L’IRM à ultra haut champ (UHC) donne accès à une résolution spatiale submillimétrique rendant possible la visualisation de structures plus fines qu’en IRM classique. Depuis quelques années, son potentiel s’est développé dans des laboratoires tels que NeuroSpin, au sein du CEA, qui a l’ambition d’étudier l’anatomie et le fonctionnement du cerveau à une échelle mésoscopique. Toutefois, pour des champs magnétiques supérieurs à 3T, le champ radiofréquence (RF) permettant d’exciter les protons de l’eau a une longueur d’onde inférieure à la dimension de la tête humaine, provoquant des phénomènes d’interférences destructives dans le cerveau. Ceux-ci s’accentuent avec l’augmentation du champ statique, engendrant sur les images des inhomogénéités de signal ou de contraste, qui empêchent d’exploiter tout le potentiel de l’imagerie UHC. Pour améliorer la pertinence des diagnostics cliniques, à défaut de pouvoir homogénéiser le champ RF dans tout le cerveau, il est essentiel de réussir à uniformiser l’excitation des spins. Dans ce but, un système de transmission parallèle (pTx) à 8 canaux a été intégré à l’imageur 7T du laboratoire. Il permet d’émettre sur chaque canal des formes d’impulsions RF différentes, à optimiser pour faire interférer le champ RF produit dans le cerveau de manière plus contrôlée que dans le mode classique à un seul canal d’émission. Ces travaux de thèse consistent à mettre au point des impulsions RF utilisant la pTx pour sélectionner des tranches d’excitation uniforme, et à les appliquer à l’angiographie du cerveau humain à 7T. A UHC, la méthode la plus courante pour homogénéiser l’angle de bascule de l’aimantation dans une coupe consiste à générer consécutivement plusieurs impulsions sélectives optimisées, appelées « spokes », à différentes positions du plan transverse à la coupe dans l’espace de Fourier de transmission. Si elle convient pour uniformiser l’excitation dans le plan de coupe, cette méthode est moins performante pour la sélection de larges tranches car les inhomogénéités de champ RF ne sont alors pas prises en compte dans l’épaisseur de tranche. Ainsi, dans un premier temps, deux méthodes originales de conception d’impulsions RF sélectives sont introduites et explorées pour uniformiser l’excitation de larges tranches : celle des « kT-spokes » qui optimise le placement des spokes dans les 3 dimensions de l’espace de Fourier de transmission, et celle des « spokes 3D » qui génère des impulsions RF optimisées point par point dans le temps. Ces techniques ont été validées avec succès sur des fantômes à 7T et ont permis de surpasser l’état de l’art en termes d’homogénéisation de l’angle de bascule pour la sélection de larges tranches. Dans un deuxième temps, ces méthodes ont été appliquées à la séquence d’angiographie 3D en temps de vol afin d’améliorer la visualisation du réseau artériel dans le cerveau humain à 7T. Cependant, lorsque les tranches sélectionnées sont larges, cette séquence est aussi sensible aux effets de saturation du sang qui empêchent d’apprécier la totalité du réseau artériel avec les profils de tranche d’angles de bascule plats habituels. Pour corriger ce phénomène, les impulsions RF à rampes sont proposées dans l’état de l’art, générant des profils d’angle de bascule qui augmentent avec l’épaisseur de la tranche. Les méthodes de conception d’impulsions RF développées ici ont ainsi été adaptées pour générer ce type de profils et permettre de compenser la saturation du sang avec succès dans les acquisitions à 7T. Ces travaux de thèse ont permis d’ouvrir la voie à une nouvelle application à NeuroSpin puisque l’angiographie n’y avait pas encore été explorée malgré le fort potentiel des UHC pour cette modalité. En outre, les méthodes développées au cours de ces travaux permettent l’excitation simultanée de tranches homogènes, constituant ainsi une perspective prometteuse pour accélérer les acquisitions et repousser les limites de résolution spatiale de l’angiographie en temps de vol à 7T. / Ultra-high field (UHF) MRI allows submillimetric spatial resolution in order to depict finer structures compared to conventional MRI. In recent years, the UHF potential has been explored in laboratories such as NeuroSpin, at Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA), to study brain anatomy and function at a mesoscopic scale. However, for high magnetic field strengths (> 3 Tesla), the radiofrequency (RF) field required to excite the water protons has a wavelength shorter than the size of the human head, causing destructive interferences in the brain. These increase with the static field strength leading to signal or contrast inhomogeneity artefacts on brain images, hindering the UHF benefits. However, failing to homogenize the RF field produced in the brain does not preclude from homogenizing the spin excitation to improve image quality and perform better clinical diagnosis. For this purpose, NeuroSpin’s 7T scanner has been equipped with an 8-channel parallel transmission system allowing to transmit independent optimized RF shapes on each channel in order to better control RF field interferences than in conventional single transmit channel. This thesis work focuses on RF pulse design strategies using parallel transmission to select slabs uniformly and on their applications to magnetic resonance angiography (MRA) of the human brain at 7T. In the UHF context, the most common method to homogenize the magnetization flip angle in a slice consists in combining several consecutive optimized selective excitations, so-called “spokes” subpulses, in different locations of the plane transverse to the slice in transmit k-space. Even though this method succeeds in homogenizing the in-plane excitation, its performance is not optimal in large slabs because through-slab RF inhomogeneities are not taken into account. In a first step, two original selective pulse design methods are introduced and explored to homogenize large slab selections: the “kT-spoke” method which optimizes the spoke placements in the three dimensions of the transmit k-space, and the “3D spokes” which consist in optimizing the RF subpulses point by point in time. These methods have been successfully validated in phantoms at 7T and surpassed the state of the art performance in terms of flip angle homogeneity in large slab selections. In a second step, these methods are applied to 3D Time-Of-Flight (TOF) MR angiography to improve the visualization of the arterial network in the human brain at 7T. As most MRI sequences, TOF is particularly sensitive to RF field heterogeneities. Moreover, for large uniform slab excitation, blood saturation effects prevent the depiction of the arterial network before slab exit. To correct for these effects, ramp RF pulses are proposed in the state-of-the-art, generating ascending flip angle profiles through the slab. The RF pulse design methods developed hereby were adapted to generate these profiles, successfully compensating blood saturation in 7T acquisitions. This work paves the way to a new clinical application at NeuroSpin, where MR angiography had not been explored yet, despite the high benefit of UHF for this modality. In addition, the methods developed hereby were also adapted for simultaneous multi-slice excitations. This allows promising perspectives to accelerate acquisitions and push further away the limits of TOF angiography in terms of spatial resolution.

京都大学 / 新制・論文博士 / 博士(医学) / 乙第13436号 / 論医博第2235号 / 新制||医||1054(附属図書館) / (主査)教授 花川 隆, 教授 YOUSSEFIAN Shohab, 教授 髙橋 良輔 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Kardiovaskulär sjukdom är den dominerande folksjukdomen i världen och därför genomgår många personer en kranskärlsröntgen i diagnostiskt syfte. Att utredas för en sjukdom kan leda till både fysiska och psykiska reaktioner hos personer. Både i Hälso- och sjukvårdslagen och i Patientlagen finns ett starkt krav på självbestämmande. För att patienten ska ha möjlighet att utöva självbestämmande och vara delaktig i vården är inflytande och information från vårdpersonal avgörande. Att arbeta personcentrerat ökar personens förmåga att ta till sig information och den ökade delaktigheten kan göra dessa individer mer förberedda både inför sin undersökning och även inför en framtida diagnos. Syftet var att undersöka fysiska och psykiska hälsoeffekter av information och utbildning hos patienter i samband med en planerad kranskärlsröntgen. Metoden var en allmän litteraturöversikt med systematisk metod. Sökord kombinerades och artikelsökningar utfördes i databaserna CINAHL och PubMed samt via manuella sökningar. Femton kvantitativa studier inkluderades i litteraturöversikten. De kvalitetsbedömdes och sammanställdes i en artikelmatris. Artiklarna analyserades via integrerad analys där likheter och skillnader identifierades. I resultatet framträdde två huvudkategorier: fysiska och psykiska hälsoeffekter. De fysiska hälsoeffekterna fick underkategorierna effekt på patientens vitala parametrar och förändringar i procedurrelaterad smärta. Underkategorierna till de psykiska hälsoeffekterna var effekt på patientens oro/ångest, stress och depression, tolerans och trygghet under kranskärlsröntgen, patientens tillfredsställelse med utbildningen och informationen samt påverkan på patientens följsamhet och livsstil. Slutsatsen var att utbildning och information i olika former medförde positiva hälsoeffekter såsom minskad procedurrelaterad smärta samt ökad tillfredsställelse och trygghet. Även bättre följsamhet till instruktioner och en mer positiv attityd till livsstilsförändringar noterades. När det gällde oro och ångest samt effekt på vitalparametrar sågs olika resultat. Majoriteten av studierna uppvisade minskad oro och ångest av information och utbildning, några visade ingen skillnad och en studie uppvisade förvärrad oro och ångest i samband med kranskärlsröntgen. Gällande effekten på vitalparametrar framkom varierande resultat med minskad eller ingen effekt av utbildningsinterventionerna. / Cardiovascular disease is the predominant public disease in the world. Therefore, many people undergo a coronary angiography for risk assessment. To be screened for a diagnosis can lead cause both physical and psychological stress reactions for the person being screened. Both the Health Care Act and the Patient Act have a strong requirement for bodily autonomy. To facilitate for the patient having bodily autonomy and being involved in care, influence and information from the health care staff are crucial. Person-centered care increases the person's ability to assimilate information and shared decision-making can make these individuals more prepared both for their examination and for a future diagnosis. The aim was to investigate the physical and psychological health effects of information and education to patients scheduled for a coronary angiography. The method was a general literature review with a systematic method. Keywords were combined and article searches were performed in the CINAHL and PubMed databases as well as via manual searches. Fifteen quantitative studies were included in the literature review. They were quality assessed and compiled in an article matrix. The articles were analyzed via integrated analysis where similarities and differences were identified. In the result, two main categories emerged: physical and psychological health effects. The physical health effects had the subcategories effect on the patient's vital parameters and changes in procedure-related pain. The subcategories of the psychological health effects were the effect on the patient's anxiety, stress and depression, tolerance and comfort during the coronary angiography, the patient's satisfaction with the education and information and the impact on the patient's adherence and lifestyle. The conclusion was that the literature review showed a positive effect of education and information in various forms in connection with the coronary angiography, such as reduced procedure-related pain, increased satisfaction and comfort. Better adherence to instructions and a more positive attitude towards lifestyle changes were also noted. Different results were identified with regards to anxiety and the effect on vital parameters. The majority of the studies showed reduced anxiety while a few studies showed no difference and one study indicated increased anxiety. The effect on vital parameters varied between reduced effect or no effect of the education interventions.

We present surgical clipping of a giant middle cerebral artery aneurysm. The patient is a 64-year-old woman who suffered subarachnoid hemorrhage in 2005. She was treated with coiling of the aneurysm at an outside institution. She presented to our clinic with headaches and was found on angiography to have giant recurrence of the aneurysm. To allow adequate exposure for clipping, we performed the surgery through a cranio-orbito-zygomatic (COZ) skull base approach, which is demonstrated. The surgery was performed in an operating room/angiography hybrid suite allowing for high quality intraoperative angiography. The technique and room flow are also demonstrated.

Background: Cerebrovascular injury (CVI) is a potentially devastating complication of gunshot wounds to the head (GSWH), with yet unclear incidence and prognostic implications. Few studies have also attempted to define CVI risk factors and their role in patient outcomes. We aimed to describe 10 years of CVI from GSWH and characterize these injury patterns. Methods: Single-institution data from 2009 to 2019 were queried to identify patients presenting with dural-penetrating GSWH. Patient records were reviewed for GSWH characteristics, CVI patterns, management, and follow-up. Results: Overall, 63 of 297 patients with GSWH underwent computed tomography angiography (CTA) with 44.4% showing CVI. The middle cerebral artery (22.2%), dural venous sinuses (15.9%), and internal carotid artery (14.3%) were most frequently injured. Arterial occlusion was the most prominent injury type (22.2%) followed by sinus thrombosis (15.9%). One fifth of patients underwent delayed repeat CTA, with 20.1% showing new/previously unrecognized CVI. Bihemispheric bullet tracts were associated with CVI occurrence (P = 0.001) and mortality (P = 0.034). Dissection injuries (P = 0.013), injuries to the vertebrobasilar system (P = 0.036), or the presence of ≥2 concurrent CVIs (P = 0.024) were associated with increased risk of mortality. Of patients with CVI on initial CTA, 30% died within the first 24 hours. Conclusions: CVI was found in 44.4% of patients who underwent CTA. Dissection and vertebrobasilar injuries are associated with the highest mortality. CTA should be considered in any potentially survivable GSWH. Longitudinal study with consistent CTA use is necessary to determine the true prevalence of CVI and optimize the use of imaging modalities.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21001号 / 医博第4347号 / 新制||医||1027(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 溝脇 尚志, 教授 辻川 明孝, 教授 小泉 昭夫 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21629号 / 医博第4435号 / 新制||医||1033(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊佐 正, 教授 柳田 素子, 教授 宮本 享 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Background: Cerebrovascular injury (CVI) is a potentially devastating complication of gunshot wounds to the head (GSWH), with yet unclear incidence and prognostic implications. Few studies have also attempted to define CVI risk factors and their role in patient outcomes. We aimed to describe 10 years of CVI from GSWH and characterize these injury patterns. Methods: Single-institution data from 2009 to 2019 were queried to identify patients presenting with dural-penetrating GSWH. Patient records were reviewed for GSWH characteristics, CVI patterns, management, and follow-up. Results: Overall, 63 of 297 patients with GSWH underwent computed tomography angiography (CTA) with 44.4% showing CVI. The middle cerebral artery (22.2%), dural venous sinuses (15.9%), and internal carotid artery (14.3%) were most frequently injured. Arterial occlusion was the most prominent injury type (22.2%) followed by sinus thrombosis (15.9%). One fifth of patients underwent delayed repeat CTA, with 20.1% showing new/previously unrecognized CVI. Bihemispheric bullet tracts were associated with CVI occurrence (P = 0.001) and mortality (P = 0.034). Dissection injuries (P = 0.013), injuries to the vertebrobasilar system (P = 0.036), or the presence of ≥2 concurrent CVIs (P = 0.024) were associated with increased risk of mortality. Of patients with CVI on initial CTA, 30% died within the first 24 hours. Conclusions: CVI was found in 44.4% of patients who underwent CTA. Dissection and vertebrobasilar injuries are associated with the highest mortality. CTA should be considered in any potentially survivable GSWH. Longitudinal study with consistent CTA use is necessary to determine the true prevalence of CVI and optimize the use of imaging modalities.

VÄLBEFINNANDE I SAMBAND MEDKRANSKÄRLSRÖNTGEN/PCIEN LITTERATURSTUDIESOFIA HEMLE JERNTORPANNETTE WIVEL Hemle Jerntorp, S & Wivel, A. Välbefinnande i samband med kranskärlsröntgen/ PCI. En litteraturstudie. Examensarbete i omvårdnad 15 högskolepoäng. Malmö högskola: Hälsa och Samhälle, enheten för omvårdnad, 2009.För att diagnostisera ischemisk hjärtsjukdom är kranskärlsröntgen ett alternativ. Kranskärlsröntgen/ PCI kan genomföras via a. femoralis och a. radialis. Som sjuksköterska måste man vara väl insatt i ingreppsrelaterade komplikationer för att kunna förebygga, förutse och fort kunna sätta in omvårdnadsåtgärder. Komplikationer och oro är sådana faktorer som kan påverka patienters livskvalité och välbefinnande negativt. Syftet med denna litteraturstudie baserad på 11 artiklar var dels att beskriva patienternas välbefinnande, dels förekomsten av blödning och smärta/oro hos patienter vid olika kärlförslutningar vid kranskärlsröntgen/PCI. Vårt resultat visade att genomgången kranskärlsröntgen och PCI höjde patienternas fysiska och psykiska välmående. Patienterna hade dock olika förutsättningar att hantera situationen beroende på socialt stöd från sin omgivning. Det framkom att kvinnor ofta hade en högre oro och ett lägre välbefinnande. Av de patienter som genomgått kranskärlsröntgen genom både a. radialis och a. femoralis var det 80 % som föredrog a. radialis. Det var av betydelse för patienternas välbefinnande med en snabb mobilisering. I flera av studierna sågs en lägre kostnad för analgetika, mindre förekomst av komplikationer samt en kortare vårdtid hos dessa patienter. Resultatet i denna studie visade också att de patienter som genomgått kranskärlsröntgen/PCI via a. femoralis upplevde mer obehag, oro och smärta än de patienter som genomgått kranskärlsröntgen/PCI via a. radialis.Nyckelord: blödning, kranskärlsröntgen, livskvalité, oro, PCI, smärtavälbefinnande. / WELL-BEING CONNECTED TO ANGIOGRAPHY/PCIA LITTERATURE STUDYSOFIA HEMLE JERNTORPANNETTE WIVELHemle Jerntorp, S & Wivel, A. Well-being connected to angiography/PCI. A literaturereview. Degree projekt, 15 credit Points. Nursing Program. Malmö University: Health and Society, Department of Nursing, 2009.To diagnose ischemia heart disease, an alternative is angiography. Angiography/PCI can be performed through the femoral artery and the radial artery. As a registered nurse one must be well-grounded in procedure related complications to predict, foresee, and to rapidly begin nursing intervention. Complications and anxiety are factors that can influence patients in a negative way concerning quality of life and well-being. The aim of this study based on 11 article´s, is to describe patients’ well-being as well as occurrence of bleeding and pain/anxiety in patients` over different ways to seal the vessels inangiography/PCI. Our study shows that a completed angiography/PCI increases patients’ physical and mental well-being. Patients have different social presumptions to handle the situation depending on their environment. It appears that women often have more anxiety and a lower well-being. 80% of patients who undergo angiography prefer the radial artery procedure as opposed to the femoral artery procedure. It is important for the patients’ well-being with a rapid ambulation. A lower cost for anaesthetics, lower prevalence of complications, and a shorter hospital stay for these patients is appreciated. The patients who undergo angiography/PCI through the femoral artery procedure experience more discomfort, anxiety and pain than the patients who undergo angiography/PCI through the radial artery.Keyworld: bleeding, angiography, quality of life, anxiety, PCI, pain, well-being