62 research outputs found
Manual adjustment of brain extraction parameters in a volumetric study
INTRODUCTION: Brain volumetry is a contemporary method used in scientific and clinical research in neurodegenerative diseases. The process can be fully automated but it allows some parameters to be manually adjusted in order to minimize errors. The purpose of the present study is to analyze the use of additional settings in the process of extracting brain tissue from the skull in volumetric assessments performed using FSL-SIENAX, to point out the most frequently used ones, and to provide recommendations for their application.MATERIAL AND METHODS: 3DT1 MRI scans of 51 patients with multiple sclerosis were processed. After conversion from the native format, brain tissue was extracted using the BET procedure. Multiple experiments were done using different parameters followed by a visual assessment of the results. Optimal values were chosen for each case. Descriptive statistical analysis was performed.RESULTS: Manual corrections of the default settings of BET were made in all studied cases. The most frequently applied parameter (100% of cases) was `-f`, which adjusts the aggressiveness of the algorithm, followed by `-B` (51%), which reduces bias field and neck voxels, `-R` (31,4%), multiple iterations of the algorithm, `-g` (25,5%), correction of the vertical gradient, `-S` (2%), removal of wrongfully identified optic nerves and eyeballs.CONCLUSION: The fully automatic volumetric assessment of the brain performed by FSL-SIENAX accelerates the workflow, but may lead to imperfections in the results. Manual adjustment trials may begin with the "-f" parameter, followed by "-Ð’", "-R", "-g", and combinations between them
Arterial spin labeling MRI - clinical applications
Arterial spin labeling (ASL) is a modern magnetic-resonance technique for evaluation of brain perfusion. One of its most important advantages is that there is no need for an injection of an exogenous contrast material. ASL generates an image by magnetically `labeling` water molecules in arterial vessels. Thus, ASL is an alternative to the invasive techniques requiring intravenous contrast medium, and in some cases, it even proves to be a better choice. There is a wide clinical application for ASL, ranging from stroke, brain neoplasms and vascular malformations, to neurodegenerative and psychiatric disorders
MRI features of cerebral small vessel disease
Cerebral small vessel disease affects brain vessels with the smallest caliber - small arteries, arterioles, venules, capillaries. There is strong association with cognitive impairment, dementia, psychiatric conditions, gait disturbances. The main markers of cerebral small vessel disease in neuroimaging are white matter hyperintensities, lacunes, microbleeds, enlarged perivascular spaces - all of which long considered to be of a separate etiology and pathogenesis. Today we have enough reason to believe that they are part of the same pathological process, in which the main role is played by the endothelium. Advances in neuroimaging allow us to give more attention to cerebral small vessel disease - an extremely important scientific and social problem.Cerebral small vessel disease affects brain vessels with the smallest caliber - small arteries, arterioles, venules, capillaries. There is strong association with cognitive impairment, dementia, psychiatric conditions, gait disturbances. The main markers of cerebral small vessel disease in neuroimaging are white matter hyperintensities, lacunes, microbleeds, enlarged perivascular spaces - all of which long considered to be of a separate etiology and pathogenesis. Today we have enough reason to believe that they are part of the same pathological process, in which the main role is played by the endothelium. Advances in neuroimaging allow us to give more attention to cerebral small vessel disease - an extremely important scientific and social problem
Multifunctionality of rapeseed meal protein isolates prepared by sequential isoelectric precipitation
Rapeseed meal is a by-product of the oil-producing industry with a currently underesti-mated application. Two protein isolates, PI2.5–8.5 or PI10.5–2.5, were obtained from industrial rapeseed meal after treatment with an aqueous ethanol solution. The alkaline-extracted proteins were sequen-tially precipitated by two different modes, from pH 10.5 to 2.5, and vice versa, from 2.5 to 8.5, with a step of 1 pH unit. The preparation approach influenced both the functional and antioxidant properties of the isolates. The PI10.5–2.5 exhibited higher water and oil absorption capacities than PI2.5–8.5, reaching 2.68 g H2O/g sample and 2.36 g oil/g sample, respectively. The emulsion stability of the PI2.5–8.5, evaluated after heating at 80 °C, was either 100% or close to 100% for all pH values studied (from 2 to 10), except for pH 6 where it reached 93.87%. For the PI10.5–2.5, decreases in the emulsion stability were observed at pH 8 (85.71%) and pH 10 (53.15%). In the entire concentration range, the PI10.5–2.5 exhibited a higher scavenging ability on 2,2-diphenyl-1-picryl hydrazyl (DPPH) and hydroxyl radicals than PI2.5–8.5 as evaluated by DPPH and 2-deoxyribose assays, respectively. At the highest concentration studied, 1.0%, the neutralization of DPPH radicals by PI10.5–2 reached half of that exhibited by synthetic antioxidant butylhydroxytoluene (82.65%). At the same concentration, the inhibition of hydroxyl radicals by PI10.5–2 (71.25%) was close to that achieved by mannitol (75.62%), which was used as a positive control. Established antioxidant capacities add value to the protein isolates that can thus be used as both emulsifiers and antioxidants.info:eu-repo/semantics/publishedVersio
Magnetic resonance diffusion and perfusion for differentiation of low grade from high grade glioma
Глиомите са най-честите първични мозъчни тумори с годишна заболеваемост от 5-10 случая на 100 000 в западните популации. Те са водещата причина за смърт сред децата и възрастните, диагностицирани с мозъчна неоплазма. Глиомите се оценяват по класификацията на СЗО чрез хистопатологични степени от I до IV. Степени I и II се считат за нискостепенни, докато III, IV са високостепенни. Въпреки че са хистологично доброкачествени, повечето от туморите II ст. ще се трансформират в злокачествените III и IV степени в интервала от 5-10 години от поставяне на диагнозата. Тези степени са важни, тъй като определят терапевтичния подход и прогнозата при пациентите с глиоми. Високостепенните глиоми се подлагат на хирургия и/или лъчетерапия, и/или химиотерапия, имат по-лоша прогноза. Нискостепенните глиоми имат понякога консервативно лечение. Конвенционалните МР образи осигуряват важна информация относно наличието на контрастноусилване, едем, далечни туморни фокуси, кръво-излив, некроза, масс ефект и т.н., които са полезни при характеризирането на туморната агресивност и оттам туморната степен. Съвременните физиологични МР техники като МР дифузия и перфузия дават информация за туморната физиология като микроваскуларитет, ангиогенеза, и целуларитет, всяка от които е също важна при определяне на туморната степен. Дифузионната МР техника оценява структурата на тумора целуларитет, водно съдържимо. Перфузионната МР техника е маркер за капилярната плътност и неоваскуларизация.Gliomas are the most common primary brain tumors with an annual incidence of 5-10 cases per 100,000 in Western populations. They are the leading cause of death among children and adults diagnosed with brain neoplasm. Gliomas are valued at the WHO classification by histopathological grades I to IV. Grades I and II are considered low-grade, while III, IV grades are high grade. Although they are histologically benign tumors most of II grade will transform into malignant grades III and IV in the range of 5-10 years of diagnosis. These grades are important because, they define therapeutic approach and prognosis in patients with gliomas. High grade gliomas were subjected to surgery and / or radiotherapy and / or chemotherapy, have a poor prognosis. Low-grade gliomas have sometimes conservative treatment. Conventional MR images provide important information on the presence of contrast enhancement, oedema, distant tumor foci, hemorrhage, necrosis, mass effect, etc., which are useful in the characterization of tumor aggressiveness and hence tumor grade. Modern techniques such as physiological techniques- MR diffusion and perfusion provide information about tumor physiology as microvascularity, angiogenesis, and cellularity, all of which are also important in determining the tumor grade. MR diffusion technique evaluates the structure of the tumor-cellularity, water content. MR perfusion technique is a marker for capillary density and neovascularisation
Gallbladder adenomyomatosis mimicking carcinoma - a clinical case
Gallbladder adenomyomatosis is hyperplastic cholecystosis of the gallbladder. This is a relatively common and benign cause for diffuse or focal wall thickening.We present a case of a 48-year-old woman with complaints from 3 - 4 years of epigastric pain, abdominal swelling, occurring after eating, with a temporary effect after antispasmodics or antisecretors. There was a reduction in body weight. All laboratory tests were normal. An ultrasound examination revealed a diffusely thickened, stratified gallbladder wall and parenchymal mass in the lumen. Due to clinical suspicion of acalculous cholecystitis, antibacterial treatment was performed, which did not lead to relief of symptoms. The ultrasound picture also did not change. Magnetic resonance imaging showed an image of gallbladder adenomyomatosis. Given the differential diagnostic possibility of gallbladder cancer, a planned cholecystectomy was performed, which, together with histological examination, confirmed the benign nature of the disease. After the surgery, the patient's complaints completely disappeared.Gallbladder adenomyomatosis is a benign and degenerative condition characterized by mucosal proliferation and thickening of the muscle layer. Given the possible premalignant character, cholecystectomy remains the treatment of choice for patients with clinically manifested gallbladder adenomyomatosis.
Crohn’s Disease: Contemporary Diagnostic Techniques
The diagnosis and follow-up of patients with Crohn's disease are undergoing rapid development and innovation. In recent decades, significant diagnostic advances have been observed in diagnostic imaging. In recent years, the rapid development of new computer technologies and the introduction of new software have increased the informativeness and accuracy of CT, MRI, and ultrasound examinations of the abdomen. The quality of the CT scan is optimized, and at the same time, the ionizing dose to the patient is reduced. One of the ways to reduce the ionizing dose while scanning patients with Crohn's disease is to use a low-dose scanning protocol. With this scanning method, patients receive a much lower ionizing dose than the standard protocol without significantly losing quality. Dual-energy and dual-layer spectral detectors are two other scan protocols and image post-processing techniques that significantly improve image informativeness. New ultrasound machines and the development of the software have greatly improved the informativeness of this harmless study. Shear wave elastography and strain elastography are new research techniques through which we can obtain information about changes in the mesenteric of the affected areas. Development in magnetic resonance techniques is also observed. New magnetic resonance methods such as MR fluoroscopy, dynamic contrast-enhanced MR perfusion (DCE MR), magnetization transfer, and others are examples of this. Thus, new diagnostic methods give a key role to diagnostic imaging in the detection and follow-up of Crohn's disease
Enhanced solubility of rapeseed meal protein isolates prepared by sequential isoelectric precipitation
The solubility of plant protein isolates is a key determinant of their potential application. Two protein isolates (PI) from ethanol-treated industrial rapeseed meal, PI10.5–2.5 and PI2.5–8.5, were prepared by sequential isoelectric precipitation of alkali-extracted proteins (pH 12) starting from pH 10.5 to 2.5 or from pH 2.5 to 8.5, respectively. Biochemical analyses revealed that PI2.5–8.5 contained a higher amount of crude protein (72.84%) than PI10.5–2.5 (68.67%). In the same protein isolate, the level of total phenols (0.71%) was almost two-fold higher than that in PI10.5–2.5 (0.42%). No glucosinolates were established in both protein isolates. SDS-PAGE analysis demonstrated that PI10.5–2.5 contained 10 to 15 kDa protein fractions in a relatively higher amount, while PI2.5–8.5 was enriched in 18 to 29 kDa protein fractions. PI10.5–2.5 exhibited high solubility, varying from 41.74% at pH 4.5 to 65.13% at pH 6.5, while PI2.5–8.5 was almost two-fold less soluble under the same conditions. Up to pH 5.5, the addition of NaCl at 0.03 and 0.25 M diminished the solubility of PI2.5–8.5, while the solubility of PI10.5–2.5 was increased. The supplementation of PI10.5–2.5 with 0.25 M NaCl enhanced the protein solubility to 56.11% at pH 4.5 and 94.26% at pH 6.5. The addition of 0.03 M NaCl also increased the solubility of this protein isolate but to a lower extent. Overall, the approach for sequential
precipitation of proteins influenced the biochemical characteristics, protein fractional profile and
solubility of prepared protein isolates.info:eu-repo/semantics/publishedVersio
Multiple proliferating trichilemmal cysts of the skalp: a case report. Multiple proliferating pilar tumors of the scalp
Proliferating trichilemmal cyst, also known as proliferating pilar scalp tumor, is a rare benign tumor of the hair follicle. While trichilemmal cysts are common intradermal or subcutaneous cysts, occuring in 5–10% of the population, only 2% will develop into proliferative trichilemmal cyst. The differential diagnosis should include lesions such as malignant proliferating trichilemmal tumor and squamous cell carcinoma. Surgical treatment is the only effective method for treating these rare cysts. We present a case report of a 78-years-old female patient who hasentered the Neurosurgery clinic of “St. Marina” University Hospital with clinical manifestation of rapidly growing from several months subcutaneous formation on the head and the presence of two smaller ones. MRI scan discovered three subcutaneous tumor formations suspicious for trichilem cysts, one of which was gigantic in size. After clinical discussion, under general anesthesia an operative treatment was performed with total extirpation of the cysts. Postoperatively, surgery-related complications were not observed. The patient was mobilized and verticalized on the day after intervention and discharged on the 5th day. As a result, a good cosmetic effect was obtained. Proliferating trichilemmal cyst is an uncommon neoplasm, and reporting of these lesions are important due to the good clinical evolution compared to the malignant macroscopic and microscopic feature of these tumor formations
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