiating histological subtypes of brain metastasis of lung cancer. METHODS: Diffusion-weighted imaging of 158 patients (mean age: 61.2±10.68 years) with brain metastasis of lung cancer (36 small cell lung cancer and 122 non-small cell lung cancer) were retrospectively evaluated. The minimum and mean apparent diffusion coefficient values of the metastasis, apparent diffusion coefficient of edema around the metastasis, and apparent diffusion coefficient of contralateral brain parenchyma were measured. Normalized apparent diffusion coefficient was calculated by proportioning the mean apparent diffusion coefficient of the metastasis to the apparent diffusion coefficient of the contralateral brain parenchyma. Minimum and mean apparent diffusion coefficient of the metastasis, apparent diffusion coefficient of edema around metastasis, and normalized apparent diffusion coefficient were compared between small cell lung cancer and non-small cell lung cancer metastases. RESULTS: Minimum apparent diffusion coefficient, mean apparent diffusion coefficient, and normalized apparent diffusion coefficient values of small cell lung cancer metastases (0.43±0.19×10−3mm2/s, 0.63±0.20×10−3mm2/s, and 0.81 [0.55-1.44], respectively) were significantly lower than those of non-small cell lung cancer metastases (0.71±0.26×10−3mm2/s, 0.93±0.29×10−3mm2/s, and 1.30 [0.60-3.20], respectively; p<0.001). Mean apparent diffusion coefficient of edema of small cell lung cancer metastases (1.21±0.28×10−3mm2/s) was significantly lower than that of non-small cell lung cancer metastases (1.39±0.26×10−3mm2/s, p=0.020). The best cutoff values of minimum apparent diffusion coefficient, mean apparent diffusion coefficient, normalized apparent diffusion coefficient, and apparent diffusion coefficient of edema for the differentiation of small cell lung cancer and non-small cell lung cancer were found to be 0.56×10−3mm2/s, 0.82×10−3mm2/s, 1.085, and 1.21×10−3mm2/s, respectively. The area under the receiver operating characteristic curve, sensitivity, and specificity values were, respectively, 0.812, 80.6, and 73.8% for minimum apparent diffusion coefficient; 0.825, 91.7, and 61.5% for mean apparent diffusion coefficient; 0.845, 80.6, and 73.8% for normalized apparent diffusion coefficient; and 0.698, 75.0, and 67.7% for apparent diffusion coefficient of edema. CONCLUSIONS: Minimum apparent diffusion coefficient, mean apparent diffusion coefficient, normalized apparent diffusion coefficient, and apparent diffusion coefficient of edema around metastasis can differentiate histological subtypes of brain metastasis of lung cancer.

Diagnostic Accuracy of Sagittal TSE-T2W, Variable Flip Angle 3D TSET2W and High-resolution 3D Heavily T2W Sequences for the Stenosis of Two Localizations: The Cerebral Aqueduct and the Superior Medullary Velum.

OBJECTIVES: This study aimed to investigate the accuracy of conventional Sagittal Turbo spin Echo T2-weighted (Sag TSE-T2W), variable flip angle 3D TSE (VFA-3D-TSE) and high-resolution 3D heavily T2W (HR-3D-HT2W) sequences in the diagnosis of primary aqueductal stenosis (PAS) and Superior Medullary Velum Stenosis (SMV-S), and the effect of stenosis localization on diagnosis. METHODS: Seventy-seven patients were included in the study. The diagnosis accuracy of the HR-3D-HT2W, Sag TSE-T2W and VFA-3D-TSE sequences, was classified into three grades by two experienced neuroradiologists: grade 0 (the sequence has no diagnostic ability), grade 1 (the sequence diagnoses stenosis but does not show focal stenosis itself or membrane formation), and grade 2 (the sequence makes a definitive diagnosis of stenosis and shows focal stenosis itself or membrane formation). Stenosis localizations were divided into three as Cerebral Aquaduct (CA), Superior Medullary Velum (SMV) and SMV+CA. In the statistical analysis, the grades of the sequences were compared without making a differentiation based on localization. Then, the effect of localization on diagnosis was determined by comparing the grades for individual localizations. RESULTS: In the sequence comparison, grade 0 was not detected in the VFA-3D-TSE and HR-3DHT2W sequences, and these sequences diagnosed all cases. On the other hand, 25.4% of grade 0 was detected with the Sag TSE-T2W sequence (P<0.05). Grade 1 was detected by VFA-3D-TSE in 23% of the cases, while grade 1 (12.5%) was detected by HRH-3D-T2W in only one case, and the difference was statistically significant (P<0.05). When the sequences were examined according to localizations, the rate of grade 0 in the Sag TSE-T2W sequence was statistically significantly higher for the SMV localization (33.3%) compared to CA (66.7%) and SMV+CA (0%) (P<0.05). Localization had no effect on diagnosis using the other sequences. CONCLUSION: In our study, we found that the VFA-3D-TSE and HR-3D-HT2W sequences were successful in the diagnosis of PAS and SMV-S contrary to the Sag TSE-T2W sequence and especially SMV localization decreases the diagnostic accuracy of Sag TSE-T2W sequence.

The Effect of Biomarkers and Optic Nerve Sheath Diameter in Determining Mortality in non-Traumatic Subarachnoid Hemorrhage.

AIM: Although radiological methods are sufficient for the diagnosis of spontaneous subarachnoid hemorrhage (SAH), additional biomarkers are needed to predict prognosis. The aim of this study was to investigate the effects of serum S100B protein, Glial Fibrillary Acidic Protein (GFAP) levels and, Optic Nerve Sheath Diameter (ONSD) on mortality and clinical severity in patients with spontaneous SAH. MATERIALS AND METHODS: Fifty-six patients who were diagnosed with SAH after first evaluation in the emergency department (ED) were included in the study group; Forty-six patients who were admitted to the ED with headache of non-intracranial etiology, were included as the control group. Cerebral computed tomography (CT) images and peripheral blood samples were obtained from all patients; at the time of diagnosis and 24 h after diagnosis. Serum S100B protein and GFAP levels were measured from the blood samples and ONSD was measured on CT. RESULTS: Serum S100B protein and GFAP levels and, ONSDs at the time of diagnosis and 24 h after diagnosis were significantly higher in the study group (p < 0.05). Both GFAP levels and ONSD at the time of diagnosis and 24 h after the diagnosis were found to be related with increased mortality (p < 0.05). A similar association was found for serum S100B protein levels 24 h after the diagnosis, but not at the time of diagnosis (p = 0.540). CONCLUSION: Serum S100B protein and GFAP levels and, ONSD were increased in patients with spontaneous SAH. All parameters were found to be associated with increased mortality.

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

PURPOSE: 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.

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

BACKGROUND: 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.

Olfactory Bulb Microstructural Changes in Patients With Nasal Septum Deviation.

OBJECTIVE: The aim of this study is to assess the microstructural changes to the olfactory bulb (OB) in patients with nasal septum deviation (NSD) using diffusion tensor imaging and to research the association between these changes and the degree of NSD. METHODS: Ninety-six patients with NSD (46 males, 50 females) who received diffusion tensor imaging were assessed by 2 independent readers. The patients were separated into 3 groups according to the NSD angle. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of the ipsilateral and contralateral OB were measured in all NSD patients by region of interest. RESULTS: According to deviation side, there was significant difference between the right (R) and left (L) OB FA and ADC values across the 3 groups. In patients with left- and right- sided NSD, FA and ADC values for the left and right OB were significantly different between groups 1 and 3, and groups 2 and 3. There was negative correlation between L-FA (r = -0.481, P = 0.001; r = -0.496, P = 0.001) and R-FA (r = -0.705, P = 0.001; r = -0.286, P = 0.02) versus age and deviation angle. However, there was positive correlation between L-ADC versus age and deviation angle (r = 0.493, P = 0.001; r = 0.482, P = 0.001), as well as positive correlation between R-ADC versus age (r = 0.646, P = 0.001). CONCLUSION: This is the first study showing ADC increase and FA decrease associated with axonal damage and microstructural integrity loss based on the side of deviation in NSD patients. It has also shown that this abnormality is directly proportional with NSD degree.

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 the combination 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%.

Assessment of the association between pre-treatment and post-treatment left atrium size and severity of disease in patients with acute pulmonary embolism by using computed tomography pulmonary angiography.

INTRODUCTION: As far as we know, left atrium (LA) imaging findings of pre-treatment and post-treatment nonmassive, submassive and massive acute pulmonary embolism (APE) have not been reported in literature. The aim of this study is to assess LA sizes of nonmassive, submassive and massive APE before and after treatment with computed tomography pulmonary angiography (CTPA) and to research whether there are differences between groups. MATERIALS AND METHODS: Sixty two adult APE patients (21 nonmassive, 31 submassive and 10 massive) who were diagnosed with CTPA and who had post-treatment follow-up images and recorded clinical information were included in the study. Pre-treatment and post-treatment LA sizes of all groups were measured by two radiologists independently. RESULT: The lowest pre-treatment LA size was found in massive APE and this difference was found to be statistically significant when compared with submassive (p= 0.001) and nonmassive (p< 0.001) groups. In addition, submassive APE patients were found to have lower LA size when compared with nonmassive APE patients (p= 0.006). In massive and submassive APE, post-treatment LA sizes were found to be statistically significantly higher when compared with pre-treatment (p< 0.001 for both groups). However, in nonmassive APE patients, pre-treatment and post-treatment LA size difference was not found to be statistically significant (p= 0.082). CONCLUSIONS: As the severity of APE increases, LA size decreases. Thus, a decrease LA size during APE can show increased APE severity. This study reported that LA size increased statistically in post-treatment massive and submassive APE patients when compared with pre-treatment. These results suggest that in APE patients, as a response to treatment, LA size can be an additional parameter reflecting the changes in cardiac morphology.

Calcification of breast artery as detected by mammography: association with coronary and aortic calcification

Background/aim: https://orcid.org/0000-0002-9740-3580 Materials and methods: A total of 404 female patients above 40 years of age who, within a 6-month period, had undergone thoracic computed tomography and mammography for various reasons were screened retrospectively at our clinic. Mammographies were assessed for BAC and thoracic CT investigations were assessed for CAC and AC. Patients included in the study were scored as 0 (none), 1 (mild), 2 (moderate), or 3 (severe) depending on the number and shape of CAC, AC, and BAC lesions observed. Results: Four hundred and four females were enrolled in the study. While BAC was detected in 123 patients, no BAC was observed in the other 281 patients. In the BAC-positive patients, the rates of CAC (45.5% vs. 19.9%, P < 0.001) and AC (67.5% vs. 32.4%, P < 0.001) were notably higher than in the BAC-negative patients. In addition, multivariate regression analysis detected the presence of BAC as an independent variable for both CAC and AC. Conclusion: The presence of BAC appeared to be a significant risk factor for CAC and AC, and the BAC grade was considered an independent risk factor for CAC.

The diagnostic value of using combined MR diffusion tensor imaging parameters to differentiate between low- and high-grade meningioma.

OBJECTIVE: The purpose of this study was to examine whether the combined use of MR diffusion tensor imaging (DTI) parameters [DTI-apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD)] could provide a more accurate diagnosis in differentiating between low-grade and atypical/anaplastic (high-grade) meningioma. METHODS: Pathologically proven 45 meningioma patients [32 low-grade, 13 high-grade (11 atypical and 2 anaplastic)] who had received DTI before surgery were assessed retrospectively by 2 independent observers. For each lesion, MR DTI parameters (ADCmin, ADCmax, ADCmean, FA, AD, and RD) and ratios (rADCmin, rADCmax, rADCmean, rFA, rAD, and rRD) were calculated. When differentiating between low- and high-grade meningioma, the optimum cutoff values of all MR DTI parameters were determined by using receiver operating characteristic (ROC) analysis. Area under the curve (AUC) was measured with combined ROC analysis for different combinations of MR DTI parameters in order to identify the model combination with the best diagnostic accuracy in differentiation between low and high-grade meningioma. RESULTS: Although the ADCmin, ADCmax, ADCmean, AD, RD, rADCmin, rADCmax, rADCmean, rAD, and rRD values of high-grade meningioma were significantly low (p = 0.007, p = 0.045, p = 0.035, p = 0.045, p = 0.003, p = 0.02, p = 0.03, p = 0.03, p = 0.045, and p = 0.01, respectively), when compared with low-grade meningioma, their FA and rFA values were significantly high (p = 0.007 and p = 0.01, respectively). For all MR DTI parameters, the highest individual distinctive power was RD with AUC of 0.778. The best diagnostic accuracy in differentiating between low- and high-grade meningioma was obtained by combining the ADCmin, RD, and FA parameters with 0.962 AUC. CONCLUSION: This study shows that combined MR DTI parameters consisting of ADCmin, RD, and FA can differentiate high-grade from low-grade meningioma with a diagnostic accuracy of 96.2%. Advances in knowledge: To the best of our knowledge, this is the first study reporting that a combined use of all MR DTI parameters provides higher diagnostic accuracy for the differentiation of low- from high-grade meningioma. Our study shows that any of the model combinations was superior to use of any individual MR DTI parameters for differentiation between low and high-grade meningioma. A combination of ADCmin, RD, and FA was found to be the best model for differentiating low-grade from high-grade meningioma and sensitivity, specificity, and AUC values were found to be 92.3%, 100%, and 0.96, respectively. Thus, a combination of MR DTI parameters can provide more accurate diagnostic information when differentiation between low and high-grade meningioma.

Contribution of 3-T Susceptibility-Weighted MRI to Detection of Intraarticular Hemosiderin Accumulation in Patients With Hemophilia.

OBJECTIVE: The purpose of this study was to assess the feasibility of 3-T susceptibility-weighted imaging (SWI) for detecting intraarticular hemosiderin accumulation in patients with hemophilia. SUBJECTS AND METHODS: Forty-one joints in 24 patients with hemophilia were imaged with conventional MRI and SWI sequences. Two experienced musculoskeletal radiologists and one general radiologist (reader 3) interpreted the images for hemosiderin accumulation. The final decision was determined in consensus by readers 1 and 2 using both conventional MRI and SWI sequences. The diagnostic consistencies of each MRI sequence with the reference and pairwise agreements between interpreters were assessed. RESULTS: For conventional MRI sequences, the diagnostic consistencies of the two experienced musculoskeletal radiologists with the reference were substantial (κ = 0.63 and 0.62), whereas the consistency of the general radiologist with the reference was moderate (κ = 0.47). The SWI interpretations of all readers had almost perfect agreement with the reference (κ = 1, κ = 1, κ = 0.97). Interobserver agreement also improved at SWI interpretations. CONCLUSION: SWI contributes to more accurate grading of intraarticular hemosiderin accumulation than is achieved with conventional MRI sequences.