Background: The aim of this study was to describe the morphological signs of the central nervous system lymphoma (CNSL) in magnetic resonance imaging (MRI). We compared morphological characteristics of primary CNSL (PCNSL) and secondary CNSL (SCNSL) and also of PCNSL and glioblastoma (GBM). Methods: We included 64 patients with PCNSL (ten of them were immunocompromised), 21 patients with SCNSL and 54 patients with GBM. The diagnosis was confirmed histologically in all patients. We evaluated morphological signs on the first MRI examination. Additionally, in patients with PCNSL, we evaluated the development of the disease on follow-up examination before histological confirmation of the diagnosis, if available. Results: In most patients with PCNSL (62.5%) the tumor was localized supratentorially and presented as multiple lesions (53.1%) or as a diffuse infiltrative lesion (23.4%). In 87.5% of the patients the lesions reached the brain surface. Infiltration of ependyma was seen in 56.3%, infiltration of meninges in 39.1% and infiltration of cranial nerves in 48.5% of patients. Restriction of diffusion in some part of the tumor was apparent in nearly all patients (97.6%) with PCNSL. After administration of contrast media, marked enhancement was usually seen. In immunocompetent patients, homogenous...

Bakgrund: MRT som diagnostisk metod ökar konstant med åren och samtidigt ökar antalet patienter som får aktiva hjärtimplantat vilket leder till att undersökningar på patienter med ej-MR-villkorliga implantat också ökar. Undersökningarna utförs med olika protokoll och många faror finns när sådana undersökningar sker, många steg tas för att minimera riskerna för dessa patienter. Syfte: Sammanställa resultat av tidigare studier med avseende på säkerhetsaspekterna vid MR-undersökningar på patienter med ej-MR-villkorliga CIED. Metod: Studien är en kvantitativ litteraturstudie baserad på kvantitativa artiklar. Artiklarna hittades genom booleska sökmetoderna på PubMed för resultat samt snowballing för att samla in artiklar till bakgrunden och diskussionen. Resultat: MRT undersökningar på extremiteter såväl som huvud kan göras med minimala risker så länge de korrekta säkerhetsaspekterna följs. Undersökningar på det torakiska området var inte heller problematiskt, incidenser såsom Power-On-Reset var oftast under 1 %. Ingen incidens av dödsfall under MR undersökningarna på grund av implantaten i fråga. I vissa studier var batterierna problematiska och visade inte korrekt livslängd för implantatet efter MRT oftast med POR som möjlig orsak. Det är viktigt att all nödvändig personal är på plats eller tillgänglig under hela undersökningsprocessen fram tills patientens implantat har bekräftats fungera som normalt. Förändringar i ledarnas impedans dokumenterades i flera studier av oklar genes. Kvarlämnade- och brutna ledare visades sig vara relativt säkra. Artefakter var förekommande men var ej-kritiska, i några fall där FOV var i toraxregionen påverkades diagnosen. Slutsats: MRT av icke-torakiska undersökningar var säkra med säkerhetsprotokoll. / Background: MRI as a diagnostic method has increased with time, at the same time the number of patients with active heart implants has increased. This means we see an increasing number of MRI’s of patients with non-MR-conditional devices. The examinations are done with several different protocols and sequences, many dangers present themselves in these examinations therefore many steps are taken to minimize the risks to the patient during an MRI. Purpose: Compile results of earlier studies with regards to safety aspects during MRI of patients with non-MR-conditional CIED. Method: This is a quantitive literature study based on quantitative articles that were sourced using Boolean search methods on PubMed for the results and using the snowballing method for background and discussion. Results: MRI examinations on extremities as well as head-MRI can be done with minimal risks if the correct safety procedures are implemented. Thoracic examinations were quite safe with incidence rate of Power-on-Reset usually under 1%. No incidence of mortality during scanning due to CIED. In some studies, the batteries didn’t show their true remaining lifespan, usually preceded by a POR. All necessary personnel are to be in place during the exam or alternately available in a short timeframe during the entire examination until the examination is over and the patients CIED is determined to be working properly. Undetermined changes in lead impedance in several studies. Abandoned and broken leads showed no increased risk. Mild artefacts were documented, diagnostic imaging was only compromised when FOV was in the thorax region. Conclusion: Non-thoracic examinations were determined safe with safety protocol in place.

Os receptores para mineralocorticoides (MR) e glicocorticoides (GR) representam importantes sítios de ligação para os glicocorticoides. Enquanto a ativação crônica e excessiva de GR leva à atrofia do hipocampo, a ativação do MR é neuroprotetora. Considerando as alterações no giro denteado (GD), decorrentes do envelhecimento, e a possível participação do MR e GR neste processo, o objetivo deste trabalho foi correlacionar o desbalanço de tais receptores com a degeneração neuronal nesta região do hipocampo de cães idosos. Para isso, utilizaram-se cortes histológicos do hipocampo de 6 cadáveres caninos jovens/adultos (até 8 anos de idade) e 12 idosos (idade igual ou superior a 10 anos), de ambos os sexos e de qualquer raça, os quais foram submetidos à: coloração de Nissl, para a identificação de células nervosas; imuno-histoquímica, para o estudo da expressão do MR e GR; e marcação fluorescente (fluoro-jade B), para detecção de neurônios em degeneração. A camada polimórfica do GD de cães idosos apresentou redução (em 16%) na contagem de neurônios e maior número de neurônios em degeneração. Em conjunto com estas alterações celulares, a menor marcação/expressão do MR e a menor relação MR:GR foram correlacionadas com a degeneração neuronal na camada polimórfica do GD de cães idosos. Além disso, cadelas idosas apresentaram menor densidade celular na camada granular, quando comparadas aos machos idosos, sugerindo uma ação diferencial dos esteroides sexuais nas alterações do GD. Os resultados indicam que o desbalanço na relação MR:GR pode interferir na sobrevivência neuronal no GD de cães idosos. / The mineralocorticoid (MR) and glucocorticoid (GR) receptors bind the glucocorticoid hormones. The chronic and excessive GR activation leads to hippocampus atrophy. By contrast, MR activation is neuroprotective. Considering the aging changes in the dentate gyrus (DG) and the possible participation of MR and GR in this process, the objective of this study was to correlate the unbalance of these receptors with the neuronal degeneration in this hippocampal region of aged dogs. For that purpose, cadaveric histologic sections of hippocampus of 6 young/adult dogs (until 8 years old) and 12 aged dogs (more than 10 years old), of both sex and any breed, were included. The Nissl staining and imunochemistry were performed to identify nerve cells and to study the MR and GR expression, respectively. Moreover, fluorescent labeling (fluoro- Jade B) was used to detect degenerating neurons. The polimorfic layer of the DG of aged dogs showed reduction (of 16%) on the neurons counting and more degenerating neurons. Together with this cells changes, the less MR expression and MR:GR relation were correlated with the neuronal degeneration in the polimorfic layer of DG of aged dogs. Besides that, aged females presented lower cell density in the granular layer, when compared to aged males, suggesting a differential sex steroid action on changes in the GD. Our results indicate that unbalance on the MR:GR relation may interfere with neuronal survival in the DG of aged dogs.

Abstract Rectal prolapse and internal rectal prolapse with symptoms of obstructed defecation and/or faecal incontinence are debilitating conditions. Often, symptoms coexist from other pelvic compartments, reducing quality of life. Robot-assisted surgery with its advanced features may offer better conditions in narrow pelvic space to correct rectal prolapses with rectopexy operation. In this thesis, we compared robot-assisted and laparoscopic techniques during the early learning curve in a ‘matched-pairs’ feasibility study (n = 30, follow-up three months) and in a prospective randomized series (n = 33, follow-up 24 months). The long-term functional results were assessed in a retrospective multicenter study with cross-sectional questionnaire assessment (n = 508, median follow-up 44 months). In the randomised series, as demonstrated with MR defecography, ventral rectopexy corrects the posterior compartment defects, external and internal rectal prolapses and recto-enteroceles. The operation restores the posterior and middle compartment anatomy and reduces pelvic organ mobility with a minor impact on the anterior compartment. Pelvic floor dysfunction and symptom-specific quality of life is improved after rectopexy; specifically, the colorectal-anal and the pelvic organ prolapse subscales in the questionnaires showed improvement. We found equality between robot-assisted rectopexy and laparoscopic rectopexy in most relevant outcome measures, which does not justify the added cost of the routine use of robots in rectopexy operations. The health-related quality of life and cost-utility analysis in our cohort indicated, however, that in long-term the technique may be cost-effective. The functional results are retained in the long term. The rate of recurrences (7.1%) and complications (10%) are acceptable and mesh-related complications (1.4%) are rare. Denovo symptoms, such as the urge to defecate or urinary incontinence, may arise, while urinary symptoms may be alleviated. In the long-run, patients with external rectal prolapse benefit more than patients with internal rectal prolapse. In part, the results of this thesis support using a multidisciplinary approach in examining patients with posterior pelvic floor dysfunction. Furthermore, the indications for robotic use in rectopexy operations need to be explored in larger patient samples. / Tiivistelmä Rektumprolapsi ja peräsuolen sisäinen tuppeuma eli interni prolapsi aiheuttavat hankalia oireita, kuten ulostusvaikeuksia, ulosteinkontinenssia ja lantion kipua. Elämänlaatua heikentäviä oireita esiintyy usein samanaikaisesti myös muissa lantion osissa. Robottiavusteinen kirurgia tarjoaa paremmat leikkausolosuhteet lantion ahtaassa tilassa tehtävään rektopeksialeikkaukseen ja mahdollisesti edut voivat näkyä leikkaustuloksessa. Tässä väitöskirjassa vertailimme robottiavusteista ja laparoskooppista leikkaustekniikkaa oppimiskäyrän alkuvaiheessa käyttökelpoisuustutkimuksessa kaltaistetussa parivertailuasetelmassa (n = 40, seuranta-aika 3 kk) sekä prospektiivisessa randomoidussa tutkimussarjassa (n = 33, seuranta-aika 24 kk). Monikeskustutkimuksessa (n = 508, seuranta-ajan mediaani 44 kk) selvitimme laajassa aineistossa laparoskooppisen ventraalisen rektopeksian pitkäaikaistuloksia liittämällä aineiston analyysiin poikkileikkauskyselytutkimuksen tulokset. Randomoidussa sarjassa MR-defekografialla todennettiin, että rektopeksialeikkauksen jälkeen peräsuolen sisäinen tuppeuma, rektoseele ja enteroseele korjaantuvat. Rektopeksialeikkaus palauttaa lantion taka- ja keskiosan anatomian, vähentää elinten dynaamista liikkuvuutta ja parantaa lantionpohjan toimintaa sekä oireisiin liittyvää elämänlaatua, erityisesti suolioireiden ja gynekologisten laskeumaoireiden osalta. Robottiavusteinen ja laparoskooppinen tekniikka olivat samanvertaisia perioperatiivisten parametrien, komplikaatioiden, anatomisten ja toiminnallisten tulosten suhteen. Vaikka kustannusvertailussa kalliimpi robottikirurgia voi osoittautua kustannustehokkaaksi pitkäaikaisseurannassa, yhdenvertaiset tulokset eivät oikeuta menetelmää rutiinikäyttöön. Retrospektiivisen tutkimuksen poikkileikkauskyselyn mukaan toiminnalliset tulokset säilyvät pitkäaikaisseurannassa, residiivien (7,1 %) ja komplikaatioiden (10 %) määrä on hyväksyttävä ja verkkoon liittyviä komplikaatioita esiintyy vähän (1,4 %). Leikkauksen jälkeen ilmenee myös uusia oireita, kuten ulostuspakkoa tai virtsankarkailua. Toisaalta virtsankarkailuoire voi korjaantuakin. Pitkäaikaisseurannassa totaalin rektumprolapsin vuoksi leikatut potilaat hyötyvät leikkauksesta enemmän kuin oireisen internin prolapsin vuoksi leikatut. Osa väitöskirjatyön tuloksista tukee moniammatillisen lähestymistavan käyttöä potilaiden arvioinnissa. Jatkossa robottikirurgian käytön indikaatioita rektopeksialeikkauksissa tulisi arvioida isommissa potilasaineistoissa.

Os receptores para mineralocorticoides (MR) e glicocorticoides (GR) representam importantes sítios de ligação para os glicocorticoides. Enquanto a ativação crônica e excessiva de GR leva à atrofia do hipocampo, a ativação do MR é neuroprotetora. Considerando as alterações no giro denteado (GD), decorrentes do envelhecimento, e a possível participação do MR e GR neste processo, o objetivo deste trabalho foi correlacionar o desbalanço de tais receptores com a degeneração neuronal nesta região do hipocampo de cães idosos. Para isso, utilizaram-se cortes histológicos do hipocampo de 6 cadáveres caninos jovens/adultos (até 8 anos de idade) e 12 idosos (idade igual ou superior a 10 anos), de ambos os sexos e de qualquer raça, os quais foram submetidos à: coloração de Nissl, para a identificação de células nervosas; imuno-histoquímica, para o estudo da expressão do MR e GR; e marcação fluorescente (fluoro-jade B), para detecção de neurônios em degeneração. A camada polimórfica do GD de cães idosos apresentou redução (em 16%) na contagem de neurônios e maior número de neurônios em degeneração. Em conjunto com estas alterações celulares, a menor marcação/expressão do MR e a menor relação MR:GR foram correlacionadas com a degeneração neuronal na camada polimórfica do GD de cães idosos. Além disso, cadelas idosas apresentaram menor densidade celular na camada granular, quando comparadas aos machos idosos, sugerindo uma ação diferencial dos esteroides sexuais nas alterações do GD. Os resultados indicam que o desbalanço na relação MR:GR pode interferir na sobrevivência neuronal no GD de cães idosos. / The mineralocorticoid (MR) and glucocorticoid (GR) receptors bind the glucocorticoid hormones. The chronic and excessive GR activation leads to hippocampus atrophy. By contrast, MR activation is neuroprotective. Considering the aging changes in the dentate gyrus (DG) and the possible participation of MR and GR in this process, the objective of this study was to correlate the unbalance of these receptors with the neuronal degeneration in this hippocampal region of aged dogs. For that purpose, cadaveric histologic sections of hippocampus of 6 young/adult dogs (until 8 years old) and 12 aged dogs (more than 10 years old), of both sex and any breed, were included. The Nissl staining and imunochemistry were performed to identify nerve cells and to study the MR and GR expression, respectively. Moreover, fluorescent labeling (fluoro- Jade B) was used to detect degenerating neurons. The polimorfic layer of the DG of aged dogs showed reduction (of 16%) on the neurons counting and more degenerating neurons. Together with this cells changes, the less MR expression and MR:GR relation were correlated with the neuronal degeneration in the polimorfic layer of DG of aged dogs. Besides that, aged females presented lower cell density in the granular layer, when compared to aged males, suggesting a differential sex steroid action on changes in the GD. Our results indicate that unbalance on the MR:GR relation may interfere with neuronal survival in the DG of aged dogs.

This diploma thesis investigates the accelerated sedimentation of the magnetorheological fuids (MRFs) using centrifuge. Experiments are carried out at room temperature as well as at higher temperatures (40°C, 60°C and 80°C). The development of the new improved measuring device for the sedimentation evaulation is described. Magnetic components of the device were designed using FEM analysis. Newly designed device is verified. To accomplish the experiments at the high temperatures the new heated chamber for experimental centrifuge is designed and constructed. In the next part of the work full experiment of the accelerated sedimentation is performed. At final the empirical model of the sedimetation velocity for various accelerations and temperatures is synthesized.

This diploma thesis deals with development of a new generation of magnetic circuits of fast magnetoreological (MR) dampers that will not use problematic ferrite materials. To ensure a short response time, eddy currents must be avoided. Using the Finite Element Method, 2 solutions were proposed - the use of soft magnetic composites with high electrical resistance and the cutting of grooves in metallic material. Subsequently, 2 magnetic circuits were produced - one from Sintex SMC prototyping material composite and one from 11SMn30 steel with 48 deep grooves 0,35 mm wide. Both were implemented into the MR damper and tested on a hydraulic pulsator. The results of the experiments were compared with 2 different MR dampers: one with 11SMn30 magnetic circuit without grooves and another with the Epcos N87 ferrite magnetic core. It has been found that both new circuits have ensured an equally short response of the damper force to the change of electric current like ferrite. At the same time, a much larger dynamic range was ensured. Compared to 11SMn30 without grooves, the new circuits provided approximately 7x faster response.

This diploma thesis deals with an engineering design of a fail-safe magnetorheological (MR) damper capable of semi-active control. The first part of the thesis is devoted to the current state of knowledge of fail-safe MR dampers and permanent magnets contained in these dampers. The next part contains an engineering design of a fail-safe MR damper, made using FEM simulations, and its subsequent testing in terms of magnetic and hydraulic properties. Finally, a design of a fail-safe MR damper with fast response time was made and simulated using verified FEM analysis. Fast response time is ensured by limiting the generation of eddy currents in the piston core by grooving.

This thesis deals with in vivo MR spectroscopy. Measurements in this thesis were performed on whole-body MR tomograph at the Institute for Clinical and Experimental Medicine in Prague. The objective of the thesis was to study differences in the biochemical processes and energy metabolism in the muscle tissue under physical workload between the groups of healthy subjects and patients with type 1 diabetes mellitus (DM1). We used phosphorous spectroscopy in combination with ergometer. The thesis is divided into five chapters. The first chapter describes theoretical introduction to in vivo 1 H and 31 P MR spectroscopy and muscle metabolism, the second chapter deals with the description of the experimental equipment and measurement, results of the thesis are reported in the third chapter and the fourth chapter is a discussion of results. Main result of this work is summarized in conclusion; we found differences between the metabolism of patients with DM1 and healthy volunteers.

(AJ) The three aims of the work were as follows: 1. Comparison of prostate magnetic resonance (MR) examination results from 1.5 T and 3 T scanners in patients with prostate carcinoma (PCa). MR findings of 103 patients (ages 44-72 years) were compared with histopathological results after radical prostatectomy. The work was focused on the accuracy of predicting local cancer staging and determining prostate tumour location. Patients were divided into three groups (A, B and C) based on the type of MR scanner and protocol used. Patient groups A and B were examined in 1.5T and 3T MR scanners equipped with surface coils in the identical multiparametric MR imaging protocol included dynamic contrast examination (DCE). Patient group C was examined in a 3T MR scanner without DCE. The highest accuracy of predicting the stage of PCa was seen in patients examined in 3 T MR scanner with DCE included in the protocol, however, no significant differences were seen between results from 1.5 T and 3.T MR scanners. No significant difference was also found in the accuracy of determining the location of prostate tumour between 1.5 T and 3T MR examinations, however, there were significant differences between sequences used, with the highest accuracy attained by using a combination of T2 weighted sequences and diffusion...