The relationship between nutritional status and white matter integrity in older adults: A diffusion tensor imaging study.

OBJECTIVES: The purpose of this study to determinate whether there is a relationship between the nutritional status and white matter integrity in older patients by using Diffusion Tensor Imaging (DTI). METHODS: The patients were evaluated by Mini-Nutritional Assessment Scale. The patients are categorized in the groups of well-nourished, risk of malnutrition, or malnourished, depending on the overall score> 23.5, 17-23.5, or 17; respectively. All patients had brain MRI and DTI. The mean diffusivity (MD), fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD) values were calculated by ROI-based method in white matter tracts. RESULTS: Total of the 224 patients; 86 patients had normal nutrition status (group 1), 107 patients were diagnosed with malnutrition risk (group 2) and 31 patients were diagnosed with malnutrition (group 3). Significantly decreased FA values of genu of corpus callosum, forceps minor and significantly increased MD values of middle cerebellar peduncle, and superior frontooccipital fasciculus were detected in group 2 in comparison to group 1 (p < 0.05). After adjusting for the folate and age, MD and RD values of cingulum remained significantly higher and the AD values of superior cerebellar peduncle remained significantly lower in group 3 (p < 0.05). CONCLUSIONS: Malnutrition was associated with deteriorated DTI values, especially in cingulum and superior cerebellar peduncle. Assessing the nutritional status of older individuals is crucial to avoid its negative impact on brain. ADVANCES IN KNOWLEDGE: Early diagnosis of malnutrition-related impaired WM integrity is important for prevention and intervention, and DTI is a useful non-invasive technique to be used for this purpose.

Diagnostic role of gray-scale and shear-wave elastography in pediatric patients with undescended testes: a prospective controlled study.

Aim: Ultrasound elastography is a simple non-invasive method for measuring tissue elasticity in relation to tissue fibrosis. The aim of this study was to compare echogenicity, volume and shear wave velocities of undescended vs normally descended testes. Material and methods: Sixty-six boys with undescended testes were included in this study. The median age range was 35.5 (10-118) months old. The cases included in this prospective study consisted of 66 patients with non-operated undescended testes, with 51 of them being affected unilaterally and 15 affected bilaterally, as diagnosed by physical examination. The control group consisted of 31 healthy boys without any particular health problems. This prospective study was performed by gray-scale ultrasonography and shear wave elastography in boys with undescended testes and healthy testes. The testicular volumes were established by ultrasound measurement, the echogenicity and shear wave elastography values were measured in boys with unilateral and bilateral undescended testes, and the results were compared with healthy boys' testes and their contralateral testes. The stiffness values were recorded for speed (m/s) and elasticity (kPa), and the stiffness values of undescended testes were compared with the healthy control group. Results: Echogenicity values were lower in the bilateral undescended testes group than in the healthy group, and the healthy group's echogenicity was normal (p <0.001). The ROC curve was used to identify a cut-off shear wave elastography value for predicting decreased testicular echogenicity by using average shear wave elastography values. The area under the curve for the undescended testes was 0.78 (95% CI: 0.70-0.85, sensitivity 83.7%, specificity 68.7%, p <0.001), with an average shear wave elastography value of 2.32 (m/s) for above the cut-off point indicates. This was found to be significantly associated with reduced echogenicity on gray-scale ultrasonography, suggesting that it may be correlated with fibrosis developing in patients with undescended testes. Conclusion: The study provides interesting findings in that it proposes an alternative non-invasive method for the assessment of testicular tissue in undescended testes. We used shear wave elastography to compare the stiffness of normal testes in both heathy patients and in the contralateral healthy testes of boys with undescended testes, with the values obtained for the undescended testes reflecting the level of fibrosis of the parenchyma. Another outcome of this study was observed in patients with unilateral undescended testes, where the normally descended testes showed increased shear wave elastography values, which could be an early indication of parenchymal change.

Diffusion tensor imaging findings in the hunger and satiety centers of the brain after bariatric surgery: a preliminary study.

PURPOSE: To investigate the alterations in the diffusion tensor imaging (DTI) parameters measured in the hunger and satiety centers of the brain before and after bariatric surgery (BS) in morbidly obese patients. METHODS: Fourty morbidly obese patients were evaluated before and after BS. Mean diffusivity (MD) and fractional anisotropy (FA) values were calculated from 14 related brain locations, and the DTI parameters were analyzed. RESULTS: After the BS, the mean BMI of the patients decreased from 47.53 ± 5.21 to 31.48 ± 4.21. The MD and FA values in the all of the hunger and satiety centers was found statistically significant different in the pre-surgery period compared to the post-surgery period (for each; p-value < 0.001). CONCLUSION: The FA and MD changes after BS may be attributed to reversible neuroinflammatory alterations in the hunger and satiety centers. Decreased MD and FA values after BS may be explained by the neuroplastic structural recovery in the related brain locations.

Evaluation of the white matter integrity in morbidly obese patients before and after bariatric surgery; a diffusion tensor imaging study.

PURPOSE: To investigate the difference in FA (Fractional anisotropy), ADC (Apparent diffusion coefficient), RD (Radial diffusivity) and AD (axial diffusivity) values of white matter (WM) tracts in morbidly obese subjects before and after bariatric surgery (BS). MATERIALS AND METHODS: A group of thirty-nine morbidly obese subjects are evaluated before and 4-6 months after BS. ADC, FA, RD and AD values of 17 distinct neuroanatomic localizations are measured and DTI parameters are analyzed. RESULTS: Following the BS, the patients' mean BMI decreased from 47.665.21 to 31.723.97. A significant difference is displayed between the pre-surgery and post-surgery FA values of SLF, SFOF, ALIC, fornix, ILF, CST, MCP (p = 0.010, p < 0.001, p = 0.048, p = 0.014, p = 0.012, p = 0.012, p = 0.040 respectively). Following BS, decrease in FA values in the mentioned areas are detected. ADC values obtained from MCP are significantly lower in the post-BS period compared to pre-BS period (p = 0.018). There was a statistically significant difference between the pre-surgery and post-surgery AD values of SLF, SFOF, ILF, ALIC, EC, CST, and MCP (p = 0.001, p = 0.022, p = 0.001, p = 0.011, p = 0.001, p = 0.000, p = 0.000, respectively). Following the BS, AD values of the SLF, SFOF, ILF, ALIC, EC, CST, and MCP are decreased. RD values measured from GCC are significantly lower in the post-BS period compared to pre-BS period (p = 0.008). CONCLUSION: Our study supported the hypothesis of the BS-induced reversibility of the low-grade inflammation in WM tracts in the morbidly obese group following BS. Our DTI results may represent the subacute period findings of the reversal of low-grade inflammation after BS.

Microstructural alterations in hypoxia-related BRAIN centers after COVID-19 by using DTI: A preliminary study.

PURPOSE: To investigate whether the diffusion tensor imaging (DTI) parameters alterations in the in hypoxia-related neuroanatomical localizations in patients after COVID-19. Additionally, the relationship between DTI findings and the clinical severity of the disease is evaluated. METHODS: The patients with COVID-19 were classified into group 1 (total patients, n = 74), group 2 (outpatient, n = 46), and group 3 (inpatient, n = 28) and control (n = 52). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated from the bulbus, pons, thalamus, caudate nucleus, globus pallidum, putamen, and hippocampus. DTI parameters were compared between groups. Oxygen saturation, D dimer and lactate dehydrogenase (LDH) values associated with hypoxia were analyzed in inpatient group. Laboratory findings were correlated with ADC and FA values. RESULTS: Increased ADC values in the thalamus, bulbus and pons were found in group 1 compared to control. Increased FA values in the thalamus, bulbus, globus pallidum and putamen were detected in group 1 compared to control. The FA and ADC values obtained from putamen were higher in group 3 compared to group 2. There was a negative correlation between basal ganglia and hippocampus FA values and plasma LDH values. The ADC values obtained from caudate nucleus were positively correlated with plasma D Dimer values. CONCLUSION: ADC and FA changes may reveal hypoxia-related microstructural damage after COVID-19 infection. We speculated that the brainstem and basal ganglia can affected during the subacute period.

Dynamic Contrast-Enhanced MR Perfusion in Differentiation of Benign and Malignant Brain Lesions.

BACKGROUND: We aimed to differentiate Glioblastoma Multiforme (GBM) from benign lesions like Developmental Venous Anomaly (DVA) and Cavernous Malformation (CM) by Dynamic Contrast-Enhanced MR Perfusion (DCE-MRP) markers such as Ktrans, Ve, Kep, and IAUC. METHODS: We retrospectively evaluated 20 patients; 10 GBM as the malignant group, 5 CM and 5 DVA as the benign group. Ktrans, Kep, Ve, and IAUC parameters were measured by DCE-MRP, within the lesion, at perilesional nonenhancing white matter (PLWM) and contralateral normal appearing white matter (CLWM). RESULTS: All benign and malignant lesions exhibited significantly increased Ktrans, Ve, and IAUC values compared to PLWM and CLWM (p < 0.001, p=0.006 and p<0.001). Subtracted Kep values between lesion and PLWM were significantly different between the benign and malignant groups, as the malignant group exhibited higher subtracted Kep values (p 0.035). For the malignant group; Ktrans and IAUC values at the lesion were positively correlated (r 0.911), while Kep and Ve at CLWM were negatively and strongly correlated (r 0.798). For the benign group; Ktrans with Ve and Ktrans with IAUC at lesion (r 0.708 and r 0.816 respectively), Ktrans and IAUC at PLWM (r 0.809), Ktrans and IAUC at CLWM(r 0.798) were strongly and positively correlated. Ktrans, Ve, and IAUC values can be used to restrict the lesion in both groups. CONCLUSION: Ktrans strongly correlates with IAUC and they can be used instead of each other in both benign and malignant lesions. Classical DCE-MRP parameters cannot be used in the differentiation of malignant lesions from benign vascular lesions. However, subtracted Kep values can be used to differentiate GBM from benign vascular lesions.

Relationship of diffusion tensor imaging parameters with neurocognitive dysfunction in patients with Behcet's disease.

Behcet's disease (BD) is a chronic, multisystemic, relapsing-remitting, progressive inflammatory disorder with unknown etiology. The aim of the study is to investigate the white matter integrity and subclinical brain parenchymal involvement in Behcet's subjects by utilizing diffusion tensor imaging (DTI) and to correlate apparent diffusion coefficient (ADC), fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD) values measured from the diverse distinct anatomic locations with the disease duration time and neurocognitive function test results. Thirty-five adults with Behcet's disease and 21 age-matched healthy controls were enrolled in this study. Neurocognitive functions of the patients were evaluated with the Brief Repetable Battery-Neuropsychological tests (BRB-N). In both groups, DTI metrics were calculated from 19 different locations in the brain. The association between the DTI parameters and disease duration time and neurocognitive function test results were investigated. In Behcet's disease, at the cingulum and the splenium of the corpus callosum (SCC), FA values were significantly lower compared with the controls (p = 0.0015, p = 0.003, respectively). The ADC values of the corona radiata and RD values of superior longitudinal fasciculus and SCC were significantly higher than the controls (p = 0.023, p = 0.028, p = 0.006, respectively). Significant negative correlations were found between the FA values of cingulum, genu of corpus callosum (GCC), posterior limb of internal capsule (PLIC) and disease duration time (r = - 0.368; p = 0.029 and r = - 0.337; p = 0.048 and r = - 0.527; p = 0.001 respectively). All BD subjects performed significantly lower test scores on the spatial recall test (SPART) (p = 0.001). In addition, negative correlation was found between the MD values of the parietooccipital white matter and the selective reminding test (SRT) results (r = - 0.353; p = 0.037). Our DTI study presented microstructural alterations in the neurocognitive-related areas and BRB-N test results even in patients without neurological symptoms which may imply insidious neurological involvement.

Effect of Quantitative and Semi-quantitative Elastography Methods for the Management of Borderline Lesions on Ultrasonography.

BACKGROUND: Elastography (strain or shear-wave) is a method that estimates tissue stiffness. INTRODUCTION: The aim of this study is to evaluate the quantitative and semi-quantitative ultrasound elastography methods for the diagnosis of BI-RADS 4a and BI-RADS 3 lesions, which are borderline for biopsy and follow-up. MATERIALS AND METHODS: 175 consecutive women with 193 ultrasound-visible breast lesions were classified on Conventional B-mode Ultrasonography (CUS) according to the BI-RADS scoring system. Quantitative and semiquantitative values from ultrasound elastography in the form of strain Elastography Ratio (SER), shear Wave Elastography (SWE) and Shear Wave Elastography Ratio (SWER) were obtained. The lesions categorized as BI-RADS 4a and BI-RADS 3 on ultrasound were subsequently re-categorized according to the elastography values. RESULTS: Except for the 13 BI-RADS 2 lesions, the remaining 180 lesions were biopsied. Pathology showed 83 lesions to be benign and 97 to be malignant. The sensitivity and specificity of the CUS were 96.9% and 75.0%, respectively with an accuracy of 86.0%. Cut-off points calculated based on ROC curves were 56.8 kPa for SWE, 3.53 for SWER and 3.81 for SER. When we downgraded BIRADS 4a lesions based on elastography results, the specificity (CUS+SER 96.9%, CUS+SWE 91.7%, and CUS+SWER 90.6%) and the accuracy (CUS+SER 95.3%, CUS+SWE 92.7%, and CUS+SWER 92.2%) were shown to be better than CUS. When we upgraded BI-RADS 3 lesions based on elastography results, the sensitivity of combined sets of SWE (99,0%) and SWER (100,0%) was better than CUS. CONCLUSION: The rate of false-negative biopsies can be decreased with the combined use of elastography and ultrasonography.

Normal Pressure Hydrocephalus: Clinical Symptoms, Cerebrospinal Fluid Flow Metrics and White Matter Changes.

PURPOSE: The aim of this study was to investigate correlations between clinical symptoms, cerebrospinal fluid flow metrics, hydrocephalus index, small-vessel disease, and white matter (WM) changes in normal pressure hydrocephalus (NPH). METHODS: Aquaductal stroke volumes (ASVs), Z Evans index, Fazekas grading (FG), and diffusion tensor imaging measurements from WM bundles of 37 patients with NPH were retrospectively evaluated. Mann-Whitney U test between clinical symptoms and other variables and Spearman ρ correlations for relationships between variables and Kruskal-Wallis to correlate FG with nonclinical variables were used. RESULTS: Patients with NPH had increased ASV (median 53 µL). No correlation was found between Z Evans index and ASV. Three groups of patients with dementia or ataxia or incontinence had increased ASV values than their counterparts without symptoms (55 vs 48.5 µL, 75 vs 47 µL, 64 vs 49.5 µL, respectively). Patients having 2 common symptoms of dementia and ataxia and patients having all 3 symptoms of dementia, ataxia, and incontinence were compared with ASV values of 63.5 versus 78 µL, respectively. Patients with FG 1 had median ASV values of 45 µL; FG 2, 82.5 µL; and FG 3, 59 µL. Patients with dementia had significantly higher apparent diffusion coefficient (ADC) values of corona radiata (CR) on both sides. There were no significant WM changes in patients with ataxia and incontinence. The Z Evans index was positively correlated with ADC values of CR on both sides and genu of corpus callosum. Fazekas grading was found positively correlated with ADC and negatively correlated with FA values of CR. CONCLUSIONS: Patients with NPH, regardless of stages of the diseases, have increased ASV values and could benefit from shunting. Decreasing ASV values of patients with FG 3 comparing with those with FG 2 support the hypothesis of decreasing compliance of brain with aging and increasing severity of small-vessel disease.

The Utility and Efficiency of Diffusion Tensor Imaging Values to Determine Epidermal Growth Factor Receptor Gene Mutation Status in Brain Metastasis from Lung Adenocarcinoma; A Preliminary Study.

BACKGROUND: This study aims to investigate the existence of any Diffusion Tensor Imaging (DTI) value differences in Brain Metastases (BM) due to lung adenocarcinoma based on the Epidermal Growth Factor Receptor (EGFR) gene mutation status. MATERIAL AND METHODS: 17 patients with 32 solid intracranial metastatic lesions from lung adenocarcinoma were included prospectively. Patients were divided according to the EGFR mutation status as EGFR (+) (group 1, n:8) and EGFR wild type (group 2, n:9). The Fractional Anisotropy (FA), apparent diffusion coefficient (ADC), normalized ADC (nADC), Axial Diffusivity (AD), and Radial Diffusivity (RD) values were measured from the solid component of the metastatic lesions and nADC values were calculated. DTI values were compared between group 1 and group 2. The receiver-operating characteristic analysis was used to obtain cut-off values for the parameters presenting a statistical difference between the EGFR gene mutation-positive and wild type group. RESULTS: There were statistically significant differences in measured ADC, nADC, AD, and RD values between group 1 and group 2. The ADC, nADC, AD, and RD values were significantly lower in group 1. There was no significant difference in FA values between the two groups. Analysis by the ROC curve method revealed a cut-off value of ≤721 x 10-6 mm2/s for ADC (Sensitivity= 72.7, Specificity=85.7); ≤0.820 for nADC (Sensitivity=72.7, Specificity=90.5), ≤ 886 for AD (Sensitivity=81.8, Specificity=81.0), and ≤588 for RD (Sensitivity=63.6, Specificity=90.5) in differentiating EGFR mutation (+) group from wild type group. CONCLUSION: A combination of the decreased ADC, nADC, AD, and RD values in BM due to lung adenocarcinoma can be important for predicting the EGFR gene mutation status. DTI features of the brain metastases from lung adenocarcinoma may be utilized to provide insight into the EGFR mutation status and guide the clinicians for the initiation of targeted therapy.

Evaluation of Auditory Pathways Using DTI in Patients Treated with Gamma Knife Radiosurgery for Acoustic Neuroma: A Preliminary Report.

PURPOSE: We aimed to evaluate the change in bilateral auditory pathways using diffusion tensor imaging (DTI) after gamma knife radiosurgery (GKR) and to determine the relationship between the radiosurgical treatment variables and DTI findings. METHODS: In this study 13 patients with unilateral acoustic neuroma and 11 controls underwent routine magnetic resonance imaging (MRI) and DTI. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured from the bilateral auditory pathways in all individuals before and after GKR. RESULTS: Before GKR, subjects' ADC values obtained from the contralateral side were higher at the lateral lemniscus, medial geniculate body and Heschl's gyrus compared to those of the controls. No statistical differences were found in ADC and FA obtained at bilateral auditory pathways before and after GKR. The ADCs measured at the lateral lemniscus were positively correlated with the maximum radiation dose delivered to the brainstem (BS) and the brainstem volume receiving a radiation dose of 10 Gy (BS V10). A negative correlation was found between the FA measured from the inferior colliculus and the maximum radiation dose to the cochlea. The ADCs at the inferior colliculus were positively correlated with the mean radiation dose to the cochlea. CONCLUSION: There were no significant differences in the degree of involvement before and after GKR, revealing that GKR did not significantly affect the auditory pathways at 4 months. The major factors that may lead to microstructural injury to auditory pathways at the brainstem level are associated with maximum brainstem radiation dose, BS V10, and cochlear dose. These findings may suggest that more attention should be paid to anatomical structures including the cochlea and brainstem during treatment planning of GKR.